Thyristor welding machine

Hello! Please help me figure it out. There is a welding transformer on the torus. I want to assemble a rectifier and a control circuit. On the secondary side of the transformer there is a tap, the voltage is just suitable for powering the control circuit. But when connected to the network, protection is triggered. All circuit elements are in good condition. One thing remains - do I need a separate winding to power the control circuit?

Welding machine diagram



  • Admin

    Even factory welding machines have a separate power supply for the control circuit.

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  • Valery

    There is no protection node in the circuit you provided, there is only a control node and a rectifier block on diodes VD1, VD2 and thyristors VS1, VS2.
    If at the tap of your toroidal transformer the alternating voltage corresponds (+/- 20 percent) to the voltage in the circuit and everything is assembled correctly, then everything should work.
    Try to turn on the device with the disconnected diodes VD3, VD4. If the protection works, check the diodes and thyristors of the bridge; do not work check the control unit.

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