Transient control circuit for occupancy detector
US5534850A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 7, 1994 |
| Grant date | Jul 9, 1996 |
| Priority date | — |
| Expiry date | Jul 7, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/26
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An electrical circuit for use in occupancy detectors for preventing false triggering when a load such as a light is de-energized. The occupancy detector includes circuitry for providing an intermediate signal indicating detection of a target object. An output stage receives the intermediate signal and in response provides a trigger signal for energizing the light or other load. An RC network, having a characteristic charge decay time, is coupled to the output stage such that the characteristic charge decay time governs the duration for which the output stage asserts the trigger signal for energizing the light or other load. Output signals from the occupancy-detecting circuitry are applied to the RC network through a first transistor switch. A second RC network, having its own characteristic charge decay time, is provided and the trigger signal is applied to charge the second RC network. When the output stage deasserts the trigger signal (thereby de-energizing the light or other load), the second RC network is discharged through a second transistor switch so as to bias the second transistor switch to its conducting state. The second transistor switch is connected to cut off the firs…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.