1D mag with 3 x P7 possible?

[big vin]

I would like to build a 3 x P7 Mag using the Heatsink and reflectors selled by Der Wichtel. I would prefer a direct drive on 1D li ion, is that possible?
The D cell lion has a capacity of 5000MAh, so that would be a discharge of wel under 2C.

Also, can the original switch handle that kind of current, or should i replace it?

Thanx, Vincent

 

[fivemega]

I would like to build a 3 x P7 Mag using the Heatsink and reflectors selled by Der Wichtel. I would prefer a direct drive on 1D li ion, is that possible?
The D cell lion has a capacity of 5000MAh, so that would be a discharge of wel under 2C.

Also, can the original switch handle that kind of current, or should i replace it?

Thanx, Vincent

Protected cells won't provide required current draw of 3 P7 which is over 8 Amps.
Serial 3x17670 is better choice to direct drive 3 serial P7 but will fit in tri bored 1.25D M*g. Not to mention voltage loss of 8 amps is much more than voltage loss of 3 Amps.

 

[jar3ds]

its sort'a one of those... yeah, its do-able... but its not at all an ideal solution...

 

[Chodes]

its sort'a one of those... yeah, its do-able... but its not at all an ideal solution...

Agree with that.

Is this short enough?
http://www.candlepowerforums.com/vb/showthread.php?t=195559

2 x IMR26500 easily fit. (2 x AW C 3300mah just fit)

So get Der Wichtels triple MC-E , you have options with wiring emitters. Then you could direct drive , 7.4V @ 4.2A for full power. Mag switch will survive that. Half hour run on full power with IMR26500s.

 

[big vin]

how is the output of the triple MC-E compared to the triple P7's?

 

[Chodes]

Similar.
It's more beam pattern that's different.

 

[big vin]

I just purchased a 1D mag yesterday, gonna turn that into a nice 1 P7 version.

So having a nice short mag now makes the length issue on this one a little less important.

What would be the nicest way to power up those 3 P7's or MC-e's?

the maximum length is 2D, but the shorter the better....

 

[big vin]

What precisely is the difference in beem patterns BTW?

 

[StefanFS]

how is the output of the triple MC-E compared to the triple P7's?

About the same in flux with corresponding flux bins, but a bit floodier or a more even flood (if I make a guess based on previous experience with MC E and SSC P7 in different configurations).

As stated, the MC E package is smaller, often you get a more even beam distribution in a setup like this. Not that it matters in real life, the SSC P7 should give you some advantage in throw. There are sometimes artefacts with most SSC P7 based lights that bother some in white wall settings.

My 3 x SSC P7 setup with DW's heatsink, two threads with beamshots:

http://www.candlepowerforums.com/vb/showthread.php?t=230807

http://www.candlepowerforums.com/vb/showthread.php?t=230807

It gets hot, outside within 20 minutes, and it need a lot of power to run well.

 

[3rdrock]

Agree with that.

Is this short enough?
http://www.candlepowerforums.com/vb/showthread.php?t=195559

2 x IMR26500 easily fit. (2 x AW C 3300mah just fit)

So get Der Wichtels triple MC-E , you have options with wiring emitters. Then you could direct drive , 7.4V @ 4.2A for full power. Mag switch will survive that. Half hour run on full power with IMR26500s.

Thats what I also want to do. :thumbsup:

 

[big vin]

Serial 3x17670 is better choice to direct drive 3 serial P7 but will fit in tri bored 1.25D M*g.

I understand that you sell adapters for those? could be interesting...

Do you have an adapter that could fit 6 lithiums in a 2D without cutting it? That way i can put in a nice driver and save me some bucks for not having to do a cutdown.
Since the length issue is not that important anymore that seems like the most sensible thing to do....

 

[mash.m]

hi,

always done:

http://www.candlepowerforums.com/vb/showthread.php?t=236497

markus

 

[big vin]

How many amps did each P7 get from the battery, and what was your runtime?

 

[Chodes]

How many amps did each P7 get from the battery, and what was your runtime?

I'd really like to hear about it. I don't want to start a debate , I've already said I don't think it's an "ideal solution" but I would value your thoughts and opinions on the build. I'll just listen

Recently I have considered a ridiculously short triple P7 0.5D? Mag with a tailswitch using an IMR26500.

 

[mash.m]

hi,

with a fresh cell it draws 6 amps. you can use the light at the highes level for 15 minutes or so, then it will get warm - not hot.
i think this setup is very good, cause the p7 are underdriven so the efficiency will be very high. the difference between 6 amps and 9 amps is not so big.
the runtime at high level will be 45 minutes. med and low not testet.
buidling is very easy. you need the heatsink and refelktors from der_wichtel and a driver. i moded my driver with a logic-level fet, so it is a direct drive. the stock switch only switches the driver, not the high current from the led´s.

markus

 

[Justin Case]

I'm not sure I quite understand your setup. In the link that you provided, the 3xP7 is described as 3 P7s wired in parallel and using a KD SKU 1845. That KD board is already a direct drive PWM controller. So I don't understand the function of the FET, which you claim allows you to run in direct drive and prevents "clipping" at 2.8A. What clipping and what is the cause? Is the PWM controller not providing 100% duty cycle at full power?

At 6A draw, yes the P7s are underdriven (nominally 2A per P7). But the small decrease in Vf at 500mA per core (versus the Vf at 700mA per core at full power) isn't really going to help all that much. You are still pumping approximately 3 * Vf * 2A watts of power to the three LEDs, or probably about 3 * 6.6W ~ 20W. and probably about 80% of that will go to waste heat, or about 16W.

What is important is how hot do the LEDs get (or as a surrogate, the heat sink), not necessarily the outside of the flashlight. If you have poor thermal conductivity between the heat sink and the flashlight, the light can feel relatively cool, which is misleading. With an estimated 16W of waste heat generated by the LEDs, I would expect the light to run hot for extended runs. I haven't done any thermocouple measurements in my direct drive 3D Mag with 1xP7, but in a SureFire KT1 TurboHead with a 2S2P MC-E Turbo Tower driven at 613mA per core, I measured 144F (62C) after 15 min and hit 162F (72C) steady state for the heat sink. I would characterize these temps as burning hot. The TurboHead surface temperature was 133F (56C).

A single 2S2P MC-E driven at 613mA per core pulls about 8.2W, of which about 6.5W is waste heat. It is hard for me to envision how 16W of waste heat from 3xP7 can run cooler than 6.5W from 1xMC-E.

Edited: Big egg on my face! I forgot my own test procedure when I measured the temperature for the SureFire TurboHeads. The THs were not screwed into any flashlight body, which would have otherwise added to the thermal heat sinking mass. I powered the LED Turbo Towers using a bench power supply and thus needed access to the driver board inputs. No doubt, if the THs had been attached to a metal flashlight body, the various measured temperatures (Tower, TH surface) would have been lower.

 

[mash.m]

the original driver clipps at 2.8 ampere. the onboard fet is not capable to drive more, cause it get hot, so i had to conect a external fet and remove the feetback resistor. now there is no clipping.

the heatsink is completley glued with arctic. the complete flashlight get warm, not only the heatsink. also the head of the mag is glued to the body for best thermal management.

markus

 

[Justin Case]

Ahh, understood. Thanks. What replacement FET did you use? The TaskLED d2Flex uses an RTQ045N03, which allows that controller to handle over 3A.

 

[mash.m]

i use an irf-xxx type (german label for logic level fet´s) but this fet is capable to drive more then 50amps...for lowest internal resistance.

markus