Desktop plastic sealing machine control circuit

It consists of power-on waiting, heating and bonding, delay and heat preservation circuits.
Step down the foot pedal, the sealing plate falls down, and the sealing part is pressed tightly. At the same time, the SB linked with the foot pedal switches to contacts 2 and 3 to close
, the capacitor C2 discharges, the relay KA closes, and the electric heater EH starts to heat. When Cz discharges to a certain value, KA is
released and EH stops heating.
    Adjust the potentiometer RP to change the heating delay time (ie, plastic solidification time).