Solar Electron

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Electronic ProjectsLast modified on 20120203

Go back to Red Rock Energy.

Actuator Brad's-Trough CDS Sensor Tracker Chace Tracker Charger Charging Temperature Damage Rich DeMartile Diversion1 EfficiencyEWB IO LED Solar Trackers MPPT Demoing my Tracker at the MREA Energy Fair New LED3X Solar Tracker NREL Maps Patent5622078

Making PC Boards PWM Relay Tracker Shunt1 Shunt2 Shunt3 Solar Trackers Surface Mount Codebook Terminals Tracker EconomicsTraxle TriPod Mount Under- oltage.

ewb

Electronics Workbench

I use Electronics Workbench Personal Edition.

This program includes circuit design cad, simulation, and auto routing PC layout. I also use PSPICE at Unisys which has more capabilities but costs6 times as much and needs to be renewed yearly.

pcb

Making PC Boardsinkjetpcb

Using Ink Jet printers to make PC BoardsThese guys review several methods and show how to modify an ink jet printer to directly print resist onto the copper board.

apc

AP CircuitsCanadaPrototype Printed Circuit Board Fabrication Since 1988

twinstar

Twin Star Inc.Excelant 1 day turn around policy for prototype quantities. And their local to me.4"x10" $12510"x10" $200The cool thing about this offer is there is no limitation on how many individual circuits that can be crammed into the area. I know of no other boardmaker that will do this. They also will do very fine lines.What a deal!

trc

* LED3X Solar TrackerA simple, accurate, low cost, single axis electronic solar tracker based on using green LEDs as photovoltaic light sensors.

Page 1 of 47Electronic Projects

2/21/2012http://www.redrok.com/electron.htm


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TRC CircuitsThese guys make boards for me when large quantities are needed.

olimex

OLIMEX Ltd.89 Slavjanska St., P.O.Box 237, Plovdiv 4000BulgariaPrinted Circuit Board (PCB) Prototypes

expresspcb

ExpressPCBThey give you a proprietary PC board cad program that allows quick turn around board processing.The program is easy to use if not overly simplistic.Printed Circuit Board (PCB) Prototypes

far

FAR CIRCUITSPrinted Circuit BoardsThy make double sided non plated through service. No email!Custom boards may be made for $.50 square inch or $4.00 minimum per board for single sided, etched, drilled and solder coated. Custom doublesided non-plated through holes, etched, drilled and solder coated boards may be made for $.75 per square inch or $6.00 mi nimum per board. A clearfilm negative is required for custom boards. Film from camera ready artwork is $8.00 per shot based on 8" x 10" film per shot. Quantity pricingavailable. Far Circuits reserves the right to change the pricing based on the complexity of the board.

smd

SMD Codebook

I generally design circuitry that uses surface mount soldering techniques.

This link has a wealth of information about surface mount package shape and connection information.

This program is intended to serve as a guide to the manipulation of data that supports the concepts and methodology for developingsurface mount land patterns that are identified in IPC-SM-782, "Surface Mount Design and Land Pattern Standard".

iorbsl

8 Bit I/O.RBSL, Redrok Bit Serial Loop

Prototype of an 8 Bit Experimental Bit Serial I/O.

I needed a universal I/O device for my computers. I had several requirements:

With these requirements in mind, and some others, I decided on a variation of National Semiconductors "Micro Wire"(TM). In general this is calleda "bit serial" interface. The interface is composed of shift registers connected in series. Each port is in a chain. Data bits are sent down the chainthrough the shift registers for output. Input data bits are similarly sent down the chain to be inputted into the computer.

My standard bit serial I/O consists of 6 wires. The wires for the standard version use an RJ11-6 6 conductor flat telephone type cable. I also have asimplified 4 wire version. This 4 wire version is predominantly used for output devices only. Pins 5 and 6 are not used. This version eliminates thedata input channel and has no self powering capability.

Bit Serial Pin Designations.

1. The ports may need to be as much as 2000 ft from the computer.

2. Ideally the I/O ports need to be easily expandable from the same control output.

3. Speed should be medium. Capable of up to several thousand bytes per second.

Pin # Color Name




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In some cases the printer port can supply all the power needed to run the interface.

IOBit Serial Interface Schematic.

Diagram of RJ11-6 Connector.

RJ11-6 Interface Data Input RJ1 -6 Printer Port Adapter

RJ1 -6 Loop Through Connector-------------------------- --------------------------| ------------------------ | | ------------------------ ||| B R G B || || B G R B |||| h l e r e l || || l e r e l h |||| i a d e l u || || u l e d a i |||| t c e l e || || e l e c t |||| e k n o || || o n k e ||||-- -- | | -- -- ||| | 1 2 3 4 5 6 | | | | 6 5 4 3 2 1 | || --- --- | | --- --- || | | | | | | || ---------- | | ---------- |

-------------------------- --------------------------View from the Cable side View from the Cable side

Cable to Plug Arrangement.

When choosing or building the cables that connect the computer and I/O boards together make sure they are the strait through type. In other words

the cable hasNO TWISTS in it.

________________ 6 Conductor < < ________________| | | Blue 6| Flat Cable > > |6 Blue | | || | | ellow 5|_______________< > |4 Green | | || | | Red 3|_______________< > |2 Black | | ||_|___|___White 1| < < |1 White___|___|_|

> >______________ 6 Conductor < < ______________

|___| RJ1 -6 | Flat Cable > > | RJ11-6 |___|_| PLUG |_______________< >__|________________|\ \ No Twists < < / /\ \ > > / /

\ \ < < / /-- > > --

Connection Diagram.

6 Blue Interface power

5 Yellow Serial Data Bit In

4 Green Serial Data Bit Out

3 Red Serial Clock

2 Black Data Strobe

1 White Ground




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-------------| || Computer || |------+


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actuators may be used. Neat huh!

actuator

I've been compiling some data about the currently available linear actuators. I'm presenting the data here.

I am also working on a simplified driver based on a PIC16C715 micro controller by MicroChip. It will be small and have over current protection.

terminals

Terminals.

Power Transistor Terminals.

The arrows in this picture point to examples of power transistors used as output terminals. The terminals are composed of two power transistorsmounted vertically and back to back. Since they dissipate so little power they don't need heat sinks. The machine screw is used to clampconventional spade terminals between the two transistors.

I use hot melt glue to hold the nut in place.

This picture shows the RJ11-6 telephone wire connection. There is also another RJ11-6 connector on the other end of the board. The secondconnector is used to connect to other boards. If this board is the last in the string a dummy data turn around jumper, or terminator, is used.

This picture shows the RJ11-6 glued down. The next revision has the connectors soldered down in the normal surface mounted way.

ledtracker

Trackertheenergydude

sunpath

Sunpath diagram.

I've been compiling some data about the currently available linear actuators. I'm presenting the data here.

coffee

Solar Coffee Roaster Contest

OK, here's a real challenge. These guys, Dave and Mike Hartkop http://www.solarroast.com , have an unusual Coffee roasting business. They haveuilt their solar powered Helios 4 coffee roaster. Essentially a large Fresnel dish on a vertical axis mount.

Up to now they have been manually controlling this dish. Actually this works pretty good as the operator must be on hand to monitor the roastinganyway. Roasting takes 10 to 20 minutes and needs to be adjusted every 2 to 3 minutes. I don't know if I'd have the patience to do this %^)

Now they want to automate the process with a solar tracker. They want someone to devise a solar t racker system to control the Helios 4 roaster. And

etter yet, they will award the winner with a grand prise of$1000 dollars. There is a $50 entry fee so they can know you are serions. (I would enterexcept my plate is to full right know, sounds fun.)

If you have questions I'm willing to assist you with your project. I would prefer initial contacts by phone:(651)426-4766

BTW, I am not affiliated with them in any way. I just like to see cool projects happen.

OK, get your buts in gear and make this happen for them.

* theenergydude's Community CallGary Carmichael, The Energy Dude, will be interviewing me about solar trackers.We will discuss solar tracking advantages and disadvantages for a number of applications.Hear us Saturday 2009/03/21 01:00 PM EDThttp://www.talkshoe.com/tc/40649




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Helios 4

About Us:

My brother and I, Dave and Mike Hartkop, started our company five years ago. It grew out of a realization we had that we could roast organic coffeedirectly with solar energy, instead of using natural gas. Our first roaster, the Helios-1, used a satellite dish covered with mirrors and a roaster madefrom a broccoli strainer! It could roast about 1 pound of coffee in 15-20 min. of solar exposure.

In 2007, we moved from Oregon to southern Colorado in order to take advantage of the nearly year-round solar exposure in Pueblo Colorado. Weopened our own retail coffee shop, called "Solar Roast Coffee", and have been in business ever since!

Our newest roaster, the Helios-4, employs a 35-foot wide solar concentrator, which we manually track to follow the sun via a pin-hole targetingcamera and switches for up, down, left, and right. The new machine can roast up to 30 pounds of coffee in 15-20 minutes, and is also outfitted withan auxiliary propane burner to augment temperatures on extremely cold or cloudy days. (We DO purchase carbon credits in order to 'offset' the fuel

we inadvertently burn.)

About the Contest:

Our contest, the 'Sun Tracker Challenge', directs teams to design and build a solar tracker system. The system must interface with the Helios-4 andwill keep it aligned to the sun through an eight-hour roasting day. Entrants can use frame-grabs from our existing video-camera, install their ownsensors, or install position encoders and use a timer- ased method to accomplish the task! The winning team receives $1000.00 cash an gets a write-up on our web site and local news. The top-ten finalists all receive Solar Roast Coffee prizes, including coffee and T-shirts.

June 10 Final Project Proposals Deadline -your team's project proposal is received. Proposal is just that: a proposal, not a finished project.

June 15 Top Ten Finalists announced -all proposals have been reviewed, ten most workable are chosen.

