Half-controlled bridge circuit useful for supplying a resistance welding device with electric current, comprises a first bridging arm and a second bridging arm

摘要

Half-controlled bridge circuit (10) for supplying a resistance welding device with electric current, comprises a first bridging arm (11) and a second bridging arm (12). Both bridging arms are arranged parallel to each other such that the bridging arms are arranged in a common input voltage. Each bridging arm has at least two series-connected and similar electrical components (13, 14, 15, 16). The first component of the first bridging arm is a semi-conductor switch. The second component of the second bridging arm is a capacitive acting electrical component, preferably a capacitor. Half-controlled bridge circuit (10) for supplying a resistance welding device with electric current, comprises a first bridging arm (11) and a second bridging arm (12). Both bridging arms are arranged parallel to each other such that the bridging arms are arranged in a common input voltage. Each bridging arm has at least two series-connected and similar electrical components (13, 14, 15, 16). The first component of the first bridging arm is a semi-conductor switch. The second component of the second bridging arm is a capacitive acting electrical component, preferably a capacitor. A connection for the primary coil (18) of a welding transformer for the bridging arm is provided between a contact point of the series circuit of the first bridging arm, and between the contact point of the series circuit of the second bridging arm. Independent claims are also included for: (1) a device for electrical supply of a welding gun of the resistance welding device with current comprising the welding transformer, preferably a medium-frequency transformer and the bridge circuit, where the primary coil of the welding transformer forms the bridging arm of the bridge circuit; (2) an inverter, preferably medium-frequency inverter for the resistance welding device with connection means for alternating voltage, the bridge rectifier for rectification of connectable alternating voltage, a direct voltage intermediate circuit for transmission of the rectified alternating voltage to the half-controlled bridge circuit, which is provided at the inverter, for changing the direction of the direct voltage into an alternating voltage with variable frequency; and (3) the resistance welding device comprising the inverter, where the primary coil of the welding transformer is arranged as bridging branch of the half-controlled bridge circuit.