| 摘要 |
PURPOSE:To enable excitation of an oscillator array with simple constitution and to reduce the size of a sector scanning ultrasonic flaw detector by exciting the oscillators by the shift register of the bit number obtd. by adding 1 to the number 1/2 of the number of the oscillators even if there are many oscillators. CONSTITUTION:A shift register 6 has the bit number obtd. by adding 1 to 1/2 of oscillators, and here a 4-bit shift register 6 is shown. Flip-flops FF1-FF4 constitute the register 6 and the signal 7 of a ''1'' is first set in the FF of the 1st bit. The signal 7 is shifted from the flip-flop FF1 of the 1st bit to FF2, FF3, FF4 at every inputting of a shift pulse 8 at the trigger input terminal. Oscillators A1, A7 among A1-A7 are connected to FF1, A2, A6 to FF2, A3, A5 to FF3 and the mid-A4 is connected to the FF4 of the final bit, i.e., the 4th bit. Ultrasonic waves are thus generated simultaneously from the oscillators A1, A7 then the ultrasonic waves are generated from A2, A6 then from A3, A5 and finally from A4. Therefore seven pieces of the oscillators are excited with the 4-bit shift register. |
