Hi--- basic question here. Suppose you have a 250-0-250 center tapped power supply rated at 25ma on the center tap. Here's the transformer in question:
https://www.ebay.com/itm/145533351712
Is it possible to run these in parallel as two separate 250V supplies at 25ma apiece, or do the secondaries need to be isolated to do that? Realizing I don't understand the difference between those two cases as well as I thought, and using the search bar is leaving me with more questions.
Thanks!
-Erik
https://www.ebay.com/itm/145533351712
Is it possible to run these in parallel as two separate 250V supplies at 25ma apiece, or do the secondaries need to be isolated to do that? Realizing I don't understand the difference between those two cases as well as I thought, and using the search bar is leaving me with more questions.
Thanks!
-Erik
Only if the 250v windings are separate. If truly centre tapped, (usualy are) then they are not.
Normally you would use full wave rectification so one diode in each 250v lead and the CT connected to 0V.
The Valve Wizard's website is an excellent source of tutorials:
http://www.valvewizard.co.uk/psu.html
Normally you would use full wave rectification so one diode in each 250v lead and the CT connected to 0V.
The Valve Wizard's website is an excellent source of tutorials:
http://www.valvewizard.co.uk/psu.html
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The idea was more B+ current. I was hoping to get 25ma out of each side at 250 instead of 25ma total at 500.
You;ll have to prise more money from your wallet for a 50ma transformer.😉
250-0-250v gives about 350v DC with full wave rectification, depending on the transformer's regulation. (total Vac / 1.43 - diode volt drops).
You could ask the seller if the windings are separate but this would normally be stated as 250-0, 250-0v.
250-0-250v gives about 350v DC with full wave rectification, depending on the transformer's regulation. (total Vac / 1.43 - diode volt drops).
You could ask the seller if the windings are separate but this would normally be stated as 250-0, 250-0v.
Thanks, that should work fine--- it's for a single stage tube mic preamp, so I should be able to work with 25ma. Just needs to drive a proper line output.