| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe, etc., capable of controlling an overcurrent generated in a transistor of an impedance conversion circuit applicable to a bipolar driving pulse without largely increasing the circuit size. <P>SOLUTION: The impedance conversion circuit is composed of an emitter follower of a high-voltage transistor 102. A resistance 103 for determining bias voltage is connected to the ground on a base of the high-voltage transistor 102. A high-voltage diode 106 is connected between a collector and a power source VCC in the collector. A resistance 105 for determining an operating current and a resistance 104 for regulating the output impedance are connected to an emitter. Further, a capacitor 110 and a coil 107 are provided between the base of the high-voltage transistor 102 and an ultrasonic transducer 202 as resonant circuits for amplifying the driving pulse applied to the ultrasonic transducer 202. <P>COPYRIGHT: (C)2013,JPO&INPIT |
