Patent ID: 8324812
Filing Date: 2012-12-04
Classification: H05B,Y02B

Abstract:
1. A method of protecting an electronic ballast for a gas discharge lamp comprising: (a) connecting a voltage interface circuit intermediate a control circuit and the electronic ballast; (b) disposing a protection circuit including first and second circuit branches extending between the voltage interface circuit and the controller connection with a voltage responsive depletion mode MOSFET switch in circuit with the first branch and a diode in circuit in the second branch; and, (c) automatically opening said voltage responsive depletion mode MOSFET switch when one of (i) an overvoltage condition occurs and (ii) the controller connection is connected to a reverse polarity power source, and when a power source voltage at the controller connection is one of (i) less than −2 volts and (ii) greater than +10 volts.