Bypass circuit for neutral-less controller in lighting control system

摘要

A device provides a bypass path for leakage current of a neutral-less controller in a lighting control system for selectively supplying line voltage to a load. The device includes a dummy load, a voltage sensor, a bypass switch, a switch controller and a delay timer. The voltage sensor senses line voltage at an output of the neutral-less controller. The bypass switch selectively connects the dummy load in parallel with the lighting load. The switch controller activates the bypass switch to connect the dummy load in parallel with the lighting load when the line voltage is low, providing a bypass path for the leakage current, and deactivates the bypass switch after a delay period to disconnect the dummy load from being in parallel with the lighting load when the line voltage is high. The delay timer implements the delay period in response to the line voltage transitioning from low to high.

主权项

1. A device for providing a bypass path for leakage current of a neutral-less controller in a lighting control system configured to selectively supply a line voltage to a lighting load, the device comprising:
a dummy load; a voltage sensor configured to sense the line voltage at an output terminal of the neutral-less controller; a bypass switch configured to selectively connect the dummy load in parallel with the lighting load; a switch controller configured to activate the bypass switch to connect the dummy load in parallel with the lighting load when the sensed line voltage is low to provide a bypass path for the leakage current, and to deactivate the bypass switch after a delay period to disconnect the dummy load from being in parallel with the lighting load when the sensed line voltage is high; anda delay timer configured to implement the delay period in response to the sensed line voltage transitioning from low to high.