Good cheap P7 drivers?

[jasonck08]

Lookin to buy some P7 drivers for cheap from like KD or DX or something.

I'd prefer to keep the cost down to around $5 each. Anyone have good success with one? I've read stories of overheating, and not driving at very high amperage etc. I want something solid.

 

[ace0001a]

Yeah, the reality is that you can't really expect put "good" or "solid" with "low cost" or "cheap" in the same sentence or phrase. With driving P7s and MC-Es, you really can't skimp that much on the driver. The ones KD has been selling have overheating issues because they use cheap diodes from what I read. The AMC7135 boards are more of a smart resistor than an actual driver and they have a limited voltage input of 6V max I think. DX just released a couple of single and multi-mode P7/MC-E drivers, but they haven't shipped any out yet and so no one has had a chance to try them yet. The reality is that if you actually want a reliable and solid P7/MC-E driver, you're going to have to spend around $30 each rather than $5 each. TaskLED has one called the hipCC and The Sandwich Shoppe has a Buck Shark driver and both places have a good reputation for making excellent reliable drivers.

 

[DM51]

I'll move this to Flashlight Electronics where it belongs.

 

[VidPro]

yes what he said ^
the AMC7135 things are what i like to think of as a voltage clipper :-)
if the amps goes to high VIA the battery voltage vrses the LED voltage, then it trims it down a bit, taking the extra Heat in resistance into itself.

this type of driver is PERFECT IMO for only very specific applications.
Like: say you were gonna DD anyway, these will trim the top of the DD overdrive off, then after that they do nothing.
SO
take the example of running a DD li-ion into the led, with this glorified resister, it will clip while the battery voltage is to high, then once the voltage drops down a bit, the only inefficency is the slight resistance still existing via the curcuit being there.

when the voltages (under the load) are much higher like say 6volts , then the chip has to take a lot of load doing the clipping to keep the current right for the led. basically blowing power out its backside.

with the higher voltages you end up with the more "regulated" type of output, because the voltage is high enough to NEED clipping, to maintain current.

seems to me if you know that, and understand that, then you can pick a time when that would be a best item for your application.

something like this would be actually more efficient, when it comes to energy savings, than a real converting power driver, as long as the voltage is not to high, and you enjoy the advantages of long declining output, which could mean severly declining.
It becomes terribly inefficent, if you want to be so fully regulated, and arent trying to get in the ZONE for its special properties.

I always wanted to write that :-)

take the example of running say 3xD Alkalines with a "driver" like this, starts out at 4.5v , for about 5 minutes :-) then basically that combo could direct drive ANYWAYS , pulling 2.8amps from the alkies they will choke down and you will be in DD. because the alklines wont really handle being slammed for big amps anyways, as the voltage droops , and its basically in DD, the load on the alkalines lightens up, and the weak alkalines deliver what they can, and the light runs lower and keeps on going.
BUT
Jam the 4th cell in, and you have to drop a good Volt for a while (20% loss of power efficency) and the poor thing is going to heat up a bit, and it might need a thermal path for that heat to go. the alklaines will drive it ok after a while, still be only capable of a max amp output anyways, and your into DD.
THEN
we jump over and shove 4x NI-?? D cells in the same thing, and now they maintain the voltage a lot stronger, and the poor leetel driver chip thing has to keep dropping a volt about and its really heating up, and your loosing efficiency, and then you got it Enclosed in a case, and it cant cool down, and mabey it doesnt do so well, and your wasting more power probably than a power converting driver.
THEN
switch to a 3Xni-?? or li-ion and your right back to clipping off the top a little while the voltage is to high, and then dwindling output forever.
Same IDEA
have it working barely OK with those little 3V lithiums primaries at the 6+volts, dropping well more than a volt, then switch up and try and use 3.7V (type) little li-ion rechargables, and the thing is going to Break completly.

the one thing i like to remember about Drivers, they A. sure as heck arent 95% efficent very often, and some can be less than 80% efficent, so when we drop 20% with a resister, WHO CARES :-) so do they. so its more about your preferances for regulation type and the input output.

its cheap, it has one singular purpose, it is efficent only if you like direct drive long run declining output, anything else a GOOD efficient driver becomes more power efficient, might handle better voltage ranges, acts more regulated, and depending on the driver , might not have a heat issue as much , due to converting instead of resistive clipping.

 

[VidPro]

By the way , now that i wrote a whole mess :-)

good cheap drivers for P7 , what does that mean ? nothing.
everytime i have to look for a driver, it is not Just the led, it almost ALWAYS is also about the Battery.
and what about control? did you want levels?
and what about how hard your going to drive the led, to "normal" specs they put in the data sheet, or the Max specs we all seem to enjoy?
you can drive a p7 with some of the really old drivers, to just "normal" levels.

so p7 drivers doesnt mean anything :-) without knowing your intended input source, at least, this is only 1/2 a question.:o
"where did you want to go today" as ms would say

 

[jasonck08]

Ok so I'll be more specific in what I'm looking for... I want to make a 3D maglite and have the P7 LED driven at 2-2.8amps. I don't care for modes, although I wouldn't mind them either...

