If it helps, Cree suggests using brackets and optics made for Citizen high intensity cobs for their CHA series. I’m guessing because they have similar dimensions and the citizens have been around for awhile so there’s more support for them at the moment than the new CHAs
Looks like I can get away with just using a reflector that perfectly mates with this LED. any ideas on a good lens? OR will pretty much any do?
The reflector spaces the lens from the led moving the lens makes the beam wider or narrower. The bracket holds the lens and reflector in place. It is best to use the reflector lens and bracket for simplicity.
I cannot find a bracket, lens, reflector, combo smallest enough for this LED. I will have to forego the reflector for sure and go with just the lens.
best I could find is this
CAn I get any 44 MM lens and mate it with that reflector and call it done?
It’s a 4 mm LED and the bottom hole on that reflector is 14mm . That’s the smallest I could find. Should I just fore go the reflector?
The reflector is to reflect light but also gives you the spacing for the lens. You can use one or the other however if only use a lens you need to be able to hold it in place. I wouldn’t worry so much about the LED opening being to big.
You also may be able to find a LED centering ring (gasket/ adapter ?) of the correct size. Or at least close. Match the LED size for the inner hole and the reflector hole for the OD of the gasket. These are sold at several places, but the Convoy store on AliExpress has a decent selection. They help with setting the reflector height and centering. Also for insulating the reflector form the MCPCB. I think a good idea when using any reflector. They are also very cheap.
Some info here:
An example, you will need to search or look for the size that you need.
https://convoy.aliexpress.com/store/1100591265/search?SearchText=+gasket
Or find something close and cut or mod it to fit. You also may be able to find someone to 3D print one for you.
Why did you specifically choose this led?
because it’s 12 volts ?
Yes and also because it doesn’t get too hot. I have a heat sink strapped to my head lol. (I do have it on plastic swivel lol)
On digi key I could only find citizen and Cree LEDs that were 12 volts that were quite small COBs. Mouser is more difficult to filter results. Let me know if you know of any other high quality COBS that are 12 volts. The Li ion battery pack I designed maxes out at 12.6.
I am ready to pull the trigger and I am buying a whole assembly for the Lens + reflector + bracket. I am using thermal adhesive to stick the LED permanently to the heat sink. Please get back to me soon, I am moving forward on this otherwise
Also I am assuming there is absolutely no way to get the LED off after the thermal adhesive has been applied. I am find with that, but please tell me if there is a way to get these off.
Can the reflector damage the LED if it touches the COB array? Is that why the gasket is recommended?
The gasket is used for centering the LED in the reflector. It sets the height of the reflector and locates it laterally (side to side). With the bezel and glass (or maybe lens in your case), it sets the tilt as well. IOW makes sure everything is square.
It also keeps a metal reflector from touching things like wires or contacts on the mounting board (MCPCB)/led to prevent shorting.
I would think that it would be possible to damage the COB if the reflector is badly misaligned and tightened down or jarred by some kind of impact.
Just so everybody has an idea of what this thing looks like, here are some pictures. Ignore
the yellow lock, it’s my gun lock I Am clearly not using at the moment.
PRetty sure I broke the LED, tooling around, the hack that I am. MAn that blows, the shipping from digi key hurts.
Maybe a stupid question, but does it still light up?
How did you do that? Might help me avoid such problems in the future.
it does not light up, IT happened because I used that lens you see pictured. The LED is super fragile and I should’ve known better. I will not make the same mistake next time. I will be careful not to have anything touch the actuall yellow LED area
Right now all the correct supplies and Lens are on the way. IT will be a permeanent install with adheisve thermal paste this time. No problem because the LED is $4, so I bought two should something else go wrong
Yeah, that is one of the reasons for the gaskets we were discussing. Though I am not sure how they would work in your case.
How are the LEDs arranged on the base that you are using for them? I can’t visualize it for some reason.
Im changing the whole setup, don’t worry lol.
Houston we have a problem.
I got all the parts from china finally but now i have a problem. A quck test revealed the lens / reflector works, but im trying to figure iut the heat sink. If i put a COB LED OVER a big old hole like that,will it stay cool? Or should i thermal ADHERE a penny in there in between the hole and it? Not sure if that will help much.please get back to me soon, im eagee to get the light up snd running again
