| 摘要 |
PROBLEM TO BE SOLVED: To provide a driving circuit, by which a piezoelectric transducer is started stably and which is driven stationarily and has simple circuit constitution, even in the piezoelectric transducer driving the load of large fluctuation at a starting time and at the time of stationary operation such as a cold-cathode fluorescent lamp and even when a temperature and load are changed at the time of stationary operation. SOLUTION: A starting control circuit 9 controls a variable oscillation circuit 1 so that the oscillation frequency of the variable oscillation circuit 1 reaches frequency close to resonance frequency (fr) at the time of the no-load of a piezoelectric transducer 4 at the time of the lighting start of a cold-cathod fluorescent lamp 7. The operation of the starting control circuit 9 is stopped after lighting, and an oscillation control circuit 10 controls the oscillation frequency of the variable oscillation circuit 1 so that an approximately constant current is flowed through the cold-cathode fluorescent lamp 7. |
