System and method for shaping input current in light emitting diode (LED) system
AssigneeSemiconductor Components Industries, LLC
InventorHyunchul Eum
Life of this patent
Estimating the term…
Abstract
A circuit for controlling a lighting system includes a phase angle detector detecting a phase angle of a rectified input signal and generating a phase angle signal indicative of the phase angle, and a current shape controller determining a current shaping signal using the detected phase angle and adjusting the rectified input signal in response to the current shaping signal. The current shape controller varies a limiting value of the rectified input signal with the phase angle.
Claims20
A circuit for controlling a lighting system, the circuit comprising:
- a phase angle detector configured to detect a phase angle of a rectified input signal and generate a phase angle signal indicative of the phase angle;
- and
- a current shape controller configured to determine a current shaping signal using the detected phase angle and to adjust the rectified input signal in response to the current shaping signal,
- wherein the current shape controller decreases a limiting value of the rectified input signal when the phase angle is decreased.
A light emitting diode (LED) driver comprising:
- a dimmer configured to generate an input signal;
- a rectifier configured to generate a rectified input signal by rectifying the input signal;
- a phase angle detector configured to detect a phase angle of the rectified input signal and generate a phase angle signal indicative of the phase angle, the phase angle being a conduction angle of the dimmer;
- and
- a current shape controller configured to determine a current shaping signal using the detected phase angle and to adjust the rectified input signal in response to the current shaping signal,
- wherein the current shape controller decreases a limiting value of the rectified input signal when the phase angle is decreased.
A method for controlling a lighting system, the method comprising:
- detecting a phase angle of a rectified input signal to generate a phase angle signal indicative of the detected phase angle;
- determining a current shaping signal using the phase angle;
- and
- adjusting the rectified input signal in response to the current shaping signal,
- wherein adjusting the waveform of the rectified input signal includes decreasing a limiting value of the rectified input signal when the phase angle is decreased.
Dependencies are inferred from the claim text.