MR Soundboard voltage/amperage question...

[Sohryu76]

According to a thread on another board, the MR sound board take excess voltage supplied and increase the amperage going to the LED, which in some cases can cause a pretty good over drive, and possibly a burn out...
I was wondering if everyone who hooks up an MR soundboard to drive the LED directly always had success? I see that Tim's tutorials for the fx conversions just show the LED being wired with the 4.5 / 3.6 volt battery holder in place...
my question is:
does this always work ok?
If i'm going to go with a 4 AAA battery pack, would a buckpuck be helpful for managing the amperage?
anyone have any idea what I am talking about?

[morpheus1977]

I have been using a lux III red wired to a MR Vader for over a year now with no problems not using a buck puck or anything like that.

[Sohryu76]

I have been using a lux III red wired to a MR Vader for over a year now with no problems not using a buck puck or anything like that.

how many volts are you running through it? out of curiosity

[morpheus1977]

well a 4 AAA pack will give you 6 volts how the board distrubutes(sp?) that I dont know. All I know is 6 volts is the MAX you want to put on a MR board.

[Lord Dottore Matto]

I drive all MR boards at 6V (either 4 alkalines or 7.2V Li-ions with a 6V regulator). They put out roughly 1A (sometimes more) to the LED and I have not lost one in over 3 years.

[Novastar]

Right, the FX board is not current-regulating; it spits out more current as it gets more voltage.

However, yup--as you'll see in many posts here @ TCSS... 6v is just about the maximum you could give it without destroying the board upon power up. 7.2v is known to kill it (although what LDM is doing with the regulator is perfectly fine since the board never "sees" 7.2v)... and some hapless fools in the past have given the board 9v, which you can probably understand the result without me saying so. :)

6v on an FX will give @1A
5v on an FX will give @950mA
4.5v on an FX (like the standard/stock packs) will give @900mA

Those numbers are just estimates... they do not reflect exact values, and with the chosen few FX boards I've used... each board appeared to be different (big surprise). I had one which was spitting out just under 1A while on a 3.7v Li-Ion (???!?!?), and some other one that was only doing 820mA or something. Hard to recall. Besides, this was told to me by an assistant with a meter... at the time--I did not know how to meter for current. :)

[Onli-Won Kanomi]

MR boards can't handle more than 6V so how did the older MR LED sabers that used 6 cell battery packs which with alkalines would be 9V...was there a 5-6V regulator that kept them from frying the boards?

[Lord Dottore Matto]

MR boards can't handle more than 6V so how did the older MR LED sabers that used 6 cell battery packs which with alkalines would be 9V...was there a 5-6V regulator that kept them from frying the boards?

it was split into 2 4.5V circuits

[morpheus1977]

If I remember reading from another thread when MR first did the sabers they were EL which required 9v once they started doing the string they only needed half of that but were to lazy to design a new battery holder so they just split the current. Which made it last longer if I remember correctly.

[Novastar]

Right Morpheus, if you have essentially 3AA + 3AA set up to take advantages of the current... you double the runtime.

So for everyone not following along, it's just like:

Li-Ion 3.7v @ 2400mAh +
Li-Ion 3.7v @ 2400mAh =
--------------------------
Li-Ion 3.7v @ 4800mAh

But:

Li-Ion 3.7v @ 2400mAh +
Li-Ion 3.7v @ 2400mAh =
--------------------------
Li-Ion 7.2v @ 2400mAh

...if you wire for the voltage! :) Parallel / serial. :)

[Darth Morbius]

And to add to Novastar's posting, there are other combinations that you can do with serial+parallel that van vary the voltage and current output of your battery packs, but that is bordering on custom battery pack making, and perhaps a little advanced for your purposes, judging by the sessions we have had at FX, regarding this very subject... ;)

[Sohryu76]

I really appreciate all the help guys...

you guys all rock!

[Matt Thorn]

Two circuits! Ah-hah. So is that why some of the MR boards used DPDT slider switches? A switch for each circuit?

I've been looking into Li-ions (which I've never tried), and am seeing surprisingly low amperages for all of them. The Trustfires Tim carries are just 900mA. Novastar, where are these 2400mA 3.7V Li-ions you mentioned? And how do the Trustfires get enough current to the LED? I know that some LEDs are happy with 700mA, but what about those that want 1000mA? :confused:

[Sethski]

But that's current (mA) rather than the capacity (mAh), which are different thangs...

...not that I could give you a proper explanation, mind, but I'm sure someone who's a better explainifier and knows their electronical stuff could ;)

[Jay Dee]

The "bigger amp ones" Nova talks about are 18650. The ones Tim has are 14500. !8650's are huge and I've yet to find a holder for them. So you have to make a pack or get one made. If you do get one made make it a stick (end to end) cause they aint fittin side by side in mhs.
Corrected sorry Nova I must of had an exra bowl of stupid that night...

[Matt Thorn]

Thanks for the clarifications. So a pair of the 14500s Tim sells would be fine for running any of the popular LEDs (Luxeon III, V) at full brightness through some kind of driver, such as a US, CF, MR, or Corbin?

[cannibal869]

I think the general consensus is that the MR boards can take up to 6.5 V, so 2 of the trustfires = 2 x 3.7 = 7.2V... so I'm guessing probably not an MR board. The other boards...well, I know for a fact that the US 2.0 and 2.1 can take the 7.2V. Dunno about Corbin's or CF.

Oh, but if you use a 6V voltage regulator, then yes, they'll work... sorry forgot about that part.

Perhaps one of the more experienced sabersmiths will chime in...

[Novastar]

Cannibal... hmm. 6v for MRs would be best. I wouldn't try 6.5v unless you simply had an endless source/supply for them. A 6v regulator would be stylin' (in my opinion). Corbin's board (all iterations) can handle 7.2v. Erv's board (all iterations) can handle 7.2v.

JayDee... no, you mean the 18650 Li-Ion cells. I'm only correcting you so that people don't go searching in vain for the other ones. And YES the 18650s will NOT fit "side by side" in an MHS. That is a good portion of why I did not use a totally MHS hilt for the Flange III sabers. :)

Matt Thorn... Sethski is 100% all over it! "mAh" and "mA" are different things, and--although they are easy to confuse--you can think of it like "miles per hour" versus "miles". One is a measurement over time... the other is simply a measurement.

By the way, 900mAh is fairly normal for 14500 cells. As "low" as that might be to some people's standards.

Regarding the DPDT switches... well... no on the MRs. That is to say... if there WERE DPDT switches being used (I think they might have some like that)... they're not tripping two circuits.

But... they CAN be used to run two circuits if the switches are indeed DPDT.

[Matt Thorn]

You folks are a font of information and wisdom. :) I still feel out of my depths, but the bottom line is that a pair of 14500s with a 6V voltage regulator will work for just about any setup I would be likely to use, no? I ask because I just acquired a pair of 14500s through Yahoo! Auctions Japan. Believe it or not, 14500 are not available through ordinary channels here in Japan, and Mouser won't ship them here. Apparently they are not approved for retail sale out of fear that people would mistake them for AA batteries and burn their neighborhoods down. ;) It was only after I won the auction that I remembered I would also need a smart recharger for them. :rolleyes: Obviously, I would have bought both batteries and charger from Tim, but he doesn't have either in stock at the moment. :(