Loom power saving automatic switch circuit

In order to solve the problem of idling when the loom is stopped and the energy is wasted. The power-saving automatic switch circuit is adopted so that the motor can automatically disconnect from the power supply when the loom is stopped
and start automatically before starting the machine, thus overcoming the problem of no-load rotation of the motor. The picture shows the power-saving automatic switch
circuit diagram     of the loom . The DC power supply is stepped down by a small transformer T, bridge rectified by diodes VD1-VD4 , filtered by capacitor C, and stabilized by voltage regulator tube VS. The power- saving automatic switch circuit in the circuit is composed of VT1, VT2, sensitive relay K, etc. Bare wires mounted on the plastic (glue) ball of the switch handle provide the operating signal. When driving, a human hand touches the bare wire, and the induced current generated by the human body excites the base of VT1 and turns VT1 on. The signal is then amplified and used as a bias current for VT2. VTZ is saturated and conductive, the sensitive relay K pulls in, its normally open contact K pulls in, the AC contactor KM pulls in, and the motor starts. After the switch handle enters the normal driving position , the micro travel switch WKX is closed, the bias current of VT2 is supplied by WKX and continues to be conducted, and the cloth machine operates normally.     When the cloth machine stops for some reason, the handle returns to the parking position. WKX is disconnected, VTZ is cut off, and the motor is disconnected from the power supply and stops. When there is no operation signal to add people. Resistor Rz makes the base-emitter of VT1 have the same potential, VT1 is cut off, and it malfunctions. SA is the manual switch to control the power supply.