| 摘要 |
PURPOSE: To improve circuit efficiency to make the output of an electrodeless discharge lamp into a prescribed condition undependably on the elapse of a lighting time, by detecting the output variation of the electrodeless discharge lamp to control a matching circuit in response to the variation quantity of the output variation. CONSTITUTION: A comparison circuit 10 is inputted with voltage E1 wherein both the end voltage of an electrodeless discharge lamp 7 is partially pressured by resistance R1 and R2 , voltage E2 wherein an electric current flowing in an induction coil 6 is detected by a current transformer CT2, voltage E3 applied to an element composing a matching circuit 5, voltage E4 wherein the output electric current of a high frequency circuit 4 is detected by a current transformer CT1 via a coaxial cable 12, and voltage E5 wherein the light output of the light 7 is detected via an optical fiber 18 and a phototransistor 13, respectively. The voltage E1 -E5 are compared with reference values E0 to each voltage E1 -E5 , and when the voltage E1 -E5 become larger than the values E0 respectively, a variable capacitor C10 is changed to control the output variation of the light 7. |
