Electronic monitoring system with malfunction indicator
US4543566A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Sep 7, 1982 |
| Grant date | Sep 24, 1985 |
| Priority date | — |
| Expiry date | Sep 7, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/945
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A contactless motion detector responsive to the approach of a ferromagnetic element, including an oscillator with a sensing coil, has an output lead connected to one input of a first Exclusive-OR gate having another input connected to a square-wave generator whose pulses appear in the output of that gate with or without phase inversion depending on the output voltage of the motion detector. These pulses are fed, via an amplifier, to one input of a second Exclusive-OR gate whose other input receives the output pulses of the square-wave generator directly but with a delay compensating a lag introduced by the first gate and the amplifier. In the absence of a malfunction, the inputs of the second gate are energized either cophasally or antiphasally to produce either a low or a high output voltage of substantially constant magnitude fed to a load; in the event of a malfunction interrupting the pulse transmission to either input of this second gate, its output becomes a pulsating voltage. Such malfunction can further be indicated by an integrator connected in parallel with the second gate to the amplifier output. A conductor connecting the output of the square-wave generator to the corre…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.