Proximity sensor and control

摘要

Sensor circuitry which detects the presence or absence of material and activates a motor responsive thereto, having a capacitor which emits electric signal responsive to the presence of the material, a signal processing unit receives the capacitor's signal and shapes it into a usable signal, wherein the usable signal is received by a timer which is held in reset thereby. When the material's presence is no longer detected, the timer counts a delay during which a control signal is output to a control transistor which responsively actuates a relay which is connected to and forms a link of a power circuit that supplies energy to the motor. A transformer is connected to the power circuit and selected windings of the transformer are connected to the relay. When the transistor is off and relay is inactive, there is a large voltage drop across the transformer thereby deactivating the motor. When the relay is actuated by the transistor, a relatively small voltage drop occurs across the transformer and a sufficient flow of energy passes to the motor and activates the same.