| 摘要 |
PURPOSE:To increase the max. rated output value in the stage of CO2 and MAG welding by increasing the one period time which is increased in the period of a reference period signal and is constituted of the on-off time of a power transistor for controlling welding output. CONSTITUTION:This power source for welding transforms the input with a voltage transformer 1 and conducts welding current between output terminals 6 and 6 via a rectifier 2, a smoothing capacitor 3, a transistor (TR) 4 for controlling welding output and a reactor 5. The TR4 is turned on and off at a prescribed period by the signal from a driving circuit 8. An instruction digital signal (n) is outputted from an arithmetic/storage circuit 11 by the set value of an output setter 12 and an output characteristic selector 13 to a frequency dividing counter circuit 9. The circuit 9 is inputted simultaneously with the reference clock signal from a reference frequency signal generating circuit 10, divides down the reference clock signal of frequency N by n and outputs the same to the circuit 8. As a result, the TR4 makes switching operation at the frequency N/n so that the increase in the one period time constituted by the on-off time is made possible together with an increase in the output set value. |
