JPH0454576U

JPH0454576U -

Info

Publication number: JPH0454576U
Application number: JP9656590U
Authority: JP
Priority date: 1990-09-17
Filing date: 1990-09-17
Publication date: 1992-05-11

Description

[Brief explanation of drawings]

第１図はサイリスタの点弧角と通流角ならびに
電圧、電流の波形図、第２図はこの考案に係る第
１の実施例の回路図、第３図は第２の実施例の回
路図である。１……抵抗溶接機、４……溶接変圧器、７……
制御装置、８……変流器、９……制御回路、１３
……基準電圧値設定器、１４，１８……比較器、
１５，１９……異常表示器、１６……インピーダ
ンス演算器、１７……基準インピーダンス設定器
。 Figure 1 is a diagram of the firing angle and conduction angle of the thyristor as well as voltage and current waveforms, Figure 2 is a circuit diagram of the first embodiment of this invention, and Figure 3 is a circuit diagram of the second embodiment. It is. 1...Resistance welding machine, 4...Welding transformer, 7...
Control device, 8...Current transformer, 9...Control circuit, 13
...Reference voltage value setter, 14, 18...Comparator,
15, 19... Abnormality indicator, 16... Impedance calculator, 17... Reference impedance setting device.

Claims

[Claims for Utility Model Registration] [1] Controlling the secondary current of the welding transformer to a constant current by measuring the primary current of the welding transformer and controlling the firing phase of the primary side thyristor based on the measured value. An abnormality detection device for a resistance welding machine using a control device that includes a primary input voltage detection means of the welding transformer, a comparison means with a reference voltage value, and an abnormality display means, the primary input voltage value of the welding transformer is 1. An abnormality detection device for a resistance welding machine, which compares the voltage with a reference voltage value and displays an abnormality when the deviation is outside a predetermined range. [2] Resistance welding using a control device that controls the secondary current of the welding transformer to a constant current by measuring the primary current of the welding transformer and controlling the firing phase of the primary-side thyristor based on that value. An abnormality detection device for a welding transformer, comprising a primary input voltage detection means of the welding transformer, a primary input current detection means, a load power factor and firing angle detection means, and an impedance comparison means, An abnormality detection device for a resistance welding machine, characterized in that the impedance calculated from the input voltage value, the power factor of the load, and the firing angle is compared with a reference impedance, and an abnormality is displayed when the deviation is outside a predetermined range. .