Trouble whit RGB led and controller

[pr0cess0r]

Hello i ordered an RGB controller that is 12v in and 12v out i also ordered RGB led that support 3 V. The controller have a brigthness controller and the lower setting keep it at 2.3 volt max. all color work but if i use fade that make the led flash very fast and they burn. i whas wondering id my led are juste bad or its the controller ?

[steve2]

Re: Trouble whit RGB led and controller

You can try using a tail light or other bulb off a car to test. Maybe when you hit flash, it jumps back to 12 volts before dropping it to 2.3 volts max.

[Th3_uN1Qu3]

Re: Trouble whit RGB led and controller

LEDs are driven in current not voltage. The voltage required depends only on the LED, as soon as the voltage input exceeds the breakdown voltage of the LED, the LED will start conducting (aka light up), and it'll eat all the current that the supply gives it. If this current is not limited the LED will burn.

12v LEDs are inherently current limited because they are just regular LEDs in series with a resistor. This is why you can dim such LEDs by dropping the voltage. You need a current source in series with your RGB LEDs. You can just use a resistor sized appropriately, so that at "max" brightness of your RGB controller you do not exceed the current rating of the LED, or check here for a simple adjustable current source using a LM317 if you need a little more control. You can find that at any radio shack or similar store.

[pr0cess0r]

Re: Trouble whit RGB led and controller

Afther some testing i found that my controller at max power output the same voltage it get from the supply. My solution is to use a 5v supply and 3 resistor for the - of each colors since they dont have the same maximum voltage. i tested it all day like this and no burn led!!! I whas thinking about using a 7805 to get 5v in my car. My project is to have all light in my car dash RGB!!

[Scenic]

Re: Trouble whit RGB led and controller

i'd rather use a switchmode step down converter. that 7805 is going to need a HUGE heatsink if you're going to connect it to the car battery..

if you don't want to build your own, look for cellphone chargers that plug into the cigarette lighter socket.

the ones for sony ericsson phones with the "fastport" connector usually put out 5V.
i've got one that looks like the one pictured in the auction below. i'd recommenc popping it open and replacing the generic crapcaps though.
http://cgi.ebay.com/120710805517

or just get one of those USB car chargers. those have to be 5V for sure lol

[pr0cess0r]

Re: Trouble whit RGB led and controller

will look at this im lazt and the 7805 looked simple!