Adapter for switching from primary to standby device upon failure of primary device
US4712051A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 2, 1986 |
| Grant date | Dec 8, 1987 |
| Priority date | — |
| Expiry date | Jun 2, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B39/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This adapter has a housing containing an automatic electrical switching circuit, a plug for connecting the circuit to an external A.C. power source, and sockets for mounting primary and standby lamps on the housing in circuit with the switching circuit. The circuit includes a conventional rectifier bridge and a transistor which is normally biased off so that the standby lamp is off, when the primary lamp lights. When the primary lamp goes off (burns out), the transistor conducts and the standby lamp is automatically turned on. When the primary lamp again operates the transistor is again biased off and the standby lamp is automatically turned off. A signal lamp in the switch circuit lights when the standby lamp is on. Motors or other power consuming devices may be substituted for the lamps.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.