Converting machine light to LED

Hi All

I bought a little centec mill recently and have been working on it, see other post. It came with what was originally a very good quality 32volt machine light which had been rewired to 240volt, not I think a great idea. This is the light as I got it with the 32volt Rowco transformer. I wanted to modify it to 12volt and reinstate it.

Attachment 326187

I paid a visit to the green shed and came away with this. A 12volt downlight kit with a transformer and a socket, it also included a 35watt halogen bulb that I wont use. I also bought a 7w LED bulb that I thought would fit the socket. It actually didn't fit the outer shell but did fit the socket itself.


Attachment 326193

My original idea was to modify the whole downlight socket to fit in the original lampshade. This proved to be difficult and unnecessary and what i ended up doing was modifying the inside of the original light to mount the small white socket that takes the LED bulb.

Here you can see the original bayonet fix core of the light with the socket for the LED mounted to it. The original core has been cut shorter at both ends and the brass ring that held the bulb has been prized off. The screws that hold the LED socket fitted through the original holes for the bulb contact pins. I drilled the original wiring posts to use as spacers under the new screws. One has been done in this picture.

Attachment 326194

The original bulb carrier, with the new socket attached then screwed back into the original top fitting.
Attachment 326195


This is the top fitting with the bulb installed and the shade back on.

Attachment 326196


This is the whole thing reassembled, the transformer is sitting on the back of the vise. It is under a skylight here but you can get some idea of the pool of light that it throws. I think that it will be really good on the machine. The LED is literally cool, I can't discern any temperature rise at all. When I reinstate it I will tuck the transformer up under the base of the mill.

Attachment 326198

This proved to be one of those rare jobs that was easier and quicker to do than I thought!

Regards

Ian




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Looks good TN. :2tsup:

Your adaptation is pretty similar to one I did a few months ago when Anorak Bob gave me a 50W Halogen machine lamp which I found a bit too hot so I modified it to take a 9W CREE LED.

https://www.woodworkforums.com/attach...d=326244&stc=1
The CREE LED globe cost $30 and is a direct electrical replacement for a 50 W halogen lamp, i.e. uses the same transformer.
Unfortunately it’s not a physical fit replacement so I had to ditch the original globe fitting and open up the Al lamp reflector with a pair of scissors
If the hole its cut accurately the LED will clip nicely into the hole.

The main problem is the LED globe is much taller than the original so to get it under the glass it pokes further back into the lamp housing so I had to move the switch from the back to the side of the lamp housing.
The switch at the back is also just a touch too big to fit neatly between the lamp fins on the side of the housing so I milled part of the fins away.
While doing so the housing came out of the chuck and pulled my thumb against the bit and it took just enough skin off to make it bleed like a stuck pig,
Within a minute the whole lamp was spotted red, Hence evidence of some residual claret under the HOT sign!


https://www.woodworkforums.com/attach...d=326242&stc=1
https://www.woodworkforums.com/attach...d=326246&stc=1

I was going to attach it to a machine but I think it will be more useful in a mobile format so I attached it to a 300 x 16 mm piece of scrap steel plate.
The base is high;y agricultural but effective, I decide to leave it as is - even the start blow hole from the laser cutter.
Also more evidence of claret or the silver part of the lamp base
.
https://www.woodworkforums.com/attach...d=326241&stc=1
https://www.woodworkforums.com/attach...d=326243&stc=1
https://www.woodworkforums.com/attach...d=326245&stc=1

Bob, where did you get that Cree downlight and what is it?

I have plenty of possum transformers but they won't run any of the LED's I have tried them with as they need 25 watts or similar to trigger them and they are AC so even when I connected multiple LEDS to one to get enough current draw they went on then off and that was it. The LED's needed DC drivers and wouldn't work on the AC possums. Long story short I had to get a LED driver to drive the downlights I had bought for my kitchen. But I would like to find some good LED globes that will work on the possums so I can make use of them.

Quote:

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Originally Posted by Burnsy

Bob, where did you get that Cree downlight and what is it?

I have plenty of possum transformers but they won't run any of the LED's I have tried them with as they need 25 watts or similar to trigger them and they are AC so even when I connected multiple LEDS to one to get enough current draw they went on then off and that was it. The LED's needed DC drivers and wouldn't work on the AC possums. Long story short I had to get a LED driver to drive the downlights I had bought for my kitchen. But I would like to find some good LED globes that will work on the possums so I can make use of them.

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I got it on special from Altronics about a year ago .
I though it was a CREE but I no realise I'm getting it confused with several others I have. Ut is similar to this one. http://www.altronics.com.au/p/x2292-...d-light-globe/
I see the price is now even cheaper than when it was on special.

I've had it for 3 months and it used to turn on first go every time but I notice now it does not always turn on first time and it occasionally requires another flick of the switch to start. The instructions said it would work with any Halogen transformer but I wonder if that problem might be the transformer.

Interesting, by all my reading it should not work with a possum, 8 watts and DC. However some further reading shows that since my fiddling with this a few years ago some LED lights now have bridge rectifiers fitted to allow them to run off AC transformers. Back when I initially looked into LED's for home many people were espousing the virtues of the redback transformers. It seems looking at the ocilloscope wave forms from the testing linked below they should give the least flicker, they are still however AC output and have an operating range of 20 to 60 watt. I thought this meant they would not switch on without having a lamp connected that draws at least 20 watt. This belief I see is wrong as these guys have them operating with a 7 watt led. It seems the LED's I trialled were just all cheaper units with no bridge rectifiers. I might just try some of these newer technology units, the 10 watt Philips Master looks like it would likely through a nice light but is probably very expensive compared to the ones you linked to.

http://www.ledbenchmark.com/faq/Tran...atibility.html

Basic rule of thumb is if it is an iron core tranny (heavy and larger normally) it will run an LED. A switchmode driver (lighter and smaller) on the other hand needs a certain draw to make it start so it will not run a small LED. Every MR16 LED i have tried has had a bridge rectifier and current limiting device built in so it can take AC as long as it is around the right voltage. LED's without built in current limiting need there own driver.
MR16 however seems to be a poor package for an LED and you won't see really high output in them unless they have some form of active cooling.

Cheers,
Ew

Thanks Bob, I am impressed with both the light and your willingness to bleed for your craft!

There is way more information about LEDs and transformers now in this thread that I ever knew...

I take it from Uee's post that what I have is a switchmode driver and that I may have trouble with it and the low wattage LED in due course? I can certainly find an old heavy transformer at need.

Regards

Ian

Hi All

A small addendum for the benefit of anyone else who might think of doing this.

When I went to reinstall the light on the machine today I found that the LED bulb wasn't as well held by the socket as I might have liked.
Fortunately the holes around the LED bulb lend themselves to the addition of a couple of retaining wires.
You can just see them in this photo.

.Attachment 328809

Regards

Ian