| 摘要 |
<p>PURPOSE:To provide an electric current sensor capable of detecting both AC and DC. CONSTITUTION:When an current Io flows in a coil N3 under a state where an excitation signal is being fed from a high frequency signal generating circuit 1 to a coil N1, a saturable magnetic substance core 2 is saturated, the excitation signal of the coil N1 is not transmitted to a coil N2 side, input V1 of an on- delay circuit 5 becomes smaller than a threshold value VTH, and output Vo of the on-delay circuit 5 is stopped. On the other hand, when the current Io is not applied, the excitation signal of the coil N1 is transmitted to the coil N2 side, an input level of the on-delay circuit 5 exceeds the threshold value VTH and when it is continued for a specified time or more, the output Vo is generated. Change of the input level of the on-delay circuit 5 due to an amplitude change of an AC can be absorbed by delaying action of the on-delay circuit 5 so that detection of the AC can be attained.</p> |
