| 摘要 |
<p>PURPOSE:To precisely measure the displacement of a core without being affected by the conditions for manufacture, etc. by having a level detecting means for detecting the output voltage level on the secondary side of a differential transformer. CONSTITUTION:The primary voltage Ep obtd. by amplifying the sinusoidal output from an oscillation circuit 4 by an amplifier 8 is supplied to the primary winding of the differential transformer. The secondary voltage Es of the transformer 9 is amplified by an amplifier 10 and is applied to an analog-to-digital converter 6. On the other hand, the cosine wave output shifted in phase by 90 deg. from the sine wave applied to the amplifier 8 is applied from the circuit 4 to a synchronizing circuit 5. The circuit 5 applies a conversion command signal to the converter 6 at the respective points of the time when the cosine wave inputted thereto rises across the zero level. The converter 6 converts the analog output from the amplifier 10 to a digital signal and applies the digital signal to a buffer 7. The buffer 7 holds the previous input value in the period until the next input value is applied thereto. Said value is outputted as the measuring output to a measurement display circuit relating to the core displacement.</p> |
