Abstract: A simple, low-cost circuit is disclosed that provides the requisite triple redundancy for a spark protection circuit for a battery-operated device having an on-board battery charger that is intended for use in hazardous atmospheres. The circuit complies with the IEC standard for intrinsically safe products.

Abstract: A simple, low-cost circuit is disclosed that provides the requisite triple redundancy for a spark protection circuit for a battery-operated device having an on-board battery charger that is intended for use in hazardous atmospheres. The circuit complies with the IEC standard for intrinsically safe products.

Abstract: A simple, low-cost circuit is disclosed that provides the requisite triple redundancy for a spark protection circuit for a battery-operated device having an on-board battery charger that is intended for use in hazardous atmospheres. The circuit complies with the IEC standard for intrinsically safe products.

Abstract: A simple, low-cost circuit is disclosed that provides the requisite triple redundancy for a spark protection circuit for a battery-operated device having an on-board battery charger that is intended for use in hazardous atmospheres. The circuit complies with the IEC standard for intrinsically safe products.

Abstract: An ambidextrous actuating mechanism configured as a mechanical interlock may be adapted to a battery operated light emitting device for mounting forward of the trigger guard of a firearm. The mechanism includes first and second mechanically coupled pivotable switch actuators disposed under and on either side of the barrel of the firearm. Operation of either one of the first and second actuator levers locks the other actuator from pivoting, thereby eliminating ambiguity and overridden operations in the control of the light emitting device. The operating motion of both actuators, either up for ON or down for MOMENTARY, is the same for both actuators. An alternate embodiment provides functionally equivalent electronically interlocked actuators.

Abstract: An ambidextrous actuating mechanism configured as a mechanical interlock may be adapted to a battery operated light emitting device for mounting forward of the trigger guard of a firearm. The mechanism includes first and second mechanically coupled pivotable switch actuators disposed under and on either side of the barrel of the firearm. Operation of either one of the first and second actuator levers locks the other actuator from pivoting, thereby eliminating ambiguity and overridden operations in the control of the light emitting device. The operating motion of both actuators, either up for ON or down for MOMENTARY, is the same for both actuators. An alternate embodiment provides functionally equivalent electronically interlocked actuators.

Abstract: A brightness control circuit for a DC-powered LED light uses a PWM generator. The LED brightness is a function of the duty cycle of a drive signal to a transistor connected in series with the LED. In several embodiments the duty cycle signal generated by the PWM is controlled by at least one momentary SPST switch, or, in one alternative, by first and second SPST switches operable in a make-before-break sequence in a voltage divider circuit.

Abstract: A brightness control circuit for a DC-powered LED light uses a PWM generator. The LED brightness is a function of the duty cycle of a drive signal to a transistor connected in series with the LED. In several embodiments the duty cycle signal generated by the PWM is controlled by at least one momentary SPST switch, or, in one alternative, by first and second SPST switches operable in a make-before-break sequence in a voltage divider circuit.