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Old 06-10-2007, 06:02 PM
  #12  
Trex
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Join Date: Apr 2007
Posts: 53
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Originally Posted by Ajoe View Post
@Matt,
Pls share me the cheap BEC

@Chellie
You are right, this charger doesn't balance each cell.
In my mind, due to each cell was charged individually, when they fully charged also become balance .
@Chellie:
By charging each cel with its own charger you dont need a balancer .. thats in general how the Cellpro 4S works...


Here is my BEC

It is built on a National Semiconductor LM350 ADJ. You can set any (as long as its below the input) output voltage by varying the drain resistor.

You can download the datasheet for the LM350 which shows the schematics for the voltage regulator setup. If you need any help or details let me know!

You dont need the capacitors but I added 1000uF on the output to make sure there arent any power surges

You do need a little heatsink.

If you dont need 3A you can also use a LM7805 (1 AMP) which can be found on soundcards, older PC power supplies and older mainboards.

In general you can recycle a plethora of parts from old PC!! My heatsink and 1000uF cap came from a mainboard

Here is a pic for size comparison. You need to assure adequate cooling under the load the are pulling from it to make sure it doesnt burn up.

I am also working on a SWITCHING 3A BEC that will be much more efficient but its harder to build.



http://img245.imageshack.us/img245/1725/becsn6.jpg
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