Light source frequency detection circuit using bipolar transistor
US7847834B2 · kind B2 · utility
0Cited by
7References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 19, 2007 |
| Grant date | Dec 7, 2010 |
| Priority date | — |
| Expiry date | Jan 27, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F30/245
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for measuring the power frequency of a light source includes a photo-sensitive transistor, a modulators and a logic unit. The photo-sensitive transistor generates an electrical signal that is responsive to light incident thereon from the light source. The modulator generates a modulated signal based on the electrical signal that toggles at a rate substantially proportional to the power frequency of the light source. The logic unit is coupled to receive the modulated signal and determine its toggling frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.