Using a transistor as a switch/amplifier with a Force FX board

[Matt Thorn]

I have been poring over my electronics books, the Internet, and scouring the forums, but I just can't get this to work.

Some of you may have been following this thread (http://forums.thecustomsabershop.com/showthread.php?t=10288), where smarter folks than me figured out a great way to use a high-output PNP transistor to both 1) boost current to the main LED and 2) do the job that a relay would do.

Well, I've been trying to do the same thing with a Force FX board, but have had no luck.

One complicating factor is the clash sensor of the positive line coming from the Force FX board. (With the 2010 Electronic Lightsaber board, the positive line from the board is not used at all, and this poses no problem.) So I tried doing everything backwards, and using an NPN transistor instead of a PNP transistor.

If I've lost you already, either I'm not explaining well enough, or you don't have the electronic expertise necessary to help me out here. ;)

I've heard plenty of people say that transistors are much more efficient than relays, yet I haven't heard of anyone using one with a Force FX board. Maybe that's because in most cases, the Force FX board provides enough current for the LED.

In my case, I'm using a LedEngin RGBA, with a 16-position rotary switch, so in some cases only one chip will be on, in other cases all four chips will be on. The board does provide enough current to light the LED, but it's not nearly as bright as it could be, and that's why I'd like to use a transistor.

I'm using a Yoda Force FX board and 4AAA alkaline battery pack.

Can any of our electronic wizzes out there toss off a diagram, or is this just not possible for some reason?

[FenderBender]

Alkaline AAA's put out less than 1A or 1A max. You can't pull more than that. Change to LI-Ion 18650s and see what happens;)

[Rhyen Skytracker]

Are you talking about the Yoda Force FX as in toy saber or the Yoda FX as in MR/Hasbro? Also, do you have pics of the board?

[Matt Thorn]

Thanks for the responses.

Fender, I think you may be mixing up mAh and mA. The AAAs have an mAh of 1000, but using the same 4AAA set-up and a BD242 PNP transistor, I was able to boost the paltry 21mA output from a 2010 Electronic Lightsaber board to 1180mA, and I recall Rhyen saying he was able to get much more current using a TIP42 transistor using AAAs.

I would prefer to use Li-Ions, but the guy I'm making it for wants alkalines, and it's all going into the teeny, tiny space of a Korbanth Luke ROTJ hilt. (Color-changing, no less, with a Hero-style control box with triangular LEDs that actually light up.) So 4AAAs is the best I can do. As you can see from the photo and video, I custom-made a battery-case/chassis (3D printed by Shapeways (http://www.shapeways.com/)), so there's no turning back.

Rhyen, I mean "Force FX" as in the "high-end" saber boards, not the toys. (Although there's a "Force Action" toy, I'm pretty sure that "Force FX" is used only for the high-end MR/Hasbro sabers.)

http://lh3.ggpht.com/_THBqz9vPciU/TJdRBfSaBCI/AAAAAAAAFgw/7T3rLqlZp9c/s400/DSCN0372.JPG (http://picasaweb.google.com/lh/photo/W82K4b9sHCd5N3qRYhTSCw?feat=embedwebsite)

http://lh3.ggpht.com/_THBqz9vPciU/TJdRZ1QQTeI/AAAAAAAAFhE/vuGZRGAIXfo/s400/DSCN0373.JPG (http://picasaweb.google.com/lh/photo/FFZVFtItMEudyF6cnKkvfA?feat=embedwebsite)

http://lh4.ggpht.com/_THBqz9vPciU/TJdRatee0CI/AAAAAAAAFhM/6ck_Vyo61HM/s400/DSCN0374.JPG (http://picasaweb.google.com/lh/photo/TaxpQj9uCwE0rivNlFrhHQ?feat=embedwebsite)

http://lh3.ggpht.com/_THBqz9vPciU/TJdQ_57QknI/AAAAAAAAFhU/RwkBh5NaUBA/s800/DSCN0371.jpg (http://picasaweb.google.com/lh/photo/j-PS1pxfNKgTbrqSCng-dQ?feat=embedwebsite)

[Rhyen Skytracker]

I was able to get around 1530mA using AA NiMH batteries not normal akaline batteries. I think with the AAA NiMH I was getting around 1300mA. You can get around 1200mA straight from the Yoda board by connecting all the 6 negative wire together. I would do that than to try to use a transistor. You can try the transistor by putting all 6 negative wires together and going to the base of the PNP transistor. I never use a transistor with the Yoda FX board because it puts out 1200 mA.

