How to use a multimeter to determine the quality of small transformers
Generally with the smallest ohm file to measure whether the primary tap, if not, then damaged. Use the X10K stall above the ohm stalls to measure the primary and secondary, primary secondary and iron core for short circuit or leakage. If there is connectivity, then the insulation is bad or has been burned or breakdown.
Small transformer primary coil is generally 1 ~ 2k ohm, the secondary coil tens of ohms. If the problem with a multimeter measuring coil or open circuit, or open. There is also a fault that there is a short circuit in the middle of the coil, so that you only take the same transformer to compare the coil resistance.
First with a multimeter resistance file RX1 or RX10 to test the transformer on both sides of the coil! Have to pass! Primary resistance large! Secondary resistance small! (Buck)
And then test the first class! Can not pass! Basic determination is good!
And then use the transformer at both ends of the primary coil to take the multimeter AC voltage 50-100 volts stalls! With a dry battery to touch the transformer secondary coil ends! At this point multimeter watch pin should have a strong swing! Induced current and mutual inductance voltage! This proves that the transformer all normal! No turn-to-turn short circuit!
