| 摘要 |
PURPOSE:To prevent separation of a detector and the occurrence of an abnormal sound by changing frequency of a reference oscillation circuit by means of a (cds) photocopier while using a light signal outputted according to a phase difference signal of a phase difference comparing circuit, and adjusting resonance frequency slightly in an ultrasonic machining device to vibrate a file, etc., microscopically. CONSTITUTION:For example, in the case of being replaced with a machine tool 6 such as to cause a load change in narrow fluctuation, operation of a changeover switch SW is not necessary, That is, a load current is outputted to a phase light circuit 4 from an electrostrictive vibrator 3 according to the load change smaller than a specific fluctuation width. On the other hand, when a constant reference voltage waveform alpha1 is outputted from a reference oscillation circuit 1, a LED of a (cds) photocoupler of a phase difference comparing circuit 4 emits light according to voltage, and changes resistance of a light receiving section R1, and changes reference frequency. Thereby, a phase difference signal Hr of a voltage value is outputted to the reference oscillation circuit 1, and a resonance condition can be created. When a large load change is caused, the changeover switch SW is switched to the variable resistance R3 side, and coarse adjustment is carried out in the first place by means of a coarse adjustment knob. |
