# P7 or MC-E buck driver (hipCC)



## georges80 (Dec 3, 2008)

Hi Folks,
if some of you have been frequenting the bike subforum here on CPF you would have seen the hipFlex development that is ongoing.

I have taken the hipFlex buck driver core and made a 'dumb' driver - the hipCC. I received production PCB's today to build up a test unit and it all works nicely just as it does integrated into hipFlex.

This is a buck driver that can run from 4.5V to 24V input and drive from 1 to 5 P7 or MC-E (in 4P) LEDs. It will be set to a nominal 2.8A output but by changing sense resistors it can be adjusted up to 3A as can be seen in the pictures below.

The board is 1.1" in diameter and single sided so the bottom can be mounted to a heatsink. I will be supplying a piece of thermal pad material (nominal 1mm thick) to use to interface from the PCB to the heatsink. There are 2 mounting holes to enable screwing the board down to a heatsink and 'squeezing' the thermal pad material.

Efficiency will be similar to that posted for hipFlex and the curves are posted below.

Reverse polarity is provided on board. Total headroom at 2.8A from battery in to Vf out is 0.5V (so very low voltage drop across the driver).

A PWM input is provided and I'll be documenting that on my website as I get the driver ready for shipping within a week or so.

I have bench tested the driver for 2+ hours with 3 P7's at 2.8A and with thermal pad material to a heatsink the driver reached around 30C (~20C ambient). I have tested 5 P7's for over an hour and it was around 35C.

So, picture of the top of the board:







and of the bottom of the board. The silvery areas with lots of vias is to optimize the heat transfer through the board from the main power components.






and a picture of the driver fired up and pumping 3A through 3 series connected P7's (with some paper to 'shade' the camera).






and a measured efficiency plot of hipFlex that is also applicable to hipCC. Note that these curves are from the hipFlex proto that used a schottky for reverse polarity protection so is a hair lower than the production hipFlex and hipCC.






cheers,
george.


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## ICUDoc (Dec 3, 2008)

Great work georges80- many people are waiting for a reliable driver for these new LEDs. Thanks, this looks very exciting.


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## ktronik (Dec 3, 2008)

:rock::bow::bow::bow::bow::bow::bow::rock:

we love you George!!!

K


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## Teego (Dec 3, 2008)

Amazing stuff. EXACTLY what I need for my new project.


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## phantom23 (Dec 3, 2008)

Teego said:


> Amazing stuff. EXACTLY what I need for my new project.



Still looking for boost driver for mine...


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## Aircraft800 (Dec 3, 2008)

Darn, I was just going to place an order, now I'll have to ad to it 
I'll have to wait till these are in stock..


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## georges80 (Dec 3, 2008)

Ok, ran some efficiency tests on hipCC. It is very close to the hipFlex efficiency, just a bit better due to this being a production board with a FET for reverse polarity protection and also due to one less item in the DC path versus hipFlex.






Oh, a boost for P7, not going to happen (certainly not in a small size driver), you would need >>2.8A at the input to put 2.8A at the output.

cheers,
george.


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## phantom23 (Dec 3, 2008)

Don't know much about electronics but 3xMC-E 2s2p (so like 6 separate emitters) + 2xLi-Ion + MaxFlex may work?


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## georges80 (Dec 3, 2008)

phantom23 said:


> Don't know much about electronics but 3xMC-E 2s2p (so like 6 separate emitters) + 2xLi-Ion + MaxFlex may work?



Depends on current. That's a LOT of heat and inefficiency due to the large delta from Vin to Vout.

6 series LEDs at say 3.5V each is 21V and only being fed with nominal 7.4V is not a good recipe for efficient boost. Lots of heat will be the byproduct and you'll have a challenge cooling maxflex or any compact boost driver faced with that scenario.

There is a reason I developed a 2.8A BUCK driver...

cheers,
george.


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## phantom23 (Dec 3, 2008)

3x4p - three leds will be better but MaxFlex delivers up to 1,2A only.

Buck means I need 4 Li-Ions to three emitters which means huuuge flashlight.


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## Aircraft800 (Dec 3, 2008)

Can this be used in conjunction with the D2Flex for multilevel?


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## georges80 (Dec 3, 2008)

Aircraft800 said:


> Can this be used in conjunction with the D2Flex for multilevel?



Yes, I will develop a firmware tweak to d2Flex to allow it to control hipCC, but if you have room the hipFlex has it all in one driver....

I have added a PWM input to hipCC and the V1.1 d2Flex has a PWM output - so the hardware is in place, just need to tweak the firmware.

I figured that the hipCC at 1.1" diameter with a d2Flex may fit in places where the 1.4" diameter hipFlex may not.

cheers,
george.


