Quote:
Originally Posted by kikkegek
hi MAtt21lutz. all the info is in the build thread. but here you go.
datasheet:
http://www.futurlec.com/Linear/LM2940CT-12.shtml
it says .47uF before and 22 uF after the voltage regulator.
this is the picasa webalbum with all my pictures:
https://picasaweb.google.com/1072267...JueyP6F4LfzxAE
Your setup is not quite right. but then again its not complete, because you cant see the whole circuitery.
look at my design:
you can see small black parts on the boards? those are very small SMD resistors. they are a pain in the ass to solder in there, but take up little space and give a clean end result.
I use one resistor per string of 4 leds to control the current running through the strings (leds).
so what you basically want is
- max brightness setup by the reistors in the strings (SMD in my case) BRAKE/TURNSIGNAL
- and reduced brightness for running lights using one bigger resistor in line with all of them.
one big resistor is the simple method for controlling brightness, but you can only dimm so much using a resistor. below a certain current/voltage the LEDS just turn off...better cleaner way is to use PWM. but also more expensive.
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So I've run through this quit a few times, I would just like to get someone else's input on the "new" design. Added the caps what I believe to the entire circuit.
There are two versions, one that uses a resistor to dim the LED's and one that uses a PWM with a lower voltage (10 volts), let me know what you think?
http://www.digikey.com/schemeit#o82