Jeff:
If you connect 110V to one side of the primary (1 side and center tap) and take the output from one side of the secondary (1 side and center tap) you'll see about 16-17 V peak (Vpeak = Vrms X 1.4). The 12V rating written on the transformer is an rms value (Vrms = Vpeak x 0.7).
Taking the output across the whole secondary winding (ignoring the center tap) would give you 24Vrms. The 36V you read is the peak value and will droop when loaded.
There may be a typo in the wiring diagram; either the fan is ac or it is connected wrong.
robotic regards,
Tom |