CF with LEDENGIN 40w RGB?

[Don Se Wion]

Had a look at the diagram and I think you need to replace at least the Power Xtender going to the RGB dies with an high power MOSFET.
I guess at full power the 3 colors will drain around 3A from the battery and the specifications for the Power Xtender report 12V/1.5A.
Probably mixing the colors you will not reach the 3A limit, but you will most likely have a steady current around 2A running through the LEDs and I bet the Power Xtender won't last very long.

[pointoforigin]

Magnus, You need to take that link off dude, Tim sells 18650's in the store. It's not allowed to post links to other places that sell the same products.

18650's are what I'm looking at yes, but four of them to reach 14.8V.

Don, thanks for that. I had not yet looked up the specs on the PEX. I'm thinking at the moment of using a buck driver on each channel that has a PWM input and a ref/ctl like the 6 wire pucks in the store. The PWM input would negate the need for a PEX to get the effects, and the fact that they're drivers would negate the need for resistors. If that makes any kind of sense.

[Darth Magnus.]

Ok will do, not 100% up with all the products on this site.

[Skottsaber]

The power extender specs may be outdated, because people regularly draw 2A+ from them, so the FET is capable.
I wouldn't go over 2.5 though. You may want to ask Erv' if he can make you a "double" Power Extender, which allows for twice the current than a normal one.

[pointoforigin]

Ahah, that is an excellent idea. I've seen him offer this to others in the past.

Would that technically just be two stacked on top of each other? So if I got two extra and bridged the same wires to the same points on both it would have that effect?

[Skottsaber]

Pretty much yeah. But I would recommend desoldering the 10k resistor on one of them. Erv' actually just stacks the FETs, not adding another resistor IIRC.

[Natesroom]

is there info on this site detailing what a power extender is and how they used it in their build?

Also why 18650? why cant you go with a 25500? Is that because the size of one of those vs having x2 18650 isn't a good tradeoff?

[pointoforigin]

http://www.plecterlabs.com/catalog/p...roducts_id=131

You'll find instructions on its use in the Crystal Focus or Blastercore manual. There may be some info in the Crystal Focus sub board of the Sound board on here, but reading the CF manual is the quickest way to understand what it is and what it does.

[Natesroom]

ok thnaks

Also why 18650? why cant you go with a 25500? Is that because the size of one of those vs having x2 18650 isn't a good tradeoff?

[pointoforigin]

For starters, four cells are required to bring the voltage up to 14.8V. 18650's are the most efficient capacity per size, meaning run times will be the best. They also output enough current for the application.

Using 25500's would mean a full 20cm of hilt space would be taken up by batteries, with no chance of stacking electronics on the sides. This leaves 10cm for a soundboard, three pots, a fan, a heatsink, a bladeholder, two switches, 7 accent LED's, two power extenders, a kill switch and a recharge port. While I'm sure someone like LDM might be able to pull that off, I wouldn't. 18650's make sense.