PC 1.5 help

[patolcott]

Hey so Just need some quick help guys If you can check my wiring schematic to let me know if it is good or not i would be much appreciative. I am including the following

1 LEDengin 10w rgbw for a amber blade with blue white foc
2 14500 7.4v power supply
3 recharge port
4 speaker
5 2 mom switches with accent LED's
6 i power indicator led

I think that is everything. any help and comments and critiques would be of great help

here is link to diagram
http://s1279.beta.photobucket.com/user/patolcott/media/PC15-16Wiringdiagram.png.html?sort=3&o=0

[Takanis]

Check your wiring on the LEDengin. You are wanting to running the colors in series. Let's take the Main Blade for an example: It looks like you want to run green and red in series. This should be the "chain" from your PC LED pads. PC LED Pad (+) to the Red (+). Red (-) to the Green (+). Green (-) to the PC LED (-) pad. It will be the same thing for the FoC™ just with the different dice.

I'm not seeing anything else that should be a problem. Its hard to tell that's going on with the Accent LED pads, but just make sure you have the switch LEDs properly resistored.

[patolcott]

thank you sir

[patolcott]

another question... I bought two momentary switches with green accent LED's with a VF of 3.3 volts. now the PC 1.5 accent Led pad Output is 3.3 Volts right? meaning in should not need a resistor for those?

[Silver Serpent]

It's good practice to slap a 1 ohm resistor on there. It's not absolutely necessary, but I'd still recommend doing it.

[patolcott]

Ok Thanks

[patolcott]

so still having Resistor troubles. I know the formula I am just scared to go forward for fear of messing it up, For my FOC the FV for it is 3.3, what i am having trouble with is since my die are wired in series what is my voltage drop? my FOC is red and green red being ~2.2 volts and green being ~3.0 volts so do I add those together? and for my amperage I know each die should be putting out 700ma so should I double it? then apply? Like i said It all looks strait forward I am just scared LOL.

[Silver Serpent]

For LEDs wired in series, you add the Vf together and current remains the same. For the red and green above, you'd need 5.2v @ 700mA.

For LEDs wired in parallel, Take the Vf of the highest, and the current is shared equally between the two. For the red and green above, you'd need 3.0v @ 1400mA to run them properly. You'd also want to put a resistor on the red LED to keep it safe.

I'm a bit confused about what you said above. First you stated that the Vf of your FOC is 3.3, and then you also stated that your FOC is red and green (2.2v + 3.0v). Which is it?

[patolcott]

For LEDs wired in series, you add the Vf together and current remains the same. For the red and green above, you'd need 5.2v @ 700mA.

For LEDs wired in parallel, Take the Vf of the highest, and the current is shared equally between the two. For the red and green above, you'd need 3.0v @ 1400mA to run them properly. You'd also want to put a resistor on the red LED to keep it safe.

I'm a bit confused about what you said above. First you stated that the Vf of your FOC is 3.3, and then you also stated that your FOC is red and green (2.2v + 3.0v). Which is it?


sorry silver I was thinking that the Vf was the supply voltage I said it wrong... that being said with the supply being 3.3 and the Vf being 5.2 i won't even need a resistor then would I?

[patolcott]

BTW thanks for the help silver I am very uninformed with electronics even while reading everything i can. oh and if the VF is 5.2 how will 3.3 even power it? that makes no sense

[DarthStallion]

hey. you'll need to use a power extender http://www.thecustomsabershop.com/Power-Xtender-20-P652.aspx to bring the voltage of the 3.3v pad to 7.4v then resistor from there. also, be sure your pc 1.5 is set to run foc. i have a couple older pc 1.5's that were flashed to unlock them but they weren't flashed for foc. it think that started with version 1.6.
check your config file. if you see any auxflashXX parameters then you're good to go.
hope that helps.

[patolcott]

ahhh so the power extender is what brings the voltage back up to 7.4 got it i was wondering how that worked. I am sure my PC runs FOC so I need a resistor for a supply voltage of 7.4 with a Vf of 5.2 @ 700 Ma. got it Ill just do the math and grab a resistor tomorrow... or today. thank you

[Forgetful Jedi Knight]

ahhh so the power extender is what brings the voltage back up to 7.4 got it i was wondering how that worked. I am sure my PC runs FOC so I need a resistor for a supply voltage of 7.4 with a Vf of 5.2 @ 700 Ma. got it Ill just do the math and grab a resistor tomorrow... or today. thank you

Something doesn't sound right here. Let's start from the beginning - what EXACTLY are you trying to do with the LED's:

What color(s) are the main LEDs?

