LED DRIVE CIRCUITRY WITH DISCONNECT SWITCH

摘要

A circuit is described which allows an LED driver to be controlled by a control signal in such a manner that at a predetermined dimming level the output current goes to zero instead of continuing to indefinitely low dim levels, thus avoiding the possibility of flickering or shimmer at extremely low dim levels. An electronic circuit for driving an LED load with a conventional LED drive circuit has inputs connected to a power source and output terminals providing regulated output power including a load disconnect switch in series with the LED load which has a control node responsive to a control circuit; and a control input which commands varying levels of input power. The control circuit is configured to be responsive to the control input so that when the control input corresponds to a certain continuous level of dimming, the load disconnect switch is opened.

主权项

1. An electronic circuit for driving an LED load comprising:
a. a conventional dimming LED drive circuit having power inputs connected to a power source, at least one control input responsive to at least one control signal and output terminals from which regulated output power is provided: and b. a load disconnect switch not enabled for pulse width modulation, separate from the conventional dimming LED drive circuit and in series with the LED load which has a control circuit responsive to said at least one control signal wherein said control circuit is configured to be responsive to said control signal so that when the control input commands an output below a certain continuous level of dimming, the load disconnect switch is opened for the purpose of preventing the appearance of shimmer in the light output as the dimming level approaches zero.