Driver circuit for an electrical load with capability for detecting a short in the load
US4214236A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 2, 1978 |
| Grant date | Jul 22, 1980 |
| Priority date | — |
| Expiry date | Oct 2, 1998 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05B47/20
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A driver circuit for an electrical load device such as an indicator lamp includes the capability to both drive the lamp and to respond to a fault condition in the lamp to disable its energization. The circuit is adapted for control by a single I/O terminal of a programmable logic device. The I/O terminal being of the type having an internal architecture that causes the terminal to be pulled up to a logic high state when unloaded, and pulled down to a logic low state by either external loading or the closure of an internal; program-controlled switch forming part of a low-impedence path to ground. A processor-implemented test routine can be used to monitor the I/O terminal voltage and close the internal switch when the driver circuit responds to a shorted condition.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.