David Wright Oldham

US Patent:

49655094, Oct 23, 1990

Filed:

Feb 13, 1989

Appl. No.:

7/310806

Inventors:

David J. Oldham - Allentown PA

Assignee:

Lutron Electronics Co., Inc. - Coopersburg PA

International Classification:

G05F 502

US Classification:

323300

Abstract:

A two-wire apparatus for controlling AC power to a load, by turning a thyristor on and off during each half cycle, includes a circuit that prevents the thyristor from being turned off prematurely. The circuit stores energy while the thyristor is off (i. e. , non-conductive). After the thyristor turns on, the stored energy flows to the gate of the thyristor to keep it on until the end of the half cycle. The circuit permits reduced electromagnetic interference and increased load power rating; without requiring a third (neutral) wire for the apparatus.