| 摘要 |
<p>PURPOSE:To make it possible to obtain a highly stable current detector having a wide dynamic range, by simple circuit constitution such that the magnetical deviation of a magnetic core due to a measuring current is detected on the basis of the change in the operation of a separately-excited oscillation circuit. CONSTITUTION:A base current is supplied to transistors 10a, 10b in an alternating manner through an exciting transformer 40 by the rectangular wave output from an exciting oscillator 41 and the transistors 10a, 10b are brough to an ON- state in an alternating manner. In such a state that a current to be measured is not flowed to winding 1-1, the current flowing to resistors 20a, 20b are respectively same in amplitude and a time width. However, when a DC current or a low frequency alternating current is flowed to the winding 1-1 of the current to be measured, the operative point of a magnetic core 1 is shifted and difference is generated between the magnitudes of currents flowed to the resistors 20a, 20b. Therefore, difference is generated between the outputs of smoothing circuits 21a, 21b and signal output voltage with polarity proportional to the magnitude of the current to be measured and corresponding to the flow direction thereof is obtained at the output terminal of a differential circuit 22.</p> |
