Thursday, January 02, 2014
work light led retrofit
Now it is an LED light which uses only 10 watts and barely gets warm while throwing lots of light.
I have retrofitted the light to use two 10 watt warm white LEDs. The LEDs run at half their maximum power from a reclaimed printer power supply which now hangs underneath the light. The LEDs get DC from AC via the power supply. Not as bright as with the halogen bulb but plenty bright enough for most situations where it will be needed.
Because of the low power consumption and the low heat produced, I think it is much, much safer than before.
The cost of parts for my conversion was about $6 ($3 for the two LEDs on Ebay from China and about $3 for a used HP printer power supply at the local recycling center, also a bit of aluminum sheet and bar and a few tie wraps and screws, possibly another dollar?). It took a pleasant evening to sort out the method and to do the conversion.
Unfortunately, I did not take a "before" picture. The light that you start with might be different from mine but I think these were very popular five, ten years ago? This is a general guide. Some of my other relevant work with LEDs has links.
The first step in my retrofit was to remove the halogen lamp and its supports and contacts as well as all the high voltage (117VAC) mains wiring from the housing. The parabolic reflector and a mounting bracket were the only parts saved.
the diy garden lamp. The 1 inch aluminum bars acts as a heat spreader from the LEDs to the aluminum sheet and the existing reflector which provide a large surface area.
I laid out the holes on one bar, drilled them carefully and then used a punch to transfer the hole positions to the other bar. I drilled the second bar and the center hole in both and then used a medium sized bolt through the center hole to clamp everything together to drill the small holes through the existing reflector and the aluminum sheet.
This is the spreadsheet with the test results I got for the particular LEDs that I am using. The LED tests are described here
Thank you for your interest in my work.
Please see my other lighting projects at the tab above.