| 摘要 |
PURPOSE:To get rid of wasteful power consumption, by utilizing the constant current characteristic of a reactor, and by permitting reactor current to flow to a laser beam source connected to a switch element in parallel with each other. CONSTITUTION:Power from an AC power source 2 is converted to the DC power of desired voltage by a thyristor rectifier 3, and a transistor switch 22 is turned ON, and direct current is permitted to flow to a series reactor 21. When the input of the direct current detected by a current detector 23, to a switch control circuit 25 is provided and the current comes to a current value set by a current setting unit 24, then OFF-command is applied to the transistor switch 22 from the switch control circuit 25, and the circuit is opened. As a result, the current with the switch 22 off is supplied to a discharge tube 11 in parallel with the switch 22 because of the constant current characteristic of the series reactor 21. The constant current flows even if the tube 11 exhibits a negative resistance characteristic. Besides, by phase-controlling the rectifier 3 with the control circuit 25, its DC output voltage can be changed.
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