June 15-August 30 -Ten finalist teams build and test their sun-tracker projects, readying them for practical test in Pueblo.

September 1-30 -Practical Testing of top-ten Projects

October 10 Final Winners Announced -One first place, and prize choices for remaining 9 teams.

Details are online at:

http://solarroast.com/suntrackerchallenge.html

Helios 4 and control room Helios 1 Sun Tracker Challenge




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Interface Details:

Controlling the array movement:

Our control system includes a set of relays that can be driven directly by the team's project. Our control box has a female 5-Pin DIN connector (seeimage 5pinDIN.jpg) which is addressed as follows:

pin 1 Track toward vertical

pin 2 Track toward horizon

pin 3 Pan Clockwisepin 4 Pan Counterclockwise

pin 5 Relays Common, floating.

ring Ground

The internal relays driven are of type:

Siemens # VKP-35F42 relay. Sealed, PC mount power relay for high-current applications. 12 Vdc, 90 coil, 130 mA. SPDT contacts rated at 30Amps. 1.02" x 0.84" x 0.86" high. The system is wired so that opposing directions can not be activated at the same time. See schematic(relaysschem01.jpg) The relay coils are electrically isolated from the control system, and are floating with respect to ground.

Powering your project:

A standard 2-socket 120VAC outlet is provided near the main control box. The outlet is GFCI protected and rated at 20A. Projects are expected tohave their own internal fuses (15A or lower) in line with line power supplied. Your project box, to be connected to Solar Roaster Control box, shouldmeasure no larger than 18" x 18" x 12", (We need room for bags of green coffee!)

Sensors and cables:

100' cables to reach tower, or to reach horizontal track motor.

Use magnets to affix sensors to the system.

A rotary encoder, if used, should be fitted with ANSI #40 1/2" pitch sprocket, (bicycle chain). You provide encoder with sprocket attached, I willmount it!

Movement and Motors:

The outer Circular track is exactly 35' in diameter. The system is driven by two 90vdc gear motors with electronic speed controls. The speed-presetscan be set by adjusting the electronic speed controller knobs internal with the system controls.

Default motor tracking and panning speeds are roughly 3/sec. The movable array weighs 5300 pounds and is supported on 18 heavy iron casters.Kind of a "Lazy Susan" on steroids. There is minimal mechanical backlash at start and stop, and the system can be controlled manually with switches

and targeting camera to an accuracy of +-1/8th, About 1/2 the Suns image diameter.

An example 'manual controller' schematic of the interface.

Manual Controller and DIN connector

opensunproject

* Open Sun Project Stepper Motor.They have a Weather Proofed Stepper Motor,

carter

* SunSeeker ProjectDavid Carter's PIC based solar tracker.Carter uses a method that acquires the sun by alternately panning in azimuth then elevation. The PIC reads output current and finds the maximum.

This is done without light sensors just the charging current sensor.

The large servos, similar to radio controlled or RC servos, are driven with a pulse width signal.

The ON time defines the angle.

pen Sun Project Stepper Motor.




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The OFF time is not critical and should be from 10mS to 30mS.

ON time of 1.0mS = 0



Interesting idea but not really the best way of tracking the sun. Light sensors work much better.

demartile

* "Rich DeMartile" * has a schematic of a solar tracker and mount based on a pair of CdS photo cells.

peterthinks

* "Peterthinks" has made a solar tracker using RC servos. The system has a tracker basedon BEAM technology. The beam circuits powered the RC servos. The tracker used only the power of the sun to move.

tag

* The Analog Guy Solar Trackers:ST2-48V5A SINGLE & DUAL AXIS SOLAR TRACKER 56V 5A MAXST2-12V DUAL AXIS SOLAR TRACKER 18V 0.5A MAXOne of my competiters.

jamesley

Jamesley Dasse's Solar TrackerJamesley made this 2 axis PV solar tracker for a college project. His professor requires that he use a stepper motor drive. I designed a preliminarycircuit for him to use. This circuit doesn't have rotation limits yet.

LED7 Solar Tracker Schematic

relaycds

Cadmium Sulfide Relay Tracker Schematic.

Electronics

Front View

Stepper DriveRear View




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CdS1This is about the simplest tracker I know of. It uses a Radio Shack 275-249A relay. Adjust the sensitivity of the CdS cells with a Sharpie permanentmarker as described ellow, in the Chace tracker. The picture tells it all.

This tracker is not as accurate as the electronic tracker but quite sufficient for use with PV panels.

While the proof of concept is good it will burn the relay contacts. This is caused by the relays being turned on or off slowly. It melted the plastic caseon the relays.

limitops

How Limit Switches Operate

Limit switches are essential for servo motor operation with solar trackers. I made this diagram to help explain how they work.

Top. Normal operation between limit switches.Middle. The left limit switch has opened to stop movement to the left. To move to the right again the diode conducts current that allows movement tothe right.

Bottom. The right limit switch has opened to stop movement to the right. To move to the left again the diode conducts current that allows movementto the left.

Sellect a diode or rectifier rated at the maximum motor current plus some margine. Also the voltage should be at leat 100V and preferably 200V.

Needles to say, the limit switch must operate before the mechanical limits are reached. If the mechanical stop i s reached before the switch the motorcan draw quite high currents and can destroy the solar tracker.

led1

LED1 LED Sensor Relay Tracker Schematic.

LED1I have been looking for truly low cost and yet accurate conventional solar trackers. The CdS tracker is pretty good but lacks accuracy and sensitivity.I was thinking about using PV cells as the sensor. I was experimenting with LEDs and noticed they generate voltage in sunlight.

Bingo! This got me to thinking.




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They generate quite a bit of voltage. The green ones generate about 1.65V, some as much a 1.74V. Not the piddley .55 volts of a silicon PV cell.How is this so? Well, it turns out green LEDs are made from Gallium Phosphide, a semiconductor with a much higher bandgap voltage.

I thought I had invented the use of LEDs as PV cells as I had never heard of this effect before. Well, after some investigating I found a number ofreferences to this. The guys that had done the most work in this area were the people form the "BEAM" project. They make tiny solar poweredrobots and some used LED photo sensors.

I had been using a very low threshold MOSFET in a TO-92 package, BS107PT. The threshold is about 1.5V. If I put two LEDs back to back, onefighting the other, the one with more light intensity wins. I thought I could use this to switch the MOSFET. And it worked.

By using one LED as a sort of power supply and the back to back pair connected from it to the MOSFET gate the circuit is complete. (This I havenot seen elsewhere.) My implementation uses three power supply LEDs, aimed East, Up, and West. The sensor LEDs are aimed about 90s fromeach other and at about 45s either side of up. Of course the easterly pair will be a little to the East and the westerly pair a little to the West. Thismakes the center have a dead zone where tracking stops.

The circuit is quite sensitive. It brings the panel back to the East just after sun rise. The accuracy is quite good. You can calibrate the sensor byending or aiming the LEDs a bit.

While the proof of concept is good it will burn the relay contacts, similar to that on the Cadmium Sulfide tracker. This is caused by the relays beingturned on or off slowly. It melted the plastic case on the relays.

led2

LED2 LED Sensor Relay Tracker Schematic.

LED2Circuit 1 tends to chatter the relays under certain lighting conditions as there is no built in hysteresis. This version uses a Schmitt trigger hex invertercircuit to eliminate the chatter. It works better but is more complex.

Note! R4 and R5 are used to force parking when it gets dark. If parking is not desired don't use R4 and R5. Parking may not be desired in low powerconsumption applications.Also, the parking resistors, R4 and R5, reduce sensitivity a bit.

led5led5s5v

LED5S5V Simplified LED low power tracker.

LED5S5VI was looking for a much lower cost tracker for low power applications. One of these applications is a small lighting heliostat. This circuit uses smallswitching transistors. The maximum motor drive current is limited to about 250mA maximum at 5V.




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I've tested the circuit on voltages from 3V to 21V. With some component changes it should be useful to 63V in a 36V PV panel system although Ihaven't tried this yet. With higher voltage and the use of heat sinks on the bridge transistors much higher currents should be possible.

The parts cost is very low. Parts cost estimated using Digikey prices. Ok, you can get stuff from the surplus stores but I will stick with Digikey.

1. 2N2222A NPN transistor 4 @ $0.21 = $0.842. 2N2907A PNP transistor 4 @ $0.21 = $0.843. 430 1/4 W resistor 2 @ $0.06 = $0.124. 5 K 1/4 W resistor 2 @ $0.06 = $0.125. 22 nF capacitor 1 @ $0.08 = $0.086. LED Green Lumex SSL-LX5093LGT 2 @ $0.12 = $0.24

Total = $2.24

$2.24, is this cheap enough?

led5s12v

LED5S12V Simplified LED low power tracker.

LED5S12V

This circuit uses small switching transistors. The maximum motor drive current is limited to about 100mA maximum at 12V.

1. 2N2222A NPN transistor 4 @ $0.21 = $0.842. 2N2907A PNP transistor 4 @ $0.21 = $0.843. 1.6 K 1/4 W resistor 2 @ $0.06 = $0.124. 47 K 1/4 W resistor 2 @ $0.06 = $0.125. 100 K 1/4 W resistor 2 @ $0.06 = $0.126. 22 nF capacitor 1 @ $0.08 = $0.087. LED Green Lumex SSL-LX5093LGT 2 @ $0.12 = $0.24

Total = $2.36

led5connections

LED5 Connections

led5forsale

I have the LED5 series trackers for sale.

Yes, I know, not everyone wants to build these from scratch so I made a PC board for the LED5 series.

The single axis board is a bit less than 1/2" x 1" and the dual axis is a bit less than 1" x 1".

paypalled5s5v

LED5S5V 5 Volt Single Axis Low Power Tracker including shipping using PayPal.$26us total.

paypalled5d5v

LED5D5V 5 Volt Dual Axis Low Power Tracker including shipping using PayPal.$48us total.

paypalled5s12v

LED5S12V 12 Volt Single Axis Low Power Tracker including shipping using PayPal.$26us total.




