QUASI-CONTINUWERKENDE INSTELINRICHTING.

摘要

The invention relates to an electrical control unit for controlling the speed of a pump motor of a pressurized fluid supply system having a tank. A pressure responsive switch unit connected to the tank has at least three switch positions corresponding to pressure levels in the tank. The switch unit outputs three different voltage levels to a transistor and circuitry responsive to the three voltage levels utilizes this input to control the speed of the pump motor. The circuitry includes an integration capacitor and the effects of charging and discharging the capacitor in accordance with the three voltage levels produced by the switch unit are utilized for controlling the pump motor.