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## Aircraft800 (Dec 3, 2008)

georges80 said:


> Yes, I will develop a firmware tweak to d2Flex to allow it to control hipCC, but if you have room the hipFlex has it all in one driver....
> 
> I have added a PWM input to hipCC and the V1.1 d2Flex has a PWM output - so the hardware is in place, just need to tweak the firmware.
> 
> ...


 
All would be nice if it fit in a standard "C" Mag tube, looks like I have a problem


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## TexLite (Dec 5, 2008)

georges80 said:


> Hi Folks,
> if some of you have been frequenting the bike subforum here on CPF you would have seen the hipFlex development that is ongoing.


 
Looks great!

And yes,I really should check that forum more often.I probably would have missed this if you hadn't posted here.

On an off topic question,how do you like the Extech?Looks like a very useful tool.

-Michael


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## georges80 (Dec 5, 2008)

TexLite said:


> Looks great!
> 
> And yes,I really should check that forum more often.I probably would have missed this if you hadn't posted here.
> 
> ...



The Extech is a pretty useful tool. I use it only for the current clamp aspect since I already have a decent multimeter. Extech also has another model that has 1 mA resolution, the one I have is 10mA. So, in retrospect I would have gone the 1mA model, but it wasn't on the shelf at Fry's a year or so ago, so I bought the 10mA model.

Regardless of model/brand, make sure that the clamp meter can read DC current. A lot of the models (especially the cheaper ones) only do AC current.

Also, at those low current levels, you want to put the clamp meter over the wire (with power off), then turn the meter on, let it settle for a few seconds, then push the 'zero' button to remove any offsets etc. Don't move the meter once it has been zeroed and you'll get pretty accurate readings.

I also have a fancy smancy current probe that I hook to my scope when I'm looking at current transients and pulses etc - but that's in a totally different $tratum.

cheers,
george.


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## TexLite (Dec 6, 2008)

georges80 said:


> The Extech is a pretty useful tool. I use it only for the current clamp aspect since I already have a decent multimeter. Extech also has another model that has 1 mA resolution, the one I have is 10mA. So, in retrospect I would have gone the 1mA model, but it wasn't on the shelf at Fry's a year or so ago, so I bought the 10mA model.
> 
> Regardless of model/brand, make sure that the clamp meter can read DC current. A lot of the models (especially the cheaper ones) only do AC current.
> 
> ...


 
Wow,thanks for taking the time to share those tips,I appreciate it.

One of these is now tops on my want list.

Thanks,
Michael


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## Fluor (Dec 6, 2008)

Nice driver!

When can i place a order and what will the price tag be?


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## 9x23 (Dec 6, 2008)

George,

I am excited to see your new drivers for the P7 and MC-E coming soon. Thanks for offering these. Paypal is standing by!

9x23


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## georges80 (Dec 6, 2008)

I'm hoping to have them available within 2 weeks. I'm just waiting for a supplier to provide one of the IC's that goes onto the board, the rest of the components are on hand.

Pricing, I'm still working out the details. Given hipCC is a 'dumb' driver it will be priced in line with my other fixed output drivers.

cheers,
george.


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## wquiles (Dec 8, 2008)

Awesome George!!!

Not only the availability of the driver itself, but also the fact that this is a high efficiency driver :twothumbs

Will


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## Bimmerboy (Jan 16, 2009)

*EDIT:* To anyone reading this post, ignore it! I was being an idiot, and started thinking the hipCC can't run a MC-E in 2S2P @ 1.4A. It can!

Carry on. 

-----

George,

Eeeesh... I just realized something. I was imagining a setup using this board to run a single MC-E in 2S2P with 10.8V (9 X NiMH) in order to get much better efficiency than running the emitter in 4P. Well, I can't do that as the hipCC is only designed to run 2.8A. 

*However*...

You mention changing the sense resistor if someone wants 3A. Can one go the other way and change the sense resistor to get a lower current, say like 2A? If possible, this would allow me to run 2S2P with 1A to each die at max.

If not, and I have to run 4P, will the hippCC produce an un-manageable amount of waste heat from such a wide delta between Vbatt and emitter Vf?


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## georges80 (Jan 16, 2009)

Bimmerboy said:


> George,
> 
> Eeeesh... I just realized something. I was imagining a setup using this board to run a single MC-E in 2S2P with 10.8V (9 X NiMH) in order to get much better efficiency than running the emitter in 4P. Well, I can't do that as the hipCC is only designed to run 2.8A.
> 
> ...



Efficiency curves are posted in this thread so you can see what is involved in a 4P configuration. Considering we're only dealing with 10W (only...) at 83% we're looking at about 1.7W loss - the driver can easily deal with that with heatsinking. 