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paypalled5d12v

LED5D12V 12 Volt Dual Axis Low Power Tracker including shipping using PayPal.$48us total.

led5plc

LED5S12V Modified for use with a PLC.

LED5S24VPLCDNThe schematic is for the "Pull Down" variant.

This version of the basic LED5 can be used as a sensor input to a PLC, Programmable Logic Controller. The output is an "Open Collector" NPNtransistor and assumes the PLC has the associated "Pull Up" resistors.

The actual voltage range is from 4V to 28V. (I can make higher voltage variants also.)

I can also make 24V LED5 trackers with totem pole outputs which have both pull up and pull down transistors. Essentially the same as the standardtrackers but with limited drive capabilities.

This circuit does not have a parking function. Parking and Reverse Inhibit functions are best performed in the software of the PLC using timingfunctions.

Note! If you don't want the 4.7K or 5.1K 1/6thW passive load resisters they can be removed by clipping one of the resister leads.

paypalled5s24vplcdn5k

LED5S24VPLCDN5k Single Axis Sensor for PLCs with PULL DOWN TRANSISTORS & 5k passive pullup resistors

including shipping using PayPal.$26us total.

paypalled5d24vplcdn

LED5D24VPLCDN5k Dual Axis Sensor for PLCs with PULL DOWN TRANSISTORS & 5k passive pullup resistorsincluding shipping using PayPal.$48us total.

Some applications need "Pull Up" transistor outputs. This is done by using PNP transistors in the output.

paypalled5s24vplcup

LED5S24VPLCUP5k Single Axis Sensor for PLCs with PULL UP TRANSISTORS & 5k passive pulldown resistors

including shipping using PayPal.$26us total.

paypalled5d24vplcup

LED5D24VPLCUP5k Dual Axis Sensor for PLCs with PULL UP TRANSISTORS & 5k passive pulldown resistorsincluding shipping using PayPal.$48us total.

ledblueplc

Another Sensor for use with a PLC.

ledblueplc1 ledblueplc1a ledblueplc2




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These sensors work nicely with a PLC input. Either you use the pullup resistor or use the pullup resistors in the PLC.

In the first sensor I used a VN10LP MOSFET which needs a bit more voltage to turn on than can be obtained with just one BLUE LED. A GREENLED is used to bias the voltage upward about 1.7V or so.

The second sensor uses a ZVNL120A MOSFET which has a bit lower gate threshold voltage of 1.5Vth and can operate using only one BLUE LED.

The first & second sensors have a single ended output.

The output is analog in nature varying from VDD to 0V.This circuit can be used with very low current motors for solar cooker applications.

The third sensor has differential outputs. This output is either West, East, or in the dead band zone where both outputs are high.The output is analog in nature varying from VDD to 0V.

Note! The diodes should be types that have a very small but not zero leakage current. In this case I used 1N4148 generic silicon diodes. Don't uselow leakage current diodes. If the leakage current is too low residual circuit board leakage currents from VDD can cause the voltage on the gates tofloat up causing both MOSFETs to turn on. Make sure the PC board is very clean or the encapsulating epoxy is clean and has no conductivecharacteristics. Normal silicone RTVs are not suitable for use here. OK, Dow does make RTVs that work here but these are not readily available andare expensive.

2l003

Grainger 2L003 Gear Motor

This is a 12VDC gear motor from Grainger's.This controller works well with the 2L003.

This motor is an off the shelf motor from Grainger's. Stock number2L003. It's rated for .45 RPM at 50 In Lbs. The motor current is less than 100mAat 12V and about 50mA at 5V.

tamiya

Tamiya has a number of Model Gear boxes.The motors supplied are rated for about 3V. They draw a bit to much current for the 2N2222A-2N2907A driver transistors.

lamble

LED5Stewart Lamble built this version.He subistuted BD135 (NPN) and BD136 (PNP) transistors.

led555

LED555 Timer Based Solar Tracker

LEDB LUE PLC 1 L ED BLU EP LC1A LE DBL UE PLC1With 5mm LEDs

LEDBLUEPLC2 LEDBLUEPLC2With 5mm LEDs




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This tracker is a bit different from most other sensor based solar trackers. Those essentially work by directly measuring voltage, current, or resistanceof the light sensor. I like using LEDs for these because they, generally, produce higher voltage than silicon sensors.

This tracker essentially measures the time it takes to charge a capacitor to a predetermined voltage. So its a timer based tracker.

All solar trackers have a characteristic I call Angle Gain Factor, AGF. AGF is in essence the amplification of aiming angle error to the sun intopower to drive the motors. The motors are moved in a way to minimize the aiming angle. The more aiming error the more power to the motor.

LED pairs inherently are very sensitive to aiming angle. A major factor in AGF is in the characteristics of the LED pair. Of course, the other actor isin the power driver circuits.

In the example U2 and U3 are the 555 timer circuits, I usually use ICM7555IN by NXP Phillips which are superior to most because they are CMOSand have an input leakage current of less than 50pA and can operate from -40C to +85C. The LMC555CN is a bit better because it can outputmore current, but it costs 5 times as much.

Refer to the timing diagram:U1 is an astable multivibrator, which can be any of the 555 variants. It periodically sets the timer Flip Flops, FF, by bringing TRG low andgrounding capacitors C2 & C3 through diodes D2 & D3. When U1 releases the timers C2 & C3 start integrating charging currents. It's a race as towhich reaches the Threshold, THR, first.If C3 gets to THR first the output drives the motor forward until C2 catches up.If C2 gets to THR first the output drives the motor reverse until C3 catches up.If C3 & C2 get to THR at the same time the motor doesn't move.Bright light causes faster charging of both C3 & C2.In the dark charging will be slower. Slow enough so neither C3 nor C2 reach THR.If even when dark the RC constant of C3 is short enough it will always reach THR and C2 is longer than that of C1 on U1 the motor will move in the

parking direction until the Limit switch is reached.

The power supply voltage range of the ICM7555IN is 3V to 16V. I have tested this circuit throughout this range and up to 18V, the maximumallowed voltage.

The sensors I have used range from infra red photo diodes to ultra violet LEDs and they all worked fine. I tried CdS photo resistive cells, theyworked OK but are highly non linear, not to good.

Now something really cool!I tested it using a pair of1N270 Germanium point contact diodes, worked just fine.Then with a pair of1N4148 switching diodes. That worked too. Cool huh!!!Actually many, if not most, semiconductors of any type are affected by light. The glass packaged diodes, plastic LEDs, ICs with windows, and anyother way that allows light to enter affects the semiconductor's characteristics. Usually leakage current but other things also. No wonder most have

lack opaque packages. Here is an article about this same thing. On the dark side.

Note! The CREE LED specification says the reverse voltage limit is 5V, other brands are similar as are the silicon photovoltaic cells. Even thoughthis voltage is lower than the supply voltage they still work fine even at 18V.

Single Ended Sensors:For the first attempt at this concept I used the single ended LED sensor circuits on the right. The capacitors get charged through the reverse biasedLEDs and resisters. The charging rate is directly proportional to the intensity of light on the sensors and limited by the resisters. (The two resistors,which could be as low as 100K, limit the maximum charging rate, but also limit current if the device shorts out. It's a safety thing.) When theyreach the THR voltage the internal FF is reset.

Of course, one will get to the THR voltage first. The OUT pin voltages will be different from each other, one HI one LOW, due to the differences incharging times. As it gets closer to the light balance point the motor drive time duty cycle diminishes to zero. A kind of Pulse Width Modulation,PWM, circuit or variable speed motor drive. Cool huh again!!!

Parking:In most of the other simple solar trackers I've described "Parking" is usually difficult to do.1. The use of a separate sensor to measure the "darkness" and park accordingly. This is not desirable as it adds complexity to the circuit.2. Add a "weak" imbalance to the sensor circuits which causes motor movement when it's dark. This is desirable, if it can be done, as just the primarysensors are used.

The main difficulty has been that the LED circuitry operates at quite a high impedance. To introduce imbalance currents very high valued resistors

were required. These, although available, are fairly expensive and tend to be impractical. One exception is the use of a "leaky" reversed biased diodein the LEDBlue tracker.

In this case I don't need high resistance resisters, instead I use the imbalance of "time" in the form of resister & capacitor, RC, time constants. Thetiming diagram helps illustrate this. (OK, in my example the two RC constant are the same.)

Differential Sensors:The single ended circuit simply stops moving when it gets dark, "No-Parking". I wanted to implement "Parking" when it gets dark. In the absence ofthe LED sensors the charging current is through the resistors. Depending on component values one RC circuit will always charge faster and tend tomove in the Park direction.(Note! Limit switch circuits are required when parking is involved.)

The back to back LED sensor circuit introduces some added differential voltage to the charging capacitors. Again one will win as with the singleended version. An alternate way is to use only one of the pullup resisters, charging current will be sent to the other capacitor through the LED pair.The rest of the circuit operates the same way.

Another advantage of this basic circuit is the output is not analog in nature. It can drive the output transistors into saturation which limits their power

dissipation allowing for greater output currents. The analog qualities lay in the PWM nature of the timing.

Please note! I have tested these circuits as published. However, your application may need other timing or light sensitivity requirements. By suitablyadjusting timing values a great variety of applications can be accommodated.




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OK, I'm showing a generic 2N2222A/2N2907A low power driver good for a few hundred mA anda high power MOSFET driver using the International Rectifier IR2111. Take your pick.

In essence the 555 is a FF. Why can't this be done with a FF. It can. It's just that the ubiquitous 555 timers are accurate and robust circuits.

ledse

SE Solar Tracker Consumes Ultra Low Power

LEDSEI needed a special solar tracker that would consume really low pow from a very small PV panel yet be capable of delivering quite high currents to amotor load.

