Author Topic: will this work?  (Read 550 times)

0 Members and 2 Guests are viewing this topic.

Offline p.larnerTopic starter

  • Frequent Contributor
  • **
  • !
  • Posts: 690
  • Country: gb
will this work?
« on: April 06, 2024, 07:59:11 am »
I ordered 2 transfos from aliexpress 230v pri sec 12-0-12v,ie 12 volt center tapped secondarys ,they sent ones with 12v secondaries with no center tap,so its a nogo sending them back,so can i wire there both primaries in series,then link the secondaries,using the link as a center tap,for +12/-12v,hope it makes sense,its only a load for swithching relays in a psu kit.
 

Offline moffy

  • Super Contributor
  • ***
  • Posts: 1877
  • Country: au
Re: will this work?
« Reply #1 on: April 06, 2024, 08:42:01 am »
Wouldn't you want the primaries in parallel otherwise if in series the secondaries will become 6V RMS windings? If you wire them with the primaries in parallel and link one terminal of a 12V RMS winding to one terminal of the other, phasing might be important, just make sure you have 24V RMS across both windings when they are connected.
« Last Edit: April 06, 2024, 08:43:33 am by moffy »
 

Offline Andy Chee

  • Frequent Contributor
  • **
  • Posts: 760
  • Country: au
Re: will this work?
« Reply #2 on: April 06, 2024, 09:44:39 am »
It’s possible to use a voltage doubler configuration to obtain +/-12V dual rails from a single 12VAC winding.

But if you’re only powering relays, that normally doesn’t require dual rail supply.

Can you post a schematic?
 
The following users thanked this post: tooki, p.larner

Online Gyro

  • Super Contributor
  • ***
  • Posts: 9718
  • Country: gb
Re: will this work?
« Reply #3 on: April 06, 2024, 09:55:09 am »
I ordered 2 transfos from aliexpress 230v pri sec 12-0-12v,ie 12 volt center tapped secondarys ,they sent ones with 12v secondaries with no center tap,so its a nogo sending them back,so can i wire there both primaries in series,then link the secondaries,using the link as a center tap,for +12/-12v,hope it makes sense,its only a load for swithching relays in a psu kit.

You description is not at all clear. If you order 12-0-12V secondaries, then you shouldn't expect to receive center tapped 12V ones (6-0-6V).

Please post a clear diagram of what you want, labeling all voltages, together with clear photos of the transformer, including labels.
Best Regards, Chris
 
The following users thanked this post: tooki, p.larner

Offline tooki

  • Super Contributor
  • ***
  • Posts: 12018
  • Country: ch
Re: will this work?
« Reply #4 on: April 06, 2024, 11:24:20 am »
I ordered 2 transfos from aliexpress 230v pri sec 12-0-12v,ie 12 volt center tapped secondarys
12-0-12 is a center-tapped 24V transformer.
 
The following users thanked this post: p.larner

Offline p.larnerTopic starter

  • Frequent Contributor
  • **
  • !
  • Posts: 690
  • Country: gb
Re: will this work?
« Reply #5 on: April 07, 2024, 09:07:31 am »
The transformer is the aux one in the schematic attatched,the orig is slightly wrong but it makes the point,basicaly i have a bunch of 12v secondary transfos that i need to use for the aux transfo in the psy schematic.,sending these back to china is a no brainer!.
 

Offline DavidAlfa

  • Super Contributor
  • ***
  • Posts: 6071
  • Country: es
Re: will this work?
« Reply #6 on: April 07, 2024, 09:36:51 am »
Connecting the primaries in series will lead to 6V+6V instead your intended 12+12.
Primaries must go in parallel, secondaries in series, emulating the center tap.
Just like this:
« Last Edit: April 07, 2024, 09:38:29 am by DavidAlfa »
Hantek DSO2x1x            Drive        FAQ          DON'T BUY HANTEK! (Aka HALF-MADE)
Stm32 Soldering FW      Forum      Github      Donate
 
The following users thanked this post: p.larner


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf