Speed control circuit for a multispeed electric commutator motor

Claim 1

A SPEED CONTROL CIRCUIT FOR A MULTI-SPEED ELECTRIC COMMUTATOR MOTOR COMPRISING A FIRST TRANSISTOR; A COMPLEMENTARY SECOND TRANSISTOR, A FIRST VOLTAGE DIVIDER, A SECOND VOLTAGE DIVIDER, BOTH SAID VOLTAGE DIVIDERS CONNECTED TO A SOURCE OF SUPPLY VOLTAGE, A NUMBER OF CONTACTS CONTROLLED BY CENTRIFUGAL FORCE DUE TO ROTATION OF THE ELECTRIC MOTOR, SAID CONTACTS ADAPTED TO ADJUST THE DISTRIBUTION OF VOLTAGE ON SAID FIRST VOLTAGE DIVIDER, PARTS OF SAID FIRST VOLTAGE DIVIDER AND SAID CONTACTS ARRANGED ON THE ROTATING PART OF THE ELECTRIC MOTOR, A COUPLE OF SLIP RING CONACTS ADAPTED TO CONNECT THE ELEMENTS ON THE ROTATING PART OF THE ELECTRIC MOTOR WITH THE REMAINING STATIONARY ELEMENTS, A CHANGE-OVER SWITCH ADAPTED TO SELECT THE REQUIRED TAP ON SAID SECOND VOLTAGE DIVIDER, THE TAP OF THE FIRST VOLTAGE DIVIDER CONNECTED BY WAY OF A LIMITING RESISTOR TO THE BASE ELECTRODE OF THE FIRST TRANSISTOR, THE EMITTER ELECTRODE OF THE FIRST TRANSISTOR CONNECTED BY WAY OF SAID CHANGE OVER SWITCH TO THE SECOND VOLTAGE DIVIDER, THE COLLECTOR ELECTRODE OF THE FIRST TRANSISTOR CONNECTED BY WAY OF A RESISTOR TO THE BASE ELECTRODE OF THE SECOND TRANSISTOR, THE EMITTER ELECTRODE OF THE SECOND TRANSISTOR CONNECTED TO ONE POLE OF THE SUPPLY VOLTAGE, ITS COLLECTOR ELECTRODE CONNECTED BY WAY OF THE CONTROLLED ELECTRIC COMMUTATOR MOTOR TO THE SECOND POLE OF THE SUPPLY VOLTAGE, A RESISTOR CONNECTED BETWEEN THE EMITTER AND COLLECTOR ELECTRODES OF THE SECOND TRANSISTOR.