Appliance control system with a zero crossing detecting circuit
US7786766B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 6, 2008 |
| Grant date | Aug 31, 2010 |
| Priority date | — |
| Expiry date | Dec 27, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/13
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A control system includes a zero crossing detecting circuit for detecting a zero crossing of an AC signal. The circuit includes a transformer having a primary portion and a secondary portion. The primary portion receives the AC signal. The secondary portion comprises first and second terminals. The first terminal is biased at a first DC voltage level. An output switch is operatively connected to the second terminal and has an on state and an off state. The output switch selectively activates an output signal of the zero crossing detecting circuit according to an activation voltage level sensed by the output switch and corresponding to the zero crossing. While in the off state, the output switch is biased at a second DC voltage level. A voltage difference between the first and second DC voltage levels substantially equals the activation voltage level. A controller monitors the output signal and controls an operation based on the output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.