ENABLE CIRCUIT FOR LIGHTING DRIVERS

摘要

This relates to an enable driver circuit for an LED drive. In some examples, the enable driver circuit may sense an input of the LED driver and enable the LED driver when a conduction angle of the input is greater than a threshold value after a set amount of line cycles of the input of the LED driver have occurred. If the conduction angle is not greater than the threshold after the set amount of line cycles, the enable driver circuit may not enable the LED driver and power may not be delivered to the LED load. In some examples, the enable driver circuit may further enable the LED driver if the conduction angle of the input increases by a certain amount and the resultant conduction angle is greater than the threshold, regardless of the number of line cycles of the ac input voltage that have occurred.

主权项

1. A enable circuit for an LED driver, the enable circuit comprising:
a line detection circuit operable to receive an input sense signal that is representative of an input of the LED driver, wherein the line detection circuit is configured to output a line signal that is representative of a determination of whether a number of detected line cycles of the input sense signal is greater than a first threshold value; a dimmer angle detection circuit operable to receive the input sense signal, wherein the dimmer angle detection circuit is configured to output a dimmer angle signal that is representative of a determination of whether a conduction angle of the input sense signal is greater than a second threshold value; and an enable circuit coupled to receive the line signal and the dimmer angle signal, wherein the enable circuit is configured to output an enable signal at a level that enables the LED driver in response to the line signal indicating that the number of detected line cycles of the input sense signal is greater than the first threshold value and the dimmer angle signal indicating that the conduction angle of the input sense signal is greater than the second threshold value.