[FenderBender]

No, I wasn't mixing MA with MAH. AAA's don't put out much more (if at all) than 1A under load. AA's will put out more, and AAA NIMH's will, but not alkalines. You're just not going to get much more MA out of alkalines without a driver that converts extra vf to MA.

[Rhyen Skytracker]

Fender is correct. It was with the NiMH AA batteries that I got the high MA out of the transistor. How much mA are you needing?

[Matt Thorn]

No, I wasn't mixing MA with MAH. AAA's don't put out much more (if at all) than 1A under load. AA's will put out more, and AAA NIMH's will, but not alkalines. You're just not going to get much more MA out of alkalines without a driver that converts extra vf to MA.
I see. Sorry about that.

Fender is correct. It was with the NiMH AA batteries that I got the high MA out of the transistor. How much mA are you needing?
Now there's the $50,000 question. I'll be using an RGBA with a 16-position rotary switch, which means all 16 possible configurations of the four chips being on or off. And I'm not sure if the net effect of the rotary switch is to have the chips wired in series or in parallel. Better check into that.

I'm going to have to put on my thinking cap and calculate whether or not I can do a one-size-fits-all solution. But I'm still convinced there must be some way to use a transistor to get more current to the LED.

I also have to buy some fresh AAAs, because the ones I'm using are dying, and while I can get each of the chips to light up, the blue is barely there at all. (Green and blue have minimum forward voltage requirements of 3.2V, but at the moment the Yoda board is passing along just 2.8V.)

[Arkhan]

in the AAA form factor:

Energizer Advanced Lithiums are rated at 1000ma continuous, 1500 peak
Energizer Ultimate Lithiums are rated at 1500ma continuous, 2000 peak

http://www.energizer.com has tech .pdf that detail the discharge curves at various loads for all their batteries, lithium primary, nimh, alkaline, etc.

Obviously, neither of them is going to last very long at those kinds of loads, but they will output significantly more than alkaline, and provide 1.5V per battery, unlike the NIMH.


Order them in bulk. Don't buy them at Radio Shack ($4 a PIECE)

[Matt Thorn]

in the AAA form factor:

Energizer Advanced Lithiums are rated at 1000ma continuous, 1500 peak
Energizer Ultimate Lithiums are rated at 1500ma continuous, 2000 peak

http://www.energizer.com has tech .pdf that detail the discharge curves at various loads for all their batteries, lithium primary, nimh, alkaline, etc.

Obviously, neither of them is going to last very long at those kinds of loads, but they will output significantly more than alkaline, and provide 1.5V per battery, unlike the NIMH.


Order them in bulk. Don't buy them at Radio Shack ($4 a PIECE)
Lithium AAA batteries!? :shock: What rock have I been living under!? I had no idea such things even existed. And I just Googled and learned that I can buy them here in Japan (both Energizer and FujiFilm). But they sure aren't cheap, are they? Thanks for that info, Arkhan.

Anyway, I just put in fresh alkalines and got 5.8V from the Yoda board. But for some reason, when I try to measure the current, my Fluke 87 III gives me an "OL" error. My only concern is giving that much voltage to the red and amber chips, since the maximum forward voltages (according to the datasheet) are 2.6V and 2.7V respectively.

My brain hurts. :-?

[Novastar]

Yes, Matt you are correct... you do not want to feed ~5v or ~6v into LEDs (in this case, the LEDEngin reds/ambers) that are best with ~3 or ~3.5v max...

BTW... a quick lesson in batteries and how they are rated for "draw"... you'll usually see something like "2C" or "1.5C" or something if a spec sheet is offered.

What that means is "2 x the current/present capacity" and "1.5 x the present capacity"...

Therefore... if your cells are at max charge and have:
a 1500mAh rating... 2 x that (or 2C) would be 3A.
a 1500mAh rating... 1.5 x that (or 2C) would be 2250mA.

However... don't forget that the total capacity (quite naturally, duh!!) lowers as you use the batteries (again, DUH)... and therefore, you max draw will decrease as the cells get used up.

This is why you want a "C" rating (amp draw) that is fairly higher than the maximum you ever wish to draw. Since (hopefully) when your pack is even at 50% capacity... you may still be able to draw what is needed.