Yes, you could replace/change the sense resistors to run at lower current. There are 3 paralleled sense resistors (to handle the power) so it would require removing/replacing a few resistors but nothing impossible.

cheers,
george.


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## nailbender (Jan 16, 2009)

Are we getting close to being able to try these jewels out George? They really look awesome compared to what else we have to work with in a stock driver.

Thanks

Dave


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## georges80 (Jan 16, 2009)

nailbender said:


> Are we getting close to being able to try these jewels out George? They really look awesome compared to what else we have to work with in a stock driver.
> 
> Thanks
> 
> Dave



Yes, FINALLY it's getting close. It has been a very painful experience getting the last IC for hipCC into my hands. 

The IC is in stock at the manufacturer (no distributor has stock), I ordered parts through a distributor based on the listed price on their website. Anyhow, due to a chain of events and circumstances that I hadn't planned for there has been a whole set of steps that needed to take place to get the parts to the distributor and the xmas break didn't help with communication etc.

I still don't have them in hand but they have been ordered and should be at the distributor late next week. Then they will be sent 2 day to me. This means I'll have parts in hand in the last week of this month. The boards are all assembled other than this one last part, so it will be installed and then I'll have boards ready to go very quickly.

Given how long it took to get parts moving from the manufacturer I doubled my order size and then doubled it again when the order finally got placed. So, I'll have a lot of IC's on hand for quite some time - unless hipcc and hipFlex start selling/shipping faster than I planned...

cheers,
george.


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## Bimmerboy (Jan 16, 2009)

georges80 said:


> Considering we're only dealing with 10W (only...) at 83% we're looking at about 1.3W loss - the driver can easily deal with that with heatsinking.



Since the driver will have it's own heatsink seperate from the emitter, that sounds manageable in a 3D Mag body. BTW, is 10W at 83% a 1.3W loss, or 1.7? Doubting myself here since as a musician, I mostly deal with math on the _sub_-conscious level... lol.

I have one thing left to ask, but will send e-mail regarding that. Thanks for putting up with all my questions!


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## georges80 (Jan 16, 2009)

Bimmerboy said:


> BTW, is 10W at 83% a 1.3W loss, or 1.7? Doubting myself here since as a musician, I mostly deal with math on the _sub_-conscious level... lol.



Tee hee - you are right - teach me to type something before my morning coffee 

Efficiency should be better with 2p2s and running 1.4A, since the Vout will be higher and closer to the battery voltage. I'm guessing it would be up around 90% (based on the 2.8A runs with 1, 2 and 3 P7's), so that's another option. Either will work with hipCC with it mounted to a heatsink via the thermal pad material, so it's really just a runtime/efficiency call by you.

cheers,
george.


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## Bimmerboy (Jan 16, 2009)

georges80 said:


> Tee hee - you are right - teach me to type something before my morning coffee
> 
> Efficiency should be better with 2p2s and running 1.4A, since the Vout will be higher and closer to the battery voltage. I'm guessing it would be up around 90% (based on the 2.8A runs with 1, 2 and 3 P7's), so that's another option. Either will work with hipCC with it mounted to a heatsink via the thermal pad material, so it's really just a runtime/efficiency call by you.
> 
> ...



Hahaha... well, teach me to type something after a long day plus beer because you're right too! I somehow started thinking last night that the hipCC can't run a MC-E in 2S2P @ 1.4A, and caused both of us a bunch of unnecessary typing. Double forehead smack for me! 

Good thing is, this eliminates the need for me to pester you by e-mail. About to edit post #21 so as to avoid confusing others.

Thanks again, George. I'll be over here in the corner keeping quiet now.


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## georges80 (Jan 31, 2009)

Ok, finally after much waiting and phone calls I received the switcher IC from the distributor. So, after over 1 month from trying to order the chip I have a whole bunch of them on hand.

I have the first batch of hipCC drivers complete, tested and ready for folk to order.

Info including tech info stuff is on the website in my signature.

cheers,
george.


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## wquiles (Feb 1, 2009)

Congrats George :twothumbs



Will


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## nailbender (Feb 1, 2009)

Woo Hoo congratulations George I know this was a big project for you, we needed another choice for these high power LEDS these should be a perfect fit.

Thanks 

Dave

PS Email sent


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## Icarus (Feb 1, 2009)

Great news!


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## sadtimes (Oct 1, 2009)

I know this is an old thread but I have aquestion...


How big of a heatsink does the HipCC require?


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## terrik_zion (Nov 9, 2009)

HipCC to the rescue!


*cue Indiana Jones theme song*

I am late to the party posting on this thread, but this driver looks like the perfect solution to my magmod! I will be ordering one asap!


Hooray for cpf!
Hooray for George!


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