| 摘要 |
PROBLEM TO BE SOLVED: To measure precisely a value of high resistance like insulating resistance between an output terminal and a case of a Zener standard voltage generator, by excluding influence of a leakage current. SOLUTION: Circuit in the upper half of the figure is a main circuit for measuring a resistance value, and circuit in the lower half is a circuit for constituting a grounding device. Rao, Rbo and Rco are Y-connected among points a, b and c with a point o set as the center. Rx which is the object of measurment is connected between points a and d. R1+r1 is connected between points b and c. Rs+rs is connected between points c and d. Rw2+rw2, Rw3 and Rw4 are Y-connected among points a, c and e. Rw1 and rw1 are connected with a part between points c and e, and e is grounded. A switch SW is connected to the grounding side. Rw4 and rw2 are adjusted and balancing is taken. Thereby the point d is equivalently grounded, so that all leakage currents relating to the insulation resistance Rx flow into the point e (grounding point). Next the switch SW is moved to the point b side, Rao and rs are adjusted, balancing of the main circuit is taken, and a value of the insulation resistance Rx is obtained. COPYRIGHT: (C)2004,JPO
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