Wot is this?

[Deigh]

I live in a bus converted to a motorhome. I did the re-building fourteen years ago and am still doing modifications. Recently I swopped all the 12v internal lights for LED ones to save power. It worked excellently except that some of them interfered with the radio reception. I did lots of experiments and eventually cleared the problem with the main one by installing a removed 'condenser' from a canibalised electronic circuit board.

I need to do the same with the other lights but I don't know what it is I have got. It is about 15mm wide and 2 to 3mm thick, blue in colour and has these markings
V14K 300 UE I
I took photos of it into my local electronic supplier but they couldn't identify it!!!

Does anyone know what I have got???

 

[Jagtech]

It is a varistor (MOV), used to protect devoces from voltage surges or overvoltage.

 

[KrisBlueNZ]

Yes, that is a metal oxide varistor, aka varistor or MOV. They are used for overvoltage protection, but they do also have some capacitance.

To suppress noise at the LED I would recommend a good quality ceramic capacitor of around 1 µF like this one: http://www.digikey.com/product-detail/en/FK14X7R1H105K/445-8310-ND/2815240

That is a non-polarised part (can be connected either way round).

 

[Deigh]

thanks for reply, I have purchased a couple of MOV from the supplier but at the moment all is working well without interference. Am waiting for things to change before experimenting. Difficult to explain but the interference is not always there and I cannot explain why not. I am on mains power when at home so the intelligent charger is in control and perhaps the thing gets in a s%$#@y mood sometimes and decides to upset me by upsetting my listening to jazz.

 

[Deigh]

It is a varistor (MOV), used to protect devoces from voltage surges or overvoltage.

Thanks for that.

 

[Deigh]

Troublesome to illustrate however the impedance is not generally there and I can't demonstrate why not

Thanks for that reply. My local supplier has only one size of varister in stock and I have purchased a couple of them and now waiting for the problem to arise again so I can experiment with a cure. The fault itself does not occur all the time and I am at a loss to find why not! Radio reception can be bad also for seemingly no reason. TV is only passably good so the only realistic reason is that it is mainly because I'm in a poor radio reception area.
Deigh