Electric workers often need to test the DC resistance value of power transformers in their work, as an important data reference when the transformer is overhauled and delivered. As a relatively conventional high-voltage power test equipment, the principle of its use is Workers need to be proficient in order to be able to use the DC resistance tester handily at work, so what is the principle of the DC resistance tester?

The stabilized voltage source of the DC resistance tester is a high-precision low-ripple power supply, which can provide a current output of 10A. The current output by the steady current source is controlled by its step-by-step switching control circuit. When different gears are selected for measurement, different stable currents are output. When the constant current passes through the resistance under test, a stable voltage signal is generated on the resistance under test. After the signal is processed by the computer, the liquid crystal display directly displays the resistance value. When measuring the DC resistance of a large inductor, after the test is over, a certain amount of charge is stored on the inductor, and both ends of the inductor are connected to a discharge circuit to quickly discharge the inductor (about 10 seconds). When the buzzer sounds, it means that it is discharging and stops. Sounds, indicating that the discharge is complete, and the test wiring can be removed only after the discharge is over.