Bridge circuit arrangement for a gas detection instrument
US4123934A · kind A · utility
11Cited by
3References
1Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 20, 1977 |
| Grant date | Nov 7, 1978 |
| Priority date | — |
| Expiry date | Jun 20, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N27/18
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A bridge circuit is provided for a gas-detecting instrument of the type using an electrically-heated resistance element or filament as a sensing element. In order to prevent use of the instrument during the warmup period after initial energization, a portion of the bridge is short-circuited for a predetermined time after energization. The short-circuiting means is preferably a transistor connected across one of the arms of the bridge and controlled by a flip-flop with suitable time-delay circuits for switching the flip-flop.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.