PURPOSE: To prevent variation in zero point, and to improve voltage linearity, by adding a voltage, generated by rectifying an AC voltage generated by an AC control current and a Hall element input resistance, to a Hall element output voltage.
CONSTITUTION: The density of the magnetic flux at the gap part of a magnetic core C having opening and closing structure is proportional to a current (i) to be measured which flows through an electric path. By an electric path voltage (e) to be measured, on the other hand, a voltae-current converter A supplies a control current Ic proportional to the voltage (e) to a Hall element H, and at the input terminal of the Hall element, an AC input voltage equal to the product IC.Ri=ei of the control current Ic and the input resistance Ri of the Hall element is developed. This voltage is inputted to an operational amplifier 3 through a diode 1 and a variable resistor 2 and added to the Hall element output voltage. Consequently, a DC component generated in the Hall element output is canceled to perform complete compensation over the wide range of the control current of the Hall element.
SHIBATA TSUTOMU
TANAKA KOUKI
| JPS5357941A | 1978-05-25 |