Visual alarm device interconnectable to existing monitoring circuitry
US5008655A · kind A · utility
Inventors
Key dates
| Filing date | Nov 20, 1989 |
| Grant date | Apr 16, 1991 |
| Priority date | — |
| Expiry date | Nov 20, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B29/02
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A visual alarm device monitors the condition of a control and indication circuit and gives a distinct visual alarm upon detection of an abnormal condition in the monitored circuit. The device uses the indicator lights of the monitored circuit itself to give the visual alarm. The alarm device interconnects with the monitored circuit locally requiring no new cabling and remains in a passive state until an abnormal condition is detected. When the monitored circuit is rendered inoperative by a thermal overload trip, the alarm device becomes active to flash the indicator lights to provide a distinct visual alarm. Included in the device is a test switch, an appropriate voltage converter, an oscillator, and a power indication light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.