Test with a multimeter

Transformer (24 V / 12 V, EI30)

Explore in Atlas

Now: Primary winding

CircuVanta 6000 counts · auto range DCAUTO•)))HOLDFUSE− HOLD LIGHT OFFV⎓V~Ω•)))FmA⎓ mA400 mACOMVΩ Primary p1 1 p1 Primary p2 2 p2 Secondary s1 3 s1 Secondary s2 4 s2
Pin 1: Primary p1 (p1) Pin 2: Primary p2 (p2) Pin 3: Secondary s1 (s1) Pin 4: Secondary s2 (s2)

Red probe Not connectedBlack probe Not connected

Hold the probe and drag it to the tip of a leg. Tapping works too: first pick the probe, then the leg.

Set the range to Ω (resistance).

Measure step by step

A transformer's primary and secondary windings are insulated from each other. Measure each winding separately: in this transformer the resistance of the primary winding is higher than that of the secondary. Between the windings it should be OL.

Take the measurements with the transformer completely disconnected from the supply and from the circuit.

  1. 1Primary winding
  2. 2Secondary winding
  3. 3Between primary and secondary