Almost lastly, I'll just say... when you have 4 dies (LEDEngins that "we" are using--we as in saber dudes)... you can wire:

* in series
* in parallel
* a mixture of these (what I like to call "paraseries" or "seriallel", lol)

FOR LEDS:

Wiring in series "keeps" the required amp draw, but DOUBLES voltage requirements...
Wiring in parallel "keeps" the voltage requirements but DOUBLES required amp draw...

For example...

LED = it wants ~3v @ 1A

Series of 2 of those LEDs = ~6v @ 1A needed/being drawn
Parallel of 2 of those LEDs = ~3v @ 2A needed/being drawn

Finally... now that I've said a THRONG... I'll close by saying that your choice of how you'll wire the dies will determine how much voltage and amp draw is going on. In some cases (of course) it's prohibitive...

Some boards can't handle ~7.4v... so you'd go in parallel...
Some boards can't handle ~4A... so you'd go in series...

And if you have problems feeding a device both ~7.4v ***AND*** are asking it to spit out ~4A--and it can't... uh oh!! Yer in trouble, and you probably need to do SOMEthing with "paraseries" or "seriallel"... lol. (if that even works)... :)

[alreadyRogue]

Matt if you are going to use the negative wire from the yoda you will still need an npn transistor. The difference between pnp and npn type transistors is the state of the base circuit. In a npn transistor the circuit is always closed (allows electricity to flow) unless voltage is applied to the emitter pin. In a pnp type transistor the circuit is normally open (no electricity) and when voltage is applied to the emitter pin the switch closes and the electrons flow.
Now if you want to use the negative wire from the MR board, all you will need to do is switch the polarity of the other wires. So if the emitter (from board) is negative, then both the base (from battery) and collector (to led) also need to be negative.
So your wiring should look something like this.
Battery plus terminal forks, goes to MR board and DIP switch, from MR board it goes to PNP type transistor ( reversed polarity as mentioned above), From dip switch it goes to the different dies of the LED. The negative wires from all the dies are combined, and that leads to the COLLECTOR pin of the transistor, thus completeing the loop.
Even though the transistor is on the negative side of the LED, the fact that it is still an open switch keeps electricity from flowing.
Hope that helps, if you want I will draw you up a complete circuit diagram.
EDIT: please note that NiMH bateries sold in the store can easily pit out 5, 6,or 7A easily where as the pcb for the Li-ions capps it at around 4.5A. I just want you to and your friend to be informed because you could be looking at 15-40 minute runtimes before you have to buy a new set if alkalines, which may not even drive the LEDs at their full capacity in the first place.

[Matt Thorn]

Nova, thanks for the info on batteries. I thought I had already learned everything there was to know on the topic from you, but it seems there always more to learn.

Rogue, sorry for the late response. It sounds like you're giving me exactly the info I'm looking for, but I haven't had a chance to wrap my head around it yet, and am working on a diagram at this very moment. I just want to clarify something. You wrote, "you will still need an npn transistor." Judging from what follows, I think you meant I still need a pnp transistor, correct?

[alreadyRogue]

Hey matt i just reread your post and found that you are using the positive wire right? but just to clear things up i decided to post a diagram of what i think you are trying to do

[Matt Thorn]

Hey matt i just reread your post and found that you are using the positive wire right? but just to clear things up i decided to post a diagram of what i think you are trying to do
That would be fantastic, Rogue, because I'm confused by this:

Now if you want to use the negative wire from the MR board, all you will need to do is switch the polarity of the other wires. So if the emitter (from board) is negative, then both the base (from battery) and collector (to led) also need to be negative.
So your wiring should look something like this.
Battery plus terminal forks, goes to MR board and DIP switch, from MR board it goes to PNP type transistor ( reversed polarity as mentioned above)
Positive or negative, whichever works is fine with me. I just know that when I tried to do something similar to what we did on the other thread (http://forums.thecustomsabershop.com/showthread.php?t=10288), it didn't work.

[Rhyen Skytracker]

If you are using a BCD rotary switch it will work in parallel. When the switch goes to pos 4 and above it will just combine the two wires internally and that is like wiring them in parallel.

[alreadyRogue]

http://forums.thecustomsabershop.com/picture.php?albumid=224&pictureid=1864
That should work
I forgot to upload the picture to my other post... sorry :|

[Matt Thorn]

If you are using a BCD rotary switch it will work in parallel. When the switch goes to pos 4 and above it will just combine the two wires internally and that is like wiring them in parallel.
I thought that was probably the case. Thanks for the confirmation!


