Simple DC to DC converter circuits:6V to 12V DC-DC Converter with TransistorsThis converter circuit can provide up to 800mA of 12V power from a 6V supply.

6V to 12V DC-DC Converter with ICThis step-up converter is intended for use in a car,  has a 6V battery and won't support a modern radio that needs 12V. The circuit described here converts 6V to 12V at 1A sustained load current.

A simple step-up converter.This step-up converter is intended for use in a '67 Citroën 2CV. This car, and I use the word loosely, has a 6V battery and won't support a modern radio that needs 12V. The circuit described here converts 6V to 12V at 1A sustained load current.

It works something like this:

When the switch is closed an extra current flows through the inductance and stores energy there. The capacitor supplies the load with current during this time.

After the switch closes the capacitor is charged by the energy stored in the inductance and an extra current starts flowing through the load, causing the output voltage to rise (energy is supplied directly from the input source also as long as the diode is forward biased). During this time, the system behaves like a RLC-circuit, so, after a while, the current decreases. The switch is then closed again and the cycle repeats. One could say that charge is pumped from input to output, increasing the output voltage up to the point where there is an equilibrium between the discharging of the capacitor while the switch is closed and the charging by the inductor while the switch is open.

The output voltage equals (ton / toff + 1) x Uin and is controlled by PWM of the switching action. For more information, see the Wikipedia article.

To implement this, I have used the LM2577T-ADJ from National Semiconductor. It operates conform the given discription and is connected like so:

IC

Switcher/regulator LM2577T-ADJ (National Semiconductor)

R1 and R2 Voltage devider for monitoring output voltage

20Kohms pot. (Bourns)

Cin Decoupling 0.1μF, 63V MKS condensator (WIMA)

L Use a good quality coil!

160μH toroïd (2.5A, 70mohms, nickel-iron core)

D Current higher than output current!

FR603 60V reverse breakdown, 3A Schottky-diode

Rc and Cc Pole-zero compensation network

2200ohms, 5% and 1μF, 63V elco (Philips)

Cout Get a low ESR type! 2200μF, 16V elco (Telecon)

You can download the PCB design here (only 4Kb). It's in CorelDraw 3.0 format (zip compressed).

If you want to design a an other DC/DC converter with different specifications, you might want to take a look at National Semiconductor's site; they have a design tool there that can design your circuit for you.

6V to 12V Converter

Home > Circuits > Power Supply > 6V to 12V Converter

Author Views Views Today Rank Comments

207,275 57 110

This inverter circuit can provide up to 800mA of 12V power from a 6V supply. For example, you could run 12V car accessories in a 6V (British?) car. The circuit is simple, about 75% efficient and quite useful. By changing just a few components, you can also modify it for different voltages.

Schematic

Parts

PartTotal Qty.

Description Substitutions

R1, R4 2 2.2K 1/4W Resistor

R2, R3 2 4.7K 1/4W Resistor

R5 1 1K 1/4W Resistor

R6 1 1.5K 1/4W Resistor

R7 1 33K 1/4W Resistor

R8 1 10K 1/4W Resistor

C1,C2 2 0.1uF Ceramic Disc Capacitor

C3 1 470uF 25V Electrolytic Capcitor

D1 1 1N914 Diode

D2 1 1N4004 Diode

D3 1 12V 400mW Zener Diode

Q1, Q2, Q4

3 BC547 NPN Transistor

Q3 1 BD679 NPN Transistor

L1 1 See Notes

MISC 1Heatsink For Q3, Binding Posts (For Input/Output), Wire, Board

Notes

1. L1 is a custom inductor wound with about 80 turns of 0.5mm magnet wire around a toroidal core with a 40mm outside diameter.

2. Different values of D3 can be used to get different output voltages from about 0.6V to around 30V. Note that at higher voltages the circuit might not perform as well and may not produce as much current. You may also need to use a larger C3 for higher voltages and/or higher currents.

3. You can use a larger value for C3 to provide better filtering.4. The circuit will require about 2A from the 6V supply to provide the full 800mA at 12V.

Related Circuits6V to 12V Converter, Portable CD Player Adapter For Car, Car Battery Charger, Automatic 12V Lead Acid Battery Charger, Solid State Tesla Coil/High Voltage Generator, 12VDC To 120VAC

Inverter, LASER Power Supply, Power Supply, High Current Power Supply, Dual Polarity Power Supply, High Voltage High Current Power Supply, Transformerless Power Supply, Fixed Voltage Power Supply, Voltage Inverter, Voltage Inverter II, Automatic Load Sensing Power Switch, 12V

To 24V DC-DC Converter, Solid State Tesla Coil

Comments

Add A Comment

william 6V to 12V Converter Friday, June 25, 2010 10:40:32 PM

Hello everyone I wanted to know if this scheme works because I put it in and throw me out scooter 6 volts alternating and I Servino 12 volts to charge a 12 volt battery always and some neon

Angelo 6V to 12V Converter Friday, June 18, 2010 10:39:41 PM

Hi i am just 12 years old and i made it work. But this circuit doesent seem to be efficient it only charges the capacitor with the 12 V inverted voltage. So this project lackks of amps. This is useful to low power 12 V appliances.

anonymous L1 info? Friday, June 11, 2010 7:10:39 PM

Hey could you give me a little more info on L1, such as actual inductance or what core you used?

