PC 1.5 help

[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.