| 摘要 |
<p>PURPOSE:To protect a feeding circuit with simple constitution and without fail by detecting the voltage difference of respective feeding circuits to feed to an A line and a B line and increasing a feeding resistance at grounding or false connection. CONSTITUTION:When grounding or false connection are generated, the difference in the electric current to flow at a B line and an A line is increased and the difference is detected by a detecting part 1. Namely, at the input terminal of mirror circuits B1 and A1, the electric current flows corresponding to the electric potential of the B line and the A line. Respective electric currents are the same at the time of normality and come to be a different value at the time of abnormality when the grounding and the touching occur. Consequently, the difference electric current to flow into the detecting part 1 comes to be zero at the time normality and large at the time of abnormality. A comparator 2 compares the electric current with the prescribed value, judges that the grounding or the touching are obtained in case of the prescribed value or above, conncts the resistance in parallel to feeding resistances Ral and Ra2, increased the feeding resistance to n times and limits the feeding electric current. Since the circuit is constructed to feed by using the mirror circuit, LSI can be easily executed.</p> |