What color(s) are the FoC LEDs?

Where did you get the idea that you could run a FoC off the 3.3V pad?

[patolcott]

I have a LEDengin 10w RGGB my GB will be my main blade and my RG will be my flash I never thought I could run it off my 3.3 v pad, I merely thought that the PEX was 3.3 as well since every pad on the pc 1.5 is 3.3

[Forgetful Jedi Knight]

I have a LEDengin 10w RGGB my GB will be my main blade and my RG will be my flash I never thought I could run it off my 3.3 v pad, I merely thought that the PEX was 3.3 as well since every pad on the pc 1.5 is 3.3

It doesn't quite work that way. The PEX allows (more or less) for "direct drive", and the supply voltage depends on the size of the battery pack.


so I need a resistor for a supply voltage of 7.4 with a Vf of 5.2 @ 700 Ma.

You can drive the LEDEngins at 1A (that would make the resistor calculations easier) ;)

IF you are going to the 2 dice FoC, you may want to figure the current (mAh) to be at least 1500mAh (1.5A). Also, you will have a VERY limited run time with the battery pack you have listed.

[patolcott]

Hmm now I am more confused... How do I configure it to run at 1 amp or 1.5 amps? i did not know you could configure that. how long will the run time be? I knew it would be shorter but I don't plan on dueling with it, so a shorter time is OK with me. Thanks for the help

[Forgetful Jedi Knight]

Hmm now I am more confused... How do I configure it to run at 1 amp or 1.5 amps? i did not know you could configure that. how long will the run time be? I knew it would be shorter but I don't plan on dueling with it, so a shorter time is OK with me. Thanks for the help


OK, Let's start from the beginning...

A PEX is basically a direct drive board, that will let you use up to the voltage of the battery pack it's attached to (typically 7.4V) and will allow up to 2A (if you have the newer PEX's) of current to flow through it. Just as you decide what the Vf of the FoC dice you use are (by choosing which dice you use - in the calculations in green) you can choose how much current (up to 2A) to use to feed them (in the calculations in RED).

In your case... you say the 2 Dice you want to use are 5.2V (2.2, 3.0). In actuality, they are more like 2.2 and 3.4. (5.6V)

So, if you want to run them at 1.5A (1500mAh)

The first half of the calculation (to determine the resistance, in Ohms) is:

R = Vf (battery) - (Vf dice) / Current => 7.4 - 5.6 / 1.5 =>1.8 / 1.5 = 1.2 Ohms

The second half of the calculation (to determine wattage)

W = R(from first calculation) * Current^2 => 1.2 * 1.5^2 = 2.7 Watts

So a 1.2 Ohm 3 Watt resistor would be what you need, which Tim seems to have in stock right now.

http://www.thecustomsabershop.com/12ohm-3w-resistor-P22.aspx

Your run time with the battery pack you have should max out at about 20 minutes, depending on how high you run the main dice. ;)

Got it now? 8)

[Silver Serpent]

I would highly recommend you try drawing up a wiring diagram for us to look at. There's more than a little bit of confusion going on here. :)

[Forgetful Jedi Knight]

I would highly recommend you try drawing up a wiring diagram for us to look at. There's more than a little bit of confusion going on here. :)

I agree with SS here. Though I think I know what you are trying to do now, you should make up a coherent wiring diagram to help you out, and to help us follow along to make sure you stay on track.

[patolcott]

Hey guys I appreciate the help I really think I get it now, I was just missing a piece in the formula. here is my diagram any critiques will be greatly appreciated. * note I already know the LED wiring is not drawn right, I wired it using Fender's tutorial on wiring 10watt LEDengine

Here is the diagram
http://i1279.photobucket.com/albums/y535/patolcott/Kyp%20Durron%20Lightsaber/PC15-16WiringdiagramLEDFix.png

[patolcott]

Last note I am adding a crystal chamber LED as well

[Forgetful Jedi Knight]

Last note I am adding a crystal chamber LED as well

And the LED for that is where?

