first mod - can you walk me through this?

[jeremiah]

Hi all, new to all this but dead keen to have a go. Been reading heaps here, but still a bit confused, so I'm hoping I can get some specific answers to questions.

I have a 4 D maglite which I never liked much, but now I thought I would dig it out again and do a P7 mod. I've got a couple of questions, and I was wondering if I should put them all into one post which I keep alive until it is done with photos, or if I keep one post per question?

Anyway, the first is, what's the deal with drivers?

- It seems to me that they are for converting the voltage from what you supply to what you need, and evening out the supply on the way.

- It seems that the voltage supplied should be a little more than what you need, because the drivers reduce, not increase voltage?

- The driver you choose has a lot to do with the battery configuration you choose, because different drivers need different input voltage.

- Would it be too much to ask someone to post a list of drivers which will run a SSC P7 at 900 lm and what are the advantages of each (or tell me how to tell one that will do the job from the specs)

Thanks a lot, really looking forward to this, hope someone can straighten me out!

 

[Linger]

Hello,

Really you need to get used to searching. More information is already written and if you could just learn how to find it quickly you'd be much happier than posting and waiting for the inevitable off/topic responses.
But, as a :welcome:, here's a few.

I've got a couple of questions, and I was wondering if I should put them all into one post which I keep alive until it is done with photos, or if I keep one post per question?

Ideally you don't make any new threads, instead you'll find posts recent that already discuss the issue. Like there's a lot of P7 m@g mods out there...lots of full guides illustrated with pictures.

Anyway, the first is, what's the deal with drivers?
usually they keep you from frying the light source, give you a longer run time, also drivers let people get different outputs from a light
- it seems to me that they are for converting the voltage from what you supply to what you need, and evening out the supply on the way.
some of them called 'buck' drivers do, while 'boost' drivers require a lower vbatt than vf (voltage forward to the emitter)
- It seems that the voltage supplied should be a little more than what you need, because the drivers reduce, not increase voltage?
sometimes, see above. Usually for most efficiency the battery and emitter voltages are close
- The driver you choose has a lot to do with the battery configuration you choose, because different drivers need different input voltage.
Desired outcome, or the parts you have to work-with, determine what happens. Really everything is negotitable. E.g. deciding you wanted a light that went 'low, med, high' for modes would mean only a few drivers were an option, and with possible brightness you'd narrow the field down right quick.
- Would it be too much to ask someone to post a list of drivers which will run a SSC P7 at 900 lm and what are the advantages of each (or tell me how to tell one that will do the job from the specs)
Yes it would. Ridiculously. But search user TorchBoy, iirc he has a list of drivers in his sig line.
In the best of faith, I tell you that if you manage a light that gives 500 lumens out the front for more than a minute after turn-on, you'll be doing very well for a first build. Advertising always over-rates things...don't get held up thinking you'll get 900 lumens from a P7. And then with sagging power supply and waste heat building up, most builds see a significant percentage decrease (so it could turn on at 650lumens and be 500 after 30 seconds)
Thanks a lot, really looking forward to this, hope someone can straighten me out!

You got lots to learn, and you're in a great place for it. My hope for you - build something, anything. Aim for $20 budget (for emitter, driver, reflector/optic, host, batteries? and whatever you can salvage for free), and see what you can do. After you've finished your first light, you'll understand more about how you should have built it. This continues with each project you finish. Keep the lowest budget for your first few lights, expect to tear them apart at some point in the future.

 

[PCC]

Aim for $20 budget (for emitter, driver, reflector/optic, host, batteries? and whatever you can salvage for free)

$20 is a low budget. It's do-able but you would be scrounging, hard, for parts to meet that. The emitter itself blows that budget. I would shoot for something like $40 or $50.

I built my C-bin P7 MagLite for $40 or so. The emitter was purchased a few years ago from DX and I bought the driver from KD. Both add up to about $36. I then made my own heatsink and used salvaged 18650s from a bad laptop battery pack so I cheated. It makes 500 lumens OTF so it's not bad, though a better bin would give me a few more lumens.

