Low Profile Tube Transformers

[mcs]

[quote author="Marik"]BTW, many of toroidals in US are made with dual 115+115V primary. I got little confused as for why it would not be possible to use one of them as a primary, and another as a secondary and make a voltage dublier?[/quote]
Because the isolation between the primary windings isn't strong enough...

Best regards,

Mikkel C. Simonsen

 

[Marik]

[quote author="mcs"][quote author="Marik"]BTW, many of toroidals in US are made with dual 115+115V primary. I got little confused as for why it would not be possible to use one of them as a primary, and another as a secondary and make a voltage dublier?[/quote]
Because the isolation between the primary windings isn't strong enough...

Best regards,

Mikkel C. Simonsen[/quote]

The Avel has 4K insulation. Is it gonna be a problem?

 

[BradAvenson]

[quote author="Marik"][quote author="NewYorkDave"]Marik,

I've seen that done before. In theory, it should work, as long as it's truly dual primaries and not just one tapped single winding.[/quote]

:thumb: :thumb: :thumb:
Avel has those for around $30. Sounds like a plan![/quote]

I've done it for a tube mic supply with the flatpack split bobbin designs with no problems. Been using the supply for about 2 years now.

 

[PRR]

> dual 115+115V primary. ...possible to use one of them as a primary, and another as a secondary and make a voltage dublier? A 30VA 6V trafo could fit the bill?

If you do that, and take all/most of your power from one "primary", de-rate it about 30%. A 30VA core fed with just one-half of a 2-part primary probably should not be asked to feed more than 20VA AC, about 10 Watts DC.

Yes, for small loads this works great.

 

[mcs]

[quote author="Marik"]The Avel has 4K insulation. Is it gonna be a problem?[/quote]
Between the primary windings? Most of them have a lot of isolation between the primary and secondary, but not a lot of isolation between the primaries. You could easily test it with a high voltage tester of course - if the transformer survives it's OK :grin:

Best regards,

Mikkel C. Simonsen

 

[Marik]

Thank you Gentlemen!