Polarity of flyback windings?

[eem2am]

Hello,

Ive just been handed a flyback transformer with one primary and one bias, and two secondaries which are 5v and 16v......so its a 5v winding which is the lower part of the 16v winding also...(autotransformer winding)

i happen to know which pins are connected to which winding but not which way round...........without powering up, how can i quickest check which way round the dots are.?
i have no winding diagram.

 

[Prototyp_V1.0]

Can you scetch up the transformer itself?

Is it important that primary and secondary side is not conductive to each other?

 

[inventor(y)]

Hi, You can simply check this with a low power square wave generator. Set the freq. to something like 200Khz and connect it to one winding. You can now check the other windings with an oscilloscope.

Cheers

 

[dr pepper]

The above is the best way, I have the gear now but when I was broke I had to do stuff without it.
I have tried a battery and a compass for this, but thats a little rough.
A quick way is to measure the inductance of a winding, then connect another of the windings in series with it, if the inductance goes up then the 2 are in phase, you have the start of one connected to the end of the other, if the inductance reduces then you have them out of phase.
Its only a guide, but this has worked for me when I couldnt be bothered going to the car to get the gear.