Photocoupler with improved anti-noise characteristics
US5182448A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 1991 |
| Grant date | Jan 26, 1993 |
| Priority date | — |
| Expiry date | Sep 24, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08C19/36
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A light receiving section of a photocoupler according to the present invention has, for example, a light receiving element, a converting circuit, an oscillator, an updown (U/D) counter, a decoder and a clock signal supply control circuit, and those devices are monolithically integrated therein. When the light receiving element receives light from a light generating section, an output of the converting circuit becomes High. At this time, an output of the decoder is delayed until the U/D counter has counted up to the preset number a clock signal supplied by the clock signal supply control circuit. On the other hand, upon having Low of the output of the converting circuit, the output of the decoder is delayed until the U/D counter has counted down to "0" the clock signal supplied by the clock signal supply control circuit. Therefore, even in the case where noise interferes the output of the converting circuit, since the output of the decoder is delayed until the count value of the U/D counter has reached the preset number or "0" in spite of switching of the operation of the U/D counter, it is not adversely affected by the noise. This results in improved anti-noise characteristics of t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.