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Obi1
05-26-2014, 01:49 PM
I'd been thinking about this idea for a long time now, how to build a color changing saber out of my first custom saber featuring a NB v1.0 (entry level electronics, well, compared to Hasbro, a NB is a formidable toy!).
At first my saber had one color. Then I made 2 connectors for my Cree XP-E RGrB module (red, green, royal blue) to be able to switch on 2 Colors at a time. For 3 connectors I did not have the space, and moreover it was not "dedicated" enough. I wanted to have real color mixing, not just switching. And then...

...:D I made it at last: a self-developed "color mixing engine" hooked to a NB v1.0. This little piece of electronics can mix the 3 base colors to get (theoretically) any color out of it, and it's close to be true in fact. It's also not magic, basically you need only a few components and it can be crammed into the hilt along with the NB.

What I like about it is the fact that it's totally in the spirit of Star Wars, a science-fiction world where all technical problems can be solved by a screwdriver and/or a well placed hit of a wench/hammer/whatever comes handy.

Here is a pic of the hilt (mix of TCSS and parts from other vendors, actually I picked one of the hilts I have , I still did not decide which of them will get this combo) and the chassis:
http://i1035.photobucket.com/albums/a432/Kunci1/2014-05-24_kicsi00005_zps27e9c0c6.jpg (http://s1035.photobucket.com/user/Kunci1/media/2014-05-24_kicsi00005_zps27e9c0c6.jpg.html)

Basically the idea is simple: I have 3 potentiometers controlling the gate voltage of 3 p-channel MOSFET's in a low-side driver configuration, which turns them into variable resistances, which are capable of delivering power to the individual LED's. By turning the potmeters with a screwdriver, I can mix the 3 Color in any combination and hue (I was insired by the cut-out scene from the Return of the Jedi, where Luke made final adjustments to his new green lightsaber with a screwdriver before setting out to Jabba's Palace). I will in the next days make some sketches of the schematics so that it becomes more clear what I mean. I also devised 2 different ways to do it:
- for setups needing more than the 2A spec'd for NB a bypass-technique
- for standard setups staying below 2A an integrated one

This is a pic of some of my favorite colors I mixed out:
http://i1035.photobucket.com/albums/a432/Kunci1/Lightsaber/RGB_mix_zps2c7d7df4.png (http://s1035.photobucket.com/user/Kunci1/media/Lightsaber/RGB_mix_zps2c7d7df4.png.html)

I also made a (maybe not so) short video to show how it works. Sorry for the coughing, last weekend the weather around here was rather Hoth :-? and I caught a bad kind of flue.
http://i1035.photobucket.com/albums/a432/Kunci1/th_DSC_2201_x264_zps49d7d024.jpg (http://i1035.photobucket.com/albums/a432/Kunci1/DSC_2201_x264_zps49d7d024.mp4)

MandoJoe
05-27-2014, 06:49 AM
Wow. Gorgeous work. I love it when Sabersmiths take what exists and modify it to do awesome things.

Obi1
05-27-2014, 01:39 PM
Thanks MandoJoe.

Now let's have the promised tutorial.

My first idea was to use potentiometers instead of serial resistances to adjust the resistance and thus the intensity of the individual colors. Simple and easy to do...BUT does not work quite as well in reality. On one hand common potentiometers are not designed to carry any power, else they get nasty big, on the other hand you need a high resistance in order to be able to fully switch off a LED, because these besties give out a decent light even with some tens of mAs.

In this way I came to the idea to use a potentiometer to control the gate of a MOS Transistor. First I tried with n-Mos (well, courtesy of having some at homr), it worked well, but when the saber was swicthed off, instead of no light, sudddenly all LED's switched on fully. I realized that the NB (and if fact all other LED Drivers from Erv) have a p-MOS low side Driver to drive the LED's, which for simplicity's sake means it connects the GND to the LED, while it's always connected to the battery. With some sketching I figured out how this can be used to make a color mixing without sacrificing all the marvelous FX's a Plecter Lab product offers.

