Where/how do I learn the basics of flashlight mods?

DHart

Flashlight Enthusiast
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Jan 8, 2009
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Oh, where to start; where to learn?

I'm finally at the point where drop-ins aren't quite doing it for me anymore (ya know the feeling? ;) ) and I am really interested in steeping up to some basic mods... like changing a driver or an emitter... things like that. I know nothing about doing this kind of thing and even though I own a soldering gun, I have no idea where to begin learning the basics of driver circuits, soldering, emitters, flashlight electronics.

I'm wondering if I should just buy a couple of bare emitters, a few driver/circuit boards, and P6 reflector and try to put them together? But I don't know what to buy or where to start. I've got plenty of Surefire & SF-clone heads, bodies, and tailcaps to host my concoctions.

Any suggestions on where to get started learning flashlight electronics? I'm super eager to get into this! Whatever suggestions or links to tutorials would be greatly appreciated. Many thanks. lovecpf
 

Greg G

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Oct 17, 2007
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Exactly which SF clone hosts do you have? Modding one of those can be pretty intense. I think a good first mod would be a Maglite. You can buy all of the parts and assemble it yourself. Something like a quad or penta Cree mag would be cool. You could build it on a 2D Mag host, and get the parts from the Sandwich Shoppe, except for the Cree emitters.
 

VegasF6

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Dec 5, 2007
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To me, the best place to start is on the bench, not in a flashlight.

Take a look at the drivers availible from all the usual suspects. Order some cheaper ones and some emitters.

Mount a led to a pc heatsink, set up some various battery holders, and pick up 4 cheapie dmm's. Or you can get a small variable power supply for about $75.

Also pick up some 5mm leds, perhaps of various colors, an assortment of resistors, some diodes and caps.

Choose a project from instructables.com and build you something maybe. Browse around national semiconductor website, it is really an awesome site.

Then you can worry about cramming it all into a flashlight.

I would say start with resistors, and linear regulators then consider switch mode power supplies. Once you start getting a feel for how it all works it kind of takes the mystery out of things.

There is a thread I was watching about someones test bench, but I can't find it :) You can imagine what it would be though, pretty much what I said above. A heatsink, a power source, some quick connects and alligator clips, meters etc.
 

Greg G

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Oct 17, 2007
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772
The most important thing to remember about modding IMO is to never let the LED + wire short to ground. You'll pop a converter board if that happens.

If you become a fanatic about that one thing you'll save yourself a lot of money.
 

Justin Case

Flashlight Enthusiast
Joined
Mar 19, 2008
Messages
3,797
Oh, where to start; where to learn?

I'm finally at the point where drop-ins aren't quite doing it for me anymore (ya know the feeling? ;) ) and I am really interested in steeping up to some basic mods... like changing a driver or an emitter... things like that. I know nothing about doing this kind of thing and even though I own a soldering gun, I have no idea where to begin learning the basics of driver circuits, soldering, emitters, flashlight electronics.

I'm wondering if I should just buy a couple of bare emitters, a few driver/circuit boards, and P6 reflector and try to put them together? But I don't know what to buy or where to start. I've got plenty of Surefire & SF-clone heads, bodies, and tailcaps to host my concoctions.

Any suggestions on where to get started learning flashlight electronics? I'm super eager to get into this! Whatever suggestions or links to tutorials would be greatly appreciated. Many thanks. lovecpf
Read the CPF FAQs to learn a little about driver boards, LEDs, forward voltage, constant current, regulation, etc.

For soldering, Google will give you many sources on how to do it. After reading, though, you really have to get some hands-on. Get some cheap, throwaway DX components (e.g., reflector/pill/spring kit, Cree P4 emitter on a 14mm base, 17mm diam driver board) and put together a simple 6P drop-in. Practice soldering wires to a driver board, connecting wires to an emitter (bare, or mounted on a base or a star), applying thin layers of thermal compound and thermal epoxy, etc.

Figuring out which driver board to select will give you some hands-on in matching a product with specifications (i.e., what driver board voltage range, drive current, etc to pick for a given LED, desired lumens output, run time, envisioned battery configuration, etc). DX has a lot of driver boards to examine and select -- boost, buck, linear regulator, single mode, multimode, various drive currents, various input voltage ranges.

