Self-compensating voted logic power interface with tester
US4687623A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 31, 1985 |
| Grant date | Aug 18, 1987 |
| Priority date | — |
| Expiry date | Oct 31, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E30/30
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
Each of the either normally closed or normally open switches, in an n out of m voted power interface circuit having parallel connected groups of serially connected switches, is shunted by a high impedance resistor to form a leakage path through each group of switches. A detector associated with each group of switches, and responsive to the change of impedance produced by actuation of a resistor shunted switch in the group, generates an output signal, preferably a one bit digital signal, indicative of the state of the switches in the group in response to a sequence of test signals which selectively actuate fewer switches than are required to actuate the load controlled by the power interface. Compensation for large variations in supply voltage is provided by incorporating each group of switches into a resistance measuring bridge circuit in which the digital output signal is generated by a comparator connected across the bridge. Preferably, the bridge circuits share common reference voltage generating legs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.