I apologize for not presenting this unusual and innovative solar tracker circuit before. It was designed in about 2004 and a PC board was made. Aswith other trackers I've made the dual axis version was done on a 1" square PC board. This board can be cut in half for a single axis version that is1"x.5". While I have a bunch of these boards the circuit is very time consuming to assemble so this tiny tracker on the tiny PC board is not costeffective to build or for me to sell.

I'm a member of a "Beam" robotics group who do similar things with Solar Engines, or "SE", circuits. This particular SE type is based on theenerable MN1381 Voltage Monitor chip. Click here to see a description of how they work..

My version used an older version of the MN1381 the MN1281 but it works the same. The MN1281 has a bit higher leakage current though. Theexact part# of mine is "MN1280-L" in an unusual "M" package and has a CMOS output. I have the "L" version which triggers at 3.0V to 3.3V andhas a hysteresis of 100mV to 300mV. This cool circuit can consume currents as low as 50A, or lower, which charges accumulator capacitor C5.When the MN1381 fires it couples a voltage increase to the MOSFET gates through the caps C1 & C2.

A voltage difference in the two caps is caused by the sensor LEDs, however there is not enough voltage to turn on the MOSFETs. The pulse from theMN1381 IS high enough though. One of the MOSFETs will turn on harder and win causing the motor to move and discharge the accumulator

capacitor. If the light is balanced both sides will fire, the motor will not move, and discharges the accumulator capacitor.ledac

LEDAC a Very Simple Solar Tracker Powered by an AC Power Source

LEDAC1

This circuit, if powered by a low voltage AC power source, can drive a reversible permanent magnet DC motor. Basically the motor, tracker, and theAC source are connected in series in any order. As far as I can tell this is got to be the simplest conventional solar tracker that can follow the Sun in

oth directions and do it accurately. It has only 6 parts, 2 MOSFETs, 2 diodes, and 2 BLUE LEDs.

True, solar cooker solar trackers can have fewer parts, as low as 3 parts, but these only track in one direction to the West.

Note! These circuits depend on the reverse body diode inherent in MOSFETs. That's the arrow in the MOSFET symbol. Essentially, this allowsconduction from the source to the drain in the opposite direction to the normal flow through the MOSFET.

This LEDAC1 circuit depends on a very low gate threshold voltage MOSFET. In this case the ZVNL120A MOSFET, 1.35Vth. Yes, this transistor

operates correctly in the circuit but the motor needs to be very small, maybe less than 25mA or so. What is need is a power MOSFET with similar orlower Vth.

mosfetssr The LEDAC1 is directly related to MOSFET based Solid State Relays or SSRs.Unlike these SSRs, which turn on or off the MOSFET switches simultaneously,this tracker operates them differentially. Essentially rectifying the AC sourcefor a pulsed half wave current output of either polarity depending on whichMOSFET is on.

These MOSFET based SSRs can benefit from the use ofBLUE LEDs andlow V MOSFETs. You could set them up to turn the MOSFETs on

simultaneously in the conventional way or operate them individually.

Or just optically isolate a single MOSFET.




16/47

Clearly the IRF3708 1.67Vth, RFP30N06LE 1.75Vth, and IRLZ44N 1.76Vth are the best power transistors with IRLI2203N 2.01Vth a close forth.

ledcooker

Solar Cooker Solar Trackers

This is an example made by Small Power Systems.

Solar cookers usually don't require a tracker that moves in both in directions. The person operating the cooker simply resets the cooker to the Eastwhen loading the food. The tracker then drives to the West stopping when aimed at the Sun.

The great simplification to these designs is the elimination of the H- ridge in the output circuit. These only need a single MOSFET transistor to drivethe motor. Cool huh!!!

LEDCooker1 was designed several years ago, mayby 10 years or so, using the IRLZ44N logic level MOSFET, $1.67 55V 47A 22m 1.76Vth.

Basically designed before cheap BLUE LEDs were available. I had experimented with the BLUE ones but abandoned the project because the circuitseemed too expensive for solar cookers, especially for 3rd world country applications.

I just revisited these designs as a request from one of my customers. LEDCooker2 satisfies my requirement for low parts cost at about $3us. Can Iimprove this further?

Instead of the 10mm Lumex LEDs I usually use, which are more expensive, I changed to 5mm types and the newerIRLI2203N MOSFET, $1.7030V 61A 7m 2.01Vth. Even better, its in a TO-220 Fullpack package, which means the heatsink tab is insulated. The hole in the MOSFET can be

used for mounting to the cooker, or a heatsink for driving larger motors, without regards to electrical connections and shorts. I.e. the whole circuit isfloating.

OK, for the absolute lowest cost one can use the 3 color version. I probably would choose to use BLUE for all three LEDs because of the greaterias voltage for more safety margin especially in high ambient temperature locations.

I like the CREE high brightness 20mA LEDs.

Look for the "CN" 30 no stand off types. These have water clear cases.

An even lower cost and parts count solar cooker tracker can be made with a TO-92 package ZVNL120A MOSFET, $0.78 200V 180mA 101.35Vth. This circuit requires LED2 to be BLUE and LED1 can be any color even infra red. Both LEDs are required to obtain a balance point. Of

course the ZVNL120A would only work with quite small motors. A possibly better use is as a solar sensor.

I should say that a single BLUE LED can be used as an absolute light sensor though.

LEDCooker3

And improved even further, the LEDCooker3 uses the RFP30N06LE MOSFET, $1.09 60V 30A 47m 1.75Vth. I've tested about 100 of these and

directly measured the Vth to be 1.72Vgs @ 5mA. Clearly the 2.25V generated by the BLUE LED can respectably drive this MOSFET. The total

parts cost including a connector is $2.31us.

ledcooker1

LEDCooker1

ledcooker2

LEDCooker2 LEDCooker2With 10mm LEDs& IRLZ44N

LEDCooker2AWith 5mm LEDs& IRLI2203N MOSFET

IRLI2203NR

ovs. V

gs

ledcooker3

LEDCooker3 Before and after encapaulation.And with the power connector.

RFP30N06LERon vs. Vgs

IRF3708Ron vs. Vgs




17/47

Cool Huh!!!A better MOSFET is the IRF3708 at $1.74us.

ledblue

Bidirectional Analog Solar Tracker or Sensor.

LEDBlueN1Bidirectional version of the LEDCooker3When powered from a DC power source, as opposed to the AC power source of the LEDAC, one needs an H-Bridge output. In this case the low sideMOSFETs are N channel IRF3708s and the high side uses P channel SPP18P06Ps.

The pair ofBLUE LEDs generate a differential voltage applied to the gates. The diodes cause these voltages to always be above ground. If one sideis higher than the other one IRF3708 MOSFET turns on harder and and enables the SPP18P06P MOSFET on the opposite corner to also turn oncausing the motor to turn. Of course, if the differential voltage is the other way the motor also turns the other way.

This circuit requires a small bias current be pulled out of the MOSFET gates to compensate for the leakage currents going into the gate from thepositive supply which could cause both MOSFETs to be turn on, a bad thing. A pair of resistors could be connect from the gates to the emitters toabsorb the approximately 20nA of leakage current. Unfortunately, I can't obtain low cost resistors in the 100M or more range. A better way is touse diodes that have more leakage current than the MOSFET gates.

The 1N4148 universal high speed switching diode has about 20nA of leakage current, more as the temperature goes up. I tested several hundred ofthese and all worked well in the circuit. The reason normal 10M resistors don't work is they consume more current than can be supplied by theBLUE LEDs. Low leakage diodes such as the BAS416 don't work in this circuit is because their leakage current is to low.

ledblueplC2

This is a variation that has pull up resistors instead of high side MOSFETs for use as a sensor for PLC or other electronics.It uses a pair ofZVNL120A MOSFETs.

Notice this is essentially the same circuit as the LEDAC except with 3 terminals instead of 2.

ledfast

LEDFAST Acting Analog Solar Tracker.

LEDFASTI needed a special solar tracker that is very fast acting. The action needed to move a PV panel from lock to lock in a few seconds. It was importantthat little overshoot occur. This circuit satisfies these requirements.

1. R7/R8 form a voltage divider to produce a voltage of 1/2 of VDD and applied to the non inverting inputs of the OpAmps.

2. The OpAmps are setup to have a gain of 1000X through R3/R1 and R4/R2. Capacitor C1/C2 limit the high frequency response of the circuit toprevent oscillations.

3. The LED sensor circuits need to be high impedance so are isolated from the gain resistors through resistors R5 and R6.

4. I use large 10mm "GREEN" LEDs with clear cases. They are made by Lumex, but all normal LEDs can work. (Don't use the White LEDs as theyare not normal types.) The LEDs act as small photo voltaic generators. Since LED1 & LED2 sensors are connected back to back the sensor that hasthe greater light intensity expresses its voltage over that of the sensor with lessor light intensity. Imbalance in the light on the sensors produces adifferential voltage which is amplified and presented to the motor. As the light approaches balance the motor differential voltage approaches zeroresulting in no motor current.

LEDBLUEPLC2 LEDBLUEPLC2With 5mm LEDs




18/47

5. The LM324 has an output current drive capability of >10mA. Transistor pairs Q1/Q2 & Q3/Q4 form unity voltage gain emitter follower currentgain amplifiers. With power transistors that have a gain of 100 the motor drive current can be about 1A or more.

6. VCC can be from about 6V to an absolute maximum of 32V. Other OpAmps can be used for a greater VCC range.

7. Note! Limit switches are required in the motor circuits. See:How Limit Switches Operate.

8. There has to be a down side though. This is a true analog circuit that drives the output transistors in a linear manor therefore power is wasted whenslowing the motors. Heat sinks may be required.

