Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: kagliostro on December 26, 2012, 05:29:30 pm

Title: PT question
Post by: kagliostro on December 26, 2012, 05:29:30 pm

If a transformer has two identical voltage and current windings

is correct to assume that it can be used as a CT transformer ?

see this one as an example

http://www.antekinc.com/details.php?p=730 (http://www.antekinc.com/details.php?p=730)

I think this can be done, on the contrary a CT transformer can't be used as a two separate windings transformer, correct ??

Thanks

K

Title: Re: PT question
Post by: sluckey on December 26, 2012, 05:38:01 pm

Quote

If a transformer has two identical voltage and current windings is correct to assume that it can be used as a CT transformer ?

Yes, but phasing is important. Hook it up wrong and you'll have zero volts end to end rather than twice the voltage end to end.

Title: Re: PT question
Post by: kagliostro on December 26, 2012, 05:43:41 pm

Thanks Steve

and is correct that a CT transformer can't be used as a double winding transformer ?

in other words, having a CT transformer is or is not possible to use two different diode bridges to rectify each single branch independently ?

Thanks

Franco

Title: Re: PT question
Post by: PRR on December 27, 2012, 05:50:52 pm

Not.

Title: Re: PT question
Post by: drgonzonm on December 28, 2012, 01:11:41 pm

My two cents.
Provide a schematic of what you are proposing. 
Also, do you have the model number of the p/t you are proposing? 

(I just can't get out of my mind polyphase applications).  My question, is how much different is K asking if I were to put bridge rectifiers on the two 120 legs of power going into my house, as that transformer feeding the house is a 120-0-120, (240 volts between legs)  (USA) If I live in an apartment, I could conceivably have 120-0-120 and 208 between legs.   

My brain is in broken mode.  After reviewing getting 12 phases out of a three phase input,  (y-input, delta and y-outputs)

Title: Re: PT question
Post by: kagliostro on December 28, 2012, 06:34:48 pm

I was thinking to some absurd rectify like this

K

Title: Re: PT question
Post by: drgonzonm on January 03, 2013, 01:18:12 pm

I with the center tap, only two diodes are needed.  Only reason for adding diodes in a series is to increase the voltage rating. 

Title: Re: PT question
Post by: PRR on January 03, 2013, 11:04:51 pm

In all three plans, half the diodes stay reverse-biased all the time. Useless.

Title: Re: PT question
Post by: kagliostro on January 04, 2013, 02:44:37 am

Quote

Useless

For sure, they are absurd

K