Transformer question (only slightly OT)

[Chuck Guzis]

On 9/2/2006 at 11:11 PM ard at p850ug1.demon.co.uk wrote:

>A useful trick is to connect a 100W mains light bulb in series with the 
>input to the transformer when first applying power (and with the 
>secondaries of the transformer unconnected). Such a bulb will easily 
>handle the magnetising current of a small transformer, anf won't even 
>glow (or drop much voltage), so you can check the output voltages, etc.

Hmmm, the way I'd do is to hook up one winding to the mains, then tie one
lead of the second winding to either side of the mains supply and measure
the voltage between the other lead and the other side of the mains supply.
If correctly phased, the voltage difference will be closer to 0 than
2xmains.  

Cheers,
Chuck