9. This circuit is not generally suitable for use with normal high efficiency solar tracking applications. It is best suitable for school projects.

led3

LED3 LED Sensor Electronic Tracker with H-Bridge Drive.

LED3I decided to make a commercial surface mount PC board using the LED2 sensor concept. It is quite sensitive and can track to a few degrees ofaccuracy in bright sunlight. If a locking shadow is used the accuracy is better then 1/4, that's about as good as you can get with an active feedbacksensor. The board is a tiny .7"x1.4".

Note! I have replaced the LED3 with the much more capable LED3X series of solar trackers. See below.

This circuit uses power MOSFET drivers and is designed to operate satellite dish linear actuators, however most any DC motor can be used. Thepower drivers are capable of delivering about 10 amps of peak current, maybe more. When better transistors become available this current can be

increased. The drivers operate the actuators in pulses of about .3 second every 3 seconds or a 10% duty cycle. This eliminates the needed for a heatsink on the transistors. Neat huh!

I haven't decided if 10% is the best duty cycle to use. Less will make the tracking slower but, we don't need speed anyway. I will determine thiswhen I get better weather. Slow tracking speed helps in partly cloudy condition. This prevents the tracker from making unnecessary movementswhen clouds move by.

No electrical adjustments are required. The LEDs can be mechanically adjusted for optimum tracking performance by aiming them after the circuitoard is mounted.

led3shadow

To improve accuracy, ie. with concentrators such as troughs or dishes, a blocking shadow can be placed in front. The shadow just covers the twoinner LEDs when aimed at the sun. Similar to the shadow on the Chace Tracker.

I have used a band of metal about .5" in width at about 6" from the LED3. If the LED3 is used for E-W tracking the band is oriented N-S.Conversely, if the LED3 is used for N-S tracking the band is oriented E-W. The shadow device is not particularly critical. For instance, I have used

lack electrical tape on the weather dome and it worked well.

led3specifications

Power Supply Voltage 8 Volts to 22 Volts inclusive.

The 8V minimum is specified to prevent damage to the MOSFET power drivers. The damage is due to operating them in thelinear region with a load. This causes excessive power to be dissipated in the MOSFET with a resultant damaging temperaturerise.

The 22 volt maximum is defined by the voltage tolerance of 24V protection zener. This zener protects the power MOSFETs fromseeing damaging breakdown voltages. During testing I had several failures when operating from a car battery while thealternator was running. It was determined that the alternator was producing voltage spikes in excess of the 30V breakdownspecification of the MOSFETs.The 24V zener has an initial tolerance of 5%. So the maximum continuous voltage that can be applied before conduction canoccur is 22.8V or so.Most PV panels don't output more than 22V in open circuit. You should check for sure. If they do go to high in voltage a simple

ower regulator should be added to limit the maximum voltage.

Load Current Continuous 5 Amp resistive.

The power MOSFETs are rated at over 10A at 25F. A conservative derating of 50% is prudent especially in hot weather

conditions.

Load Current Intermitant 10 Amp intermitant at 10mS width once per timing cycle.

The Power MOSFETs have an absolute maximum current rating of 30A, but this is with ideal conditions where the temperatureis 25F and very fast gate rise times. The LED3 has a relatively slow gate rise time and may be operated at quite high




19/47

semiconductor

Transistor's I've Used

temperatures sue to the weather. I think 10A at about 10mS is adequate for normal tracking applications.If higher current motors are required a power amplifier may be needed. See:http://www.redrok.com/electron.htm#power

I should note that the satellite dish actuator I use normally consumes about 290mA of current at 13.8VDC. This actuator iscapable of driving a 15' dish with 1500lb of force. You don't need a high powered drive, just a slow forceful one.Think slow!

Operating Temperature -40F to 185F or -40C to 85C

mosfetnch ------ ------ ------ ------ ------ ------ ------

IRFB59N10D 100V 59.00A 25m 5.5V Single N-Ch TO-220,TO-262

ith integral 100VZener

+-30V Gate

$2.99

IRFP460 500V 20.00A 270m 4.0Vh

Single N-Ch TO-247 ith integral 500VZener

$6.28

IRF840 500V 8.00A 850m 4.0V h Single N-Ch TO-220 ith integral 500VZener

$2.79

FQP46N15 150V 45.60A 42m 4.0V h Single N-Ch TO-220 +-25V Gate $2.08

STP40NF12 120V 40.00A 32m 4.0Vh


$1.87

IRF520N 100V 9.70A 200m 4.0V h Single N-Ch TO-220 ith integral 100VZener

$1.23

NDP708AE 80V 60.00A 22m 4.0V h Single N-Ch TO-220,T0-262AB


$?.??

IRF2708 75V 82.00A 13m 4.0V h Single N-Ch TO-220,T0-262AB ith integral 75VZener $2.78

IRFZ48V 60V 72.00A 12m 4.0V h Single N-Ch TO-220 ith integral 60VZener

$2.13

IRFZ44N 60V 55.00A 16.5m 4.0V h Single N-Ch TO-220 ith integral 60VZener

$1.68

RF1S50V60 60V 50.00A 22.0m 4.0V h Singl e N-C h TO-2 62AA ith in te gra l 60VZener

175C

$?.??

MTP50N06V 60V 42.00A 28m 4.0V h Single N-Ch TO-220 ith integral 60VZener

$?.??

IRFZ34 60V 30.00A 50m 4.0V h Single N-Ch TO-220 ith integral 60VZener

$1.38

IRF1405 55V 169.00A 5.3m 4.0V h Single N-Ch TO-220 ith integral 55VZener

$3.02

HRF3205 55V 100.00A 9.0m 4.0V h Singl e N-C h TO-2 20AB ith in te gra l 55VZener

175C

$?.??

IRF3315 150V 27.00A 70m 3.21Vh

@34.0V

h


IRF3315 Ron vs. Vgs

$1.86

IRLR2905 55V 42.00A 13.5m 3.0V h Single N-Ch DPAC ith integral 55VZener

175C

$1.55

IRF7313 30V 4.00A 29m 3.0V h Dual N/N-Ch SO-8 ith integral 30VZener

$2.37

2N7002 60V 0.30A 5000m 2.5V h Single N-Ch SOT-23 Phill ips NXP + -30VGate

$0.41

VN2222LL 60V 0.23A 7500m 2.5Vh

Single N-Ch TO-92 $0.57

2N7000 60V 0.20A 5000m 2.45V [email protected] h

Single N-Ch TO-92,SOT-23

+-20V Gate

2N7000 Ron vs. Vgs

$0.42

VN0106 60V 2.50A 5000m 2.4V h Single N-Ch TO-92

VN0106 Ron

vs. Vgs

$?.??

ZVN3306A 60V 0.30A 5000m 2.4Vh

Single N-Ch TO-92 $0.78

VN2106 60V 0.30A 6000m 2.4V h Single N-Ch TO-92 $0.72

HUF76137P3 30V 75.00A 9m 2.15V h@3

3.0V h

Singl e N-C h TO-2 20AB ith in te gra l 30VZener

HUF76137P3 Ron vs. Vgs

$?.??

STD50NH02L-1 24V 50.00A 20m 2.15V h@3

1.8V h

Single N-Ch TO-261IPAK


STD50NH02L Ron vs. Vgs

$0.40

RFD14N05L 50V 14.00A 100m ???V h@3

2.0V h



$0.81




20/47

IRLU014 60V 3.90A 200m ???V h@3

2.0V h



$1.40

IRLU2703 30V 23.00A 65m ???V h@3

2.0V h



$1.58

IRLI2203N 30V 61.00A 7m 2.01V h@3

2.5V h

Single N-Ch TO-220InsulatedFullpack


IRLI2203N Ron vs. Vgs

$1.70

IRL540N 100V 36.00A 44m 2.0V h Single N-Ch TO-220 ith integral 100VZener

$1.23

IRL530N 100V 15.00A 160m 2.0V h Single N-Ch TO-220 ith integral 100VZener

$1.70

VN10LP 60V 0.30A 5000m 1.92V [email protected] h

Single N-Ch TO-92

VN10LP Ron

vs. Vgs

$0.68

SI3442DV 60V 4.00A 70m 1.8V h Single N-Ch TSOP-6 +-8V Gate $0.66

IRLZ44N 55V 47.00A 22m 1.76V h@3

2.5V h


IRLZ44N Ron vs. Vgs

$1.67

BS107PT 200V 0.10A 28000m 1.76Vh@30

2.5V h

Single N-Ch TO-92 E-line

BS107PT Ron

vs. Vgs

$0.91

RFP30N06LE 60V 30.00A 47m 1.75V h@3

2.0V h

Single N-Ch TO-220TO-263AB


Gate Protection Zener

RFP30N06LE Ron

vs. Vgs

$1.09

IRF3708 30V 62.00A 12m 1.67V h@3

2.0V h

Single N-Ch TO-220TO-262


IRF3708 Ron

vs. Vgs

$1.74

ZVN2106A 60V 0.45A 6000m 1.65V [email protected]

h

Single N-Ch TO-92 E-Line

ZVN2106A Ron vs. Vgs

$0.72

2SK3065 60V 2.00A 320m 1.5V h Single N-Ch SC-62 Gate Protection Zener $0.83

ZVNL120A 200V 0.20A 10000m 1.35V [email protected] h

Single N-Ch TO-92

ZVNL120A Ron

vs. Vgs

$0.78

DMN5L06VAK 50V 0.30A 2000m 1.0V h D ual N/ N-C h SOT -5 63 ith in te gra l 50VZener

$0.58

DN2530 300V 0.17A 12000m -1.0V h Single N-Ch TO-92,SOT-89

Depletion Mode $0.71

DN3545 450V 0.20A 20000m -1.5Vh

Single N-Ch TO-92,SOT-89

Depletion Mode $0.82

CPC3703 250V 0.36A 4000m -1.6V h Single N-Ch SOT-89 Depletion Mode

VSG vs IS @ VDG of15V,10V,5V

$0.95

nchpch ------ ------ ------ ------ ------ ------ ------

Si4539ADY 30/-30V 4.90/-3.70A 36/53m 1.0/-1.0V h

Dual N/P-Ch SO-8 $2.06

Si4511DY 2 0/- 20V 5.80/ -3.710A

33/500m 1.8/-1.4V

h


Si4500BDY 20/-20V 5.30/-3.10A 30/100m 1.5/-1.5V h


pch ------ ------ ------ ------ ------ ------ ------

Si1023X -20V -0.40A 1200m -0.8V h Dual P/P-Ch SOT-563 $0.52

IRF7410 -12V -13.00A 7m -0.9Vh

Single P-Ch SO-8 ith integral -12VZener

$2.03

Si4947ADY -30V -3.90A 80m -1.0V h Dual P/P-Ch SOIC-8 $1.22

SPP18P06P -60V -18.60A 130m -2.34V h

@30-2.8V h

Single P-Ch TO-220

SPP18P06P Ron vs. Vgs

$1.31

MTD5P06V -60V -5.00A 340m -2.86V h Single P-Ch DPAC 3 pin ith integral -60V $1.07




21/47

@30-4.0V h

Zener

MTD5P06V Ron

vs. Vgs

VP0610T -60V -0.12A 10000m -3.5V h Single P-Ch SO-23 -+30V Gate $?.??

