Two-stage led driver with buck PFC and improved THD
US8957600B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 1, 2013 |
| Grant date | Feb 17, 2015 |
| Priority date | — |
| Expiry date | Oct 1, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B45/375
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A two-stage light emitting diode (LED) driver for powering an LED load at a substantially constant current, and related methods and systems. The first or front end stage of the LED driver includes a buck topology power factor correction (PFC) circuit, the buck PFC circuit and a PFC controller. The second stage of the LED driver includes a conventional isolation and regulator circuit configured to receive the DC voltage and DC current output by the buck PFC and then to provide the substantially constant current to the LED load. By squaring the rectified input voltage sensed by the PFC controller, the input AC current drawn by the buck PFC circuit has a much improved total harmonic distortion (THD), which is achievable without the need for using an expensive PFC controller. The rectified input voltage is squared using a Zener diode ladder circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.