| 摘要 |
PURPOSE:To discriminate whether a resistance value is good or not by detecting the difference between a drop voltage in the first reference resistor and a reference voltage and providing a constant current similar to that of a constant current circuit which controls the resistor so that this difference is zero and supplying the output to a terminal to be measured. CONSTITUTION:In case of measurement of the total resistance value of a resistor 24 to be measured, a switch 58 is connected to the side of a terminal 26, and a voltage Vx of a terminal 25 is measured. In this case, the output of the terminal 25 is supplied to a comparison amplifier 38 through a buffer amplifier 61 as required to measure the voltage of the output terminal. Assuming that a constant current Ix is flowed, a resistance value Rs of a reference resistor 51 is so set that the value obtained by dividing a total resistance value Rx of the variable resistor to be measured by the value RS becomes constant. Further, a resistor 55 for power setting is provided to change the value of (n) of 10<n>, and the number of used standard resistors is reduced. Thus, it is discriminated whether noise measurement and the total resistance value are good or not.
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