That should work
I forgot to upload the picture to my other post... sorry :|
Brilliant! Can't wait to get home and try it. If it works, I should be able to finally finish this saber this weekend. :D

[alreadyRogue]

haha thanks
BUT
dont forget to put resistors/buckpucks/drivers between the bcd rotary and the led

[Matt Thorn]

haha thanks
BUT
dont forget to put resistors/buckpucks/drivers between the bcd rotary and the led
Okay. I was wondering if the 4.5V regulator was intended as a substitute for resistors on the red and amber LEDs. So, why did you include a regulator?

[alreadyRogue]

i have heard that 6 V will fry the FX boards
which is why the voltage regulator will save it
but what the transistor does is act like a switch
when voltage is applied to the emitter pin (middle one) it closes the switch between the base (left) and collector (right) so all the juice from your battery pumps into the rotary switch and in turn into the LEDs

[Matt Thorn]

i have heard that 6 V will fry the FX boards which is why the voltage regulator will save it
but what the transistor does is act like a switch when voltage is applied to the emitter pin (middle one) it closes the switch between the base (left) and collector (right) so all the juice from your battery pumps into the rotary switch and in turn into the LEDs
I've used plenty of Force FX boards at 6V with no problems. In terms of getting the brightest, most predictable results, having buckpucks for all four chips would be ideal, but there's no way I could fit more than one buckpuck inside this hilt, and even one might be hard to squeeze in. If only buckpucks were smaller. :?

[alreadyRogue]

Here is what I would suggest
replace the alkalines with the NiMH from the shop, they will have a much better battery life as they will not loose their energy to heat through the resistors (due to the impossibility of buckpucks) because their voltage is closer to the voltage needed for the LED
because the dies are in parallel, they will draw much more current, and if at all possible i would HIGHLY suggest replacing the 4AAA pack with a 4AA pack, plus you can put the sound board over it and save space
the run time would be tremendously improved (2.6 TIMES AS MUCH)
I can modify my diagram to show you exactly how to wire in the recharge port if you want
I believe it is a necessity

[Matt Thorn]

Here is what I would suggest
replace the alkalines with the NiMH from the shop, they will have a much better battery life as they will not loose their energy to heat through the resistors (due to the impossibility of buckpucks) because their voltage is closer to the voltage needed for the LED
because the dies are in parallel, they will draw much more current, and if at all possible i would HIGHLY suggest replacing the 4AAA pack with a 4AA pack, plus you can put the sound board over it and save space
the run time would be tremendously improved (2.6 TIMES AS MUCH)
I can modify my diagram to show you exactly how to wire in the recharge port if you want
I believe it is a necessity
Rogue, thanks for the advice. I'll be sure to tell the guy I'm making for that Ni-MHs are preferable, but I can't control what he puts in it, so I'll choose resistors based on 4AAA=6V.

Unfortunately, the 4AAA arrangement can't be changed at this point. The guy does not want a recharge-port setup. (Using two 14500 Li-Ions and a recharge port would have made this project much, much easier.:rolleyes: Oh, and I've wired plenty of recharge ports, but thanks for the offer or help anyway.;))

Run-time is a low priority for this guy, since it's primarily for show, rather than dueling. Here's what it looked like in green, before I knew he wanted it to be color-changing.
http://lh4.ggpht.com/_THBqz9vPciU/S3DwHMZLBWI/AAAAAAAAD1k/I0chXuQ592c/s800/IMG_1671.JPG (http://picasaweb.google.co.jp/lh/photo/ButhCjTBjL4c3hQPH88FVA?feat=embedwebsite)

[Matt Thorn]

http://forums.thecustomsabershop.com/picture.php?albumid=224&pictureid=1864
That should work
I forgot to upload the picture to my other post... sorry :|
Wait. Looking at your diagram again, I'm confused. You show a bundle of wires coming from the Yoda board, joined into a red wire. The bundle from the board would be negative. And since the crash sensor is on the positive line...not hooking up the positive line from the board would seem to not be an option. I'm hoping the sketch of the negative wires from the board is an error, and that I can leave the negatives from the board unused. Otherwise, I may be back to square one. :( (Note that I am not at home right now and can't test this directly.)