IRF7316 -30V -4.90A 58m -3.0V h Dual P/P-Ch SO-8 ith integral -30VZener

$1.17

IRF9Z34 -60V -18.00A 140m -3.13V h@30

-4.0V h

Single P-Ch TO-220 ith integral -60VZener

IRF9Z34 Ron vs. Vgs

$1.39

IRF4905 -55V -74.00A 20m -3.30V h@3

-4.0V h

Single P-Ch TO-220 ith integral -55VZener

IRF4905 Ron vs. Vgs

$2.81

IRF5305 -55V -31.00A 6m -4.0V h Single P-Ch TO-220 ith integral -55VZener

$1.61

IRF5210 -100V -18.00A 60m -4.0V h Singl e P-C h TO-2 20 ith i ntegr al -100 VZener

$2.66

bipolarnpn ------ ------ ------ ------ ------ ------ ------

KSC2330YBU 300V 0.10A 1.0W 120H e Single NPN TO-92L $0.11

2SD667 80V 1.00A 0.9W 160H e Single NPN TO-92MOD $?.??

2N2222A 75V 0.60A 0.5W 35H e Single NPN TO-18 Metal Can $0.96

TIP120 60V 5.00A 1000H e Single NPN TO-220 Darlington.12K/8K

$0.68

BC337 45V 0.80A 0.625W 60H e Single NPN TO-92 $0.44

BC550 45V 0.10A 0.5W 110H e Single NPN TO-92 $0.52

BD135 45V 1.50A 12.5W 40He

Single NPN TO-126 $0.62

MPSA18 45V 0.10A .625W 400H e Single NPN TO-92 $0.52

2N3904 40V 0.20A 0.625W 40H e Single NPN TO-92 $0.42

pnp ------ ------ ------ ------ ------ ------ ------

2N3906 -40V -0.2A 0.625W 40He

Single PNP TO-92 $0.46

BC327 -45V -0.80A 0.625W 100H e Single PNP TO-92 $0.43

BC560 -45V -0.10A 0.5W 110H e Single PNP TO-92 $0.29

BD136 -45V -1.50A 12.5W 40H e Single PNP TO-126 $0.62

2N2907A -60V -0.60A .4W 75He

Single PNP TO-18 Metal Can $0.92

2SB1181 -80V -1.00A 1.0W 180H e Single PNP SC-63 $0.98

TIP127 -100V -5.00A 1000H e Single PNP TO-220 Darlington.12K/8K

$0.60

regulator ------ ------ ------ ------ ------ ------ ------

LM317 40V 1.50A 1.25Vadj 100A 2.5V Positive TO-220

LM317L 80V 0.10A 1.25Vadj 100A 1.9V Positive TO-92

LM317 Positive Excel file

opamp ------ ------ ------ ------ ------ ------ ------

LM124A 32V 20mA 3000Vos 0.5mHz 0.25V/S Quad DIP-14

LM358A 32V 20mA 7000Vos 0.5mHz 0.25V/S Dual DIP-8

AD8639 16V 19mA 23Vos

1.3mHz 2.50V/S

Dual SOIC-8

comparato ------ ------ ------ ------ ------ ------ ------

LM339A 36V 6mA 2mVos 1.3S 300nS Quad DIP-14

LM393A 36V 6mA 5mVos

1.3S 300nS Quad DIP-8

tempsensor ------ ------ ------ ------ ------ ------ ------

LM50BIM3X 4.5V-10V

130A 100mV @ -40C

1750mV @125C

+-2C Analog SINGLE SOT-23

diode ------ ------ ------ ------ ------ ------ ------

1N5404 400V 3.00A 1.00V@3A

3.00W 150C DO-201AD Silicon

1N4004 400V 1.00A 1.10V@1A

3.00W 175C DO-201AD Silicon

HSS82 200V 0.125A 1.00V@100mA

0.40W 200C DO-34 Schottky

1N4148 100V 0.30A 1.00V@10mA

0.50W 175C DO-35 Silicon

PMBD7000 100V 0.215A 0.82V@10mA

0.25W 150C Dual SOT-23 Silicon

BAW56 85V 0.200A 0.855V@10mA

0.35W 150C Dual SOT-23 Silicon

MMBD4148 75V 0.200A 1.00V@10mA

0.35W 150C SOT-23 Silicon

BAS416 75V 0.20A 1.00V 0.25W 150C SOD323 Silicon




22/47

chace

The circuit board and sensor assembly of the Chace tracker.

The circuit is not water proof so a protective plastic dome is needed. I have used 2 liter clear plastic soda bottles. They last a long time, at least 5

years for one I have used, probably a lot more. This circuit will fit into the 20 Oz. size. The plastic bottle chosen needs to have a round bottom, thetype that comes with the black plastic bottom which is removed. The type with the molded in feet don't work very well as they diffract the light toomuch.

Glass jars are even worse optically if looking through the bottom.

Any one out there with a good idea for a better weather dome?

In Minnesota I have snow that builds up on the top of the dome. This snow is quite reflective and can confuse the sensors as to the correct directionfor the brightest portion of the sky when in the sky is overcast. It's easy to just brush the snow of but this is not always timely. I have experimentedwith putting black opaque paper inside the dome to eliminate the light from the snow. Another paper light blocker can be put under the sensors tostop the reflected light from the snow on the ground.

dome

Dome on Chace tackerThis weather dome is made from a 2 liter pop bottle.

jiff

I have tried and like using plastic Jiff Peanut butter jars

dcb

DCB's implementation of the LED3 tracker with Pyrex Weather Dome.This dome is made from an unusual deep style Petri dish.

@10mA

1N270 50V 0.040A 1.00V@200mA

0.05W 90C 0.8pF DO-7 Germanium

SB540 40V 5.00A 0.55V@5A

2.75W 125C DO-201AD Schottky

RSX501L-20 20V 5.00A 0.39V@3A

1.50W 125C SOD-106 Schottky

G331 20V 0.050A 1.00V@5mA

0.05W 75C DO-7 Germanium

zener ------ ------ ------ ------ ------ ------ ------

2EZ110D5 [email protected]

17mA 2.00W 4000 150C 5% DO-41 Zener

1N4757 51V@250A

20mA 1.00W 1,5K 175C 5% DO-41 Zener

1N4625 5.1V@5mA

70mA 0.40W 1.5K 175C 5% DO-35 Zener

BZX84C2V7LT1 2.7V@5mA

83mA 0.225W 1.5K 150C 10% SOT-23 Zener

Jiff peanut butter jar.

Jiff peanut butter jar with only the lid.




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doc

Doc's implementation of the LED3 tracker with a Fruit Jar Weather Dome.

Doc emailed this to me:

The power produced from the system is run to the main house. In the house, the 120 volt service is connected to its own fuse box to run all of my 120olt stuff. The LED3 increased the output of the 4 panel array by 50%, as compared to the output of an identical 4 panel array mounted on the roof.

During mid-day, the power output of my system bulk charges the batteries and the C40 disconnects the solar panels to keep from over-charging theatteries. This never occurred before I installed the LED3. This is great!!

danbennet

Dan Bennet's Dish.

12 foot parabolic dish with 10,300 1" pieces of mirrors on it. It weighs around 1,200 lbs with the boiler .

wolfendale

Martin Wolfendale's implementation of the LED3 tracker with a machined plastic Weather Dome.

Martins PV panel mount is homemade and looks very nice. He is in Austrailia so things might seem a bit reversed to us northerners.

East View

West ViewAssembled

Top View Without DomeView From Below

Long View

The Base

LED3 in Fruit Jar PV Panel

PV Panel

Panel with LED3 Back of Mount

Power Controller

Battery Pack

LED3 in Fruit Jar




24/47

gary

Gary has suggested making the dome from Lexan. He wrote:It's fairly easy to make a perfect dome out of Lexan.

Make a 2 piece mould out of whatever you can find that's the right size.Heat up a piece of Lexan in your oven at about 200F for about 5 min.Put it on the mould and press and release.Trim off the excess after it cools.If you want really good optics leave room in the mould for a piece of flannel on each side.Scratches are polished out with toothpaste.I Got this from EAA Sport Aviation to make nice wing tip strobe light covers.

mrea2001

Demo of my tracker at the 2001 Midwest Renewable Energy Fair

mrea2002

Demo of my trackers at the 2002 Midwest Renewable Energy Fair

Overall View Closer Mount and Connections

Wearher Dome in Upper Corner Closeup of Weather Dome

LED3

Look at all the people

Having fun igniting sticks of wood at the prime focus of the dish. Thatflash of white is smoke after about a second. It also melts holes inaluminum cans in about 1 second.

