Transformer connection ,Confused and unsure. - Page 1
Forum section: electronics / testgear

author: sampler1
author_rank: Regular Contributor
timestamp: March 26, 2022, 01:25:02 am
content: Building a leakage tester.I purchased a transformer and before I make a mistake and fry it ,I was hoping someone could clarify the connection for me.I need to connect it to 115Volts and I need the highest AC out put possible. I am quite sure its good for 50ma.This is how the add was marked:" alt="" class="bbc_img" />I think I need to use 115V Blue and Brown250V Black and Yellow.Thanks

author: purpose
author_rank: Frequent Contributor
timestamp: March 26, 2022, 01:32:54 am
content: If you run the 250V secondaries in series Yellow to Violet, then 500V should magically appear at Black and Grey.P.S. Run the primaries in parallel. Red/Blue and Yell/Brown. Being careful not to use the secondary Blue.

author: AVGresponding
author_rank: Super Contributor
timestamp: March 26, 2022, 01:26:34 pm
content: Quote from: purpose on March 26, 2022, 01:32:54 amThe picture quality is terrible, but I see no yellow/brown primary, but I do see a yellow/green screen. It looks like the second primary is blue, brown. Very confusing colour scheme overall.

author: tooki
author_rank: Super Contributor
timestamp: March 26, 2022, 01:40:53 pm
content: Quote from: AVGresponding on March 26, 2022, 01:26:34 pmHe means to join the red wire and blue wire for the neutral and join the yellow wire and brown wire for the line.

author: AVGresponding
author_rank: Super Contributor
timestamp: March 26, 2022, 01:53:46 pm
content: Quote from: tooki on March 26, 2022, 01:40:53 pmAh yes, I see it. Still, I stand by my statement about the colours being confusing overall.

author: tooki
author_rank: Super Contributor
timestamp: March 26, 2022, 02:03:37 pm
content: What’s confusing about it??

author: AVGresponding
author_rank: Super Contributor
timestamp: March 26, 2022, 05:30:25 pm
content: Quote from: tooki on March 26, 2022, 02:03:37 pmYou have three blue wires and two yellow, not to mention that in the US, black would normally be phase, white neutral, and green earth. In the EU, brown is phase 1, black is phase 2, grey is phase 3, and blue neutral. Oh, and in the UK old colours (still prevalent in many installations and equipment) would be red for phase 1, black for neutral, blue for phase 2 and yellow for phase 3. EU and UK both use green+yellow for earth.Frankly it would be better to have all white wires and number them.

author: tooki
author_rank: Super Contributor
timestamp: March 26, 2022, 09:37:33 pm
content: Quote from: AVGresponding on March 26, 2022, 05:30:25 pmYou haven’t spent much time with toroidal transformers, have you? It’s not uncommon on those to have secondaries whose outputs are the same color. They’re clearly designed to be used independently and never connected to the other secondary.The reuse of colors between primary and secondary poses no problem at all: they likely emerge from different areas of the transformer, and will be of different thickness. Easy to tell apart.The transformer in the picture is not a toroidal but an R-core transformer, which is typically used for high end audio due to its favorable EMI characteristics. (The downside is the high cost, since it’s a much more complex winding process.) But like a toroidal transformer, these generally use flying leads rather than solder lugs or pins like EI-core transformers.Regardless, transformers don’t have to use the same color codes as mains wiring anyway. If this transformer is enough to confuse you, then you should likely find a different hobby…

author: Jeff eelcr
author_rank: Frequent Contributor
timestamp: March 27, 2022, 03:38:32 am
content: Yellow/green-screen Ground or not connected.Jeff

author: AVGresponding
author_rank: Super Contributor
timestamp: March 27, 2022, 09:58:38 am
content: Quote from: tooki on March 26, 2022, 09:37:33 pmYes, your life coach skills are clearly great and I shall throw away my many qualifications and decades of experience and go join the circus.Seriously...The potential for confusion is there, and if I'd been handling the thing in person, I'd have had a good look at it and probably added some number/letter ferrules to reduce the ambiguity. Disambiguation is a word, and an important one in some areas.Quote from: Jeff eelcr on March 27, 2022, 03:38:32 amI'd connect it to earth ground. I shouldn't think your application cares about noise, but it's always a good idea to connect floating conductors to earth ground in a mains application.

author: sampler1
author_rank: Regular Contributor
timestamp: April 09, 2022, 09:21:29 pm
content: ROFL.This is actually so funny if you read it from top to bottom.. LOL.i was correct to start off with..Thanks all for more confusion.