SSS trafo

[grtamp]

Hi can be ok a TF-130 PT for a SSS project.

I contact TMI Transformers for ask info about this power trafo.

They answered that have some data sheet but are not very clear because they are old documents.
Here the specific they told me:

The currents are :

Pri. I (p) = 3.86 A

Sec. (340v) = 0.6 A

Sec.(60v) = 0.5 A

Sec. (6.97Vct) = 3.7A


And excitation current is 230mA


3.7A seems a bit low!!!

[Structo]

Those specs don't look right at all.

[ToneMerc]

I believe it's 3.7A across each half of the filament tap, other than that it looks ok, actually a bit beefier than I would have thought.

TM

[martin manning]

340VAC and 600mA is pretty stout! I don't know why they would spec half of the filament winding, as the whole thing has the same current flowing in it all the time.

[ToneMerc]

With about 7.5A filament rating would explain why HAD used this with a quad of EL34's. I've squeezed 345@575mA, 60@ 500mA , 6.3@2A and 6.3VCT@8.5A on the Twin frame and it was about maxed out.

It appears that some SSS filament winding were loaded from around 98% to as much as 110% and they worked fine. I would imagine that you could just follow HAD's lead and use a stock Twin PT transformer.

TM

[martin manning]

With about 7.5A filament rating would explain why HAD used this with a quad of EL34's...

Not sure I understand, how do you get 7.5A? I'm wondering if that 3.7 shouldn't be 8.7 or something like that, which is about right for 4x EL34 and a half-dozen or so small tubes. I don't think HAD was the kind of guy who would under-design anything.

[ToneMerc]

With about 7.5A filament rating would explain why HAD used this with a quad of EL34's...

Not sure I understand, how do you get 7.5A? I'm wondering if that 3.7 shouldn't be 8.7 or something like that, which is about right for 4x EL34 and a half-dozen or so small tubes. I don't think HAD was the kind of guy who would under-design anything.

Martin, my thought was 3.7 * 2. I've seen a design sheet where the 3.15-0-3.15 filament winding was broken out for each half verses the entire winding. That may not even be the case here though.

TM

[martin manning]

That's where I trip... The two halves of the winding are in series as far as the filament current is concerned so they won't add like that.

[pazzo63]

Hi you should ask Mr AYAN , he is the Master i thinh he can give some focused informations about the spcs the tf 130 transformer, he used them in his fantastic past builds if i recall correct CHEERS

[ToneMerc]

Also, see this thread.

https://tubeamparchive.com/viewtopic.php?t=19056

TM