EDIT: Double wait. This description...

Battery plus terminal forks, goes to MR board and DIP switch, from MR board it goes to PNP type transistor ( reversed polarity as mentioned above), From dip switch it goes to the different dies of the LED. The negative wires from all the dies are combined, and that leads to the COLLECTOR pin of the transistor, thus completeing the loop.
...contradicts your diagram. :confused::confused::confused:

[Matt Thorn]

Sorry to double-post, but this is not an addition to my previous post, but rather A Whole New Thing™.

I actually brushed away the cobwebs, turned my brain on (chug chug chug), did some studying, and may actually have comprehended exactly how the whole using-a-transistor-as-a-switch thing works, and how to make it work here.

I have yet to test it, but theoretically, this diagram should work. Note that the transistor is an NPN, not a PNP. I now understand why it has to be an NPN, but don't ask me to explain it. :neutral: (Yeah, I have read numerous explanations of how it works, but since my brain was turned off and gathering cobwebs, I couldn't wrap my head around it till today.)

I left out the latching switch, clash sensor, and speaker, because they are hooked up in The Standard Fashion™.

EDIT: I added a 7805 5-Volt regulator, because the TIP120 NPN transistor can only handle 5V. (Still untested, though.)
EDIT 2: I simply could not get this to work. It looks good on paper, but either I'm messing something up, or something in the Force FX board renders this set-up unworkable. (Possibly the clash sensor on the positive lead?)

http://lh5.ggpht.com/_THBqz9vPciU/TKmMmOMjRiI/AAAAAAAAFq4/YwX504updK0/s800/RGBA%20Force%20FX%20transistor%20diagram.jpg (http://picasaweb.google.com/lh/photo/jSImcdiG7ZGel3pPJIYDtQ?feat=embedwebsite)

Now, I'm hoping some electronics-savvy member will check this for me, but in the meantime, I'll actually put it to the test. (Right after dinner.)

[Rhyen Skytracker]

Also keep in mind if the rotary switch is NOT a BCD then you would need to use a bunch of resistors to get the exact colors you want plus you would need to use diodes to keep the mixed colors from backfeeding when in different switch positions.

[Matt Thorn]

Also keep in mind if the rotary switch is NOT a BCD then you would need to use a bunch of resistors to get the exact colors you want plus you would need to use diodes to keep the mixed colors from backfeeding when in different switch positions.
It is in fact BCD. But I had to look up the meaning of "BCD" and check the datasheet (javascript:location.href='http://www.components.omron.com/components/web/PDFLIB.nsf/0/3C731DDE02C68B0885257201007DD673/$file/A6A_1109.pdf') to confirm. :oops: Thanks, Rhyen. So that tiny little switch has something like Zener diodes built in to prevent that sort of thing? :shock:

[Matt Thorn]

O-o-o-kay.

So much for theory and my capacity for comprehension thereof. Within seconds of connecting the ground line to the emitter and the positive from the Yoda board to the base, my TIP120 NPN transistor was giving off wisps of smoke. Which is particularly puzzling considering that the board wasn't even turned on, so the circuit should not have been complete. At least the board seems to be all right.

:(

I am flummoxed, and back to square one. *sigh*

EDIT: Oh. Maybe it had something to do with giving 6V to a transistor rated for 5V. :oops:

[Skottsaber]

EDIT: Oh. Maybe it had something to do with giving 6V to a transistor rated for 5V. :oops:

Oops!
Was it a mistake on your part, or will you need a different transistor?

[Matt Thorn]

Hey, Skott. I'm pretty sure it was my mistake in not using a 5V regulator. Fortunately, I have a couple more of the TIP120s left. But it's pushing 2:30 a.m. here in Kyoto, so I'm calling it a night.

[Arkhan]

If you use a 4xAAA battery holder, you can always use 3xAAA batteries and a dummy cell, to get 4.5V

In that way, your alkaline/Lithium Primary setup would closely match a 4xAAA NIMH setup. 4.5V for 3xAAA non-rechargeables, or 4.8V for 4xAAA NIMH

My daughter's Cleopatra saber is currently running a 4xAAA holder, with 3XAAA batteries and a home-made dummy cell. If I wanted to drop NIMH into the saber, all I would do is pull the alkalines and the dummy cell, replace with NIMH x4

I made my dummy cell from a bolt, cut to length, and put heatshrink on the length of it to prevent any possible short-circuits. Only the ends of the bolt are exposed metal, to match up with the contacts of the battery pack.

