| 摘要 |
PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp lighting apparatus having a simple circuit structure and manufactured at low cost by using a signal with lower frequency than the driving frequency of a high frequency circuit supplied from an electric power circuit as a timing signal to intermittently stop the output of a detection circuit. SOLUTION: In an abnormality detecting circuit 19, resistances R1 , R2 connected in series are connected with an induction coil 6 in parallel, a diode D8 and a capacitor C10 connected in series are connected with the resistance R2 in parallel, the connection point is connected with a negative pole terminal of a comparator Q4 , and a positive pole side of a standard electric voltage source E6 is connected with a positive pole terminal of the comparator Q4 . Further, in a high frequency control circuit 20, a diode D6 and a switching element Q6 are connected between a gate and a source of a transistor Q3 and a resistance R5 is connected between a gate and a source of a switching element Q6 . The driving frequency of the voltage raising chopper circuit 3 is set to be lower than that of a high frequency circuit 4. The driving frequency of the voltage raising chopper circuit 3 is used as a timing signal to intermittently stop the output of the detection circuit, so that an electrodeless discharge lamp 7 can be turned on with a simple circuit structure and manufactured at low cost. |