I dubbed this add-on a "direct drive", due to the fact that the whole circuitry including the Color mixing is connected still between LED+ and LED-, see the schematics below:



http://i1035.photobucket.com/albums/a432/Kunci1/CMS_directdrive_zps26543ae6.png (http://s1035.photobucket.com/user/Kunci1/media/CMS_directdrive_zps26543ae6.png.html)




Basically the potentiometers can pull the gate of the p-MOS (I used IRLML6402TRPBF, because I had them as leftovers from another project) from LED+ (battery, in this case nom. 3.7V from a 18650 battery pack) to LED-. When pulled to LED+, the transistor turns off, shutting off the LED, when pulled to LED-, it turns on, turning on the particular LED connected to it's Drain.
The FX's like shimmering and vibrations are still there, because the p-MOS Output stage of the NB will still connect the GND to the color mixing circuitry. If the blade is switched off, the potentiometer will pull up the gate of the transistor to LED+ no matter where you tweak it, because the GND connection gets removed, so the mixed color will "retract".

I hope you will find this description useful if you ever decide to make a simple color changing saber. I already plan to have a NB v2.0, using the color mixing with a RGBW module, saving off the white LED for flash-on-clash.


------------------------- beware, this 2nd part of the tutorial is only for those who want to Experiment ----------




What comes now is part tried out, part speculations. This "direct drive" can be slightly modified to be able to get more power to your LED's than the absolute max Ratings of the NB of 2As. I tried out this configuration, dubbed "Bypass drive", because the power drawn from the battery(s) bypasses the NB, avoiding any damage to it.


http://i1035.photobucket.com/albums/a432/Kunci1/CMS_bypassdrive_zps2dbff0ca.png (http://s1035.photobucket.com/user/Kunci1/media/CMS_bypassdrive_zps2dbff0ca.png.html)


Difference to the direct drive is that the LED's are now between the Battery+/LED+ and Battery-/GND, the NB "only" controls the gates.
Cons: one big problem with this is that the FX's are dimmed, i.e. the NB will not be able to fully overpower the potentiometer if turned on fully to LED-, the blade becomes static.
Pros: Bypasses the NB, you can draw more than 2As from the battery to power your LED's. With a careful selection of the Vgs of the p-MOS, you can even compensate the above described Cons. I tried it with the above mentioned parts (under direct drive), and if the LED's were partly switched on, I could still see the shimmering if the values in the config file were tuned to extreme values, but with more light the blade turned static.

The main reason I described this method - albeits the Cons - is that - and here begins the speculations, as I never tried this but theory says it must work - this Bypass method can be used to supply your LED's with more than 3.7V, like using 2x18650 for 7.4V or 4xAA's for ~6V, giving you more power for the extreme powerful LED's.


http://i1035.photobucket.com/albums/a432/Kunci1/CMS_powerbypass_zpseb9a3e54.png (http://s1035.photobucket.com/user/Kunci1/media/CMS_powerbypass_zpseb9a3e54.png.html)


I dubbed it "power Bypass" and included 2 batteries to drive the LED's. This method could be quite complicated and needs a careful selection of the transistor you use. Due to the fact that the source of the transistor is at say 7.4V and the gate at max 3.7V, you need a Transistor with Vgs parameter below -3.7V in order to turn off the LEDs when the saber is turned off.

Don Se Wion
05-30-2014, 06:25 AM
Many thanks for the diagrams, it's a very interesting solution.

Regarding the bypass method and the problem with missing flickering, perhaps it's a problem caused by lack of proper load on the NB output.
I don't have a board to test right now, but I guess a possible test would be to wire one of the dies through the standard NB LED output to provide load and wire the other two dies through bypass.
What do you think ?

Obi1
05-31-2014, 10:07 AM
Buongiorno Don Se Wion! You brought me to an idea! It has to do with the load all right, point being the working point of the transistors in the NB on one side and in the driving ones on the other side. With the direct drive method the mixing Transistors all all fully open and therefore the current to the LEDs is regulated by the power stage of the NB in the linear mode of the driving transistor. In case the NB acts "only" as a control signal, it depends on the Ugs (voltage between gate and source) characteristics of the mixing transistors how far the NB can "modulate" the current to the individual LEDs.
I use p-MOS Transistors designed for low voltage digital signals, and has an Ugs= (-1V) (around). This means that it turns fully on very early and is already in the saturation stage at voltages where the NB tries to module it. That explains also why the modulation of the shimmering and co. works when the LED intensity is still low: the Color mixing Transistors are themselves in the linear Region like the NB Transistor.
Solution might be to match the driving transistor in the NB to that of the color mixing transistors, so that they are both approximately in the same working region.

What do you think, might it be the explanation?

Don Se Wion
06-01-2014, 03:30 AM
That's probably right.
Perhaps Erv can help us with the model of MOS transistor used on the NB to try another test.
I'm not that good at recognizing SMD devices :D

Knowing which MOS is used could virtually enable us to get the signal from the gate of the NB transistor to drive the additional ones, in the same fashion used to take the 3,3V signal from the capacitor on the left of the microcontroller used to drive an LED that turns off in deep sleep mode.

