Low capacitance protection circuit for telephone equipment
US5422777A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 23, 1993 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Aug 23, 2013 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04M3/18
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An overvoltage protection circuit comprises three protection components (21, 22, 23) connected by their first terminal to a common point (C) and by their second terminal to a first conductor (A), second conductor (B) and ground, respectively. Each protection component comprises the anti-parallel association of a protection component (T1, T2, T3) and a diode (D1, D2, D3), the common point being connected to a same polarity terminal of each protection component. In case one of the conductors exhibits, at the normal state, a polarization difference higher than the other with respect to ground, the cathodes or anodes of the protection components are connected to the common point according as the higher polarized conductor is negative or positive with respect to ground.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.