Electronics > Repair

About replacing SMPS or Battery Backup UPS transformers

(1/4) > >>

ThermallyFrigid:
Hello,

Today I have a dilemma.
I'm repairing an APC XS1500 Battery Backup.
The problem is that a capacitor leaked electrolyte and did some board damage but worst of all, it shorted an EE19 Class 130B transformer which has been rendered garbage because it shorted and burned inside.

The Transformer I need is an EE19 Class 130(B), 430-0601-Z, BCK-EE19-4699A.  Maybe you can shed light on obtaining one of these?
[attachimg=1]
This is the exact specs of the bobbin.  I contacted CoilTech and they replied immediately.  The minimum purchase is 5000 units.
And that is assuming I could successfully rewind the bobbin to OEM specs.  Ideally I could get 10 of them to experiment with rewinding.
[attachimg=2]

I'm wondering if you've run into a situation like this with a transformer?  what did you do?
How UNlikely is it to ever find a perfect match for an SMPS push pull or even flyback transformer that has burned out on a given board?
I mean, all it takes is a small change in wire diameter, number of turns etc to have a totally different transformer, even with the exact same bobbin, right?

I looked through Mouser and DigiKey but neither had anything close to a substitute / replacement.

What to do?

Thanks



ThermallyFrigid:
Well ok then.

What do you guys do when you need a transformer that isn't readily available?

Any sources?

Alex Wolf:

--- Quote from: ThermallyFrigid on October 15, 2021, 05:52:19 pm ---What do you guys do when you need a transformer that isn't readily available?

Any sources?

--- End quote ---

I know only 3 sources:
1) "recycling" (scavenging) from e-junk;
2) doing it by yourself from e-junk;
3) placing a small custom order in China.

For all of the above, you need to unwind the original transformer, count the number of turns in the windings, measure the diameter of their wires and calculate their cross-section, draw a diagram with respect to its terminals and winding layers, and write off the parameters of its core (although in this case there is a marking). However, it is possible to calculate a new design, there are not so strict requirements for work.

ThermallyFrigid:
Thank you.
This is what I suspected but was wanting affirmation.

Much appreciated Alex.

Does this forum do group buys where a number of people might go in on things like this?

Alex Wolf:

--- Quote from: ThermallyFrigid on October 16, 2021, 01:24:55 am ---Thank you.
This is what I suspected but was wanting affirmation.

Much appreciated Alex.

--- End quote ---

I'm glad to help.

And yeah, that's why they are so invaluable. Usually they don't fail, but when it does happen, the repair is not economically feasible as a rule with the very few exceptions. 😔 It's a small backup, just 1.5 kVA: so if you don't have 100 of them, I don't think it would be advisable to place a custom order for the transformer. It’s just cheaper to buy a new UPS. But maybe, just maybe, you can find a manufacturer on Alibaba/AliExpress and such, which will agree to accept your the very small order (usually from 10 pcs).

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version