Obi1
06-02-2014, 04:47 AM
Me neither, and some of the parts on the NB do not have the markings any more (for sure on purpose). Going by the package does not help, alas I use the same package, but different transistors (Micro3 package). Next time I build a color mixing for NB I will anyway change the package type, these Micro3 devices are damn hard to solder in a hobby-home environment, and then I might ask Erv about some of the Basic characteristics of the MOS he uses (simple Output characteristics curve would suffice).
Another idea: although I never used a PEX, it's basically the same, just without the gate controlling potentiometers. They could also be used, although that would take up an aweful lot of space - welcome to cram-fu land.

Don Se Wion
06-02-2014, 03:12 PM
One thing I forgot to ask.
What are the specs for the pots ?
Something in the range of 100K Ohm or less ?

Obi1
06-03-2014, 01:35 AM
I used 1MOhm potis, mainly because my first idea was the bypass one and there the potis are connected all the time between GND and battery, drawing a constant current, being 3 of them in parallel would give ~3uA of quiescent current flowing. With the direct drive method you can use any, size matters the most.

Don Se Wion
06-03-2014, 08:54 AM
Many thanks again.
I actually have a saber in store for a friend that wants a purple blade, and we all know that the proper shade of purple is absolutely subjective.
I guess I'll try your solution to be able fine tuning the shade and be sure he gets what he wants, and perhaps to provide full colors, we will see.
It will take time, but I'll let you know the results ;)

Obi1
06-04-2014, 05:49 AM
Good luck with the build! Based on your saber I've seen so far you are a formidable saber smith, but maybe one though: use an activation box (I guess you would anyway), because even with small potis and small transistors, this mixing module takes up quite a lot of space. I'm still waiting for an activation box, because I cannot cram-fu the mixing module in while the switches still poke halfway through the hilt.

I'm exited to see the result.

Ps.: Another idea: if you do the build with a PC3.0 and Bypass the VR (i.e. using a single 3.7V cell), you have in-built color mixing capability without resistors using the main and the 2 FoC channels, this can even work with RICE, I tried it just the other day.

RobieRob
06-09-2014, 06:38 PM
Hey Ob1, I sent you a pm about part numbers, more than anything because we're not supposed to post outside websites here; any chance you could take a look and respond? Thanks.

Obi1
06-09-2014, 11:08 PM
Hi RobieRob, sorry, I was not expecting any, so I did not look! I will correct my grave mistake :) I'll get back to you in the coming days. It will also give me a chance to look for alternative parts.

Don Se Wion
07-02-2014, 10:49 AM
Hello Obi1,

As promised I have some updates ;)
I used SMD components to bring your diagram to life and I can say I'm happy with the result.

http://i952.photobucket.com/albums/ae9/DonSeWion/ColorMixingBoard/th_ColorMixingBoard001.png (http://s952.photobucket.com/user/DonSeWion/media/ColorMixingBoard/ColorMixingBoard001.png.html) http://i952.photobucket.com/albums/ae9/DonSeWion/ColorMixingBoard/th_ColorMixingBoard002.png (http://s952.photobucket.com/user/DonSeWion/media/ColorMixingBoard/ColorMixingBoard002.png.html) http://i952.photobucket.com/albums/ae9/DonSeWion/ColorMixingBoard/th_ColorMixingBoard003.png (http://s952.photobucket.com/user/DonSeWion/media/ColorMixingBoard/ColorMixingBoard003.png.html)

As you can see I used only two channels to tune purple, but the board is small and fits very well on my 3D printed chassis.
It could be even smaller if printed more professionally with photo-etching and not the old style as I did.

I also thought about a possible solution to have 3 channels and solve the 2A limit.
Two channels can stay under the MosFet from the NB to avoid problems and the third can be connected with a Power Extender.
The MosFET from the NB and PEx should be exactly the same, so it should be possible to wire the gate of the PEx to the gate of the MosFET on the NB.
This way they should work in parallel and provide all the juice needed for 3 LEDs.

Perhaps it's something to be tested sometime in the future.

Obi1
07-03-2014, 08:17 AM
Bongiorno Signore Don Se Wion!

I'm absolutely impressed. You made a much cleaner work of the intergration of MOSFET and pot than I did... Now it's time in turn for me to learn from a Master, what kind of pot's did you use, they look much smaller than the ones I used.

