Optically isolated interface circuits
US4079272A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 1976 |
| Grant date | Mar 14, 1978 |
| Priority date | — |
| Expiry date | Mar 31, 1996 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/795
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
Circuitry for providing electrical isolation between an input signal source and other circuitry which utilizes such input signal. The isolation circuitry uses an optical coupling means comprising a light-emitting diode circuit and a photo-responsive element, the input signal being supplied by a bridge circuit which provides a unidirectional voltage from the input signal which is then applied to a normalizing, or limiting, circuit which converts the unidirectional voltage to a substantially constant value which is supplied to the light-emitting diode circuit. The circuit is responsive to an input signal which can be an AC signal or a DC signal of either polarity, such circuit having a high degree of noise survivability even in the presence of transient noise signals such as "showering arcs" having extremely high amplitudes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.