Switching circuit including current limiting and initializing signal isolation
US4603234A · kind A · utility
13Cited by
7References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 4, 1983 |
| Grant date | Jul 29, 1986 |
| Priority date | — |
| Expiry date | Apr 4, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/785
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The A and B leads of a telephone circuit are resistively connected to the drain and source of an FET switch having its gate connected to the emitter of an optoelectric transistor that is also resistively connected across these leads. The collector of a control transistor is also connected to the gate, with its base-emitter diode and emitter bias resistor connected across the source bias resistor for turning on the control transistor and limiting current in the FET when conduction of the latter exceeds a prescribed rate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.