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Led downlight transformer converting to a battery charger/power supply? Answered

I know everyone will just say make the Ible and be done with it, but...

I got a bunch of 11.5V LED downlight transformers, 35-105W.
Upon inspection I realised their design is dirt simple but quite effective.
Switchmode for the beginners so to say LOL
The pros:
Changing the output voltage is as simple as adding or removing windings from the output transformer.
In my first test I was able to go up to 20V with no problems by adding a few turns and down to 5V by replacing the secondary with far less but thicker windings - impressive 12A until my windings started to produce smoke LOL
Only imple parts, no microcontroller or other complicated stuff like opto couplers...
The big con:
These transformers are about 20 years old, so I would say first or second generation of LED transformers.
That means I have no clue if something very similar or even identical can still be bought in shops or online.
And what is the point of an Ible that noone can do because the main ingredient is nowhere to be found?

I can take some pics of the circuit board later on for comparison but it would be great if some people with LED downlight transformers could provide some pics too.
If it turns out other transformers are still in the same simple design I would like to use all provided for an Instructable.
Credits for the pics will be left if you want or simply add your username to the pic as a watermark or such.



9 months ago

I'm not familiar with the term downlight ?

Could that be a term be meant for outside overhead LED lighting ?

Not just outside.
You the times where everyone was keen on these halogen lights?
Just a tiny ring in the ceiling to hold a 20-100W spot light.
The LED lights are a direct replacement for these and the transformer is to provide them with the 12V instead of mains power what the old lights used.
Just do a Google search for

led downlight transformer
and you see lots of examples for the lights and transformers used.

Wow, a whole sector unknown to me, low voltage LED ceiling lights..

They all seem to use switching transformers but as I understand you are looking for standard EI transformers with simple constant current regulator to drive the assorted LEDs, yes ?

Nope, interest in pics of the circuit boards used, both sides preferably.
Since mine are really old I would like to know if current (cheap models) still are as simple.
And of course I don't want to buy them with 20+ working ones around LOL
End goal would be to create an Ible showing how to use these things for other purposes - cheap and beefy power supplies for example.

Got it now.. Will look into some old storage at a friend's warehouse..