| 摘要 |
PURPOSE:To prevent elements from being overheated or destroyed, by correcting the inductance of a coil with a correction circuit according to the state of a ceramic oscillator. CONSTITUTION:So far as a power source for an oscillator is concerned, an inverter circuit 22 is connected to a driving DC power source 21. The inverter circuit 22 with the positive pole of the DC power source 21 connected to the center of the primary winding 24 of a transformer 23 is composed of a first and a second transistors 26, 28, and an oscillation circuit 29. Besides, to the transformer secondary winding 31 of the inverter circuit 22, a ceramic oscillator 32 is connected, and is driven. In this case, to the secondary winding 31, the secondary winding 37 of the controlling transformer 36 of a correction circuit 35 is connected, and to its primary winding 38, an inductor 39 removing AC component from the winding 38, and a DC variable-power source 40 are connected. Then, so far as the correction circuit 35 is concerned, by its comparator circuit 41, the state of the oscillator 32 is discriminated, and the voltage of the DC variable-power source 40 is varied, and an inductance is changed, and resonance frequency is set to be equal to the frequency of the oscillator 32. |
