Transformer terminal ID help. D:

[LukeeeeBennett]

So, recently my Line 6 POD X3 Live Guitar effects pedals power adapter got a bit worn and the wire on the output side of the transformer snapped. Instead of paying for a new one I thought that I'd just clip the wire and re-wire onto the transformer.

However, whilst doing so, I did my usual not thinking things through and didn't take note of which wire was connected to which terminal of the transformer. So now I'm in a muddle and have heard scary things about transformers so don't really want to continue to experiment or even plug it in.

Does anyone know how to identify the positive and negative terminals of a transformer or know a way to find out? I have some pictures below.

**broken link removed**
The side I need to connect


**broken link removed**
The power input side



**broken link removed**
General view




**broken link removed**
Another general view

 

[crutschow]

Transformers have no positive and negative polarity although they can have phasing (0 or 180 degrees) which can be important for transformers with multiple windings. If it just has two wires from the mains and two output wires than the order of the wiring makes no difference.

 

[carbonzit]

I won't make fun of you, even though this is a total newbie question.

The good news is, it doesn't matter! There is no positive or negative on a transformer, since it's AC, which doesn't have positive and negative as such. So use either one.

Disclaimer: As some who want to pick a nit will point out, transformers actually do have polarity. That's why you sometimes see a dot on schematics indicating the top or bottom end of a winding. However, this only matters in circuits where the phase difference is relevant. It is not here.

 

[LukeeeeBennett]

Wow! Thanks a lot. So speedy as well.

Yeah, that's urmm... Embarrassing.

Thanks A LOT though. I may get this done in time.

 

[carbonzit]

Yeah, that's urmm... Embarrassing.

Please don't say that. Really.

The only truly dumb question is the one you should have asked but didn't ...

 

[LukeeeeBennett]

Thanks for the help.

I just did and still getting no power. But, it gave me confidence to use my multimeter next to it and I'm reading 245V on the input side and 0V on the output so I'm guessing I shorted out the Secondary coil when the wires got worn out and crossed over?

 

[carbonzit]

Yes, one side or the other of the transformer has an open (burned wire) in it. Probably the primary (high-voltage) side.

If you want to check, use your multimeter on its resistance (ohms) setting to check the primary side. With the transformer unplugged, place the meter probes across the plug prongs. You should get some non-zero reading. If it's zero, the transformer's fried.

Some transformers have built-in fuses, in which case the fuse could be blown. It might be hidden under the tape, though. They're not really meant to be replaced; if they go, you usually need to replace the transformer (though I have replaced them, being a cheapskate).

Fortunately, transformers are easy to come by in today's world. Let us know your progress.

 

[LukeeeeBennett]

Yep. You're spot on. 0 Ohm reading and no continuity reading either.

Well, at least I'll only have to buy a new supply and not a whole new pedal board.

 

[Boncuk]

If you want to check, use your multimeter on its resistance (ohms) setting to check the primary side. With the transformer unplugged, place the meter probes across the plug prongs. You should get some non-zero reading. If it's zero, the transformer's fried.

I guess I learned something new today.

Till now I checked transformers the same way.

If the resistance was ∞ or had an extremely low resistance the transformer was fried.

With the primary winding having a few 100Ω (or KΩ, depending on rated power) I knew the winding was OK.

The same method worked for the secondary winding with much less resistance.

Boncuk

 

[carbonzit]

Sorry, my bad: I should have said "You should get some non-infinite reading." Good catch.

 

[LukeeeeBennett]

Thanks again guys. You've re-ignited my electrical fire and I'm ordering various components for my next build and lesson now. ^^
My physics teacher would be proud. :')

 

[KeepItSimpleStupid]

Bear in mind, in your study of electronics, MAGIC SMOKE is very precious. It should never be let out of components. Once the smoke is gon, the component doesn't work. Be warned.

 

[LukeeeeBennett]

LOLOL. I'll keep that in mind.

 

[Boncuk]

Errare humanum est.

 

[LukeeeeBennett]

Indeed. ^^