Patent ID: 8004866

Claim:
A DC load removal circuit for use with DC loads, comprising: a) a power input for connection to DC power from a power source; b) a power output for connection to a DC load; c) an energy sink coupled across the power input; d) a blocking diode connected between the power input and the power output, oriented such that it blocks current from the power input to the power output but passes reverse current from the power output to the power input; e) a bypass switch in parallel with the blocking diode, having a control input, such that when the control input causes the bypass switch to be closed the blocking diode is bypassed and current can flow from the power input to the power output; f) an inductor connected between the blocking diode and the power output; g) a clamp switch across the load, connecting a point between the blocking diode and the inductor and a side of the power input, having a control input, such that when the control input causes the clamp switch to be closed, reverse current flows from the load through the inductor and when the clamp switch is open reverse current can flow from the load through the diode to at least the energy sink; h) a current sensor in the circuit loop of the inductor and the clamp switch, having an output representative of current flowing through the inductor at least when the clamp switch is closed; i) a controller having an input coupled to a power on/off signal input, and a reverse power signal output; j) a reverse power modulator, having an input coupled to the reverse power signal output of the controller, an input coupled to the output of the current sensor, an output coupled to the control input of the bypass switch and a control input coupled to the control input of the clamp switch; the controller being programmed such that when power is to be removed from the power output, the controller sends a signal to the reverse power modulator and the reverse power modulator opens the bypass switch and operates the clamp switch such that reverse current from the load is routed into the energy sink.