Abstract: A protection circuit detects short circuit and/or current overload conditions based on one of a current level and a current change rate di/dt of a current through a load. A detection device uses an inductor to detect current change rate and a resistor to detect current level, and generates a first voltage signal based on the voltages of the inductor and the resistor. A comparator generates a second voltage signal based on the voltage signal and a reference voltage signal. A switching circuit allows or interrupts current through the load based in part on the second voltage.

Abstract: A circuit and method for controlling two or more electric relays, wherein at least one of the relays are rated to handle a higher voltage level while at least one of the relays are rated to handle a lower voltage level. A controller selectively activates the relays such that the higher voltage rated relay(s) open before but close after the lower voltage rated relay(s) within the system.