Power source voltage checking device particularly for checking the voltage of a battery in a camera
US4376265A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1980 |
| Grant date | Mar 8, 1983 |
| Priority date | — |
| Expiry date | Sep 9, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/16542
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In the disclosed device, a signal forming circuit produces a signal having a frequency corresponding to the voltage of a power source. A level detector detects the level of the voltage of the power source and is arranged to produce a signal when the voltage of the power source drops below a predetermined level. A control circuit coupled to the signal forming circuit is arranged to change the frequency of the signal produced by the signal forming circuit in response to the signal produced by the detector. An indicator operates at the frequency of the signal produced by the signal forming circuit. In a specific embodiment, a detector detects whether the voltage of a battery is at and below a first level, between the first level and a second higher level, and at and higher than the second level. A signal former responds to the detector for producing a first signal having a frequency below a first frequency when the voltage is below the second level, a second signal having a frequency twice the first frequency when the voltage is at the second level, and a signal having a frequency higher than the frequency of the second signal when the voltage is above the second level. An indicator r…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.