The violet color you mixed out looks fantastic, from the photo it looks just right for a Mace Windu style blade.

The idea with the 3rd PEX will work in my opinion. Probably the 2A limit might affect some LED's, the ones I use from Cree will never go beyond 2A even if t fully turn on all LED's, according to spec the max current is 700mA(R)+1A(B)+1A(G), totalling to 2.7A, but in reality you get the max intensity at a much lower current already (just experience). Knowing that PL builds a significant safety margin, I guess "standard" HP LED's can all be driven/mixed with NB...

Don Se Wion
07-04-2014, 03:17 AM
Hi Obi1

I used this trimmer (http://uk.rs-online.com/web/p/trimmer-resistors/1001240/?searchTerm=100-1240&relevancy-data=636F3D3126696E3D4931384E525353746F636B4E756D6 265724D504E266C753D656E266D6D3D6D61746368616C6C267 06D3D5E5C647B337D5B5C732D2F255C2E2C5D5C647B332C347 D2426706F3D313426736E3D592673743D52535F53544F434B5 F4E554D4245522677633D4E4F4E45267573743D3130302D313 2343026) (url embedded ... it was far too long to be posted)
Even if they are SMD, it's easy enough to solder them if you use a small tip on you solder iron.

Next time I guess I'll try to use a 500KOhm to see if it can make any difference, just out of curiosity.

I'm happy that you like the shade of purple I got, actually my girlfriend says it is a bit too pinkish, but that's why I say that purple is absolutely subjective.
Next step is to show the saber to his owner and check if he likes the shade too, elsewhere I'll change it.
The saber is using a LedEngine RGBW because the order at TCSS was made about one and half year ago (it remained in the box for a looong time at owner's home), but I also like very much Cree XP-E leds, they are my first choice when I can.

Obi1
07-06-2014, 12:45 PM
Gracia mille! I found the trimmers from a local source, they are already on the way!

TXATC
08-07-2015, 09:43 AM
Any updates here?

Obi1
08-09-2015, 12:12 PM
Hi TXATC,
In what sense ?

TXATC
08-09-2015, 05:41 PM
Oh wow hey!

Great job here Obi1! I saw this thread and was transfixed by it. I JUST finished my first pvc saber for a friends daughter and wanted to integrate your schematic in my 2 daughters sabers. I was just wondering if you had done this with v2 yet?

That's what I'll be using, and the TriCrees. I'm no electronics wizard but I can read a schematic. Did you try the Crees at all? I'm just trying to figure out the best way to go about this. Everybody says to use individual resistors for the dice, but from what I understand, you just used the pots and gates as variable resistors right?

The idea of being able to change the colors infinitely on a whim with a screwdriver is quite alluring. I love the idea and have already started planning my next 4 builds around your design. I'm glad you responded. Wasn't sure anybody was watching this one anymore. Any insight would be much appreciated. Thanks for taking the time, and again, great job and thanks for the schematic!

Obi1
08-10-2015, 02:38 AM
Hi,
Glad I can help! Although I did not try it with a NB V2 yet, it should work just as well. But to be sure I need to look into the manual. I recall the V2 has some Kind of FOC, well, although you can skip it, it might Need some consideration if you wanna use it (i.e. if you have a white die, you might want to use that on clash, but I guess the TriCree is called Tri cause it has 3 dice...). And yes, I did use Cree for this build, but any RGB will work. If you use the standard 3.7V battery, you only Need to consider a resistance for the red not to overdrive it too much. 1 Ohm might be a bit too daring, 2 Ohms more than enough.
It is also a good idea to design the hilt in a way that the potentiometers are accessible from the outside. That makes changing the colour much easier. With a PVC based saber hilt that should be not an issue,

Have fun and don't forget to post the pics!

As in the sommer I do not check Forums that often (being most of the time outside), please drop me a mail if I do not respond (kun.andras@yahoo.de)

Don Se Wion
08-11-2015, 12:53 AM
I can confirm the circuit works fine with a NB v.2, so far I think I assembled 5 or 6 sabers with this solution.

On my NB v.2 saber I actually used a 3-channels circuit to drive RGB dies, adding a third pair of trimmer/mosfet to the diagram.
In theory all colors could be mixed with this solution, but one should try to avoid having all colors lit at their max not to overcome the maximum capacity of the NB (max 2A).
Since I wanted FoC as well, I used a Cree XM-L Color LED.
It has RGBW dies and basically same specs as the XP-E (actually the red can run at 1000mA like the XP-E2).

