Variable frequency PWM LED control circuit and method
US11212892B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 18, 2020 |
| Grant date | Dec 28, 2021 |
| Priority date | — |
| Expiry date | Jul 10, 2040 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF21Y2115/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control circuit for a light source comprises: a light source, a drive circuit applying a pulse width modulated (PWM) drive signal to the light source; and a pulse width modulator generating the PWM drive signal having a PWM ON time ratio responsive to a control signal and a PWM drive frequency that varies over a range of frequencies repeatedly and substantially continuously. A method for controlling a light source comprises: applying a pulse width modulated (PWM) drive signal to the light source; generating the PWM drive signal having a PWM ON time ratio responsive to a control signal and having a PWM drive frequency that is varied over the range of frequencies repeatedly and substantially continuously. The PWM drive signal causes the light source to produce light at the varying frequency, whereby light at a frequency exhibited by a moving object does not continuously illuminate a moving object.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.