| 摘要 |
PURPOSE:To set ballast resistors having values of several kinds to resistance values maintaining stable discharge easily by fitting the ballast resistors in a gas laser oscillator and selecting and adopting one of them by a changeover switch, etc. CONSTITUTION:Ballast resistors having values of several kinds are fitted in a He-Ne gas laser oscillator as ballast resistors 6, and one of them is selected and adopted by a changeover switch 7. Accordingly, a stable resistance value maintaining stable dischrge can be selected and adopted simply in negative resistance by discharge currents-to-inter-tube drop voltage characteristics of a laser tube, stable resistance and stable discharge maintaining current characteristics determined by a closed loop containing a power supply. That is, stable discharge can be maintained easily by selecting and adopting a proper stable resistance value by the changeover switch on the dispersion of the initial discharge currents-to- inter-tube drop voltage characteristics of the laser tube and the change of the stable resistance value for stably maintaining discharge due to the variation of said characteristics with the increase of the operating time of the laser tube. |
