Method and apparatus for device-dependent calibration of relays for high accuracy operation at zero-crossing of input power signal
US6566882B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2001 |
| Grant date | May 20, 2003 |
| Priority date | — |
| Expiry date | Jul 16, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R31/3278
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method are provided for ensuring increased accuracy of individual relays (e.g., within a control system including a sensor) to close substantially coincidentally with respect to a current zero-crossing of an incoming power supply waveform. To determine timing of contact operation, a microcontroller operates the contacts in response to one of a series of test pulses, and determines the amount of time required for contact operation. The difference between timing of contact operation and zero-crossing is determined and adjusted to offset errors incurred by microcontroller threshold variations and power supply voltage variations. The calibrated value is then provided to the sensor in order to extend sensor life.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.