US 6,321,167 B1 · Resistance-welding power supply apparatus

Abstract

Disclosed is a resistance-welding power supply apparatus comprising a large-capacitance capacitor for storing a welding energy in the form of electric charge, a charging unit for charging the capacitor up to a predetermined voltage, a transistor group electrically connected between the capacitor and a welding electrode on one hand, and a control unit for causing a switching action of the transistor group at a predetermined frequency during the weld time to provide a control of a welding current I. The charging unit includes a charging transformer and a rectifying circuit. The control unit includes a main control unit for providing a control of the switching action of the transistor group by way of a drive circuit. The control unit further includes various sensors, measuring circuits and an arithmetic circuit, for providing a feedback control of the welding current, an interelectrode voltage or a welding power.

Claims22

Dependent claims

A resistance-welding power supply apparatus for resistance welding materials to be welded by causing a welding current to flow through a pair of welding electrodes which are in press contact with the materials to be welded, said resistance-welding power supply apparatus comprising:

a capacitor having one end electrically connected to one electrode of the pair of welding electrodes for storing a welding energy in the form of an electric charge;
charging means for charging said capacitor;
a transistor having a first terminal electrically connected to the other end of said capacitor and having a second terminal electrically connected to the other electrode of the pair of welding electrodes;
and
control means electrically connected to a control terminal of said transistor for providing a switching control of said transistor at a predetermined frequency during a preset weld time.

2 more elements

a capacitor for storing a welding energy in the form of an electric charge;
charging means for charging said capacitor;
a first transistor having a first terminal electrically connected to one electrode of said pair of welding electrodes and having a second terminal electrically connected to one end of said capacitor;
a second transistor having a first terminal electrically connected to the other end of said capacitor and having a second terminal electrically connected to the other electrode of the pair of welding electrodes;
a third transistor having a first terminal electrically connected to the other electrode of said pair of welding electrodes and having a second terminal electrically connected to the one end of said capacitor;
a fourth transistor having a first terminal electrically connected to the other end of said capacitor and having a second terminal electrically connected to the one electrode of said pair of welding electrodes;
control means electrically connected to a control terminal of each of said first to fourth transistors for providing a switching control of said first and second transistors or of said third and fourth transistors at a predetermined frequency during a preset weld time.

4 more elements

Dependencies are inferred from the claim text.

Resistance-welding power supply apparatus

Life of this patent

Resistance-welding power supply apparatus

Life of this patent

Abstract

Claims22