| 摘要 |
<p>An electrical circuit for a resistance welder comprises 2 rectifier connected to an AC source, typically of 60 Hz. If the source is a three-phase source it is convenient to apply the source voltage to a full-wave bridge rectifier to produce an output voltage that has both a DC and an AC component. This output voltage is applied to a controlled thyristor inverter that transforms it into a wave that is substantially rectangular. An electronic circuit controls the thyristor inverter to determine the length of time it operates, the relative pulse width of the rectangular wave, and other desired features of the inverted voltage. The output of the inverter is applied to a step-down transformer which has a center-tapped secondary. The secondary is connected through a full-wave rectifier to welding contacts that supply welding current and the necessary force to a workpiece to accomplish resistance welding.</p> |
