2-phase doorbell transformer parlor trick
 

So grab a single-phase 120v/24v doorbell transformer, a couple 12v lightbulbs, some hookup wire and a dual-trace scope.

Apply 120v single phase to the transformer primary and connect the light bulbs in series to the transformer secondary as shown below:

( Transformer L1 ) ----------- ( lightbulb ) ---------- ( traitor's magic junction ) ---------- ( lightbulb ) ----------- ( Transformer L2 )

You should see the bulbs light up.


Next, connect a dual trace oscilloscope to the lighting circuit as follows:

- Connect the two scope trace common leads to ( traitor's magic junction ) between the lightbulbs.

- Connect scope trace Lead 1 to ( Transformer L1 )

- Connect scope trace Lead 2 to ( Transformer L2 )


Your scope will now display 180° 2-phase 24v output coming from a single phase transformer.


[Hugh Jorgan takes a bow]