Multiple mode variable speed motor control circuit

Claim 1

A variable speed motor control circuit adapted to be actuated momentarily by push buttons for running the motor at a predetermined speed after the selected push button is released, comprising a. a source of potential, b. a master control switch coupled to said source of potential, c. a plurality of serially connected resistors adapted to be coupled to said source of potential by said master control switch for providing a control voltage thereon, d. a plurality of push button switches capable of being momentarily operated, selectively coupled to said resistors and having a common output for providing thereat a different control voltage in accordance with the push button selected, e. a motor, f. a motor control circuit having an imput coupled to said common output of said push button switches and an output coupled to said motor for controlling the speed of said motor in accordance with the push button depressed, g. said motor control circuit having a high betaa transistor, a zener diode and a silicon controlled rectifier, said high beta transistor having an input thereof coupled to said common output of said push button switches and an output coupled to said zener diode, said silicon controlled rectifier coupled to said zener diode and to said motor whereby said motor speed is controlled by the controlled voltage applied to said transistor which controls said zener diode for switching said silicon controlled rectifier to apply power to said motor, and h. memory means coupled to the input of said motor control circuit for providing a predetermined control voltage to said motor control circuit in accordance with the push button selected thereby requiring only a momentary activation of the push button selected.