[Silver Serpent]

Interesting.

I was trying to come up with a cheap way to make a dummy cell for another project. I think I'm gonna steal your bolt idea, Arkhan. It's far simpler than some of the ideas I was coming up with. :)

[jjshumpert]

i just solder in a jumper wire, not the best practice but it works...

[Arkhan]

soldering in a jumper wire is a good solution if you don't plan to switch back and forth between 3 and 4 battery config.

If you do switch back and forth, you might not want to have to redo the wire.

The dummy cell did wiggle loose once, being slightly under diameter, so I taped the dummy and other 3 cells once around so they won't come loose.

[Rhyen Skytracker]

Have you tried it with a TIP42 transistor?

[RevengeoftheSeth]

Easy way to make a dummy cell is get a section of dowell rod the same size as your cell, drill out the center, then run a wire through the middle and solder it to a metal thumb tack on each end (the flat ones). Hot glue the hole and when it dries, push the thumb tack into place on each end.

[Rhyen Skytracker]

Or just machine one on a lathe and then put some heat shrink on the outside of it. :-D

[RevengeoftheSeth]

Or just machine one on a lathe and then put some heat shrink on the outside of it. :-D

Darn you kids and your lathes!

*crazy incoherent old man ramble*

[Matt Thorn]

Actually, I like Seth's idea for a dummy best. Lightweight, simple, don't have to waste a good piece of aluminum...

But I think I'll go with the regulator anyway. ;)

[Arkhan]

the reason I made one out of a bolt: I didn't have thumb tacks on hand :)

[RevengeoftheSeth]

LOL, I couldn't even find them at Walmart last time I went. I had to go to the Dollar Store.

[Matt Thorn]

Here is the corrected, updated diagram, but I didn't find time this weekend to test it. Although this project is complicated by the color-changing aspect, if this works as I hope it will, the basic NPN transistor set-up should be able to boost the brightness of any basic Force FX-based conversion/mod without using a relay.

EDIT: I simply could not get this to work. It looks good on paper, but either I'm messing something up, or something in the Force FX board renders this set-up unworkable. (Possibly the clash sensor on the positive lead?)
http://lh5.ggpht.com/_THBqz9vPciU/TKmMmOMjRiI/AAAAAAAAFq4/YwX504updK0/s800/RGBA%20Force%20FX%20transistor%20diagram.jpg (http://picasaweb.google.com/lh/photo/1jqTBCg9yQR8rGLFUYM6DA?feat=embedwebsite)

[RevengeoftheSeth]

Are you sure VDD should go to the base of the transistor?

EDIT: Oh, I'm thinking PNP. Nevermind.

[Skottsaber]

So exactly how much could you boost the output of the FX board?
Enough to run a 10w no problem?

[Rhyen Skytracker]

You should be able to get around 1530 mA out of that set up if you use AA NiMH batts. I am not sure exactly how much you would get it you used a transistor for each color LED.

[Matt Thorn]

I just could not get this to work. I was getting lots of heat and no light. And when everything was hooked up exactly as you see in my diagram, I was getting a "clash loop", wehre the clash sound would just repeat over and over again. I suspect the fact that the clash sensor is hooked into the positive lead from the Force FX board has something to do with this. It may simply be that the Force FX board will not work with this set-up. But it might also be that I screwed up somewhere.

