| 摘要 |
PURPOSE:To set low the starting voltage of discharge tubes and perform sure ignition by changing over the frequency to a frequency higher than that of high frequency output in the case of regular discharge at the start of discharge. CONSTITUTION:When discharge starting signals are given, high frequency output is applied to discharge tubes 9-11 from a coaxial cable connector 25 through a coaxial cable 3 at high frequencies 27.12MHz (54.24MHz) and ignition- discharge takes place in the discharge tubes 9-11. Once discharges occur in the discharge tubes 9-11, current transformers 12-14 detect a discharge current and the output of a discharge detecting circuit 15 is inputted to a frequency change-over circuit 26. Then the output of the frequency change-over circuit 26 is inputted to change-over switch circuits 17, 20, and 23 and their circuits 17, 20, and 23 select low frequencies 13.56MHz. Consequently, the high frequency output having the low frequencies 13.56MHz is outputted from the coaxial cable connector 25. Then, ignition discharge is surely performed in the discharge tubes 9-11 by applying low frequencies 13.56MHz to the discharge tubes 9-11 and then the frequencies are changed over to low rated frequencies in the case of regular discharge. |
