Category : Transformer Testing | Posted on 2021-08-18 20:11:23
There are two main types of
transformers available in the market: the linear transformer and power
transformer, which differ in their design and application. Thought, they both
have coils wounded together on the iron (ferrite) core.
In real world application, transformer
failures occurs in case of a too high voltage or current passing through the
coil leading to the circuit breakdown by heating of the windings. Linear transformer can be tested in the absence of
load. The breakdown of the windings (primary / secondary) can be checked
by the signs of overheating. It is done by applying ac voltage to the primary
winding and checking the very low or negligible voltage from the secondary winding
of the transformer.
On the other hand, the power
transformer works on load. Thus, a power
transformer is tested by firstly disconnecting it from the board and then investigating
the primary winding and the secondary windings for failures. The ringer test and/or
the resistance checks method is applied to check the coil winding failures. The
ringer tester is performed by connecting its probes to the primary winding and instantly
shows the results in the form of bar graph. A reading of 4-8 means good
winding, while 1-2 bar signifies partial shortening and switching off of the
represents heavy damage in the coils.