| 摘要 |
PURPOSE:To select the transmission frequency of an ultrasonic wave automatically and easily and simplify device constitution by using plural plasma trigger spark gaps to discharge charging and discharging capacitors selectively. CONSTITUTION:The respective charging and discharging capacitors C3a-C3d are discharged by a common high-voltage power source 1 through a resistance 2, diodes 43a-43d, a generating coil 6, and a diode 43e. Then, a controller 44 drives trigger electrode charging and discharging circuits 39a-39e selectively at prescribed timing to discharge, for example, the capacitor 3a, so that the discharging current at this time is the exciting pulse current of a transmitting transducer 40. In this case, plasma trigger spark gaps 19a-19d are selected optionally to select various transmission frequencies automatically according to the combination of capacitors C. |
