| 摘要 |
<p>PURPOSE:To provide a current detector which does not cause the fluctuation of the output voltage of a magnetic sensor even when the power supply voltage of an amplifier circuit fluctuates and has excellent current detection accuracy by constituting the current detector in such a way that a coil through which a current to be detected is made to flow is wound around a magnetic core with a gap in its magnetic path and the magnetic sensor is inserted into the gap, and then, a magnetic field in the gap formed when the current to be detected is made to flow to the coil around the sensor is detected and amplified as the output of the sensor. CONSTITUTION:A Zener diode ZD2 is connected to the collector and base of a transistor Tr1 through a resistance R1 and the voltage across both ends of the diode ZD2 is inputted to an operational amplifier circuit IC1 the output of which is connected to one current bias terminal of a magnetic sensor 3. The other current bias terminal of the sensor 3 is connected to the collector of another transistor Tr2 and the collector output of the transistor Tr1 is connected to the base of the transistor Tr2.</p> |
