Zero voltage switching solid state relay
US4176288A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 1977 |
| Grant date | Nov 27, 1979 |
| Priority date | — |
| Expiry date | Sep 6, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/902
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A solid state relay or controlled switch for connecting an AC power source to a load includes a solid state switching circuit in which a semiconductor controlled rectifier element, such as a photothyristor, thyristor or light-AC controlled element, is ignited by an external control signal, thereby to feed a load with an alternating current. A zero voltage switching circuit which executes switching when the instantaneous value of the amplitude of the supply voltage of the AC load current is zero or a value close thereto is connected to the rectifier element. As an improvement, a series circuit consisting of a resistor and a capacitor are connected between the base and emitter of a transistor in the zero voltage switching circuit. Thus, a zero voltage switching solid state relay whose withstand voltage build-up rate is enhanced and whose switching is endowed with a hysteresis characteristic is provided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.