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How to make a 4 LED switch Answered

So I am making a deadmau5 helmet and i want to add 4 LEDs to the inside. I was wondering how i would set this up and what kind of power supply I would need such as 4AA batteries or that. The LEDs need to be able to be flipped off by an SPST switch and they should be able to run for around 3 hours before switching the batteries out(more if possible describe as many possible ways as you can). I only really plan to go to radioshack and visuals are my preferred resource here because electrical components are not my cup of tea. Here is the link to the LED http://www.radioshack.com/product/index.jsp?productId=2062551

P.S. I'm kinda new to circuitry so I may ask for further clarification.

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mpilchfamily

4 years ago

Google an LED calc and enter the information you have such as the LED specs and the power source you would like to use and it will give you the shematic and resistor values needed to make it all work. Add you switch in line with the negative power lead from the batteries and your all set.

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anthonyv4mpilchfamily

Answer 4 years ago

Ok so I used this site http://led.linear1.org/led.wiz with the inputs( in this order) 15V(I will be using a 9V with 4AA batteries) 3.0V forward voltage, 20mA forward volatge, 4 LEDs. Do i need to change any of the specs and does the end of that section connect to the negative side of the battery and how long do you believe that will last for?

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icenganthonyv4

Answer 4 years ago

4AA batteries in series is only 6 volts and you can put a switch in series any where you want ( Positive, Negative or the middle side )

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anthonyv4iceng

Answer 4 years ago

I understand that 4AA batteries is only 6V but the added 9V will have it add to 15 which is 3 over the drop rating on the LEDs.

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icenganthonyv4

Answer 4 years ago

Here is a 15 Blue LED strip running from a single 9V battery using 8.87ma.

The strip is wired as a parallel group of five sets of

( 3LEDs in series with a 150 ohm Resistor )

My strip will run for 54minutes on a 565mAh alkaline battery

and 2Hrs on a 1200mAh lithium battery.

===============================================

Taking two of your green LEDs in series with a 200 ohm resistor

and adding a second same string in parallel should run 36ma

Using a 1200 mAh lithium 9V battery the 4 green LEDs should run for only 30min

Using 6 AA lithium 3400mAh batteries 4 green LEDs should run for 90min..

-------------------------------------------------------------------------------------------

The efficiency of LEDs is the difference.

BTW you should Never mix AA with 9V batteries !!

9V-HorStrip.JPG9V-15LED.JPG9V-LED-Res.JPG9V-A.JPG
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anthonyv4iceng

Answer 4 years ago

I understand that 4AA batteries is only 6V but the added 9V will have it add to 15 which is 3 over the drop rating on the LEDs.

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anthonyv4mpilchfamily

Answer 4 years ago

Also forgot to ask what kind of resistor should i get, please be specific.