[Silver Serpent]

Apart from the 10w LED being wired all wonky, there is one change I'd make. The negative wire that runs from the battery to the PEX should run from the PEX to the left terminal on your recharge port. If you do that, then everything will properly have the power cut when the kill key is inserted. Do that, and straighten out the LEDEngin wiring, and you should be good to go.

[patolcott]

thanks silver I appreciate it. I know that the 10 watt is wired wrong in the pic... I fixed that with Fenders tutorial. but I will make sure to wire the pex to the recharge like you said. again thanks you guys I feel like i have a much better grasp on the whole thing now.

[patolcott]

so let's see if I am doing this right, I need to find resistors for two LED's one is my ACCENT LED the other is my CHAMBER LED. The accent will go on the accent pad provided on the PC, the chamber will go to the main LED pad and the Batt neg pad both output pads are putting out 3.3 V

SO

R= Vf (batt) 3.3

Both LED's are 2.2 at 20ma

SO

Vf (LED) 2.2
current .02?

with that the equation is as follows

R=Vf(Batt) 3.3- Vf(LED) 2.2 / current .02

this gives me 55 ohms
then to figure the wattage I take ohms X the current squared

55X(.02)^2= .022

so I need a resistor of 55ohms and .02 watts.

I did the equation multiple times got the same answer every time, However
IF i did The equation right I cannot find one ANYWHERE radio shack TCSS not even mouser has a resistor with those exact measurements can I use a substitution resistor?

[Silver Serpent]

Your math looks fine. There are certain standard sized resistors, and 55ohm 0.02w is not one of them. There is a 56ohm, 1/4w resistor in the store that will work just fine.

One bit to pay attention to: the *accent* pads on the board are 3.3v all the time. The calculations for your accent LED are fine. If you're wiring up your chamber LED the way you've described it earlier, then the source voltage is going to be the same as the Vf for your Main LED. With your main blade being Green and Red in series, their combined Vf is going to be a good deal higher than 3.3v.

[patolcott]

hmm but I thought that the main LED pad voltage was 3.3 and that the combined voltage of the two LED's in series is 5.6. so the source is 3.3 still? right? because I was under the impression that all pads on the PC were regulated to 3.3. I understand that the PEX brings my voltage back up to 7.4 so that there is enough to run the FOC LED's in series, which now that I say it It seems odd that you would have to raise the voltage with the PEX yet when running the main LEDs of the PC they are only at 3.3... UGH frustrating. I know that my main LED's work because I have had them hooked up and they worked great. I need to take a class on this stuff

[patolcott]

So please don't take this as complaining I love ervs stuff, but I went through the entire 1.6 booklet and it only says what the accent LED pads are at 3.3 all it says about the main led driver is that it is a High power driver. The good new is I totally understand the formula now and how it works... LOL

[Obi-Dar Ke-Gnomie]

For the main blade LED, the Plecter products self-regulate the voltage depending on what the LED needs. You set the amperage, and the board sorts out the LED forward voltage by itself.

[Silver Serpent]

Obi-Dar is correct. The LED driver built into the board will figure out the correct voltage for your main LED (and ONLY the main LED). If you have a main LED that needs 5.6v, then that's what will be coming out of your main LED pads.

The PEX doesn't increase the voltage. It's more like a switching station. When it gets the signal from the FoC pad of the board, it sends the full power of the battery pack (whatever that might be) to your FoC LEDs. If you have a 7.4v battery pack, it sends 7.4v. If you have a 14.8v battery pack, it'll send all of that. That's why you MUST use a resistor for your FoC LEDs. Otherwise, you're effectively hooking them straight to the battery.

[patolcott]

aaaaahhhh OK this is making so much more sense now. I totally get it. So the MAIN output is equivalent to the VF of y LED's in series. Understood gentlemen and thank you so much for hanging with me for what must have been a painful process. I am good at replicating but Unless I know the why i wont be able to deviate, this helps so much thanks again.

[Obi-Dar Ke-Gnomie]

I hope you get it sorted. Keep us posted.

[patolcott]

Will do sir, All I have left is the resistors and my shapeways chassis gets here sat so I hope to be done next week. My main build thread is in A-Z builds under My Kyp Durron


--- BTW Mods this thread Is a GREAT thread for resistor calculator and exactly how the PC's LED functions work, It really helped me alot Maybe sticky? i feel that Silver Serpent and Forgetful Jedi Knight did a top notch job of explaining things that after hours of searching I could find nothing on. just a suggestion.