Smoke alarm activated portable lamp
US4258291A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 1978 |
| Grant date | Mar 24, 1981 |
| Priority date | — |
| Expiry date | Nov 1, 1998 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG08B17/10
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A smoke alarm activated portable light or lamp for providing emergency illumination in response to an alarm signal from a smoke alarm device includes a frequency selective microphone, several amplifier stages, a peak detector, an isolation or buffer stage, and a power stage comprising a pair of cascaded transistors and a light bulb. The lamp includes a bracket for positioning same in proximity to a smoke alarm and a switch which is closed upon removal of the lamp from the bracket. A power saving circuit includes a photoelectric cell and an amplifier and is operative to saturate or overdrive the first gain stage to override any signal from the microphone whereby the lamp is rendered unresponsive to the smoke alarm signal upon illumination of the photocell by daylight or artificial light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.