SU567570A1 - Power supply source for hf contact microwelding with self-tuning - Google Patents

Description

(54) POWER SUPPLY FOR CONTACT MICROWELDING CURRENT OF INCREASED FREQUENCY WITH AUTO CONSTRUCTION

MODE

a battery of capacitors 12; current interrupter 13 or switch, working capacitor 14, relaxation generator 15, diodes 16, 17, inverter thyristors 18, 19 (thyristor bits), 2O welding transformer, inductance 21 in the discharge circuit (operating capacitor, inductance 22 for reloading and switching . capacitors, thyristors 23-26, switching capacitor 27, pulse transformers 28, 29 and zener diode 30.

The source works as follows.

After turning on the thyristor 26 through the inductance 21 begins. charging the working capacitor 14; With the appearance of a voltage on the working capacitor 14, the excitation system 3 emits a control pulse to one of the thyristors 18, 19 of the inverter. Connects; one or the other. The primary winding of the welding transformer is parallel to the working capacitor. Thus, simultaneously with the charge of the working capacitor 14, the current begins to increase through the parts being welded, and the voltage on the welding electrodes increases. When the voltage on the electrodes supplied through the amplifier 10 and the rectifier t9 to the comparison circuit 8, exceeds the reference voltage from the software device 7, the output voltage of the control circuit 8 to the control amplifier 11 and the control pulse occurs at the output of the comparison circuit 8. then, the thyristor 25 is turned on to the control electrodes of the thyristor 25, the thyristor 25 is turned on, and the charged switching capacitor 27 is connected parallel to the inductance 21. The thyristor 26 is applied in the direction opposite to its conductivity s, and it is locked. The capacitor 27 through induction 21, the pulsed power transformer 28 and the thyristor 25 recharges, and when the voltage on the switching capacitor reaches a value approximately equal to the stabilization voltage of the zener diode 30, the thyristor 26 opens, which shifts the inductance current 21 to the thyristor 25 The voltage is applied in the direction opposite to its conductivity, and the thyristor 25 is locked. When the thyristor 25 is locked, a reverse current surge through the pulse transformer 28 is applied to. thyristor control electrode 24, which opens. Condensator 27 Through the thyristor 24 and inductance 22 is recharged to its original state. The voltage value at the switching capacitor 27 is set by a zener diode 30

and is chosen such that after reloading the switching capacitor to the initial state, the voltage across it is somewhat greater or equal to the input one.

After the thyristor 26 is disconnected, the working capacitor is discharged to the welding transformer 20. Since the discharge process is oscillatory, the working capacitor 14 is recharged, and a voltage surge is observed on the welding electrodes, which varies slightly with the resistance of the welding contact. At transition of a current of a power contour

through zero, the discharge thyristor, which is in its conducting state, is locked. When the thyristor is closed, the relaxation generator 15 is energized. The voltage also goes through the delay time of the relaxation generator

15, determined by its elements and the voltage value on the working capacitor 14, is given by the relaxation generator impulse to the thyristor 26, which opens, and the process of recharging the working capacitor 14 is repeated only with the difference that when voltage appears on the working capacitor 14 a different thyristor is opened to invert Hanpsi on the welding electrodes.

When the load resistance decreases, the voltage on the electrodes reaches a set value with a higher voltage on the working capacitor and it is reset.

The voltage reaches a higher negative voltage, and the delay time of the relaxation generator 15 becomes shorter. The following frequency (welding current pulses increases. At the electrodes, the voltage set by the software device is maintained. Through the time interval for which the electronic time relay is set, a signal is sent to the starting device 5, the trip contact 2. The relaxation generator 15 is disconnected from the control ( the thyristor electrode 26, and the welding process is carried out.

Claims (1)

Invention Formula A power source for contact micro-welding with a high-frequency current with auto-tuning, containing a working capacitor with inductance in the charge circuit and a welding transformer in the discharge circuit, charging and discharge thyristors with their excitation system, a switching capacitor connected in parallel with the inductance in the charge circuit , rechargeable thyristor, characterized in that, in order to increase the stability of welding, a relaxation generator is switched on as an excitation system of the charge thyristor, interrupting union of its input through the winding of the welding transformer to the operating capacitor in parallel induktsh Lost circuit charging thyristor is turned on, and the switching capacitor is connected in parallel circuit of series-connected thyristors and inductance, Sources of niformapia accepted in pimanna during examination: , 1, Copyright certificate No. 432993, B 23 K 11 / 2.4, 1972.