SU45675A1 - Contact device for measuring electrical resistance - Google Patents

Description

When measuring small electrical resistances (for example, windings of electrical machines) using the ammeter and voltmeter method, contact devices are usually used, representing handles made of an insulating material, equipped with two protruding electrodes connected by flexible insulated conductors with a current source and measuring instruments. When measuring, two such devices are pressed by electrodes to the ends of the resistance, one pair of contacts used to connect the resistance to the main current circuit, and the second is connected to a sensitive voltmeter, which serves to measure the voltage drop in the circuit under study. To improve the contact, the electrodes are supplied with springs. The disadvantage of existing devices of this type is that both circuits (ammeter and voltmeter) turn on simultaneously and if the measured resistance is broken, the full voltage of the source is applied to the voltmeter, which causes damage to the device.

The present invention aims to eliminate this disadvantage. The proposed fixture consists of ebony (234).

A hollow handle 7, provided at one end with electrodes 4 and 6. An electrode in the form of a rod that passes through the tubular electrode 4 and protrudes normally from it, is equipped with a spring 5 and, when pressed, enters the inside of the handle 7.

As already indicated, two such devices are required for the measurement. The elongated electrodes (5 are used to sum up the main current, and the tubular electrodes 4, to connect an accurate voltmeter. Making measurements, take the devices in their hands, apply them by electrodes 6 to the resistance being measured, but does not bring the electrodes 4 into contact with the resistance Having verified by the ammeter that the current strength is normal, he presses the handles harder, thereby turning on the voltmeter, and then reads the magnitude of the voltage drop.

The subject matter of the invention.

Contact device for measuring electrical resistances by the method of an ammeter and a voltmeter, which serves to connect the measured resistance to the current circuit and is equipped with two electrodes, different from that of the NTO to eliminate the possibility of overloading the voltmeter in the event of a break in the measured circuit, the current-making electrode is longer than the potential electrode.

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