What is this electronic component?

[sams93]

I use a dehumidifier at times to keep the workshop/shed moisture down. Recently my one broke and i'm reluctant to just throw it. I have taken the thing to pieces and the most obviously looking poorly component is this. I think it is some kind of transformer or a choke?

I notice one is also present on this circuit board I found here although I really would like to just buy the component but would need to know what i'm looking for.

The numbers on the top are U1570, but a google search doesn't reveal anything much useful.

I am hoping someone on here can help!

 

[Sachakins]

Looks like a standard capacitor.
Try here
https://uk.rs-online.com/web/c/?searchTerm=capacitor+u1570

 

[sams93]

Sorry, I am talking about the two copper coils with a green magnet in. The capacitor cover is torn but it seems fine,

 

[sams93]

OK I think i've found it, but the minimum order is 200....

https://www.alibaba.com/product-detail/Kool-Mu-Toroids-77254A7-77438A7-77089A7_60794137677.html

Alternatively I could order whatever this is for £5 off ebay, which looks like it has two of what I want on, and then remove them & solder into my board.

 

[Sachakins]

Ferrite core wound inductors
Like these
https://uk.rs-online.com/web/p/leaded-inductors/1223282?gb=s

 

[Spectric]

There must be a reason they are on the same core, the coils will be magnetically coupled and it is not toroidal wound as they use a doughnut core . Could you not re-solder that broken turn .

 

[Sachakins]

Another good source for electronics is Mouser
Eg
https://www.mouser.co.uk/c/i/passiv...ode-chokes-filters/?termination style=SMD/SMT

 

[XTiffy]

On YouTube there is a contributor who loves to breakdown electronic circuitry and reverse engineer. bigclicedotcom. See if you can contact him. Very interesting channel and he knows his stuff.

 

[porker]

Looks like a switch mode power supply. If that is all it is, it might be cheaper to replace the whole board if you know the voltage and current requirement. The electrolytic capacitor next to the inductor looks damaged as well.

 

[porker]

I am wondering what made the inductor fail. Often the switching part of the circuit fails which breaks something else. I would check the primary of the transformer to ground for a short circuit as I suspect the switching FET on the high voltage DC side could be shorted.

 

[sams93]

There must be a reason they are on the same core, the coils will be magnetically coupled and it is not toroidal wound as they use a doughnut core . Could you not re-solder that broken turn .

I could do, but I assume the coil is made of insulated copper so i think I’d risk compromising the whole coil.

Also i don’t know if you can see but the reason the coil broke appears to be corrosion, there is blue/green copper oxidation which looks like it’s eaten the top few layers of the coil. If you look elsewhere on the coil there is more. I wonder if that makes it non-repairable.

Looks like a switch mode power supply. If that is all it is, it might be cheaper to replace the whole board if you know the voltage and current requirement. The electrolytic capacitor next to the inductor looks damaged as well.

The capacitor damage is just me being
Inaccurate with a screwdriver, I have just torn the heat shrink plastic covering. In principle I would be prepared to replace the board I could have a look.

I am wondering what made the inductor fail. Often the switching part of the circuit fails which breaks something else. I would check the primary of the transformer to ground for a short circuit as I suspect the switching FET on the high voltage DC side could be shorted.

I am wondering if it was caused by the corrosion visible on the coil (photo in this post above) I will check the components you mention as best I can though.

Thanks

 

[Sideways]

It looks like an common mode interference suppression choke (inductor) but could be a differential version.

Read this.
https://www.coilcraft.com/en-us/edu/series/a-guide-to-understanding-common-mode-chokes/

These are absolutely common in switching type power circuitry but the windings made of flattened copper are a bit unusual. They should give it a proportionally high current capcity and pack more turns onto a small component for higher inductance.

Reverse engineering the component to find a substitute may be possible if you like physics and are willing to do the research to understand it and figure it out. Inductance is a function of the physical parameters of a coil, so number of turns, proportions, the core material etc. But my guess is a substitute will be quite different in size and won't fit on the board.

I was going to say fix it but enamelled copper that shows clear signs of corrosion is on the way out even if it weren't broken. Time for a new PCB.

 

[MorrisWoodman12]

I second @Sideways it is a Radial Leaded Common Mode Chokes / Filter. Farnell has over 2000 listed but it's going to be an almost impossible job finding that particular one assuming it isn't one made for that particular design.
Whereabouts in East Sussex are you? I'm just outside Uckfield.
All the best
Martin

 

[SammyQ]

On YouTube there is a contributor who loves to breakdown electronic circuitry and reverse engineer. bigclicedotcom. See if you can contact him. Very interesting channel and he knows his stuff.

Big Clive. He wires the Tattoo for Edinburgh Castle.

His youtube channel is one of the very few that is factual, objective and filmed from a 'face for radio' basis. The Big Monn keeps his midge filter exposure to a minimum, and concentrates on the hardware under scrutiny. Hilarious analyses with a serious point. He has pointed up some very bad - read "lethal" - gadgets released to make a profit from the unscrupulous, foisted on the unaware.

 

[Spectric]

Those flat windings are unusual, it has to be more difficult to wind than std wire and why not just increase the wire gauge instead. If this device is on the incoming mains to the machine, then it's purpose would be to prevent noise spikes from passing back up into the distribution system and then to prove the point of failure you could remove this from the PCB and temporary just bypass to see if it the machine works but without seeing the PCB you would need to do a bit of circuit checking.

 

[MorrisWoodman12]

Those flat windings are unusual, it has to be more difficult to wind than std wire and why not just increase the wire gauge instead. If this device is on the incoming mains to the machine, then it's purpose would be to prevent noise spikes from passing back up into the distribution system and then to prove the point of failure you could remove this from the PCB and temporary just bypass to see if it the machine works but without seeing the PCB you would need to do a bit of circuit checking.

I cannot recommend your suggestion unless the OP knows what he is doing. Otherwise it could be lethal.

 

[Spectric]

but without seeing the PCB you would need to do a bit of circuit checking.

That is why I said he would need to check the circuit himself, if he could do that then he could proceed otherwise new board.

 

[sams93]

I second @Sideways it is a Radial Leaded Common Mode Chokes / Filter. Farnell has over 2000 listed but it's going to be an almost impossible job finding that particular one assuming it isn't one made for that particular design.
Whereabouts in East Sussex are you? I'm just outside Uckfield.
All the best
Martin

I'm fairly close to you, not far from lewes.

Having reviewed all 2400 of the chokes on farnell , I think that what I have might be this: https://uk.farnell.com/multicomp-pro/mpl2d-10-203/common-mode-choke-1a-20mh/dp/4264632

@Sideways I am going to measure my one and compare it with the data in the technical sheet for the one in the link. I'll also count my coils and compare too. Then like @Spectric suggests I will have a look and check whether I can bypass it to confirm this is the faulty component and go from there...

 

[Sideways]

That does look like it - well spotted.
Does a 1 amp rating sound consistent with the power of your dehumidifier ?
240 - 250 Watts ?

 

[sams93]

It's a 40w unit, photos of board attached too. The component is on the input side of the PCB which was a point you raised earlier about it's purpose.