A signal generator provides an output signal having a series of pulses and a pulse repetition rate. The signal generator includes an energy storage circuit and a switch control circuit. The energy storage circuit includes a switch operated by the switch control circuit. After delivery of a pulse of the output signal, the switch control circuit operates the switch in a first mode to provide the pulse repetition rate of the output signal. The switch control circuit also operates the switch in each of the first mode and a second mode at a switching rate, wherein relatively more energy from a battery is stored as a consequence of the second mode than is stored as a consequence of the first mode. Energy from the battery is stored for delivery in a pulse of the output signal. The switching rate is compensated in accordance with a temperature of the battery and a voltage of the battery. Compensation maintains the battery voltage above a minimum value. Operation according to the value avoids current draw from the battery at a rate that may lead to an under-voltage condition of the battery. In one implementation, the power supply provides a high voltage for charging a capacitor for each cycle of an electric discharge weapon. Another value conveyed by the serial data provides a maximum pulse delivery rate for such a weapon.