Intermediate frequency welding machine heating control method?

The intermediate frequency welding machine control system includes EMI filter circuit, transformer rectification filter voltage stabilization circuit, synchronization circuit, CPU program control circuit, start-up circuit, drive circuit, separately excited switching power supply circuit and pulse generation and output circuit. The EMI filter Circuits IN1 and IN2 are connected to AC380V voltage, and output from OUT1 and OUT2 to the control transformer through filter LL6.

Through the transformer, rectification, filtering and stabilizing circuit, the voltage is transformed into AC28V, AC9V and then rectified, filtered, and stabilized to output DC5V and DC24V to supply power to the working circuit; it has the advantages of simple structure, perfect function, and convenient adjustment. The anti-interference function enables the controller to work reliably and stably in an environment with unstable grid voltage and high-intensity electromagnetic interference; the current ramp-up function can effectively suppress welding sparks and make solder joints stronger.

The welding current at the intermediate frequency point includes: switching the branch of the primary coil of the welding transformer, the adjustment method of changing the number of wire turns, and the phase method of controlling the primary side voltage. The phase control of the primary voltage in the above methods and the method of adjusting the welding current are called For heating control mode.

The thyristor used as a switch (switch) in the resistance welding machine has the function of switching (on and off) the primary current to control the power-on time during welding, and also has the function of controlling the primary voltage of the transformer and adjusting the size of the welding current. Function.

Most of the previous controllers used metal sheet temperature control, which has low control accuracy and poor reliability. With the continuous development of mechanical technology, the function of single-chip microprocessor is increasing day by day, and the price is moderate.