Another nice, slightly more advanced project is to build one of AW's Turbo towers (search the CPF Marketplace Dealer's Corner). PM me if you want some guidance on selecting a driver board and LED.

A fairly easy project, if you have a Blackhawk Gladius, is to upgrade the Luxeon II to a Seoul P4. The hardest part might be opening the head.

An approachable, follow-on project could be one of those Maglite mods for a Cree MC-E or Seoul P7.

Then, you can start looking on CPF at the various projects others have done and figure out for yourself what is within your interests and capabilities. Cracking open a SureFire KL4 and mod'ing it for a Cree MC-E could be the next step.

For a soldering iron, even one of those cheap $10 Radio Shack pencil irons is probably good enough to start. It is nice to have a better iron though at some point. The Xytronic 379, Hakko 936, and Circuit Specialists CSI Deluxe Station all seem like good choices (I need to get one of these for myself!).

Handy tools/supplies (besides the soldering iron and solder):

- Digital multimeter
- Lux meter
- Fujik thermal compound
- Fujik thermal silicone glue
- Arctic Alumina thermal compound
- Arctic Alumina thermal epoxy
(the Arctic Alumina products are preferred, but they are much more expensive, so maybe just get the Fujik stuff first, which is very inexpensive)
- regular hardware store epoxy
- diagonal wire cutters
- Teflon-insulated, stranded wire (various gauges, but certainly 24 ga and 26 ga, and various colors). Very useful for wiring up various projects. Standard PVC-insulated wire is much harder to solder neatly to flashlight electronics because the PVC tends to shrink/melt back when the soldering iron gets close.
- small magnets (useful for connecting batteries in series temporarily, etc)
- test LED (e.g., a bare Luxeon I emitter or even a Cree P4 on a 14mm base) mounted on any sort of metal substrate for a heat sink -- Put down some thermal compound under the LED and then apply some regular epoxy around the periphery of the LED to secure it to your makeshift heat sink. No sense in wasting expensive Arctic Alumina epoxy. Solder wires to the emitter terminals and also solder some small alligator clips to the ends of the wires. You can easily test driver boards for function with this test LED, measure driver board current, etc.
- needlenose pliers
- sharp knife (like an Xacto knife)
- third hand soldering stand, with magnifier
- tweezers
- isopropyl alcohol (good for cleaning things before soldering, cleaning the gummy Seoul emitter domes). Don't get IPA with colored dyes or perfumes.
- microfiber (lintless) cloth (such as for cleaning AR-coated eyeglass lenses)
- jeweler's screwdrivers

Edited to add: A Dremel tool can be another useful tool. The jeweler's (pecision) screwdrivers are usually available at Radio Shack. Same with the third hand (also on Amazon). Magnets, Arctic Alumina stuff available from Lighthound and-or The Sandwich Shoppe. Deal Extreme has low prices for basic electronic components. PhotoFanatic is a great source for LEDs and Arctic Alumina. Mudman cj sells teflon wire. The Fujik stuff is available from Deal Extreme.
 
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kosPap

Flashlight Enthusiast
Joined
Mar 1, 2007
Messages
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Location
Naoussa Greece
good job Justin.....

No may I suggest something to all?

How about the really experienced guys setup a workshop for newbees at the next CPF meet?

Topics might be:

-P60 module assembly
-Maglite Switch dissasembly
-Resistored Drive and Seies and Parallel Connectons theory
-Soldering skills
-Demo of tools like step-drills, dremel bits etc

Just an Idea....
 

DHart

Flashlight Enthusiast
Joined
Jan 8, 2009
Messages
2,436
Location
Sonoran Desert ~ Scottsdale, AZ
Wow.... Justin, Vegas, Greg... you guys are awesome for your help. Thank you so much! (I'm sure other newbies around here are really appreciating your time and suggestions as well!) The very specific recommendations are really helpful because between acronyms and the vast array of different spec'd components, it really is easy for a newbie like me to get stuck.

I've been pouring through threads here and elsewhere on the web gathering some basic knowledge and trying to connect the (sometimes) widely spaced dots... I will start getting some of the recommended supplies and tools and dive in! And if anyone else has any other specific suggestions or recommendations, or links, I'd sure appreciate hearing them. :) Thanks, guys, from me and probably a lot of other newbies who read this now or will read it in the future.
 
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