A small Stirling engine mounted where the electronicssed to be on the small PrimeStar dish. Reflective

Mylar was glued to the surface.

The north view

View from the SE. This mount is similar to that of a Poulek Traxle.This mount is very sturdy compared to the conventional Daisy mount.

Solar trackers

led5dlighting

Lighting "Receiver Axis" heliostat with dual

led5spv

Small PV Panel with LED5S5V solar tracker. Thisone is powered from the PV panel it controls.

Two "Receiver Axis"heliostats




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mrea2003

Demo of my trackers at the 2003 Midwest Renewable Energy Fair

ledshex3

LED3 Schematicledshex3layout

axis LED5D5V solar tracker.

Back of large "Receiver Axis"heliostat.

bisectordrive

Bisector Drive on large "Receiver Axis"heliostat.

led5ddome

Dual axis LED5D5V solar tracker on large "ReceiverAxis" heliostat.

mrea2003trackers

A bevy of 4 solar trackers and mounts.

mrea2003ledtv1&dome

Prototype LEDTV1 solar tracker. The

eather dome is a Lexan canister I got atWall-Mart. The tracker is based on aMicroChip PIC12F675 8 pinmicroprocessor.

mrea2003ledtv1b

Prototype LEDTV1 solar tracker. In thiscase it drives an Alliance U-100Tenna Rotor TV antenna rotator. Thissetup charged 2 junk car batteries tooperate both this and the dish trackers.

mrea2003ledtv1c

Prototype LEDTV1 solar tracker. In thiscase it drives a Cornell Dubillar hamradio antenna rotator. It was great funcooking mini killbasas on the Primestardish.

mrea2003smallpv

Small PV Panel with LED5S12V solartracker. This one is powered from thesmall PV panel it tracks and suppliespower to it and the LE D5D12V heli ostattracker.

mrea2003heliostat

Lighting "Receiver Axis" heliostat withdual axis LED5D12V solar tracker. Thisheliostat continuously illuminated myRed Rock sign. The Red Rock Energy sign. I apologise for

not taking the picture earlier because mytent was blocking the light.




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Layoutledshex3molex

Molex ConnectorThe tracker consists of pairs of LED photo sensors. Each pair controls the voltage applied to one terminal of the actuator motor.

led3operation

When the easterly pair says go west the minus terminal is grounded. When the westerly pair says go west the positive terminal is connected to plusand we get westerly movement. Or vise versa for easterly movement

When they disagree then either both motor terminals are grounded or have plus on them, and we get no movement. There are four operational statesfor the sensors to be in.Each LED pair tends to move the tracker East or West.An LED pair tends to move to the West orAn LED pair tends to move to the East.Each of the LED pairs controls one side of the H- ridge.

Note! Unlike most H-Bridge drivers where both sides are always driving the load this circuit has independent drives for each side. This allows themotor to stop when both sides are high or low. The motor moves when they are different.

In addition, both sides have the top MOSFETs turned off most of the time until the clock enables movement by periodically pulling R9 and R11 low.

Q3 and Q4 form a gated level shifter. To see how this driver works think of the bottom end of R9 and R11 being grounded when the top transistor isto be enabled.

Also the driver for the left side are inverted from the driver on the right side. This is a method for returning the tracker to the east, for parking, if R2and R3 are used. This way Q1A will be enabled and Q2B will be on when in the dark.

parking

In cloudy or overcast weather the tracker seeks the brightest part of the sky. At night it moves to the easterly parking position. The parking positionputs the panel at a steep angle so night time snow doesn't accumulate as much in the winter. A westerly parking position is obtained by mounting thetracker upside down and reversing the leads to the actuator motor.

led3x

LED3X LED Sensor Electronic Tracker with H-Bridge Drive.

LED3X Solar TrackerThe LED3 using surface technics was just to hard to assemble in a timly manor as sales were increasing. I needed a circuit that could be built withmostly through hole components. At the same time, there were other features and enhansments that I thought were needed. This was the impetus forthe LED3X series of solar trackers.

This circuit uses power MOSFET drivers and is designed to operate satellite dish linear actuators, however most any DC motor can be used. Thepower drivers are capable of delivering about 50 amps of peak current, maybe more. When better transistors become available this current can beincreased. The large power MOSFETS, 72A, when operated at low duty cycle or low currents eliminates the needed for a heat sink on the transistors.Neat huh!

The duty cycle is adjustable from 0% to nearly 100%. Idealy tracking from stop to stop should be 10 to 30 minutes. The duty cycle helps to slowdown the motor drive speed. Less duty cycle will make the tracking slower but, we don't need speed anyway. Slow tracking speed helps in partlycloudy condition. This prevents the tracker from making unnecessary movements when clouds move by.

LED Pair 1-3 LED Pair 2-4 H- ridge Left H- ridge Right Movement

West West Low High Move West

West East Low Low Stopped

East West High High Stopped

East East High Low Move East




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led3xshadow

To improve accuracy, ie. with concentrators such as troughs or dishes, a shadow blocker can be placed in front. Similar to the shadow blocker on theChace Trackeror like this:

OK, this is an example of a dual axis version.The single axis version uses a strip of metal.Cool weather dome!! As I recall the dome is polycarbonate and from the oil or water traps on air lines and regulators.

I have used a band of metal about .5" in width at about 2" from the LED3X sensor. If the LED3X is used for E-W tracking the band is oriented N-S.Conversely, if the LED3X is used for N-S tracking the band is oriented E-W. The shadow device is not particularly critical. For instance, I have used

lack electrical tape on the weather dome and it worked well.

led3xremotesensor

LED3X Remote Sensor

The remote sensor comes can be configured in several flavors.1. Single axis2. Dual axisAnd parking or no-parking on either axes.

The PC board is configured in 2 halves. Each half is an individual single axis sensor. For single axis use the board is cut in half or dual axis if leftwhole. Depending on which components, positions, and jumpers installed all the configurations can be obtained.

led3xremotesensorschematic

Dual Remote Sensor Schematic

led3xs24vspecifications

LED3X Specifications

For a more detailed set of specifications, options, and pictures see the web page devoted to assembling the kit. And a lot more pictures andapplication information.

Power Supply Voltage 10.5 Volts to an absolute maximum of 44 Volts inclusive.

The 10.5V minimum is specified as the under voltage point. Less voltage protects the power mosfet in the H - ridge drivercircuitry.

The 44 volt maximum is defined by the voltage tolerance of the 51V protection zener. This zener protects the power MOSFETsfrom seeing damaging breakdown voltages.The 51V zener has an initial tolerance of 5%. So the maximum continuous voltage that can be applied before conduction canoccur is 48V or so.Most PV panels don't output more than 44V in open circuit. You should check for sure. If they do go too high in voltage a simple

ower regulator should be added to limit the maximum voltage.

Load Current Continuous 9 Amp resistive.

The power MOSFETs are rated at over 70A at 25F. A conservative derating of 50% is prudent especially in hot weatherconditions.

Load Current Intermitant 20 Amp intermitant at 1S width once per timing cycle of 60S.

The Power MOSFETs have an absolute maximum current rating of 72A, but this is with ideal conditions where the temperature

is 25F and very fast gate rise times. The LED3x has a relatively slow gate rise time and may be operated at quite hightemperatures due to the weather. I think 20A at about 1S is adequate for normal tracking applications.If higher current motors are required a power amplifier may be needed. See:http://www.redrok.com/electron.htm#power




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led3xforsale

LED3XS24Vc3 For Sale

Please go to this page:http://www.redrok.com/led3xassm.htm#led3xforsale

power

Some have expressed an interest in driving high powered loads beyond the capabilities of the H-Bridge driver transistors. To this end Ideveloped several high powered driver circuits, (actually their almost the same circuit as in the relay trackers).

relaydc1

RelayDC1Relay circuit that uses DC relays with 12VDC coils. The DC motor in this case is a permanent magnet type that is reversible.

relayac1

RelayAC1Relay circuit that uses AC relays with 12VDC coils. The AC motor in this case is a capacitor run type.

relayac2

I should note that the satellite dish actuator I use normally consumes about 290mA of current at 13.8VDC. This actuator iscapable of driving a 15' dish with 1500lb of force. You don't need a high powered drive, just a slow forceful one.Think slow!

Operating Temperature -40F to 185F or -40C to 85C




29/47

RelayAC2Relay circuit that uses AC Solid State relays with 3 to 32 VDC control inputs. The AC motor in this case is a capacitor run type.

manualops

led3manualled3xmanual

LED3XManualSome have expressed an interest in adding a switch to manually move the array for test purposes. One of these circuits, when added betweenthe tracker and actuator, will allow manual movement. The first circuit has a fast and slow position. The second circuit is slow only butsimpler. The first circuit is the nicest.

Since I do the assembling variations can be easily made for such things as a change in the timing of the oscillator for other duty cycles or todisable the parking feature. I am currently selling the assembled units without the parking feature.

assemblyled3x

Assembly & Opperating Instructions for the LED3X series. Plus a lot of pictures and examples.

led3xenergy

The circuit draws about 15mA when idling. It can operate at temperatures to -40F or up to 158F. Its designed to operate from a 12V or 24V




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lead acid power source. I generally recommend using a 36V actuator on 12V.

