How do I know what type of transformer I have?

2 May 2021
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United Kingdom
Apologies if this is a dumb question!

I need a new dimmer switch, and figured I may as well upgrade to one that's compatible with LED bulbs (the previous dimmer was used with halogen bulbs).

The Varilight V-Pro JQP401W seems to have good reviews. However, when checking the specifications I noticed it's not suitable for use with 'wire-wound or toroidal transformers'. I'm not sure whether I have one of these.

I've been doing some googling to see how I can find out, but I've not found anything useful, probably because I'm not even 100% sure if I have a transformer or what exactly it's for in this case.

Would anyone be able to help me out please? The switch looks perfect in every other respect; I just want to make sure I don't burn my house down by using it with the wrong transformer!
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I may be wrong, but I suspect, from what has been said in the other thread, that what the OP currently has IS a "230V light", with no 'transformer' of any sort.

Yep, it's a regular ceiling light with a single regular 100w halogen bulb hanging down (i.e. not a mini spotlight). I'm not sure what the voltage is as it doesn't say on the bulb and I was daft enough not to keep the box! Is this likely to be a 230v light? And is there a way I can test this?

Also, it sounds like from what you're saying that not all lights actually need a transformer so I may not even have one; is this correct? And if so, does this mean I'd need to install one to use a dimmable LED bulb instead of halogen?

I don't see any sort of little box on the bulb or light that might be a transformer, but I also don't know what's inside the light or hidden in the ceiling.

I'm not trying to do anything fancy with multiple bulbs or little spotlights; I just want to be able to swap the current bulb for an LED equivalent and have it work with the new dimmer in a way that's safe! :)
Remove the lamp and take a pic of the contact end of the lamp, and of the socket that the lamp connects to.
Post the pics on here.
Remove the lamp and take a pic of the contact end of the lamp, and of the socket that the lamp connects to.
Post the pics on here.

Here you go. I've also just noticed that on the glass end of the bulb it says "220-240v 100w". Does this mean I'm good to go?


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