Abstract: A foot pedal operated motor control is provided for controlling the speed of a motor. The entire motor control circuit is mounted in a foot pedal housing which circuit includes a generally disc shaped potentiometer having a rotatable and a stationary member with the movement of the rotatable member with respect to the stationary member determining the resistance of the potentiometer which controls the current to a motor whose speed is to be controlled. The disc shaped potentiometer has an opening therethrough. A foot pedal is pivotally mounted on the housing overlying the potentiometer and a helical member extends between the foot pedal on one end thereof and into the opening of the disc shaped potentiometer on the other end thereof.

Abstract: An automatic control circuit is provided for diluting a chemical concentrate in a container by the proper proportion, dispensing the mixture, indicating that the container is empty, and repeating the process. The container has a plurality of conductive probes which extend to different depths within the container. A pair of relays having contacts which control drain and fill solenoid valves in the container are controlled by the probes, depending on the level of the liquid in the container. Both visual and audible alarms are provided to indicate when the tank is empty and needs concentrate to be added thereto.

Abstract: A multiple mode variable speed motor control circuit is provided having a master control switch for applying a source of AC potential to the circuit. A diode rectifies the source for applying a DC potential across a string of resistors from which a control voltage is selected by a plurality of push button switches having a common output which is connected to a motor control circuit including a silicon controlled rectifier (SCR). The SCR is coupled to and operates a motor in the conventional phase-control manner. A memory in the form of a capacitor is coupled to the input of the motor control circuit in one position of the master control switch, allowing the push button to be activated momentarily, with the memory maintaining the speed of the motor at the selected rate. In another position of the master control switch the push button corresponding to the motor speed selected must be continually actuated for running the motor at the selected speed.