Design Coil Gun Replacement

[anijjar]

Karan wants a coil gun board that uses a capacitor bank rather than a dead short from the main power supply. This board will need a CAN bus connection for production and also a USB Connector for easy programming. Use a mosfet switch to switch the capacitor charge circuit to the launch circuit.

The charging circuit will be an RC network, so the time constant is RC. Meaning the capacitors will fully charge 5*RC. Design accordingly.

Once the caps switch, the charge stored in the electric field will be dumped into a solenoid (with a flyback diode to dissipate energy) to launch the projectile. The force induced by the inductor is directly proportional to the number of turns of the wire and the current being sinked.

An important note is that adding a series resistance to the launch circuit will reduce the amount of current dumped greatly, but it will remove any-sort of oscillations. Oscillations are a problem because the direction of the current will flip, causing the projectile to lose force. 1 ohm power resistor should be fine, but this doesnt need to be included in the schematic.

Use screw-in connectors for the solenoid connection.

Keep your power traces thick and untented (exposed)

[anijjar]

Board designed, reviewed and ready to be ordered.

I should show the circuit to Jens once and get roasted. Before the order on thursday

[anijjar]

Rather than using electrolytic caps, which would require high voltage, I went with super capacitors because they can store much greater charge at lower voltages. Robosub has a 55V potential limit before we need to get permission, so this solution is better. The supercaps provide more energy than Karans prototype so I predict that the projectile will launch with a greater force.