Detecting a defective suppressor diode in a coil driving circuit
US4847728A · kind A · utility
5Cited by
4References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 11, 1987 |
| Grant date | Jul 11, 1989 |
| Priority date | — |
| Expiry date | May 11, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H47/002
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A driver circuit for the coil in relay contains a suppressor diode across the coil terminals. Two light-emitting diodes are connected in reverse polarity so that one diode operates when the coil is energized and the other diode operates if there is current flowing in the reverse direction when the suppressor diode fails to clamp the coil voltage. The diodes may be of different colors and may be positioned close to each other to produce the composite color when they are energized at the same time or in rapid succession.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.