Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on December 11, 2010, 07:43:20 am

Title: A strange Transformer ???
Post by: kagliostro on December 11, 2010, 07:43:20 am
From an old transistor television I recovered this transformer

220v / 15v

secondary has a section of the wire of 0.035in (0.88mm)

I've seen transformers (PT) with the secondary winding

1) wrapped on the primary

2) wrapped (in a separate neck) near the primary

and OT

3) primary and secondary wrapped alternating each other


this transformer is of the first family but has a big difference

between primary and secondary there are at least 6 mm of free space, only air there (and something that I think is as to control overheat)

Have you never seen something like that ?

which is the reason for that unusual way to wrap windings ?

there are particular advantages to do that ?

If there are advantages why we don't see often this architecture ?

Thanks

Kagliostro

Title: Re: A strange Transformer ???
Post by: PRR on December 11, 2010, 06:54:21 pm
Somebody was REALLY worried about primary to secondary shorts.

Did not want the TV chassis to EVER be directly connected to the wall-power.

If it was 2V-6V it might be for the 20,000 volt end of the CRT or the HV rectifier. But it's too big, 15V is unlikely, and CRT/HV heat was usually a few turns on the horizontal scan transformer.

Unless there is some unusual situation or law, this construction is just expensive.
Title: Re: A strange Transformer ???
Post by: Tiny_Daddy on December 11, 2010, 08:10:55 pm
Maybe it was designed for short periods of high current, with forced air cooling. Not enough voltage for arc welding though.... Auto battery charger?
Title: Re: A strange Transformer ???
Post by: kagliostro on December 12, 2010, 02:11:38 am
Thanks PRR & Tiny_Daddy

those was a little, "transportable" television but there were no batteries

so

Quote
Did not want the TV chassis to EVER be directly connected to the wall-power.

that is the answer

Kagliostro