TXATC
08-11-2015, 09:52 PM
Great! The xml was exactly what I was looking for. Correct me if I'm wrong, but did you run NO resistors at all? Just the pot/fet for rgb? Optics? I'm assuming because of the footprint, you just used a single die based lens? Any shots of the 3 pot board? Sorry for all the questions, as I said before, not an electronics wizard. But I can read the heck out of an instructable to find out how to do it lol!

Thanks for all the help guys! It really is appreciated.

Don Se Wion
08-12-2015, 12:48 AM
Well, you have to use resistors on the LED as if you would be using them connected to the NB board directly.
If my memory assist me, I used no resistor for Green, 0,5 Ohm for Blue, 2 Ohm for Red and probably 1 Ohm for the White since I didn't want it to wash out completely the blade color when lighting for FoC.
For the lens, I used the same 8.7 degree lens sold in the store for the Rebels, it works just fine.
Unfortunately I don't have any picture of the 3 channels board, but if you look at the picture I posted earlier it's just a little larger and fit the same spot on my chassis.

TXATC
08-12-2015, 12:15 PM
Got it, resistors still needed. Ohms law will take care of the values on that. Did you use inline resistors(spliced to the wire)? I was trying to fit everything on an etched board to fit in a chassis. Nice and clean like. I was thinking maybe smd's mounted on it. There's this little electronics shop here that will put a board together for me. I was thinking of using those but was worried about how much power they could take.

Edit: Nevermind, just retread the entire post again. Helps if you don't keep skipping pg 2. �� i guess I should have asked if you used the direct drive or bypass method for the xml?

Edit......again: I am a little confused. Maybe I am not understanding correctly. The xml red die with 3.7v/225 Vf @350ma gives me a 4.7Ohm 1W resistor. More than the 2Ohm you both recommend. I know I'm missing a part of the equation here. Any pointers in the right direction? I'd really like to actually understand why I need to use the parts I do, not just have you guys spoon feed me values. As always, thanks for your help and patience.

Tex

Don Se Wion
08-13-2015, 12:44 AM
Well, 350mA is the standard current specified in the LED datasheet, while the max current for the XML is 1000mA for each color (also from the datasheet).
Normally we apply Ohm's Law targeting the LED's max current in order to have the maximum light output as possible without pushing the LED too far.
In short words we can say the more current you feed to the LED, the more light it will produce.

I forgot to mention that you need to choose the proper wattage for the resistors, I normally use 2W resistors, good bargain between dimension and safety.
If you go for SMD, just be sure to tell the shop guys to use 2W or higher resistors.

TXATC
08-13-2015, 04:36 AM
Ahh, I think I see now. Instead of the standard current, we push closer to max, ie 500-700ma? Is it safer to do a midrange or can I just push to the max? More current brighter blade. Thanks for the explanation!

Forgetful Jedi Knight
08-13-2015, 06:13 AM
You could also just use the Prizm sound card (which was actually DESIGNED for color mixing) attach a RICE port, and accomplish the same thing, and get more fonts in the process. Once you have configured the colors you like, you can just save them, and you can then leave the tiny screw driver in the drawer.

TXATC
08-13-2015, 07:58 AM
Hey FJK,

I had considered that, but if I was to do that for 4 lightsabers, the mrs. would go all Palpatine on me! Those boards are definitely nice and when my girls get old enough to build their own, I will steer them that way. This is more of a "can I do it?" And "the girls have another thing to fiddle with and adjust" thing. This feels like I'm able to learn more about the circuits and workings this way. Maybe it's just me. BTW I've seen some of your stuff, awesome!

Tex

Elmarco38
11-25-2015, 09:40 AM
Cool Idea on how to get color mixing with NB. I'm currently doing almost the same thing only my circuit incorperates a counter IC to turn on and off the individual dies on the fly with an RGrB tri cree. My design only requires one extra momentary switch to cycle through all the available colors. I'm using N-channel enhanced MOSFETS to handle the current and actual switching of the LEDs. I've already breadboarded the prototype and it works. I might have to incorperate your potentiometer design to achieve true color mixing. Really great work.

Obi1
11-25-2015, 02:44 PM
Cool Idea on how to get color mixing with NB. I'm currently doing almost the same thing only my circuit incorperates a counter IC to turn on and off the individual dies on the fly with an RGrB tri cree. My design only requires one extra momentary switch to cycle through all the available colors. I'm using N-channel enhanced MOSFETS to handle the current and actual switching of the LEDs. I've already breadboarded the prototype and it works. I might have to incorperate your potentiometer design to achieve true color mixing. Really great work.

