Controlling LED 5050 RGB Strip

led strip

I'm trying to figure out how to control the color in the LED 5050 RGB strips–how are the 4 contact points usually mapped (my strip does not indicate). I'd also like to ratchet down the brightness–the strip currently runs on 12V/5 amps. To ratchet down the brightness, is that a reduction of voltage or amperage; how far can I ratchet down and still expect the LED strip to function; and how best to ratchet down?

Best Answer

The 4 conctact points are usually R/G/B anode/cathode and the 4th is common cathode/anode. AFAIK both variations exist.

To control the brightness, the normal way is to use PWM - switch on the required power for a short period of time, switch it off. Do this at a high frequency.

By altering the time it is on/off, you can control the brightness.