Transformer fed non-arcing motor acceleration control for an electric car including anti-slip circuitry

Claim 1

AN ELECTRIC CAR CONTROLLING APPARATUS FOR SWITCHING THE SUPPLY VOLTAGE OF THE MOTOR AND PREVENTING DAMAGE DUE TO SLIPPAGE THEREOF, COMPRISING A MAIN TRANSFORMER SUPPLIED FROM AN ALTERNATING-CURRENT TROLLEY AND HAVING A PLURALITY OF VOLTAGE TAPS IN THE OUTPUT, A DIRECT-CURRENT TRACTION MOTOR, CONNECTING MEANS OPEATIVELY CONNECTING A SELECTED ONE OF SAID TAPS WITH SAID TRACTION MOTOR INCLUDING RECTIFIER MEANS OPERABLE TO RECTIFY THE A.C. CURRENT FROM SAID TRANSFORMER INTO D.C. CURRENT AND AT LEAST ONE PAIR OF SUPPLY VOLTAGE REGULATING MEANS OPERATIVELY INTERPOSED BETWEEN SAID TRANSFORMER AND SAID RECTIFIER MEANS, SWITCHING CONTROL MEANS OPERABLE TO CHANGE SAID VOLTAGE TAPS UNDER SUBSTANTIALLY NON-ARCING CONDITION WHILE CONTROLLING SAID SUPPLY VOLTAGE REGULATING MEANS, MEANS OPERATIVELY CONNECTED WITH SAID MOTOR FOR PRODUCING A VOLTAGE PROPORTIONAL TO THE SPEED THEREOF, AND A SLIP-PREVENTING CIRCUIT MEANS OPERABLE TO SENSE SAID VOLTAGE PROPORTIONAL TO THE SPEED OF THE MOTOR AND OPERATIVELY CONNECTED WITH SAID SUPPLY VOLTAGE REGULATING MEANS TO RAISE THE IMPEDANCE OF ALL OF SAID SUPPLY VOLTAGE REGULATING MEANS IN ACCORDANCE WITH THE SENSED OUTPUT.