Donald E Vollrath

US Patent:

43487181, Sep 7, 1982

Filed:

Feb 12, 1981

Appl. No.:

6/234064

Inventors:

Donald E. Vollrath - Greenfield WI

Assignee:

Litton Industrial Products, Inc. - Beverly Hills CA

International Classification:

H02P 1324

US Classification:

363 87

Abstract:

A timing generator for use with multi-phase controlled rectifier systems is disclosed in which a ramp signal is produced in phase synchronization with the power source and compared with the value of a command signal. The command signal is indicative of the desired SCR ignition angle. A sequencing circuit, having a finite number of output states is cyclically stepped from one state to the next by the comparator. The sequence circuit couples a source of SCR-gating pulses to the appropriate SCR in accordance with its state and with a predetermined pattern of SCR ignitions which characterize the multi-phase source. One aspect of the invention concerns the multiplexing of the comparator output whereby the command signal is offset by 60. degree. (electrical) after each comparator transition to set up conditions for the next transition. A further aspect of the invention concerns the generation of an alternate ramp, 180. degree.

US Patent:

44634153, Jul 31, 1984

Filed:

Aug 9, 1982

Appl. No.:

6/406310

Inventors:

Donald E. Vollrath - Greenfield WI

Assignee:

Litton Industrial Products, Inc. - Beverly Hills CA

International Classification:

H02P 1324

US Classification:

363 87

Abstract:

A timing generator for use with multi-phase controlled rectifier systems is disclosed in which a ramp signal is produced in phase synchronization with the power source and compared with the value of a command signal. The command signal is indicative of the desired SCR ignition angle. A sequencing circuit, having a finite number of output states is cyclically stepped from one state to the next by a comparator. The sequencing circuit couples a source of SCR-gating pulses to the appropriate SCR in accordance with its state and with a predetermined pattern of SCR ignitions which characterize the multi-phase source. One aspect of the invention provides the multiplexing of the comparator output whereby the command signal is offset by 60. degree. (electrical) after each comparator transition to set up conditions for the next transition. A further aspect of the invention provides for the generation of an alternate ramp, 180. degree.