Great to hear that people try such creative enhancement of the existing saber boards! Hope to see the outcome once finished, Keep up the good work! Cheers!

was
11-26-2015, 01:13 PM
Just when i heard and wanted to mix colors using resistors and potentiometers this thread popped up on top :)

I like to try this way of mixing with the trimmer potentiometers. I tried to understand the diagram and drew a draft version with 4.5v source. What happens when the mosfets are removed? Can someone look at the draft and help me on my way so that i know how to know: which resistors, mosfets, potentiometers i need (and where i should add the resistors?). I want to make sure that 3 leds combined can't go over 2A (when turning all tree potmeters max).
Thanks in advance

12451

EDIT: i decided not to mix colors

NoSloppy
06-09-2016, 11:24 PM
First post. Hope I'm not breaking a resurrecting-old-threads rule. Just wanted to say thank you for this awesome creative idea. Using the diagram and parts listed in this thread, I soldered this up last night. It's a 1 inch board. Works great on the bench with battery as source. Next to test with Nano Biscotte v3. I am wondering if the flicker is going to come through.

I had to slant stuff due to SMDs on premade breadboard without adapters. It works for version 1, plus it keeps the size down and less work adding additional components.
Each color is slightly laid out differently as I modified as I went along, but essentially it's the diagram, which I made after seeing the best way. Other jumps and stuff could be done of course, this just worked for me with what I had. Took me about an hour total. Again, THANK you!
1412214123141241412514126

Cire Yeldarb
06-10-2016, 11:47 AM
First post. Hope I'm not breaking a resurrecting-old-threads rule. Just wanted to say thank you for this awesome creative idea. Using the diagram and parts listed in this thread, I soldered this up last night. It's a 1 inch board. Works great on the bench with battery as source. Next to test with Nano Biscotte v3. I am wondering if the flicker is going to come through.

I had to slant stuff due to SMDs on premade breadboard without adapters. It works for version 1, plus it keeps the size down and less work adding additional components.
Each color is slightly laid out differently as I modified as I went along, but essentially it's the diagram, which I made after seeing the best way. Other jumps and stuff could be done of course, this just worked for me with what I had. Took me about an hour total. Again, THANK you!
1412214123141241412514126

Nice! what are you going to put it in?

NoSloppy
06-10-2016, 12:30 PM
Saberforge Epoch dual tone hilt.

**EDIT** maybe. so small inside.

Hey, am I going to have an issue with this on the Nano Biscotte V3...the board has a 2A max, no? Running all 3 dice, yes, but since not all at full blast....ugh. Here goes the math again.

Don Se Wion
06-13-2016, 12:47 AM
A common workaround for this problem is to install a Power Xtender (http://www.thecustomsabershop.com/Power-Xtender-20-P652.aspx) in parallel to the LED transistor do double the power rating.
If you look around here or at FX-Sabers you can find the instructions about how to wire the PEX for this application.

NoSloppy
06-13-2016, 11:29 AM
It's working as is....I am not driving more than one LED 100% at a time so it seems to be happy without getting out the meter and math right now. Also I barely fit everything in the hilt as is. Had to change to a wired battery instead of a holder and some serious cram-fu of the wires (there's 8 coming off the LED alone with 3x .5 5W resistors and a ceramic 1.5...all in the choke...WITH the switch...all in a unibody hilt. UGH.
Thanks for the reply.

Aziara
01-03-2017, 04:12 PM
Sorry to resurrect this thread, but this is very close to what I want to do with my current build.
Can this be done without a board? I'm trying to save money on my build by leaving out sound (I dislike the noise anyway. *ducks* Nobody lynch me please)
What works in my head is to have the proper resistor on each positive led wire, then the potentiometer (I understand that wiring only one outer prong and the center prong of the potentiometer makes it a variable resistor), then splice all positive together and all negative together and connect them to the battery wires.
Will this work, or am I making a huge rookie mistake?

Don Se Wion
01-04-2017, 01:19 AM
Technically the solution works, but has something to be taken into account.
The majority of the potentiometers does not support currents up to 1A, which is pretty common with the LEDs we use today.
A required workaround is to put the potentiometer in series to the proper resistor for each LED.
This way the fixed resistor will take out the majority of the voltage drop (and obviously wattage/heat), but it remains an inefficient method.
Honestly I warmly suggest to drop the idea and try to use this circuit.
It's not that difficult all to build it, as you can see few posts up.