Mr.HornY 6V to 12V Converter Monday, November 23, 2009 10:54:15 AM

Thanks for your stupid circuit, Iv got some problem with reading this... 1- Any punctual value for darned L1? 2- Why you didn't connect ground together?

wizard 6V to 12V Converter Sunday, August 30, 2009 2:13:38 PM

hello. i am trying to understand how things working.. you said that the circuit will require about 2A from the 6V supply to provide the full 800mA at 12V... if you use smaller amperage from 2A like 100mA and convert the current within the circuit, you cant get 800mA at 12V? i am looking forward for your reply Thank you

Newton Brawn 6V to 12V Converter Monday, August 17, 2009 1:21:29 PM

It is Working! And the load is 988mA! COULD YOU PLEASE GIVE THE ALL DIMENSIONS OF FERRITE CORE ?? regards

danan 6V to 12V Converter Tuesday, August 04, 2009 2:45:51 AM

how to make the coil L1 please give to me the clue

Daniël 6V to 12V Converter Monday, July 27, 2009 9:42:36 AM

I build it and the results are very good, I used the centerring of an old car-amplifier to make the coil and put 80 turns of 0.8mm D3 became 15V and the output is 15-16V with an input from 7.5-

15V It gives al little noise ... it works very good with only a few comonents. current is 0.75A

Luca 5V to 12V Converter Friday, July 24, 2009 4:37:04 AM

Hello everyone, Let me know that I have to perform changes to your model, to build a converter from 5V to 12V. why would I need to take power from usb port of the laptop and maintenance of an antenna that operates at 12V and consumes only 6W. Could you help? Thanks in advance. Luke.

Bones 6V to 12V Converter Monday, June 29, 2009 5:43:10 PM

Is there any way to reverse this circuit? to convert from 12V to 6V? i've been checking out voltage stabilizer circuits and i found a few good ones but i have no idea what ratings too look for in resistors and diodes etc. any help would be highly appreciated. thanks,

The last 10 comments are currently shown. Show All Comments. Add A Comment

Name:

Email:

Subject:

Comments:

Anti Spam Code:Please enter the exact text shown in the image above into

the box below. Browser cookies must be enabled to comment on circuits.

160 http://pow ersupplycircuit.blogspot.com/2009/05/dc-dc-converter.html6-12conv

anonymous

anonymous

6V to 12V Converter

Submit Comment Clear

Privacy Policy

DC-DC Converter With Variable VDC Input

A DC-DC converter or another name known as buck regulator or switching regulator (because the input voltage can be either above or below the desired voltage output), provides stable regulated output voltage to supply electronic circuits.

LM2576 converter circuits perform same function as the commonly known voltage regulator LM7805 from National Semiconductor. The 7805 voltage regulator dissipates a lot heat. The higher input voltage, the more heat is generated. The extra input energy is converted to heat, keeping the output voltage regulated at 5V.

LM2576 DC-DC Converter CircuitsThere a variety of capacitors out there in the market. Capacitance, voltage rating, dielectric material, etc... . Choose a suitable voltage rating across the capacitor. The circuits deals with high current, therefore it will be better to choose a low ESR (equivalent series resistance) Aluminum electrolytic capacitor. As a general guide, a higher voltage rating has lower ESR rating.

The inductor coil use should be able to handle the current passing through the inductor coil. If the wire is too thin, the coil may be burn or just fail. My previous circuit uses small wattage inductor (package like a big resistor). The circuit couldn't work and was later found to be IC problem. I have not yet do a test to check on the possibility of the inductor contributing to the failure.

Using a inductor meter to measure the inductance will be easier. Inductance value can be observe immediately for any modification to the coil of wire. The inductance value can also be calculated, depend on the coil size, number of turns, wire size used, dielectric of the core etc... .

The 1N5822 is a high current, high speed, schottky diode and is suitable for this digital switching circuit. Schottky diode (Schottky Barrier Rectifier), means that the forward voltage drop is low. For this application, a low forward voltage diode is necessary.

12 to 28V Boost Regulator LM2585

This boost regulator is for those times when you have a 28v relay, but want to use it with a 12v source. The circuit is built around the National Semiconductor LM2585, and uses the energy stored in an inductor to boost the 12 to 28v. Output voltage can be varied by adjusting the ratio of resistor values on the feedback pin.

The voltage regulator circuit does it's switching around 100 Khz, but generates no noise if SMT components are used. Output is good for about half an amp continuous, enough to power two or three large microwave relays. The board measures 1.5"x2".

It is important to note at least these three cautions before powering up the board:

A short-circuit on the output will kill U1 and D1. Always use a 1 ohm 5w resistor, or a 2.5A fast fuse on the 12v input lead.

Do not omit the LED (D2); It provides a visual indicator of a properly operating boost condition, but more importantly, it also provides a minimum load for the output, preventing an output "spike" which will otherwise appear when the load is disconnected abruptly.

Keep the ratio of r2 and r3 to 22 or less to keep the output voltage within the ratings of C4 (C4 on my board is rated at 35wvdc). This ratio plus 1, multiplied times 1.25v, determines the output voltage.