How/how to use a multimeter to judge the quality of the transformer

How/how to use a multimeter to determine the quality of a transformer?

1) With the resistance meter of the universal meter, it is possible to measure whether the transformer's wire harness is broken. It is also possible to roughly test whether the wire package and the iron core are short-circuited.

2) After rough testing, you can try the transformer connected to the power supply. If the AC power is connected, the transformer quickly heats the soup, indicating that there is a short circuit between the turns.

3) In the case of secondary open circuit (no load), the primary current (no-load current) of the transformer should be small (this is related to the capacity of the transformer), the smaller the quality of the core is, the better.

That is, using a multimeter and energizing can roughly determine the quality of the transformer.

Of course, this only refers to the general home small power transformer.

If you must use a multimeter to determine the quality of the transformer, there is only one way: power up, measure the voltage!

The joke, the multimeter is not measuring the quality of the transformer, he can only measure the DC resistance of the transformer, and the quality of the transformer depends on his DC resistance can not judge him good and bad, you have to use Shake the table to measure insulation.