Cheap Vader sound card installation questions

[Waisulee]

Hey y'all. Found some great info on wiring a cheap Vader sound card I've recently gutted. I'd like to use 2x 14500 li-ion cells. This diagram seems like the best way to go
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Was wondering what resistor is used. Also, since the cheap Vader card is a little wider then some others will it fit in a 1.25" ID tube with this part?
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Is my understanding correct in that this setup will be bright? - I don't mind the blinking on power on/off. I plan on using a green rebel star.
Any help/advice would be greatly appreciated. Thanks :)

[Silver Serpent]

Yes, the vader will fit any MHS parts with a 1.25" ID. You can quickly find an appropriate resistor value with http://led.linear1.org/1led.wiz

The Source Voltage for that diagram is 5v since it's coming off the regulator.
Rebel Greens have a Vf of 3.4v and run at 1000mA.

It should be plenty bright. I have a setup that's virtually identical, and it looks quite nice.

[Waisulee]

Wow, thank you very much :) Great calculator. If I plugged in the info correctly I think I need a "1.8 Watt capable or greater 1.8 ohm resistor". Is this correct? If so how do I use this info to select the right resistor. Not sure if TCSS has the correct one. Thinking I should buy the resistor elsewhere...

[Silver Serpent]

Recommended wattage is a minimum. You can always select a higher wattage resistor. You should try to get one as close as possible, since the higher wattage resistors are physically larger and take up valuable hilt space.

Either of these two will do the job:
http://www.thecustomsabershop.com/15ohm-5w-resistor--P13.aspx
http://www.thecustomsabershop.com/22ohm-5w-resistor--P11.aspx

The 1.5 ohm will be brighter, but you will be overdriving the LED a bit. Somewhere around 1200mA. The 2.2 ohm will be a bit dimmer, and you will be running the LED at about 800mA.

[Waisulee]

Ahhh I see. Very good to know ;) Thanks. I'd rather play it safe and not overdrive the LED. If my thinking is correct, would I do better with a green Seoul p4 using a 1ohm 5w resistor? Also, I do own a 1000 mA buckpuck. Wouldn't that give me the best result regardless of the LED, ensuring I use a LED that runs at 1000mA, plus negating the need for a resistor?

[Silver Serpent]

The 1 ohm resistor (either 2 or 5 watt in the store) would do fine with the P4 green LED.

You are correct on the use of a buckpuck. Since you already have one, I'd recommend using that instead of the resistor. You'll get more efficient use out of your batteries, since less energy will be wasted as heat.

[Waisulee]

Ya, I'll just pull it out of my graflex. I won't need for when I install my Anakin MR card. It's great just to learn about the cheap Vader card as well as resistors. Thanks again.
With the use of the buckpuck do I just wire it in the same as the resistor as seen in the above diagram, or can I use a better config since the buck puck has terminals for batteries switch and speakers? I'm thinking not.

[Silver Serpent]

It's wired in similarly to the resistor. It doesn't matter if you have the 4-wire or the 6-wire buckpuck; you only have to be concerned with 4 of the wires.

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VIN(-) goes to the battery negative.
VIN(+) goes to the middle leg of the PNP transistor.
LED(+) and LED(-) go to the positive and negative pads on your LED.

If you have this: http://www.thecustomsabershop.com/MWS-BuckPuck--P748.aspx then substitute B+ and B- for the VIN(+) and VIN(-), and substitute L+ and L- for LED(+) and LED(-). You'd also need to connect the two SW wires together to make it permanently on.

I'm not sure which buckpuck you have, but I've never seen one with terminals for connecting speakers.

[Waisulee]

Thanks, that's what I figured.
Yup have this one: http://www.thecustomsabershop.com/MWS-BuckPuck--P748.aspx . My bad, no speaker terminals.
So, with all this in mind my wiring would look like this:
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I'll place this pic in the proper thread as well ;)

[Silver Serpent]

That looks like it'll work.

The buckpuck needs a minimum of 5v to work properly, and it'll be getting 5v since it's on the output side of the 5v regulator. On the off chance that it doesn't turn on/off properly or seems a bit wonky, there's a change you can make. Instead of connecting the red wire from the top pin of the 5v regulator to the third pin of the PNP, connect the battery pos directly to the third pin of the PNP. You'll be feeding the full 7.4v of your batteries to the buckpuck, and the sound board will still be receiving 5v and be safe.

It should work just fine the way you have it drawn out. Just in case it doesn't, that's something else to try.

[Waisulee]

Awesome! I totally get what youre saying. Thanks a ton. So in other words the red wire from the 3rd pin of the PNP would be better connected to the red wire between the 1st pin of the 5v regulator and battery positive. Not connected to the red wire between the 3rd pin of the 5v reg and sound card?
Thanks again for the help :D

[Silver Serpent]

Correct.