Sock knitting machine fault shutdown circuit

VT1 and VT2 form a bistable state. Since the resistance values ​​of R and R4 are different, the bias voltages applied to the base are not equal.
Therefore, after the power is turned on, VT1 is turned on, VT2 is turned off, and the relay K does not pull in, so the electromagnetic If the clutch DL is not connected to the DC power supply and
the indicator light is on, it means that the sock knitting machine is not running yet (because the machine is powered on first to run the motor and then drives the sock knitting machine to run through the electromagnetic disconnector
).
    Press the micro switch VK and input a positive pulse to flip the trigger. VT1 is cut off; VT2 is on, K is energized, and DI. When connected to the DC power supply
, the sock knitting machine will start running and the indicator light will go out.
    When a fault such as broken yarn or bad needle occurs, the process contact point is connected and the base and emitter of VT2 are short-circuited. VT2 changes from on to off,
the K relay is powered off, and the electromagnetic clutch is disconnected from the power supply. The sock knitting machine stops running and the indicator light comes on, indicating a malfunction.
  After the fault is eliminated, you can press the moving switch VI (. A positive pulse is input to make the conductive tube VT1 return to the cut-off state, the VT2 fork
returns to the conductive state, and the sock knitting machine also resumes operation. If you want to knit If the knitting machine operates intermittently (i.e. starts and stops), the micro switch VR can be pressed continuously
to cause the trigger to flip over continuously, thereby achieving the purpose of intermittent operation of the sock knitting machine.