Introduction: Gooseneck Shop Light LED Conversion
Bought a gooseneck light from a garage sale for a few dollars. It had a hook on the end to hang it, that was useless, not sure what it was meant for, but it had to go. I converted it from using a small incandescent bulb to 24x 0.5w Cool White LEDs in a 10mm package, 12w total. Wanted to keep it as simple as possible, run it from mains AC and build a more useful way to mount it. I used a surplus clamp style base, a 2x2, a 1/4" bolt and some Shapelock plastic to create a versatile mount.(That was all recycled or scavenged)
Powering LEDs from Mains AC:
There is a lot of information out there on how to do this, it gets a bit hard to sort through as there are many different configurations people have used. And none that I found had used these type of 0.5w LEDs.
I found these sites to be quite helpful:
This circuit uses the reactance of a capacitor to limit the current supplied to the LEDs. This method is a lot more efficient and safer than trying to rectify the AC and then use resistors to limit the current. The 0.5w LEDs require 100ma and 130ma Peak. I wanted to keep it in the safe area as I want this to last, rather than trying to make it brighter.
Through trial and error on a calculator and checking what capacitor values were available to me, I settled on a 1.8uF, 250v, X1 type capacitor, the X1 designates it as a fail-safe capacitor which I required.
Reactance of a 1.8uF at 60hz = 1.474kohm
Peak: 170 vac / 1.474 = 115.33ma
Nominal: 120 vac / 1.474 = 81.41ma
- C1: 1.8uF, 250v, X1 type. Such As This
- C2: High uF Capacitor,(I used an 18uf I had around) Smooths the rectified DC, 100v or higher
- R1 & R2: 100ohm 1/4w, prevent transient currents and act as a fuse.
- R3: 1 Mohm or so, bleeds the capacitor when power gets turned off. Note I used two 3.3 Mohm in parallel to get a 1.65 Mohm
- R4: Most designs have this, I did not include it in my device.
- Diodebridge: 250v or higher, I made mine out of 1n4007s
- LEDs: 10mm, 0.5w(100ma), Cool White LEDs Find Some Here
Take a look at the Image notes for more details.
Thanks for looking, please Visit My Profile for more Projects!
And checkout my website at www.ChromationSystems.com for projects, kits, parts and more.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Participated in the