CDROctober 9, 2008

Mike OertliJonathan Karnuth

Jason Rancier

Division of LaborMike O.

Program MCUMatlab interface

Jonathan K.Construct railsAssist in control system design and coding

Jason R.Construct capacitor arrayDesign voltage sensors

Block Diagram

MSP430F169

Power Supply

Keypad

LCD

Railgun

Capacitor Array

KillSwitch

LEDs

Inductor

Voltage Sensor

Voltage Sensor

Pneumatic Starter System

Encoder

Item Qty. Needed Cost Per Total for item

Brass Rails (36") 2 58.68 117.36

Garolite G-10 (39") 1 92.16 92.16

Teflon (12") 6 9.21 55.26

Aluminum (12") 2 17.41 34.82

Capacitors 50 Donated 0.00

PCB 2 33.00 66.00

Microcontroller 2 0.00 0.00

Air compressor 1 56.10 56.10

Air tank 1 62.00 62.00

Solenoid Valve 1 170.00 170.00

Pressure Regulator 1 35.00 35.00

Transformer 1 100.00 100.00

Plastic housing 1 50.00 50.00

Sensors/Miscellaneous 200.00

Grand Total 1,038.70

Safety FeaturesVoltage sensors on rails, cap bank, &

sourceKill power if out of expected range

Plexiglas casingo Keep user isolated from high voltages and

short circuited rails

Pressure Regulatoro Added ability to safely release tank pressure

Power System Diagram

Capacitor Battery50x 450V 3.7mF Capacitor

Donated by CDEArray of 3 banks of 16 in parallel

Overall: 1350V ~ 20mF

Capacitor Battery

Basic Charger

Power Parts2x 200KOmh @ 3W1x 800Omh @ .25 W50x 100kOmh @ 3 W3x 22KOmh @ 50 W1x 120V 15 Amp AC switch1x Fuse Holder 120VAC1x 1600v Power Diode2x High Voltage Switch(1000V)1x Microwave Transformer1x Variac Variable TransformerCopper PlatePlexiglass Box

Cylindrical Rail DesignDesign Difficulties• Material Tolerances• Material Loss• Toxic materials• Difficult to machine at

desired barrel length

Efficient Design method• Maintain physical contact despite material disintegration

Machined & Fabricated Parts

Compressed Air Injector Adapter

Injector Adapter Drawing

Brass RailsComposite: ~70% Copper, ~.07% Lead,

~.05% Iron, Remainder ZincElectrical Conductivity: 28% IACSElectrical Resistance: 6.2µΩ/cmFriction: Very low with Most metalsMelting Point: 910oCInner/Outer Diameter: 0.87”/1”

ProjectileMetal: Aluminum

Composite: 2011Temper: T3Part #: 88615K411

Melting point: 540oC Electrical Conductivity: 45%

IACSElectrical Resistivity: 3.8µΩ/cmDiameter: 7/8”Length: ~1”

Pneumatic Kick-start Avoids spot welding projectile

Added kinetic energy

Eliminates static friction coefficients

Compressed Air systemActivated by Microcontroller post safety checks

Additional safety with inclusion of Pressure Regulator

Injection System

Complete SystemCompressed Air

TankCompressorSolenoid ValveBall ValvePressure RegulatorManufactured Parts

Railgun Adapter Tank Adapter Compressor Adapter

Electromagnetic Solenoid Valve

Pressure RegulatorFeatures

High Pressure capabilities

Very Low Flow

1/150 Flow of the Solenoid (.06 Cv)

Adjustable Pressure Range

Low leakage Value

3600 Psi Capabilities

Chassis SpecsInner Support Outer Sheath

Composite Teflon PTFE Grade G-10/FR4

Crosswise Tensile Strength

3,900 PSI 35,000 PSI

Melting Point 335oC ~384oC Max Temp

Dielectric Strength 19.7MV/m 15.7MV/m

Inner/Outer Diameter

.875”/1” 1”/1.375”

Cost $9.21 per 12” $92.16 for 39”

Part # 8547K29 8668K49

Parts List- Control SystemVoltage SensorMM74C922 16 key encoderKeypad, 3-line LCDMaster kill switch“Hot” switch

Parts List- MCUMSP430F1692 ADC1 RS232Voltage regulatorLEDs

InterfacesMSP430F169 Matlab

RS232

Key Encoder KeypadMSP430F169Wire-wrap/Solder Wire-wrap/Solder

MSP430F169P6 I/O (ADC)

Voltage Sensor

3-Line LCDMSP430F169Wire-wrap/Solder

Keypad Pin LayoutTruth Table

Pins 2 4 12 13

1 1 2 3 ST

3 4 5 6 PT

14 7 8 9 TI

5 CL 0 FX PI

1 2 3 4 5 6 7

14 13 12 11 10 9 8

Key EncoderMM74C92216 KeyDebounceContinuous row scan

Keypad & Encoder Schematic

Software- MCULanguage: C++Inputs: Keypad (via encoder chip on P1),

voltage sensors (1 on ADC on P6, 2nd via off board ADC), power (6V)

Outputs: 3-line LCD (P2), Matlab (RS232), capacitor charging control (switch based on sensors), safety/kill switch

MCU Logic

Software- MatlabPlot time domain analysis of sensor readingsKeep test-run informationInputs: Data from MSPOutputs: GUI showing dataInterface: RS232

Questions?