| 摘要 |
<p>PURPOSE:To prevent a fault such as runaway by amplifying differentially double curent signals of opposite phase on a balanced line, rectifying its output in full wave, applying the result to a Schmitt trigger circuit triggered at a prescribed threshold voltage and detecting a level change. CONSTITUTION:When the phase of two signals is deviated from each other, a portion where an analog signal level is 0 for processing period exists as signal for a phase shift period in figure B. When the signal va. is fed to a full wave rectifier circuit 41, an output signal vb is as shown in a waveform for a phase shift shown in Figure C and when the signal vb, is inputted to a Schmitt trigger circuit 42, since the output level is below a threshold level Avx, the output signal vo is dropped to 0V as shown in figure D. The occurrence of a fault is kept by detecting the output state of 0V and storing it.</p> |
