Saturday, October 16, 2010

Retrofit a lab lamp with LED

During my last visit in Dallas I went to Ikea and I bough a nice lab lamp, ideal to be converted as LED lamp.
I choose to put the power supply outside the lamp, in a small box because it's dimensions were too big to be fitted in the lamp body.
The 10W warm white LED was glued to a heat-sink and mounted over an old fluorescent lamp base, after removing the fluorescent lamp and it's electronic of course.
The glue used, a thermal compound, was supposed to be very strong, however after a couple of months of use, it lost the grip and the LED detached from the heat-sink.
That caused  the LED to become VERY hot, melting in part the power supply cable, causing a very strong and uncomfortable smell.
I had to rebuild the LED attachment, this time drilling the heat-sink.

After removing the old glue from the heat-sink and the LED base, I placed a new coat of thermal glue and then screwed the LED to the heat-sink.
I also used a different kind of wires, supposedly more heat resistant than the previous ones.

Since the power supply is outside the lamp,  the lamp socket is not carrying anymore the 110V.
I decided to don't modify the mechanic of the lamp, so the original rotating switch is still in place but not used (switch left always in the ON position).

The new switch for the lamp is on the power supply box.
Here some pictures and notes :
The lab lamp working (a Red Roomba is under maintenance :-) )
Note the small black box containing the LED power supply close to the soldering iron.
The 10W LED glued to the heat-sink.
This picture was taken  the first time I built the lamp.
After a while the heat caused the LED to be detached from the heat-sink.
The black/red wire I used started to melt too, causing a very bad and strong smell. Not good at all !
The new assembly.
Now the LED is glued AND screwed to the heat-sink and I used a more heat resistant wires.

This lamp is perfect to work in the electronic lab, on the main desk.
I recommend to use a warm white LED, not a clear white one.
This LED provides around 560 Lumen concentrated on a small area.

No comments:

Post a Comment