CF with LEDENGIN 40w RGB?

**pointoforigin** · 09-07-2011, 11:18 AM

I have a CF yay! I'm planning now. I'm not sure if this has been done before, though it has been talked about.

After doing MUCH reading here and on FX, this looks correct to me:

But I am by no means an expert with anything to do with electronics.

Because CF can handle up to 11 volts, and the voltage requirement of the 40w green (the most voltage hungry) is 13.5@1A, power to the board must be regulated. Essentially I'm treating it like you would when using a cheap Hasbro board.

Potentially, the resistors could be swapped out for buckpucks or similar, with the potentiometers controlling them.

What I am not sure of is ... a few things actually hehe.

Number one, does my wiring look right?

Two, is a 9 volt regulator a good choice?

Three, are 15Kohm pots a good choice?

Four, am I missing anything? (Aside from the rest of the components like switches, speaker, accent LED's. These get wired to the CF as normal.)

**Sunrider** · 09-07-2011, 01:55 PM

Hey. I'm thinking of doing something similar.

I don't know if that setup will work. I think its too much power for a kill key setup. The pots would have to be 10 watters to keep from burning up, and those are HUGE.

Some obstacles to overcome.
1. Batteries. If you want more than 15 min run time you 18650s or similar size.
2. VF for blue & green are 12v. 3 li ions will have a end of charge voltage of 7.3v. Not enough!
3. Heat... Extra cooling necessary.

4. Optics... and the star is a 28mm not 20!!!

5. Something is needed to switch all that power and were running out of room!

Hmmmmmm....

**Skottsaber** · 09-07-2011, 03:33 PM

The switches surely wouldn't have to be very highly rated, because they are still using the small signal from the board.
Also, I would suggest some form of heatsinking for the power extender running the main LED. With extended use those small FET packages can generate a reasonable amount of heat.
Either that or use a larger package MOSFET rated for more power, and with a heatsink on the back like your regulator has.

The wiring looks alright though

**Sunrider** · 09-07-2011, 04:32 PM

Yeah. I'm not sure the PE can handle all that Powah. I don't think the recharge port will last very long with all the power going through it ether. Instead of 15k pots 10 or 100 ohm will give you more adjustment. I am looking at a regulators in the 8v range myself. And the wiring could work.

**pointoforigin** · 09-07-2011, 07:11 PM

Cool. So I am on the right path, at least, that's good to hear.

Battery wise, I was going for 4x 18650s. Pretty sure they will handle it no probs.
The cooling - I was intending to run a fan like you would an on indicator LED, that is when the kill key is pulled, the fan goes on. So even when you turn the blade off, the fan is still going, cycling the air.
Optics will be fun. I'm quite aware of the difference in size of the star

I think it was your thread I was reading on the subject, Sunrider. Finding one that covers the dome of the LED and spreads the light properly will be interesting.

So possibly use a high rated toggle switch instead of a kill key to handle the power? And a more powerful version of the PEX, with some kind of heatsink solution. Mounting it within the airflow of the fan should help also.

I'm slowly building this up as a 3d model to make sure all the parts fit in a hilt before buying them. The only parts I have at present are the CF, one PEX and a speaker :P This all SHOULD be able to fit within 12 inches of space. It does so far.

**thejedilestat** · 09-07-2011, 07:31 PM

WOW....

way over my head all this talk = something cool =P

good luck

**Sunrider** · 09-07-2011, 09:24 PM

Yes. 4 18650s will be plenty of power. But fitting them in a 12 in hilt with all the other stuff will be a challenge.

I was thinking I would try to get away with using 3. I think the star can be ground down to 20mm to fit into a MHS BH. Fans draw enough power that they need regulators or battery voltage. I would use a real switch rated at a few amps. Recharge ports are not as good beyond a couple amps. MTFBWY

**pointoforigin** · 09-07-2011, 10:16 PM

The problem with three is you only get 11.1 volts... with the green die running at 13.5, it's not hitting full potential. It would probably light up, and there would be a significant amount more room in the hilt with only three, but the ideal way is with four. I'll probably run some bench tests with both three and four to see how significant the difference is before committing to that hilt design to house them. I've toyed with designs that go for either way.

A regulator for the fan is a given. I was toying with the idea of running it off the 3.3v pad on the CF, but am not sure if that would give it enough juice. If not, a seperate regulator would be needed - or it could be run in paralell to the CF board, taking directly from the pos and neg battery pads that would already be regulated. A lot of costumers use 12v fans at 9v with no issue, just a slightly slower fan.

Can anybody tell me the inner diameter of the new style heatsink, the aluminium part just after the threads, not the blade side? From the images it looks to be around 25mm, but I don't have one on hand to confirm. This would tell me how much the LED star needs to be ground down. I'm not sure it can go as far as 20mm - I think that would destroy the solder pads.

**Sunrider** · 09-07-2011, 10:37 PM

I think I will have to grind the star down to 20mm to fit. The big pads will be lost but I think I can work with what is left. If not it's time to make a PCB. I'm gonna go for purple with 3 series parallel sets for 7v each at 3amps and the rest for flash.