Zero crossover detector
US4268764A · kind A · utility
7Cited by
3References
26Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | May 1, 1979 |
| Grant date | May 19, 1981 |
| Priority date | — |
| Expiry date | May 1, 1999 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/175
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An A.C. zero crossover detection circuit compensates for RC phase lead by adding hysteresis to the reference voltage. A reference voltage is applied directly to a first input of a differential amplifier and indirectly through first and second resistor connected field-effect-transistors to a second input of the differential amplifier. An output of the amplifier is coupled to the gate of an MOS switch which, when turned on, reduces the reference voltage by a predetermined amount to compensate for early crossover detection resulting from the phase lead.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.