The daily energy consumed is quite small. My actuator draws about 290mA and can go from stop to stop and back in about 5 minutes. So:((.015A * 24hr/day) + (.290A * 5min/day / 60min/hr)) * 13.8V = 5.3Whr/dayOr about 5Whr/day, which is pretty small.

trickle

A very small 5W or even a 2W PV panel and small wet cell lead acid battery is a good combination for the power source to run the system.Wet cell manufacturers say you can "trickle charge" them continuously at 1% to 2% of the amp hour capacity. A trickle charger has no

oltage regulation.A 12V 5W panel can deliver about 400mA of current. So the smallest lead acid battery can be about 20Ahr of capacity.A 12V 2W panel can deliver about 170mA of current. So the smallest lead acid battery can be about 8Ahr of capacity.Periodically these batteries need to be watered with distilled water.Note! I used to say it was OK to use gel cell lead acid batteries. This was a mistake on my part. Trickle charging by definition is overcharging and gel cells are damaged when over charged wet cells are not.

While trickle chargers are simple it is often better to use a small solar charge controller such as the Morningstar SunGuard SG-4 or others.Make sure you select one that has Temperature compensation. This solution will greatly reduce the watering requirements of wet cell

atteries or use of gel cells.

I intend that this circuit will supplant the Chace tracker as its simpler to build and adjust.

For two axis tracking two circuits are needed. However, for PV panels the second axis only adds about 5% on the average and may notarrant the added expense.

economics

Many have said that it makes no sense to use a solar tracker with PV systems as it is cheaper to just add an extra panel for every three. Tothis I say bunk.

Using the NREL data:My link.http://rredc.nrel.gov/solar/pubs/redbook/redbook_index.htmlI find that in Minnesota a single axis tracking PV panel will have a 40% increase in output in December and a 100% increase in June.In Minnesota:A PV panel with 15% efficiencyin December tilted to your latitude plus 15s.http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/

2 to 3 kWhr/m2/day lets say 2.5 solar

2.5 kWhr/m2/day * 15% = .375kWhr/m2/day electric

Or a single axis north-south tracking panel at lat. +15.

3 to 4 kWh/m2/day lets say 3.5 solar


.525 / .375 = 140%This shows 40% improvement with a tracker in December.

Lets do it in June:

4 to 5 kWhr/m2/day lets say 4.5 solar


Or a single axis north-south tracking panel at lat. -15.

8 to 10 kWhr/m2/day lets say 9 solar

9 kWhr/m2/day * 15% = 1.35kWhr/m2/day electricThat's a 100% improvement with a tracker in June.

Of course your location will have different results. For instance I just did it for San Jose, CA and got an increase of only 14% in both Juneand December. Clearly this is not the best place to do solar tracking.

Here are the 4 maps that I used.

nrelmaps

Click the map!

The full set of maps from NREL are here.

I don't have a cost for the tracking mount but the actuator I'm using costs about $140us and my tracker is $35us. PV panels now are about$5us/W so a 100 watt panel costs $500us. Using a system of 3 panels this is $1500us.

Since the tracker delivers at least 40% more output, in December, it would be fair to say that the tracker has an equivalent value of $600usin a 3 panel 300W system. I can't see the tracking mount would cost $600-$140-$35=$425 more than the equivalent stationary mount thathas to hold at least 4 PV panels. Of course, the comparison is even better in June with the 100% increase.

Today there are many obsolete C- and satellite dishes. These have polar axis mounts which are almost ideal for use with arrays of PVanels. Remove the dish and install racks to support the panels. They are well designed and very strong. They have all the needed hardware

including the motor actuator. Besides they are often free for the asking.

tripod




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TriPod Mounts

I am convinced that the best and strongest mount for PVs at ground level is one based on the design example of:

poulektraxle

* TraxlePoulek Solar

y Martin PouleGary A. Werner, President GWM CorporationPolar mount with tracker.The tripod support arrangement is very strong with light weight construction.

aps

* APS Solar's "Tilt Tracker".Similar to Poulek Solar's Traxle, with a clockwork tracker. The second axis, the tilt axis, is adjustable for a few percent improvement intotal output. The actuators are hydraulic.

powerlight

PowerLightA bigger version, similar to Poulek Solar's Traxle

sunpower

* SunPowerSunPower purchased PowerLight

szymanski

* Martin Szymanski's variation of a Tripod Tracking Mount

pvc

PVC plastic TriPod Mount

This is my version of Poulek's mount. I call it the TriPod Mount. This mount is cheap and crude but easy to make,especially for demonstrations. It's easy to build and knock down. Its quite portable.A proposed Stationary Receiver Dish on a Tripod Mount.A proposed Stationary Fresnel Lens on a Tripod Mount.

It's made from PV plastic sewer pipe.

1. The legs are fitted with end caps.2. The foot caps are drilled and have long bolts protruding through to be pushed into the ground.3. The support legs have "I" bolts fitted to the top caps.4. The main polar axis leg has a large bolt that is fitted through the "I" bolts of the support legs.(The Primestar mount doesn't allow the pipe to go all the way through so I made a compromise and have this large top bolt mounted to the




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dish support. Although the Primestar mount has a method to manually adjust for declination.)5. The polar leg needs to rotate. To do this side pipes are glued on to the polar and one of the support legs.6. The satellite dish linear actuator is fitted to the side pipes.7. To set it up just adjust the support legs until the polar tube is aimed at the pole star. This is due north and angled at exactly your latitude.8. To make sure the thing doesn't blow away I have a heavy nylon cord, ( not in the pictures ), tied from the top of the polar leg down to theearth. I used a screw into the ground dog leash stake.9. Don't bolt the dish and PV panel to tightly. This will allow some manual adjusting.

There are some compromises to this example.1. The actuator can only rotate the polar leg about 150. A better way would be to have a pulley and cable to get the rotation to 270 or so. 2.

The Primestar mount is not ideal. A better mount would allow the polar leg to protrude fully.3. A longer polar leg would allow more rotation without interfering with the supporting legs.

Improvements1. For larger equipment one should make the tripod from steel cold water pipe. This would make things much sturdier.2. Make the polar rotating device using a large pulley and cable to allow more rotation.

led4

LED4 LED Sensor Electronic Tracker with Simple Solar Charge Controller.

LED4The "LED3" light sensor works very well. It is sensitive, accurate, and cheap. A couple of years ago I had devised a simple solar chargecontroller I called "Shunt 2". I thought it would be a good idea to combine them into a single PC board called the LED4.

Note! I no longer sell the LED4 as it was replaced by the much more capable LED3X. Ok, the LED3X doesn't have a charge controller butthis isn't really required to run the tracker.

The design philosophy for this tracker was to make it more robust and self contained. I included a charge controller for rechargeableatteries intending them to be NiCds to run the actuators. Since the charger is there it might as well be capable of running a large PV panelith lead acid batteries.

Note! this charger is not intended to charge the expensive system batteries. Leave that job to the high end smart charger such as those byTrace, Outback, and others.

It can also run a very small PV panel to charge the local NiCds or NiMH batteries. These batteries work well over a wide temperaturerange.

I will test the ability of the sensors to be at the end of a long cable. I will test this using 1000' of 4 wire telephone cable. 8 wire Cat5 cableshould also work with the extra wires driving the actuators.

With the use of long Cat5 cable the main board can be inside a heated battery room. Of course you still have to run the heavy gauge maincharging wire pair to the battery room. The advantage of having the batteries in a heated room is temperature compensation won't beneeded.

ledshex4

LED4 Schematic

LED4 Layout

led4connections ledsensor01




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led4features

LED4 Features

vdish1

Virgil Vinz's faceted dish with LED4 tracker in a plastic Peanut Butter Jar Weather Dome.

This dish is to be used to run a small steam engine. The mirrors are 6" Lucite squares. The ribs are cut from parabolic sections.

The receiver is a flash tube type. The spiral copper tubing is cast into an aluminum block. The Pyrex cooking dish is the transparentinsulating cover. The backside is insulated with fiberglass. The indicated temperature is about 1100F. The concentration ratio is about 20Xor so given the receiver is larger than the mirror tiles.

LED4 PinoutAlternate LED4 Sensor Schematic

Separate LED LightSensors

The signal sent back from the sensor can be sent a considerable distance since the current flow is minimal. However, static electricdischarge could be a problem if the sensor is more than about 6 feet or so from the main board. If long distances are needed pleaseEmail me for advice.

Under voltageShutdown Protection

Shuts down the actuator motor drive when the battery voltage drops below about 10 volts.

Built In ChargeController

Designed for use with nominal 13.8 volt battery systems. The charger is designed for controlling 13.8 volt 125 watt PV panels. Thereis no provision for either temperature compensation or multiple charging strategies.

Larger PowerTransistors

The power MOSFET transistors are much more robust than in the LED3. It uses IRF5305 and IRLZ44N transistors fromInternational Rectifier. The IRF5305 P-channel MOSFET has an on resistance of about 60 and the IRLZ44N N-channel MOSFET has an on resistance of about 20 .

No need for a heatsink

A 125 watt PV panel can deliver about 9 amps of current. The maximum wattage dissipated by the IRLZ44N shunt transistor underthese conditions is about 1.6 watts continuously. The Schottky Barrier series protection diode is rated for about 9 amps.The H- ridge transistors are pulsed at about a 10% duty cycle. I'm rating the actuator maximum pulsed current at about 16 amps.If you want to continuously drive the actuator keep it below 5 amps.The IRF5305 has a maximum current rating of 110 amps and the IRLZ44N has a maximum current rating of 160 amps so if thecurrents are kept to below my system rating no heat sinks will be needed.

Built with ThroughHole Components

Through hole construction allows the average home brew guy the ability to easily put the LED4 tracker together either as a kit orscratch built.I can supply the PC boards separatly for $9.00us.

OperatingTemperature Range

-40F to 185F or -40C to 85C

vdish1overall

Faceted Dish

vdish1mount

Steam Generator Mount

vdish1steamgenerator

Steam Generator

vdish1melting

Melting aluminum cansith a propane powered

vdish1flashtube

Spiral copper flash tubesimbeded in the aluminum.The tubing is 3/8th inchtubing and about 4' in vdish1receiver




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concentratortemperature

Calculations of Concentrator Temp

Documents

Solar Electron