I just had an idea:
The idea is to elevate the transformer cores to 200v or so, and enclose the cases so that no one can touch them.
But presumably these transformers look pretty? And you want them on show?
How about enclosing them in transparrent acrylic? It could make for a unique "glassy" design.
May be you think I'm mad? But it would work as long as you leave some distance between the acrylic and valves.
The idea is to elevate the transformer cores to 200v or so, and enclose the cases so that no one can touch them.
But presumably these transformers look pretty? And you want them on show?
How about enclosing them in transparrent acrylic? It could make for a unique "glassy" design.
May be you think I'm mad? But it would work as long as you leave some distance between the acrylic and valves.
Re: Tango XE20S
Well the Tango XE20S can certainly handle the voltages but it is not designed for use in DRD applications. Its a gapped single ended transformer which can handle quite a bit of DC current. A copy of the datasheet can be found here:
http://www.pmillett.com/images/Tango_XE20S.PDF
Since its designed to run with a lot of DC current, its inductance is somewhat limited and its also physically larger than needed. In the DRD application there is no DC current in the primary so you don't need the same airgap and you can have a lot more inductance.
If I had a pair of XE20S transformer then I'd probably build a more conventional singled ended 300B amplifier and get rid of that DRD capacitor, but thats just me.
---Gary
tonitze said:
Well the Tango XE20S can certainly handle the voltages but it is not designed for use in DRD applications. Its a gapped single ended transformer which can handle quite a bit of DC current. A copy of the datasheet can be found here:
http://www.pmillett.com/images/Tango_XE20S.PDF
Since its designed to run with a lot of DC current, its inductance is somewhat limited and its also physically larger than needed. In the DRD application there is no DC current in the primary so you don't need the same airgap and you can have a lot more inductance.
If I had a pair of XE20S transformer then I'd probably build a more conventional singled ended 300B amplifier and get rid of that DRD capacitor, but thats just me.
---Gary
Re: Re: Tango XE20S
Konnichiwa,
I would like to note that you are quite mistaken. In the DRD application around 90mA standing DC current flow in the primary. I would STRONGLY advise against using a transformer without airgap there, as would Jack Elliano, if he where to read this....
Sayonara
Konnichiwa,
GaryB said:
I would like to note that you are quite mistaken. In the DRD application around 90mA standing DC current flow in the primary. I would STRONGLY advise against using a transformer without airgap there, as would Jack Elliano, if he where to read this....
Sayonara
Bas Horneman said:Gary B, I think you are thinking of a Parafeed setup
DRD is a different cup of tea ofcourse.
Mea culpa - thanks to Bas and Thorsten for pointing out my error. It was early Monday morning and I must not have had enough coffee
.For the DRD circuit it looks like the XE20S would work fine.
Thanks,
---Gary
Yes I would think so. Since the cathode resistor with the 2k2 resistor forms a voltage divider as well..in other words there is not the full 700V across the transformer but probably closer to 500volts.
However I don't know what the voltage spec is for the Tango. But I guess it would be higher than 500V.
However I don't know what the voltage spec is for the Tango. But I guess it would be higher than 500V.
An important issue in transformer voltage ratings is the potential between any winding and the core/case. It will have been flash-tested at a much higher voltage (maybe 2KV or 3KV) than the rated voltage. However continued use can cause breakdown as the insulation can deteriorate under stress and time.
This is why I agreed with Toni's caution until the transformer's rating was known, and suggested a way to get round the problem if it was insufficient.
The bottom line is: Find the Tango spec. and act accordingly.
NB The peak voltage (with respect to chassis) of this system will exceed 1400V. If Tango say 700V is OK then they will have accommodated for this.
This is why I agreed with Toni's caution until the transformer's rating was known, and suggested a way to get round the problem if it was insufficient.
The bottom line is: Find the Tango spec. and act accordingly.
NB The peak voltage (with respect to chassis) of this system will exceed 1400V. If Tango say 700V is OK then they will have accommodated for this.
That is very good advice John. But I've never seen a voltage rating on a transformer dataheet (apart from Lundahl)
My transformers are pretty unique in that they have a datasheet. (One Electron) but there is no voltage rating declared. Luckily one can email John Atwood
Best thing to do I think is to post another thread with the heading : "Tango XE20S voltage rating?"
someone out there must know...??
Assumptions have led to many a disaster. However is it not safe to assume that Tango (one of the premier transformer companies on the face of the planet) ...have built this tranny for the 300B which typically has b+ of 400-480Vdc? (and is that not the effective voltage across this transformer, even in the DRD circuit?)
I'm not challenging your way of looking at it John....that is the safest way.....I'm trying to have you guys have a look at my assumptions .
XE-20 data sheet
Tango is still around. They were re-organized as "ISO / New Tango" a couple of years ago. The only place I know of that sells them is Noguchi Transformers in Tokyo, and EIFL Export (somewhere in Japan).
Unless you speak Japanese, though, I doubt that you can get any info from Tango directly.
Here's the XE20S datasheet:
http://www.pmillett.com/images/Tango_XE20S.PDF
Unfortunately no mention of voltage rating.
Pete
Tango is still around. They were re-organized as "ISO / New Tango" a couple of years ago. The only place I know of that sells them is Noguchi Transformers in Tokyo, and EIFL Export (somewhere in Japan).
Unless you speak Japanese, though, I doubt that you can get any info from Tango directly.
Here's the XE20S datasheet:
http://www.pmillett.com/images/Tango_XE20S.PDF
Unfortunately no mention of voltage rating.
Pete
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