As far as your project goes, jeremiah, your light is a longer 4D model and that can be good and/or bad. Good in that you have room to fit more batteries and don't need to use Li-Ion batteries or AA battery adapters to increase the voltage but bad because you are carrying a heavy baseball bat around. Lights like that usually stay home or in the car so they get limited usage. For this very reason I would not feed it alkalines as alkalines left in lights for a long time destroy more flashlights than you can imagine.

 

[jeremiah]

Thanks for the reply Linger:

"Ideally you don't make any new threads, instead you'll find posts recent that already discuss the issue. Like there's a lot of P7 m@g mods out there...lots of full guides illustrated with pictures."
Fair enough, if I just wanted to follow along I'm sure I could, but most such threads don't say much about the "why", which is really what I'm interested in here. Teach a man to fish....

"search user TorchBoy, iirc he has a list of drivers in his sig line."
thanks, will do.
and PCC,

"For this very reason I would not feed it alkalines as alkalines left in lights for a long time destroy more flashlights than you can imagine."
Now that wouldseem a shame. Mine would come out fishing with me so it won't be wasted. I have more questions about batteries later, but I'm in Australia and NiMH batteries seem to be the standard for rechargeables here (maybe everywhere, I don't know), so I was thinking along the lines of using these.

 

[cdog]

8*7135 driver will be perfect for your setup. 6 volts is max, so four D alkaline = 6 volts. it also works great with 4 nimh battery.

 

[Linger]

nimh's a great starting point. (get low discharge, I hope)
A key decision in the light is what sort of battery tech you are comfortable using. Low discharge nimh's could be a great place to start and can be a great supply for a P7 m@g. The driver cdog suggested (the ShiningBeam 3mode 8x amc7135) is a good option.

>" but most such threads don't say much about the "why", which is really what I'm interested in here.

I'll bite, what does this mean?

 

[jeremiah]

I'll bite, what does this mean?

well, mostly a tutorial will say "I used this driver" or "I used this battery config", which is great if you want to do exactly the same thing, but if you want to learn and to do your own designs, you need to know something about why they did it that way, that's all.

I'm already learning plenty from the replies.

I suppose it is a bit like the difference between reading a manual and having a chat with someone who knows.

 

[Mettee]

I think what the OP is getting at is that he wants to make a perfect recipe, and he wants to know why the perfect recipe is perfect. He isnt finding the answers in his searches. And I agree, this stuff can be hard to understand when your new.

I agree with your post and I think it was fine to post a new thread on it asking questions about a deeper answer.

I would ask what you are going to use the light for first?

Do you want it really heavy or really light? Or do you not care?

I think a P7 is a good choice for this format, there are other options but the P7 is good to work with.

A P7 mod will cost you a bit more unless you are planning on making your own parts such as a heat sink and or driver. Heat sinks range from 20 to 30 shipped usually from sources here on CPF. A driver or regulated board that supplies the proper voltage at the right current can be had for as little as 10 shipped to as much as 30+ shipped. Then you need batteries and depending on what you chose in your recipe that will give you your cost. I would chose what type of battery you want first, that will tell you the range of drivers/boards you can use or vice versa. You already know that you are using a P7 and that tells you that you need about 3-4v and 2.8a. You could direct drive a P7 as well, meaning no regulation, but the batteries have to be perfectly matched as to not kill the led.

So you are starting with a P7, they are typically a 3-4v LED that needs 2.8amps to be run in spec. The LED binning is what tells you its performance specs.

So a combination of batteries that you chose has to be about that voltage(3-4v). Now in some cases you would use more voltage, say when you have a "buck driver". There are many rules to be applied with a buck driver depending on the recipe of parts, I dont want to get into all of them here. The driver you chose needs to be closely matched to the LED and supply it with the right current at 2.8amps as well(for P7). So both voltage and amperage needs to be set to the LED specs. Sometimes in certain cases you can push the voltage and amps to get more performance as well, meaning with incans and led.

But the incan rules and led rules dont really cross over completely. So you will have to learn them both unless you only care about led.

Here are a few links that I learned from

Triple P7 build tutorial
http://www.candlepowerforums.com/vb/showthread.php?t=230807

Driver list and battery info, this is a huge list of different things
http://www.candlepowerforums.com/vb/showthread.php?t=133440

Hope that helps...

