| 摘要 |
In a power supply apparatus of an electric spark (discharge) machine for generating high frequency pulse by a switching circuit from a DC power supply, stepping up the voltage by a high frequency transformer, generating a dire current by a rectifier, and feeding the DC power to the electric spark gap, the voltage of OP amplifier (221) for detecting an output voltage and an OP amplifier (222) for detecting an output current and converting it to a voltage are inputted to a summation OP amplifier (223). The output voltage and the output current are controlled so as to have a negative proportional linear relation via feedback circuit (220) for performing feedback to a fly-back switching circuit (210) through a voltage comparison/subtraction OP amplifier (224) for comparing and subtracting the sum of the voltages with and from a reference voltage. |
