Switching circuit providing adjustable capacitive series voltage dropping circuit with a fractional horsepower motor
US4992709A · kind A · utility
49Cited by
12References
15Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 20, 1989 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Jun 20, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P25/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control circuit for a fractional horsepower fan motor connected between hot and neutral wires in and AC circuit is shown. The control circuit includes two or more duplicate branches. Each branch is serially connected, and each branch includes a triac, series resistor and series capacitor. The triac has a gate terminal which is connected to an optical coupling circuit for isolation and responds to a control signal from a low voltage small current source. In an alternative embodiment, a single triac and optical coupling circuit can be used with different capacitors being switched in or out of the circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.