Pultec power transformer question?

[Coldsnow]

Hi all,
On the first tranformer below, it is rated at 2x12v on the secondary.  This is what I want, so would I wire the secondary in series or parallel?  My guess is parallel.  Series would bump it up to 24v, correct?

Also, Both are rated at 2amp.  The schematic calls for 1.5.  Does this mean I would need two sets to power 2 Gyraf Pultecs?



I have these two transformers
2x12v.
http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=te62062-nd&x=0&y=0
2x6 v
http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=237-1046-nd&x=0&y=0

 

[rotation]

Hi all,
On the first tranformer below, it is rated at 2x12v on the secondary.  This is what I want, so would I wire the secondary in series or parallel?  My guess is parallel.  Series would bump it up to 24v, correct?

Also, Both are rated at 2amp.  The schematic calls for 1.5.  Does this mean I would need two sets to power 2 Gyraf Pultecs?



I have these two transformers
2x12v.
http://search.digikey.com/scripts/DkSearch/dksus.dll?lang=en&site=US&WT.z_homepage_link=hp_go_button&KeyWords=te62062-nd&x=0&y=0
2x6 v
http://search.digikey.com/scripts/DkSearch/dksus.dll?WT.z_header=search_go&lang=en&site=us&keywords=237-1046-nd&x=0&y=0

This transformers have dual secondaries and are intended for use when you need +-12V and +-6V. Gyraf Pultec want two transformers with single secondaries wired back to back.
I think you could use your transformers if you wire first transformer's secondary in parallel for + and take two wires in the middle for -.
For the second transformer: i would wire secondary in series, so upper side is +, lower side is -. Two wires in the middle of the winding connected together are your -. 2 amperes is more than enough for 1ch G-Pultec.

Ask someone for confirmation, but i'm quite sure i'm right.

Miha

 

[Harpo]

you need both transformers (1st a step down for heater, 2nd connected backwards to the 1st for step up).

Connect secondary side of the 2x12VAC in parallel by joining green with brown and red with blue.
Connect primary side depending on your AC-mains.

Connect secondary side of the 2x6VAC in series by joining pin 6 with 7, outer pins connecting to your 1st transformers secondary winding.
Connect primary side in series by joining pin 2 with 3, outer pins is your HT voltage.

@Miha There is no + or - side in AC.

 

[rotation]

@Miha There is no + or - side in AC.

I like to mark it because when it comes to audio AC it should be known for correct phase. But you are right, it doesn't matter for what we have here, i just wanted to make sure he knows what i'm talking about...

 

[Coldsnow]

The data sheet on the second one states
"Secondary:  series 12.6v, Parallel 6.3v"
The layout schematic on Gyraf's site states (for 110VAC)  TRAFO1 = 110:12v, TRAFO2 = 110:6V,
So, for the second one Don't I want it to run near 6V and in Parallel on the secondary?

Thanks again,

 

[Harpo]

12:220V or 12.6:230V is the same step up ratio of 1:18.3 as 6:110V or 6.3:115V.
Your transformer with dual primary and dual secondary winding has the option to wire it either way - 6:110V for more current - 12:220V for maybe better match. Just try it. 2500V isolation voltage should be sufficient for both sides in parallel.

 

[JoleFIN]

Hmm probably a stupid question but why do you need to have a 12:220 transformer for the heater if you can have the 220vac (or 230) straight without a transformer? Some kind of an insulation issue?

This one should be sufficient for the purpose of 220:12 (and also 12:220) ? Any other options out there? I don't find any straight 220:12 plain transformer from Farnell, they all have 2x secondaries which are probably more pricey than one with a single secondary.
http://fi.farnell.com/jsp/search/productdetail.jsp?sku=9530363

 

[ilikeit]

hi
i m from France so the primary should be an 230V
Can give me myself the references both transfo that I have to buy reference
Farnell for example
because i m loosing myself betwen the VAC the secondary the amp ....
Thx

 

[ilikeit]

nobody??

 

[snipsnip]

What is it you are getting confused with? you need a primary that can work with your 230v, and a secondary of either 12 or 15v. make sure the ampage is enough to handle the circuit, which is info you can get from the schemo.

Jake