How To Find Common Faults Of Dc Double Bridge Of Power Fittings?

How to find common faults of Two Pole Distribution Blocks?
The DC double-arm bridge is more complicated than the single-arm bridge in terms of line structure. Therefore, when repairing, we must first find the fault location and analyze the cause of the fault, and then repair and eliminate the fault. Here, we take the QJ44 double-arm bridge (see Figure 10-7) as an example to introduce the method of repairing the DC double-arm bridge.
Line segmentation inspection method:
The line segmentation inspection method is to remove the bridge dry battery, select the multimeter RX 100 gear, and refer to the principle circuit diagram of Figure 10-7 (a). Check according to the following steps:
① Connect the multimeter test rod to the positive power supply terminal and terminal P: of the double bridge, press the GB and G buttons, adjust the ratio arm (multiplier) X0. 01~X 100 five gears, and write down the multimeter reading every time the multiplier changes: Then, connect the multimeter test rod to the positive power supply terminal and terminal P2 of the double bridge, and follow the same method. Write down the multimeter reading. If the two measurement results are consistent, it means that the resistance of the inner and outer arms of the bridge is good.
② Connect the multimeter test rod to the positive power supply terminal and terminal C: of the bridge, press the GB button, and the multimeter has a reading, which means that the standard resistor and the circuit are intact.
③ Connect the multimeter test rod to the negative power supply terminal and terminal C2 of the bridge, and the multimeter has an indication, which means that the circuit is intact.
④ Connect the multimeter to the terminals Pr and P2 of the bridge, press the G button, and the multimeter has a reading, which means that the galvanometer is intact.