Security circuit with magnetic proximity sensor having a magnetic settable and electrical resettable latched output
US5491412A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 24, 1994 |
| Grant date | Feb 13, 1996 |
| Priority date | — |
| Expiry date | Jan 24, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/9517
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A security circuit includes a Hall-effect sensor for generating an output signal in response to a sensed variation in magnetic field strength. A supply voltage source is connected to the Hall-effect sensor. A latch circuit receives the Hall-effect sensor output signal and generates a latched output signal. The latch circuit operates between a set and a reset state. Circuitry is provided for monitoring the supply voltage source and for generating an output signal applied to the latch circuit. The latch circuit generates the latched output signal in response to the Hall-effect sensor output signal and the output signal generated by the monitoring circuit when the supply voltage is at a predetermined level. The latch circuit is reset when the supply voltage is below the predetermined level.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.