Ultrasonic test probe

Claim 1

An ultrasonic test probe comprising a housing in which is disposed: (a) a piezoelectric transducer element adapted to transmit an ultrasonic seach pulse into a workpiece and to receive ultrasonic echo signals from such workpiece; (b) an electrical circuit coupled to said transducer element for periodically energizing said transducer element with a high voltage pulse, said circuit including; (i) an electrical inductor coupled with one of its two terminals for receiving a trigger pulse; (ii) an electrical switching means coupled serially between the other terminal of said inductor and ground potential; (iii) control means coupled to said switching means and controlled by said trigger pulse for periodically rendering said switching means briefly non-conductive when said switching means is in its conductive state; (iv) a capacitor coupled with one of its two terminals to the junction between said inductor and said switching means, and (v) a resistor coupled with one of its two terminals to ground potential and with its other terminal to the other terminal of said capacitor, whereby responsive to the provision of a trigger pulse said control means renders said switching means non-conductive to cause a high voltage signal to form across said inductor which charges said capacitor with a potential, and responsive to said control means subsequently rendering said switching means conductive said capacitor discharges its potential to provide a high voltage pulse across said resistor which pulse is applied to said transducer element to energize said element.