Abstract: A starter motor energized through a relay is protected from low voltages by a circuit which senses low voltages and turns off the motor relay via a transistor switch. A generator voltage sensing circuit also turns off the relay via the same switch when a generator voltage threshold is reached. For operation over a wide system voltage range, the coil of the relay is protected against high voltages by a chopper circuit which operates the transistor switch at a duty cycle of 100% at low voltages across the coil and lower duty cycles at high voltages. For a 12 volt relay the average current at higher voltages is maintained at a value approximating that obtained at a steady state 12 volts.

Abstract: The invention is an electronic circuit with several inputs, several outputs, a timing circuit, and two switching circuits used to actuate the firing of certain firearms. The circuit is partitioned into a voltage boosting circuit, a machine gun firing circuit and a cannon firing circuit. The voltage boosting circuit produces a voltage that is larger than the supply voltage, which is used to facilitate the operation of MOSFET switching circuits. The machine gun firing circuit connects a low impedance voltage source to a particular output only so long as a particular input is electrically asserted. The cannon firing circuit connects a low impedance voltage source to a particular output for a specified period of time only in response to a stimulus on one particular input and only if an additional arming input is electrically asserted.