Welding arc stabilizer
AssigneeMiller Electric Mfg. Co.
InventorsThomas A. Bunker, Kenneth A. Stanzel
Life of this patent
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Abstract
A welding arc stabilizer including a source of high voltage and a switch for switching the source of high voltage across the electrode and the workpiece in the event the arc rectifies. The high voltage is switched across the electrodes within the completion of the half cycle in which rectification occurred. The source of high voltage includes a resonant LC circuit. An arc sensing circuit, including a resistor, a capacitor, and a zener diode is provided in parallel with the arc. In the event the voltage applied to the electrode and workpiece exceeds the zener diode breakdown voltage, indicating the arc has rectified, an SCR disposed between the resonant circuit and one of the electrode and the workpiece is turned on, thus connecting the source of high voltage to the electrode and workpiece.
Claims17
A welding arc stabilizer for an ac power supply capable of providing an arc drawn between an electrode and a workpiece, said arc having a plurality of positive and negative half cycles, comprising:
- a source of high voltage disposed for application of high voltage to said arc in the event of its rectification, said high voltage derived from the ac power supply;
- a switch in electrically operative association with said source of high voltage and at least one of said electrode and said workpiece, said switch including a control input;
- and
- an arc sensing circuit in electrically operative association with the arc and the control input of the switch,
- wherein, upon detection of arc rectification, said switch is closed within the completion of one-half cycle of the output and said high voltage is applied to said arc to stabilize it.
A welding arc stabilizer for an ac power supply wherein the arc is drawn between an electrode and a workpiece comprising:
- a source of a high voltage pulse derived from the ac power supply, including a resonant circuit including an inductance in electrically operative association with a first capacitance;
- a circuit, including a resistance, a second capacitance having a capacitor voltage and a zener diode having a breakdown voltage, in parallel with the arc, wherein the breakdown voltage is greater than the arc voltage;
- and
- an SCR having a gate, the SCR being in electrically operative association with the first capacitance and at least one of said workpiece and said electrode, wherein the second capacitor voltage is applied to the gate.
A method of stabilizing a square wave arc output having a plurality of cycles, the output being applied to an electrode and a workpiece, comprising the steps of sensing the presence or absence of arc rectification and deriving a high voltage signal from a welding current power supply, providing the high voltage signal between the electrode and the workpiece within the completion of one-half cycle of the output in the event a rectification of the arc is sensed.
Dependencies are inferred from the claim text.