I purchased a 940 nm led with mcpcb off mountainelctric and a 1amp driver. I soldered the mcpcb and the driver to each other and then made sure to electrocally isolate the mcpcb with “ARCTIC ALUMINA THERMAL ADHESIVE TWO-PART ADHESIVE” off ebay. i checked with a multi meter like 20 times. let it dry maybe 10 minutes, got impatient and put the pill into the flashlight and tried it… nothing, not a spark, a flash, nothing. ded it was. I now have the pill soaking in some acetone to dissolve the thermal adhesive. overall I can see some areas that i might have burnt the LED out . but overall i don’t understand how i f@@@ed this up.
I have one more IR 940 mcpcb combo, driver and spare pill that i am going to attempt round two tonight before i loose my sh!t. Any steps of suggestions are more than welcome. thanks again guys.
I only have one picture of my handy work. so ill post that up momentarily
Before installing any star into a pill, I always test the star to make sure it works. I use an old radio-shack 1xAA battery carrier with a 14500 in it. I soldered better wire to it and touch that to the ± pads on the star. Very briefly… just enough to make sure it lights. That way you can rule out reflow problems before sticking it into the light.
For isolating the star from the pill? I’ve never installed an Oslon so haven’t had to do that. I like being able to remove the star though in case of problems or for emitter upgrades. I’d probably do the following:
Apply a thin layer of arctic alumina to the bottom and sides of the pill where the star will rest or sides of the star may brush. Use a flat piece of aluminum or special x-acto knife blade as a scraper to make sure this layer is as flat as possible, but still insulating.
Let this layer cure. After the arctic alumina layer has cured, visually inspect it to make sure there is no visible aluminum and the place for the star appears fully insulated.
Then treat it like any other star install: Spread a thin layer of AS5 thermal grease onto the bottom of the pill and install the star.
I have a Car dash cam that has the IR filter removed. Also even though it is bad for my eyes, the LED does glow red to a degree. you just wont see it from 5 feet away since red is not a color you detect very easily. hence the reason cops use a red light inside their car when they are trying to catch speeders since its harder to see it at night. but yeah. i know it was not working. but the idea of testing it is good and i will attempt this in a moment. but… it is ok to use a small battery to test an led? i wont hurt it or anything right?
Did you try testing to see if you soldered the LED in reverse?
At only one amp, I would have used a regular aluminum star so isolating the MCPCB would not be necessary.
might sound like a dumb question, but how can i test it safely? I only had two and im considering the fact that i just messed up the first one to be a big possibility.
Just test it with some leads from a battery. Just touch them to the +\ pads on the star. You can use a cr123, 14500, 18650. I wouldn’t worry about harming the emitter. You just have to touch long enough to get a flash.
You can test it with your DMM put it on the diod setting and just touch the leads to the negative and positive and it will light up. To check if your driver is working take an 18650 battery and tape wires onto each end of it with electrical tape.
It’s easy to not get the emitter on the noctigon properly. So test that first. Once you know that your emitter is set in place and you have the negative and positive correct then attach your driver and check it with the 18650 battery with the wires attached. Now you will know that you have the driver and emitter working correctly.
If it’s still not working after you have assembled it then you can almost be sure that your problem is the current path. Make sure that your negative is actually making contact, press fit isn’t always going to be enough so try and solder the driver to the pill or whatever it’s supposed to be contacting.
Oh and one other thing you can check is your tailcap switch. Once it’s all together, instead of trying it with the tailcap on, try it with the tailcap off and use something metal to contact the negative on the battery with the non-anodized part at the end of the flashlight. A screwdriver or something similar will work just fine.
Yep just a light touch to see if it lights up, your DMM will also do the same with it set to the diod reader spot. (same as you would use to check for a short) With the DMM it’s not going to create enough current to blow the emitter either.
That is strange, mine works that way perfectly. Not if they are wired up already though. It’s how I test mine all the time so I don’t fry my eyeballs with that flash.
alright! first mcpcb was a dud, but i totally got the second one to work and show signs of life!!! thanks so much guys, today was a huge learning experience for me.
Just wanted to say that every time I scan down the page and see this thread title, my brain sees:
first time mother, need some adivce
...and before it registers I'm already thinking "Yeah, I've got some advice. How about some basic punctuation and spelling so that poor kid doesn't grow up to... oh, modder. Well, that's totally different then, isn't it?"
