Patent ID: 6844779

Claim:
An optically isolated bias control circuit, comprising: a bias voltage source connected in series with a diode, the anode of said diode being connected to the positive terminal of said bias voltage source, the cathode of said diode being connected to the collector of a first phototransistor, the negative terminal of said bias voltage source being connected to a floating ground; an energy storage capacitor and a low inductance capacitor both connected in parallel with each other and in parallel with said series connected bias voltage source and said diode, wherein the positive terminal of each of said energy storage capacitors and said low inductance capacitor is connected to said collector of said first phototransistor, the negative terminal of each of said capacitors being connected to said floating ground; and a second phototransistor and an inductor, said inductor being connected between the collector of said second phototransistor and the emitter of said first photo-transistor, the emitter of said second phototransistor being connected to said floating ground, and the collector of said second phototransistor being further connectable so as to drive the input of a high input impedance switching device for switching a voltage across a load impedance.