Petit Crouton with Boost Regulation?

**hybridspecies** · 01-20-2012, 10:50 PM

Anyone know if the latest version of the PC (Ver 1.6) supports boost regulation? I could have sworn I read that it does now, but haven't been able to rediscover that post after much searching. I'd like to use a 7.4 volt pack to run a series wired amber LZ4 at 1.5A, but that would require around 12v (18W) out of the PC. I read the updated PC 1.6 manual that Tim posted, but didn't see max output voltage specs or even max power rating listed.

**pezzer75** · 01-21-2012, 03:01 AM

Power supply: 4.5 to 9 V / 2A (with the High-power LED). 2 li-ion cells (18650 or 14500) batteries recommended. copied from page 4 of the manual.
this thread should help with the wiring http://forums.thecustomsabershop.com...e....for-noobs

**hybridspecies** · 01-21-2012, 03:28 AM

Thanks, but those specs aren't what I need and I already read through that link long ago. Unfortunately it only addresses the parallel-series configuration, which limits current to 2A total or only 1A per pair of dice if driven directly by the PC Ver1.6. I want to run all 4 dice in series at 1.5A, which would require about 12 volts total output to satisfy combined VF. If the PC is buck regulated only, the best I can get from the output would be less than 7.4V and I'd have to employ a power extender or relay to drive the LED at 1.5A. If boost regulated and capable of at least 18 watts then I'm in business with driving directly from the PC. Anyone know if the PC V1.6 is boost regulated?

**Sunrider** · 01-21-2012, 09:52 AM

The pc is a buck only driver. No boost. That would be cool though. The easiest way to put that much power to a 10w would be to run the dice parallel and use a seperate driver (see my Praxis saber build).

**hybridspecies** · 01-21-2012, 07:14 PM

Thanks Sunrider - your Praxis is incredibly beautiful btw. Did you make the 6.6A driver yourself? I'm still inclined to run all 4 dice in series, but if I can't find a a boost regulator with small enough footprint maybe I'll cheat and use a 14.8V pack and resistor or equally inefficient LM317 constant current circuit.

**Sunrider** · 01-21-2012, 07:59 PM

I can tell you where to get that driver. I did not make it. Boost setups are much more complicated and need more space. Parallel 10w pcbs can be found so that makes such setups so much easier. With the pwm input you get effects. You wont get 12bit pwm control with the 317.

**hybridspecies** · 01-22-2012, 10:19 AM

I'm definitely interested in getting the driver - the store only lists 1.5A versions. I saw something similar on KD, but was sold out. The reason I'm shying away from a parallel LZ4 setup is the 3+ Amps I'd have to pull from the batteries to power it. In series, I'd only need half the current for the same brightness. Theoretically the power requirements would be the same because of the higher voltage, but in practice the higher current requirements of the parallel config would result in greater heat losses and wear/sag on the 14500s I plan to use, plus it's kinda hard on 26g wire. I had issues with spring retention battery holders turning into toaster coils under high current draw before I started using battery packs for these leds - not fun.

**Sunrider** · 01-22-2012, 11:43 AM

In series 4 green dies have a vf of 16 or 17v. Then you would need 6 li-ions for a 20v pack. Protection pcbs are MASSIVE at that voltage. From actual "practice" ,

Trust me when I say 2 18650s and parallel dies is the way to go. 24 or 22 gauge can work for 6 amps. Heat loss is minimal, the 6 amp driver is 85% efficient. Always make a pack btw. Taskled has the driver.