[SanDegan]

Thanks for the help.

The entire problem was of my own doing. In that test set up, I connected the mains supply from my dim bulb tester to the filament winding’s. Yes, the bulb got brighter as the voltage was increased. I failed to grasp the concept.

Now that I have figured out my error, everything now tests as it should and all voltages are as expected. In the correct configuration the bulb did not light up as expected as there was no load on the transformer.