Are there any tips and tricks someone can give me for using a DX or KD driver? Such as if you heatsink it well, maybe it won't have overheating issues?

 

[spencer]

If you are using 3D cells then I would say use the AMC option. Stephan FS has a tutorial on how to make one of these in the H&M forum.

 

[ace0001a]

DX has been having trouble getting the AMC7135 drivers. If you're just doing a 3D Mag using 3 D batteries, you don't need a driver unless you plan on using 4 C batteries in it. I have done many direct drive 3D P7 Mags and they run fine without any problems. Even if you use Alkalines, with a P7 they'll drop under load almost immediately (not 5 minutes) from my experience and end up being around 3.6V instead of 4.5V. But with Alkalines, the emitter will usually only end up seeing 1.8A because the batteries can't sustain high current output. In a 3D direct drive Mag, NiMH Ds are highly recommended or you can buy a 9AA-to-3D-Parallel adapter from mdocod and use 9 AA NiMH batteries. The benefits of using direct drive in a 3D Mag is that no power is lost to a circuit and usually you can run the batteries until they're near depleted (not recommended to go too far down with NiMHs) or completely depleted with Alkalines--all the way to the point of "moon mode".

Elektrolumens sold direct drive 3D P7 Mags last year and his CPFMP thread has alot of good info on it:

http://www.cpfmarketplace.com/mp/showthread.php?t=177152

 

[Mike Painter]

"Maglite 3D, EL Post Heat sink installed with SSC P7 LED. Up to 900 lumens!"
Check out electrolumens. Most of what he does is direct drive.

 

[ecotack]

I bought one from KD recently:
sku.1845 3.1v-4.5v $3.99

But, they sent me this one:
sku.5595 5.5v-15v $12.11

I wanted to run a Cree MC-E from a single 18650 (using 5595), fortunately it turned out that torch was two narrow for the 18650, so I used two CR123A. From fully charged CR123As I get 2.8A at the LED. Only problem I had was a +V track close to the edge shorted on my torches aluminium heat sink, burning out my switch (no other damage).

 

[jasonsmaglites]

nice informative post. im looking to build my first light with drivers. will this multi mode work with a mag switch.

http://kaidomain.com/ProductDetails.aspx?ProductId=1801

how does that work with the mag switch?

 

[VidPro]

nice informative post. im looking to build my first light with drivers. will this multi mode work with a mag switch.

http://kaidomain.com/ProductDetails.aspx?ProductId=1801

how does that work with the mag switch?

that uses the same 7135 chip thing, plus a bit of PWM for a low mode.
having only 3 of these 7135 things in it, it will output only 1000ma max.

The Levels on these things are changed by quick disconnection of the power, then reconnection of the power.

with a foreward clickee it is a little "harder" to get a quick connect quick disconnect but still totally possible.
like with a momentary useing fwd clickee , like the mag you Pop the switch PARTWAY down a couple a times to reach the "level" that you want, and then press it all the way down to keep it in that level.
This works out great, uless you want to continually switch levels back and forth after having the mag switch all the way on.

once you have the switch fully engaged for permenent on, you would have to fully unswitch it to change modes again.

so if you want to find a mode on turn on, then stick with that mode, the mag switch would work ok for it, once you figure it out.

IF you want to jump back and forth in levels, WHile the light is still on, and the switch fully engaged, then you will not like it.
potentially you could add in a secondary switch that disconnects the power (SPST Momentary normally closed) which could be used to do the power disconnect then use the main mag switch for a full disconnect.

 

[jasonsmaglites]

good info. thanks. where can i find some of those 7135 drivers that are single mode only. dx and kia seem to only want to sell a multi mode one.

 

[VidPro]

good info. thanks. where can i find some of those 7135 drivers that are single mode only. dx and kia seem to only want to sell a multi mode one.

i dont know they were both selling 750s amcX2 , 1000s amcX3 and 1400 amcX4 and 2800 amcX8 in 10 and 20 packs, then they ran out, and i donno why they arent restocking them?

 

[linterno]

Litemania sells that. Read Part 2 : Sgt. BURKETT _ 18650 Twisty EDC but go to first part (Sgt. BURKETT _ 18650 Twisty EDC). There you will find item #9-1. 7135 Driver : 4US$ each.

 

[dspencer]

New guy here and may be a stupid question, but in a 3d 3 Nimh Maglite with a Dbin P7 configuration, is there a problem with this? Also is there a mode board out there that will allow me at least a second output of between 20 and 30 percent.

Thanks.