Parallel inverter having higher frequency at start-up

• US 3,333,179 A
• Filed: 05/12/1964
• Issued: 07/25/1967
• Est. Priority Date: 05/12/1964
• Status: Expired due to Term

• Current Assignee: Magntek Incorporated
• Original Assignee: William H. Freeman
• Inventors: Freeman, William H.
• Application Number:
  US04/366,772
• Time in Patent Office: 1,169 Days
• US Class Current: 363/49
• CPC Class Codes: H02M 7/517 with special starting equipment

Claims

1. AN INVERTER DEVICE FOR CONNECTION ACROSS DC LEADS COMPRISING A TRANSFORMER HAVING A PRIMARY WINDING, A SECONDARY WINDING, AND A CORE STRUCTURE MAGNETICALLY LINKING SAID WINDINGS, THE MID-POINT OF SAID PRIMARY BEING CONNECTED TO A POSITIVE DC LEAD, A PARALLEL COMMUTATING CIRCUIT HAVING TWO LEGS AND BEING CONNECTED BETWEEN THE ENDS OF SAID PRIMARY WINDING AND A NEGATIVE DC LEAD AND INCLUDING IN EACH LEG THEREOF AND SCR, TRIGGER MEANS FOR ALTERNATELY APPLYING PULSES TO THE GATES OF SAID SCR'"'"''"'"'S FOR OPERATING SAID INVERTER AT A PREDETERMINED OPERATING FREQUENCY, AND MEANS FOR INCREASING THE FREQUENCY OF THE PULSES SUPPLIED BY SAID TRIGGER MEANS TO SAID GATES AT THE TIME OF START-UP, SAID TRANSFORMER BEING A LEAKAGE REACTANCE TRANSFORMER WHICH INCLUDES AN EXTENDED SECONDARY WINDING CONNECTED IN SERIES WITH SAID FIRST MENTIONED SECONDARY WINDING, A CONDENSER CONNECTED ACROSS BOTH OF SAID SECONDARY WINDINGS TO PROVIDE A CONDENSER CIRCUIT, THE CROSS SECTION OF SAID CORE BEING SUCH THAT THE SECONDARY PORTION THEREOF OPERATES IN THE SATURATION RANGE WHEN A RESISTIVE LOAD APPROACHING RATED CAPACITY IS CONNECTED ACROSS SAID FIRST MENTIONED SECONDARY, RESISTANCE MEANS CONNECTED IN SERIES IN SAID CONDENSER CIRCUIT, CONTACT MEANS SHUNTING OUT SAID RESISTANCE MEANS TO PROVIDE A HIGH Q CIRCUIT AT RATED OUTPUT FREQUENCY, AND A SLOW ACTING RELAY FOR ACTUATING SAID CONTACT MEANS INTO CLOSED POSITION AFTER THE FREQUENCY OF SAID TRIGGER MEANS IS STABILIZED AT SAID PREDETERMINED OPERATING FREQUENCY.