Dimmer detector for bleeder circuit activation

摘要

A circuit to be utilized for an LED driver bleeder activation. The circuit comprises a circuit block for timing a duration of any removed portion of a rectified line signal. The input of the circuit to be coupled to receive the phase controlled rectified line signal through a voltage divider. Comparing the divided rectified line signal with a threshold voltage and output a comparison result. A timer coupled to the comparator and responsive to the comparison result to time the duration of the removed portion of the rectified line signal and activate the bleeder activation circuitry to turn on the switching element of the bleeder to sink a controlled current from the input line.

主权项

1. A circuit for timing a duration of any removed portion of a rectified line signal, the circuit comprising:
an input to be coupled to receive the rectified line signal; a voltage divider coupled to the input to yield a divided rectified line signal; a first comparator coupled to compare the divided rectified line signal with a first threshold voltage and to output a comparison result; and a timer coupled to the first comparator and responsive to the comparison result to time the duration of the removed portion of the rectified line signal.