Can anyone identify this component

[Michael Etherton]

The photo of the item attached is a component of my old CIG mig welder which yesterday burnt out. Can someone please advise what you would call this component and where I may be able to source a replacement to match the correct specifications. I assume it is a 240V AC transformer?, converting to 24V AC with an output of 1.25 AMPS??? It also has 4 terminals on the output side, I am not sure why. Any help would be greatly appreciated. ( Trying to get the part direct from CIG seems to be way too hard for them!)

 

[Harald Kapp]

Looks like a transformer. See this website.
240 V in, 2*24 V out

[Edit] Unfortunately this exact model PL48/60VA doesn't seem to be available there.

[Edit] Possibly any transformer with dual 24 V output rated at 1.25 A or more per output will work.

 

[Michael Etherton]

Thanks Harold, that is what I found also, that model PL48, not in catalogue. I am wondering if you can direct me to a website that sells similar transformers but of any manufactory's make?

 

[Bluejets]

dual 24v 30w on Ebay...maybe parallel 2 if you need more current.

https://www.ebay.com.au/itm/Power-T...hash=item33c5836ab0:m:mbZKABbkuQ7K34hXt7fG2LA

Edit...just checked on both RSComponents and Farnell (Elements14) Both have torroid 2 x 24v 60va.
Rather costly though.(around Aus$75)

 

[(*steve*)]

Aaah, the good old Ferguson transformer.

Somebody left a number of new old transformers at my local hackerspace. I'm pretty sure there was one very similar to this.

I'll see if it's still there.

What state are you in?

 

[Michael Etherton]

Thanks Bluejets, it is a great old welder so the cost ($75) would be worth it. I am not great with electronics but I assume I am looking for 24v output with no greater than 1.25 amps. The ebay item quotes 30W output and I think that would convert to about 1.25 amps. Am I correct?

 

[Michael Etherton]

Thanks Steve that is very kind of you. I am in Victoria.

 

[Bluejets]

Thanks Bluejets, it is a great old welder so the cost ($75) would be worth it. I am not great with electronics but I assume I am looking for 24v output with no greater than 1.25 amps. The ebay item quotes 30W output and I think that would convert to about 1.25 amps. Am I correct?

you need 2 x 24v outputs.....the transformer is basically a 48v output split into 2 via a centre-tap. Hence 24-0-24
Still it depends on what it drives in your welder.

So, 24v + 24v ( 2 windings) * 1.25A = 60VA.or as some places say (w)

When I showed the transformer from Ebay, 30w (30va) it was the highest they have so if you need 60va then you can put 2 of these in parallel. Just have to watch the connections are correct.

Other alternative was as I mentioned from Elements 14 or RSComponents which is just the one transformer @$75 odd.

Hope that makes it a bit clearer. Cheers ...Jorgo
I assume that the makers of the welder would have used what was required .ie 2 * 24v output.

 

[(*steve*)]

you need 2 x 24v outputs.....the transformer is basically a 48v output split into 2 via a centre-tap. Hence 24-0-24

These transformers have 2 separate windings that may be used in parallel, series, or independently.

Unless you know for sure, or can check (and it's not that hard) it is best to replace with a transformer with 2 separate windings.

 

[(*steve*)]

Thanks Steve that is very kind of you. I am in Victoria.

The initial indication I've been given is that the one we have left may be 16V rather than 24V, but someone is going to check for me.

I'll get back to you.

 

[Michael Etherton]

Have sourced this one (see photo). Will this tiny little one replace the old Ferguson one that weighed half a ton? The specs look OK to me but when I contacted "Element 14" they said they would not recommend it as a replacement without saying why. It still looks like my best alternative, especially @ $25.

 

[Harald Kapp]

Looks a perfect match.

 

[Bluejets]

$25.00 ....good find.

 

[(*steve*)]

It will probably weigh about the same

Assuming that there's room to fit it, it seems good.

Depending on how the original transformer was used, you may have to be careful with the phasing of the windings.

Also consider that transformers are very rugged devices that can handle significant short term overloads. Transformers don't fail by themselves, do you know what caused the previous one to fail?

 

[Bluejets]

do you know what caused the previous one to fail?

By the look of it in the photo, probably combination of rust, corrosion, bit of moisture blowing the primary open....?

 

[Michael Etherton]

Yes old transformer was showing it's age, it may have had a bit of oil run in behind it. It has an inline fuse to its 240v input side (yellow/blue). I have attached a photo of the circuit board it provides 24v power to. Should I wire in the new transformer treating the brown wires as one (neg / pos) circuit and the other output to the reds (appears to be nothing to distinguish which is neg and which is pos!) wires?

 

[(*steve*)]

Are either of the red wires connected to either of the brown wires?

On the original transformer, if the wires remain in approximately the same position, the two red wires connect to one winding, the two brown ones to the other.

If neither of the red wires connect to either of the brown wires, the connection of the windings from the toroidal transformer probably don't matter a great deal.

On the old transformer, the connections go start, end, start, end. The new transformer will indicate this somehow. Try to match it.

 

[Bluejets]

If you look in the spec sheet, they show details of the toroid.
The "dot" near each winding shows the way the windings relate to each other.
This is important in the primary in this case as you will be using both windings in series for your 240v.

So primary side, connect one incoming 240v line to say the brown wire.
The Violet and Grey will connect to each other and insulate in a separate connector.
The Neutral of the 240v supply then goes Blue wire.

Of the secondary, Orange and Yellow can connect to say the original Brown pair, and the remaining Red and Black connect to the Red pair. No difference which way around.

Now a word of caution here as the secondary two sets of cables MAY be connected to form a split supply within the welder.

Under normal circumstances, if this were the case, they would bring out just 3 wires, but check anyhow.

Check with a multimeter set to low ohms scale, for any connection between the welder cables Brown and Red.

Oh, by the way, it also shows the weight at 0.8Kg so not "small" by any means.

 

[(*steve*)]

Of the secondary, Orange and Yellow can connect to say the original Brown pair, and the remaining Red and Black connect to the Red pair. No difference which way around

It will make a difference if either of the existing brown wires is common with either of the existing red wires.

 

[Bluejets]

It will make a difference if either of the existing brown wires is common with either of the existing red wires.

I believe I already covered that...

Now a word of caution here as the secondary two sets of cables MAY be connected to form a split supply within the welder.

Under normal circumstances, if this were the case, they would bring out just 3 wires, but check anyhow.

Check with a multimeter set to low ohms scale, for any connection between the welder cables Brown and Red.