Either way, I have given up on this project, and did a simple straight-from-the-board drive, putting 1.5 Ohm resistors on the red and amber chips. It works basically well enough, but the red and amber are current hogs, so any time one or both is on, other chips that are also on tend to be dimmer than I would like, and the red and amber dominate among the 15 different combinations. You can see this pretty clearly in the accent LEDs, which become quite dim any time red or amber is on.
http://lh6.ggpht.com/_THBqz9vPciU/TKkQ57hRuTI/AAAAAAAAFoE/FWjMhl93lJE/s144/DSCN0449.JPG (http://picasaweb.google.com/lh/photo/HHUJVMCb0KfdxBMCjGrxFg?feat=embedwebsite)
http://lh3.ggpht.com/_THBqz9vPciU/TKkQ4lQHX9I/AAAAAAAAFn4/BV0htPlXgeU/s144/DSCN0448.JPG (http://picasaweb.google.com/lh/photo/E8VcYR7wr2sGtwZlbnxmqQ?feat=embedwebsite)
http://lh4.ggpht.com/_THBqz9vPciU/TKkQ6nRgdwI/AAAAAAAAFoM/WvQ6PDl4juo/s144/DSCN0450.JPG (http://picasaweb.google.com/lh/photo/MaSJtbB-13vECQh7SHdV_Q?feat=embedwebsite)
http://lh4.ggpht.com/_THBqz9vPciU/TKkQ7oZMjEI/AAAAAAAAFoU/bFB2iEcKT9Q/s144/DSCN0451.JPG (http://picasaweb.google.com/lh/photo/uegpBWJCGw8zERNHBp9XZQ?feat=embedwebsite)
http://lh3.ggpht.com/_THBqz9vPciU/TKkQ8pKz1LI/AAAAAAAAFoc/-wS6o2lMCRg/s144/DSCN0452.JPG (http://picasaweb.google.com/lh/photo/rb6D5w_mS5jG6AMduhqntg?feat=embedwebsite)
http://lh5.ggpht.com/_THBqz9vPciU/TKkQ9bpWxxI/AAAAAAAAFok/VVV_8goucsA/s144/DSCN0453.JPG (http://picasaweb.google.com/lh/photo/kBVI6uOW9q-NdX3Co5hVSQ?feat=embedwebsite)
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http://lh4.ggpht.com/_THBqz9vPciU/TKkRCHSu72I/AAAAAAAAFpQ/sUoQ-OMS5Qo/s144/DSCN0458.JPG (http://picasaweb.google.com/lh/photo/W7ApOl3qjiVMjHjzh8wupQ?feat=embedwebsite)
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http://lh6.ggpht.com/_THBqz9vPciU/TKkREExUxUI/AAAAAAAAFpg/DJ7NkF1M-hQ/s144/DSCN0460.JPG (http://picasaweb.google.com/lh/photo/W0rshenoA8dXv49vKi9qgQ?feat=embedwebsite)
http://lh5.ggpht.com/_THBqz9vPciU/TKkRFBdL_9I/AAAAAAAAFps/0xCER6f7nmw/s144/DSCN0461.JPG (http://picasaweb.google.com/lh/photo/hR0F6KWi0pGMgiNXXbuxEw?feat=embedwebsite)
http://lh4.ggpht.com/_THBqz9vPciU/TKkRGAGWEuI/AAAAAAAAFp0/6_8sSnlMz7s/s144/DSCN0462.JPG (http://picasaweb.google.com/lh/photo/V-pXd8o_F3Woy1VTxgJi8A?feat=embedwebsite)

[bk_renesis]

Just to add my 3.5 cents i tried using a pnp with a 616 and just couldn't get it to work. I applied the setup as per we do with 2010 w/dvd soundboards but no ignition.

I wonder if a relay would work for the 616 or i could always go down the DPDT swich option i guess.

I hope this definitely gets looked into as it would open up a whole new world for led options using force fx boards.

Cheers.

[Matt Thorn]

Just to add my 3.5 cents i tried using a pnp with a 616 and just couldn't get it to work. I applied the setup as per we do with 2010 w/dvd soundboards but no ignition.

I wonder if a relay would work for the 616 or i could always go down the DPDT swich option i guess.

I hope this definitely gets looked into as it would open up a whole new world for led options using force fx boards.

Cheers.
The 616 is a very fragile, quirky board. It was popular as soundboard for a while because it was relatively cheap and available, but it's not a board I would choose to work with if there was an alternative. I suspect that if there is any success to be had in this area, it will be with the more "standard" Force FX boards.

[bk_renesis]

I hear ya loud and clear but the 616 aside r&d into your idea for the fx boards would be a great advancement for saber building. I mean the base idea and schematics are up and ready they just need to be tweaked to make them work.

I hope the experts are rolling up there sleeves on this one!

[Matt Thorn]

I hope the experts are rolling up there sleeves on this one!
As do I. I have a feeling it's the presence of the clash sensor on the positive lead that is gumming up my seemingly perfect diagram. :p

[Rhyen Skytracker]

You should be able to get that set up to work using a PNP transistor and use one of the 6 negative wires from the FX board to go to the base of the transistor and the batt + go to the emitter of the transistor and the collector of the transistor go to the BCD rotary switch and the - of the LEDs go to the battery -. I don't think it will work right (even using NPN) by using the VDD off of the board. Try this set up and it should work.

