This is to convert a old halogen shop light into a modern and much brighter led version.
Parts list in the photo along with a wiring diagram.
This is my first instructable so let me know where I can improve.
Thanks for reading
Step 1: Disassembly of Donor Light
Begin by totally disassembling the light. Save the parts as you’ll need some of them when you reassemble. What you want is the bare housing to start your project.
Step 2: Measure and Cut Time
Measure the width of the heatsink as you’ll want to cut out the back of the lamp housing so the heatsink will fit inside. I would suggest a dremmel tool, small grinder, etc. I could only find my monster angle grinder which was overkill but boy did it cut fast...
Step 3: Mount Heatsink and Glue It in Place.
I used JB Quick which is an epoxy resin to bond the heatsink to the housing. It sets up fast, maybe 8 mins or so. I left it alone for 24 hours so it could get fully cured and reach maximum strength.
Step 4: Solder and Mounting of the Led Module.
In order to mount the led I drilled 4 mounting holes into the heatsink. Those holes have to be tapped (threaded) to hold the screws. I used 4/40 x 1/2” machine screws as that was the smallest size I could find locally. Its always a good idea to test components before you go to the trouble of installing them. I tested the led module by briefly hooking it up to a power supply (which also proved that worked too) and noting which side was the positive terminal. That’s where I soldered the red wire on followed by the black wire on the other side.
The heatsink had some factory applied heatsink compound but since it wasn’t enough to cover the led module I wiped it off first. Then I smeared heatsink compound on the back of the led and screwed it in place.
Step 5: Fan Resistor and Wiring.
I used a 5W 100 ohm resistor to step the 36v from the power supply to the 12v needed for the cooling fan. This website has a handy calculator for figuring out the resistor value and wattage required. http://www.gtsparkplugs.com/Dropping_Resistor_Calc.html
I hooked that up alongside the led module so it wouldn’t get too hot. More epoxy used to hold it in place.
Step 6: Power Supply and Connections
The next part is to figure out where to mount the power supply module on the outside of the light. I chose the top so it wouldn’t interfere with the stand being able to angle the light. I also relocated the original power cord and connection box. That will require a few holes to be drilled. Two for the connection box and you’ll likely need another couple for the wires to pass from the outside to the inside or the light. This is for the wires that go to the led module and the cooling fan wires.
Step 7: Complete Wiring and Reassembly
Wire the led module power supply AC connection into the power connection block. Don’t forget the ground connection. Wire the DC or output side of the power supply module to the led module. Double check all connections and then if all is good plug in the power. Led module should light and the cooling fan be running. All that remains is to put the shop light glass, protective screen and mounting base back in place.
Please we don’t stare at the led. It’s very bright and at the very least you’ll be seeing a white square for a while. You only get one set of eyes so be careful.
Thanks for reading