(Antek) Transformer Wiring: Series/Parallel?

[ncoak]

Greetings folks,

I'm building a G-Pultec, utilizing 2 Antek transformers...110:12V and 110:6.3V (I'm in the US). As of now I'm blowing the PCB fuse (250v/4AT as recommended) every time I fire it up, leading me to believe I've got some sort of fundamental misunderstanding with regards to the wiring of the transformers.

The color coding is a little different on these guys, primaries are red/black red/black, secondaries are blue/green blue/green.

The schematic supplied looks like this:

Red          \          /      Green
Black  115v/          \ 12v Blue
Red          \          /      Green
Black  115v/          \ 12v Blue

http://www.antekinc.com/pdf/AN-0212.pdf

My two questions are:

What is the correct configuration with these wires to achieve parallel and series?

How exactly can I test to ensure that I've got things wired up correctly?

I've done a ton a reading on the subject and all the descriptions of the testing process I've come across are extremely vague - I don't want to fry myself! If someone could give me a step by step explanation of how to proceed here (or point me to a reliable resource online on the subject) I'd be eternally grateful.

Thanks in advance.

 

[bezen4uk]

Hi,
there is a picture:

 

[gemini86]

you're trying to run the 12vac into the secondary of the 6vac transformer, correct? That doesn't work. The low impedance of the second transformer's 6v winding will cause the first transformer to overheat/blow fuses.

 

[ncoak]

@ bezen4uk: perfect, just what i was looking for. thanks!

@ gemini86: right - i've seen this mentioned here and there, but the overlay files on the gyraf site specify 12v & 6v trafos and others claim to have been successful with it...did you experience that with your own build? guess i'll give it a shot and if all else fails i'll just use another 12v one. thanks for the heads up.

 

[gemini86]

yes I had this problem, but I was just prototyping a circuit and had not installed a fuse yet, the first transformer generated a lot of heat and the output on the final HV side was very low, almost half what it should have been.

 

[ncoak]

ok thanks. i had noticed some transformer hum in the second or two preceding the fuse blowing, which others had mentioned as a symptom of an overloaded toroid. i'll try to figure things out today and post the results.

 

[ncoak]

got it all squared away; even with utilizing the above diagram (which confirmed the way i was thinking about it - wasn't quite as clueless as i thought ;D) i wasn't able to make the 12v/6v configuration work - popped a few more fuses before i swapped the 6v out for another 12v.

presto - 236v right off the bat, perfect. thanks a ton for the help!

 

[kazper]

Glad you got it figured out.

I can't remember if I posted /PM you about the 12V/6V issue. I know I had looked at the schematics while I was in Florida about it. but not sure if I pointed it out. Our conversation could have steered you wrong because I used the same type of transformers, just a less rated VA for T2.  Simply put to use an 6V T2 would be a wiring change from my 12V T2. Series with a 6V and parallel with a 12V.

 

[ncoak]

right! i realized that was probably what was up - even switching to series with the 6v it was humming loudly (briefly) and popping the fuse - went through a bunch of them trying to figure it out before popping the 12v in there.

thanks to everybody for the help, got a much better understanding of things!