Wiring Help

IF YOU EVEN VIEW THIS PLEASE RESPOND!!! ANY HELP APPRECIATED!!! Ok, well i've been trying to get my wiring worked out. I did this: 9 volt- 9volt -aa- aa- led- led- fan- switch- fan- led- led - (back to nine volt). I put the switch in the middle cuz I want it under my chin...but when finished soldering, it didn't work. So I took the switch out and tested everything else...nothing. HELP!!! THe radio shack guy said it should work. Should I switch out the AA's for 9v's?


Jr Member
Try making sure all the positives and negatives are going the right way. Also, you should add up all the voltage for your batteries, and then find the max and min amout of voltage for your fans and leds, and see if the voltage is right. And i'm not completely sure, but i dont think you can use 9v with AA batteries. I cant think of anything that uses a combo of two different types of batteries. And i also think using LEDs and fans together is also a no-no, as they use different voltage. Good luck, I'm sure you'll figure it out. If worst comes to worst, you can always sue radio shack!


Jr Member
koobs said:

That should solve your problem, although, how you described your wiring was confusing...
.... that won't work properly i think... you cant power that all by just one 9v battery.. i think you need more tbh
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Spurks Donut

Active Member
You do. 2-3 9v's will work nicely. I have used 3 9v's on 1 just PSU fan. Probably isn't too good for it, but hey... it really puts out that air! Maybe try 2 9v batteries and see how it works. If the fan is slow, and LED's dull, add one more. Wal-mart has a 2 pack for $0.94. They don't last VERY VERY long, but they last plenty long enough for a contest or party. :)
Hey i got it to work so thanks for all the help. It took an electrician at Radio Shack to figure out how I wanted my setup and what would work. Ive now got a sick dual fan system, and a 4 led system, all waiting to be installed in my helmet WIP. The wiring's pretty cool so I'll post it sometime.
It wouldn't b/c I'm running two fans that require 10-13v. It now uses 2 9v. Then, my led circuit has 4 12-16 volt LED's. Its running on 2 12v "N" battery's. They're awesome. They're smaller than a AAA but powerful.


Jr Member
link4044 said:
1 9v will run all that
but 1 led will prolly need ~3v.. how can 1 battery run 4 leds + fan then?

master chef: 4 12-16v leds running on 24v? how is that possible? =P
48v>24v or am i just thinking wrong
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New Member
FirePhoenix NL said:
but 1 led will prolly need ~3v.. how can 1 battery run 4 leds + fan then?

master chef: 4 12-16v leds running on 24v? how is that possible? =P
48v>24v or am i just thinking wrong
yup, u are ^^

it all depends on "how" u connect them. if u connect all devices in parallel, then the needed voltage won't go up. let's make this asumption:

u have 10 devices. each consume 3Volts and 100 Ma (Miliamps). if u connect all those in parallel (meaning, u attach the positive end of every device to the positive end of the power source, same for the negative) your entire system WILL consume exactly 3 Volts. however, it will consume 1 Amp (100 Ma * 10). in the contraire, if u hook them in series (meaning, from the positive end of the power source to the positive end of the 1st device, then from the negative end of that device to the positive end of the next one, and so on until u reach the negative end of the last device, and from there to the power source) the system will comsule exactly 30 Volts, and 100 Ma.

Now to further clarufy, it will depend on many things, the kind / brigtness / Power consumption of the leds u got, size of the fan, etc. for a quick reference, 1 AA baterry (1.50V) is more than enough to light a normal led (resistor needed). also 9V batts aren't your best choice here. i would get a rechargeable battery pack (12V) of at least 600 Ma (1AMP is way better).

Here's a scheme:

here are some good examples of what i would get (if i lived in the US that is T_T)

Battery Pack - Small

Battery PAck - Large

i hope this cleanses a few doubts ^^
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My circut is wired as a parallel and I did the math and I have enough volts running to everything. Just to clarify, the leds and fans are not on the same circut. They're seperate. Also, the lights run brightly and the fans fast, so I think thats a good visual indicator that they are getting enough power. I will soon post pictures of the circuts and then eventually them mounted in the helmet.


anything over 3V on an LED will damage it. over 5 will blow it instantly.

3 LEDs in series with a 9V battery should be fine, but it might have voltage spikes and kill all 3 LEDs, but it happens only rarely.

3 LEDs in parallell with a 9V batt means
9v goes to each LED.
from what i know, you'll blow all 3 led's this way.


Jr Member
Do you guys know how resistors work?...

ok... let me explain this to you... if you have a 2 3v leds, you will need 2 3v resistors to control the electiricty flowing through each of the 2 leds if they are sharing a 9v battery...... If you have 3 leds running off of one 9v battery you will not need any resistors..
Make sense?

So in essence if you are running 4 leds and a fan on one 9v battery, you will not have enough power to operate all of them or they will all be running at non optimal levels.

Be smart, use the right amount of wattage... if you feel that the 9v batteries are too heavy, then switch it up to camera batteries which can go up to 12 volts, distribute power evenly and on top of it they are lithium ion so they last longer than nicad.....


Jr Member
Master Chef said:
Yeah it worked out so that I wouldn't need any resistors. I'll post pics once I finish my Italian homework. Ughh
Here in Tennessee we have no language classes other than Spanish.
Italian.. I'de like to take that..
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