 

[old4570]

Hmmm , cheapest SSC P7 ive seen is about $13 shipped ..
Heatsink ??

Driver ?? what batteries do you want to run ??

4D mag ?? 4 x 1.2v Nicads = 4.8v or more like a bit over 5v
So the SB and KD 4.2v drivers should be able to handle that ...
The set up would also run on Alkalines and dry cells but with less output .

You need to decide on the power source , and work from there .

 

[Linger]

/OT - with the $20 cap, I wasn't suggesting using a P7. Again the premis of starting with a >$20 diy mod is that the creator doesn't feel intimidated by it, and there's no incentive to ponder over little choices and its about getting the creator to that feeling of success with a first build light (I hate the wandering 'uber build' threads where you just know the first post newbie isn't going to ever build the monster)

jeremiah , still some key choices to make re: what performance expectations does this light need to meet.
Best,
Linger

 

[PCC]

@ Linger - Gotcha. Just do a mod, any mod, get the success and progress from there. Start with a lower budget mod so that it isn't as intimidating so that the success rate would be higher.

WRT to battery and driver choices: When you are in the design phase of modifying a light you have to decide on what types of batteries you want to use in this light based on what driver you want to use. There are drivers that do many different things: single-mode, three-mode, multi-mode programmable, etc. A single-mode is a simple on/off affair. Three-mode drivers offer three modes (low, medium, high, for example). You need to research the features that you want and figure out of the particular driver will work for you and your choice of LED. These different drivers have different voltage requirements. Let's say, for example, that you want to run a TaskLED hipFlex driver to power your P7. The hipFlex is a buck driver so your battery voltage has to be higher than the Vf of the LED. The hipFlex has a minimum input voltage of 7V so you would need at least two Li-Ion cells or six NiMH or alkaline cells (based on the voltage drop under load). Now, your light is a 4-cell Mag so you have plenty of room for two of the largest Li-Ion cells you can find but not enough room for 6 D cells. Putting a sleeve into your Mag for C cells would only allow for 5 C cells, which isn't enough. You could use 3AA to D adapters and fit 12 AA cells in there but think about the trouble of charging and matching those 12 cells! An alternative would be to run two or three Li-Ion cells and a spacer to take up the difference but that means that you have a longer flashlight than you need unless you want to use it as a club and need the extra length.

Boost drivers require less input voltage than the Vf of the LED.
Buck drivers require more input voltage than the Vf of the LED.
Typical white LED emitters have a Vf of between 3 an 4V but most newer ones are in the low 3V range. P7s, being a multi-die emitter have a Vf of around 3.6V.

It took me about a year to figure out what I wanted to put into my first mod, buy the parts, and assemble it. Most of that was because of indecision or just not having the money to buy a part because I wanted to order too many parts at a time. Now that it's done I want to take it all apart and rebuild it with a different driver, heatsink, batteries, essentially rebuilding it all over again, moving the parts over to a smaller host to give to my son. In the end it's really satisfying using the light and showing it off to people who look at it and expect a meager 50 lumens of spotty incandescent beam only to get a 500 lumen wall of light.

 

[jeremiah]

OK, so its starting to come into focus (excuse the pun).

I don't really want to mess with Li-ion batteries yet unless someone can tell me that they are amazingly better. I know they are lighter, but not too fussed about that for now.
in terms of preferred power source, I will probably stay with the D-cell batteries, and use NiMH. I price 4 of these out at just under $100 AUD from jaycar, which makes it by far the most expensive part of the project, but for me it has to be rechargeables of some kind.

For the driver, I am after at least three power modes (don't care about strobe), and any features that give high power and long burn time.

Thanks for explaining the buck/boost driver, is there any reason to choose one or the other except to match battery configuration?

In terms of need/end use, the main use will be taking it fishing so i can spot things in the water at night, and the 4 D is good for a bit of security there too in lonely spots late at night. Having a bright light makes me feel a bit safer too.