Also, if you want to get colors that you can tune to the color that you want try using a single pole 8 position switch and for the mixed colord use diodes to keep the voltage from backfeeding and messing up your other colors. I am working on a project like that now but haven't gotten to the diode part yet. I was able to get 6 colors by using a 2 pole 6 position switch. By doing it this way your colors can be what ever you want them to be and not predetermined like with a BCD rotary switch.

[Matt Thorn]

Thanks, Rhyen.

You should be able to get that set up to work using a PNP transistor and use one of the 6 negative wires from the FX board to go to the base of the transistor and the batt + go to the emitter of the transistor and the collector of the transistor go to the BCD rotary switch and the - of the LEDs go to the battery -. I don't think it will work right (even using NPN) by using the VDD off of the board. Try this set up and it should work.
When I started this, that's what I planned to do. I don't remember the details, but the reason I went with the NPN set-up had to do with the RGBA factor. I think I couldn't figure out how to get the RGBA, rotary switch, and Force FX board all working together with a PNP transistor. Next time I get a chance, I'll try the PNP set-up with a single-color LED.


Also, if you want to get colors that you can tune to the color that you want try using a single pole 8 position switch and for the mixed colord use diodes to keep the voltage from backfeeding and messing up your other colors. I am working on a project like that now but haven't gotten to the diode part yet. I was able to get 6 colors by using a 2 pole 6 position switch. By doing it this way your colors can be what ever you want them to be and not predetermined like with a BCD rotary switch.
I keep hearing this, but exactly what kind of diodes are we talking about? (After all, an LED is itself a diode.) I've done some studying on Zener diodes, and I don't see how these can be useful here. They are used to regulate voltage with low-current applications (http://www.reuk.co.uk/Zener-Diode-Voltage-Regulator.htm), but with a saber, where you use low voltage but need high current, you would need a Zener diode with a low voltage rating and extremely high wattage, and such creatures apparently do not exist. One person who suggested I use a "diode" offered as examples a Zener diode and a rectifier diode, but the latter is used to convert AC to DC. Are people using these in ways they weren't intended to be used? :confused: I would love it if someone would explain this to me (based on actual experience, rather than just assumptions). Actually, what I would really love is for members who are really experts on things electrical and electronic would do a series of tutorials on stuff that could be useful to sabersmiths. :)

[Rhyen Skytracker]

You shouldn't have any problems using the PNP with the rotary switch.

As far as the other way with the diodes I just got normal diodes, not zenner diodes. I just don't want it to allow the voltage to backfeed. Lets use purple for instance. With purple you need the red and blue (resistor the red on that position of the switch to get the shade of purple you want too) but when you turn the switch to go to just the red position with out the diodes the blue LED would still come on too. The diode would keep the voltage from backfeeding and give you a red when on the red switch (plus this way for the red only you can remove the extra resistance that you used to dial in the shade of purple you want and have a bright red instead)

I will be sure to make a video and take pictures when I do mine.

[vargose]

You can use diodes to increase the voltage drop on the red and amber lines. Which will keep them from hogging the current. You may need more than one per line to get the drop you want.

http://www.kpsec.freeuk.com/components/diode.htm

Forward Voltage Drop
Electricity uses up a little energy pushing its way through the diode, rather like a person pushing through a door with a spring. This means that there is a small voltage across a conducting diode, it is called the forward voltage drop and is about 0.7V for all normal diodes which are made from silicon. The forward voltage drop of a diode is almost constant whatever the current passing through the diode so they have a very steep characteristic (current-voltage graph).

[Matt Thorn]

As do I. I have a feeling it's the presence of the clash sensor on the positive lead that is gumming up my seemingly perfect diagram. :p
It just occurred to me (as I sit here at my desk at work) that if I have the positive side of the clash sensor attached to the positive lead from the regulator, instead of to the positive lead from the board to the transistor, the weird behavior I'm getting might be solved. In other words, the fact that there is a ground from the board between the positive from the board and the transistor is keeping the transistor from doing its job. Just a theory until I actually test it.

Oh, and the correlate is that the negative lead from the clash sensor should be bundled with the other negatives.

EDIT: Doh. The negative lead remains as is between the board and the sensor, and the positive lead gets connected to the positive from the regulator.

I think.