Series secondaries?

[Phil Y]

Hello all,

I am messing around with a project and have found a problem with the transformer I'm using. The secondary is supposed to be 250-0-250 but one half is low and this can be seen as a lopsided waveform on the first reservoir cap. The high ripple is causing some hum. There is an unused 6-0-6 winding. Is there any reason I can't put this winding in series with the "low" half of the HT winding to even up the voltage?

Would that work or would it do something funny to the transformer?
Obviously the phase relationship would need to be correct for the voltages to add.
Advice gratefully received.

Phil.

[bikerhifinut]

Give it a go and see what happens. You should be ok with it.
i'd question the quality of the transformer though if there was a significant discrepancy in windings that caused such an imbalance.

Andy

[John Caswell]

That's perfectly acceptable, think about a tx with two 12V 1A secondaries. You can either series them for 24V at 1A or parallel them for 12V at 2A. As you say you need to keep the phases correct.

John

[Phil Y]

Thanks chaps, I'll give it a go.

Phil.

[Phil Y]

It seems to be working, many thanks.
Not quite even but much better, I may replace the transformer at some point but it is serving a purpose for now.

Phil.