I have actually recently pulled apart a dynamo 5 LED torch with a broken dynamo, and am figuring out what to do with it. When freshly "wound" it is pretty bright for what it is, so I might put it in a new housing and run it off batteries (the little rechargeable pack in there was 3.6 V). So I shall run that in parallel as my low cost project.

One of these days I would like to build a head lamp, a flood light for night squid fishing, some grow lights for indoor plants...... but I figure the P7 mag is a good start but a serious light.

Thanks again,
J

 

[Linger]

It took me about a year to figure out what I wanted to put into my first mod... Now that it's done I want to take it all apart and rebuild it

Exactly! That is the meaning of, 'when you finish the first light, then you will understand how you should have made it.'
If I'm successful, Jeremiah will hack together a >$20 light (maybe that little dynamo number?) before the m@g mod that is this threads namesake gets done.

PCC, if you just want a show-off light, consider a few hundred mah 3s lipo pack from HobbyKing (say $5=3s,11.1v@550mah) and a $1.60 Hikari JC5607 6v20w mr11 bulb. For under $8, you can have a many hundred lumen (+950lumen to 2K lumen, depending on who's test results you look at). The bulb prongs fit right in the JST plug of the battery, the whole unit fits in the palm of your hand (or hides inside a coffee cup). Anyway, point being if its just a show-off light, incan is totally the way to go, very cheap and easy options.

Decision triangle of lights.
Choose any two:
Bright // Long run time // cheap small battery

 

[PCC]

For my 2D Maglite it's not strictly a show-off light so I want to keep it LED for longer run times. Had I wanted a "WOW!" light I would have built a ROP.

jeremiah, I think you would use a buck driver for the 4 NiMH config. Someone correct me if I'm wrong, here.

 

[jeremiah]

I've been wondering what an incan is, and I just figured it out - incandescent!

soon I'll know what I'm doing!

here's one I haven't figured out yet - what is binning, C-bin etc?

 

[Linger]

Jeremiah, google for the spec sheet for the P7, (maybe try typing in 'seoul semiconductor p7 spec sheet'). I've got the pdf's for most emitters on my laptop. Anyway, emitters are sorted by various ways, including tint, working voltage (forward voltage), and output (flux). Your question is about the rated output of the P7's, the higher the letter the brighter the emitter. D bin's are the best P7's presently release, C bins are a few years old, not as bright and should be available cheaper.
For example, I put a nice vanilla tinted 'D' bin in a torch for a field search (i wanted bright and efficient), and used the B bin I removed for an auxillery task light (slaved to a 4D camping lantern base as a power supply).

 

[ti-force]

I have these handy, so I thought I'd post them. Linger has explained this to you, so I'm just supplying the charts mostly. As an example for these charts, I'm going to say you're looking at an SSC P7 emitter with the following binning: CSXPI.

This is the luminous flux chart. You will use the first letter of the emitter binning with this chart. CSXPI. The "C" is the luminous flux bin. You would use the chart below to find C and its relative luminous flux for the specified drive current in the datasheet.

Here's the corresponding chart for the next three letters CSXPI, which represent the color bin of the emitter. By looking at the chart, we can find SXP and that tells us that this emitter will have a tint of around 6700K (6700 on the Kelvin Scale):

And the corresponding chart for the last letter CSXPI which represents what vf (voltage forward) the emitter is:

I'll only add one more thing. You should keep in mind that this is the way Seoul Semiconductor bins and labels their emitters. What I mean is, if you go to Cree or Luminus, the charts, labeling and binning will be different. They basically give you most of the same information, but each one has their own way of doing it. I say tuh-mey-toh, you say tuh-mah-toh .

 

[Mettee]

ti, good help there. Reading those charts can be mind numbing, but after a while it will get easier. That is a great learning tool.

J, sorry I should have typed out incandescent in my post.

 

[SmurfTacular]

If you want a Hi-Med-Lo driver to power a P7, you should use this one. Really easy to use, and its inexpensive; great for a first time Mag modder. You would also need a Maglite P7 heatsink witch could be found here, and the P7 can be bought either here or here. And your going to need some thermal epoxy to glue the LED onto the heatsink witch could be found here. Other tools you'll need are a hack saw and a soldering iron.

 

[Mettee]

Whats the hack saw for?