excuse my ignorance im i to understand that this is 3 leds in 1 with a common ground and i could simply plug the shared ground to -5v then take 3 variacs from +5v to each of the led terminals to control the brightness?
@prankmypants Yep, the three LEDs are in one plastic lens with a common ground, so it has 4 pins in total. The voltage/current characteristic of LEDs is very nonlinear, and so variacs would sort of work, but not that great. For brightness control, Pulse Width Modulation is the best way to go with LEDs, or you can also use a variable current source. A variable voltage source or variac won't work so well.
wow thanks for speedy response. yeah really all im looking to do is replace all the LEDs in my computer fans and have a colour switch and possibly a colour pulse mode depending on how hard this is. what would you recommend?
@prankmypants Cool, that'd look pretty neat. The ultimate solution would be a microcontroller with PWM outputs, but you could probably get started quicker using an LM317 and a potentiometer as a variable current source
thanks again, i looked up the LM317 and feel confused. do you possibly have a link to picture or something that shows the circuit you had in mind so I may understand what im doing better?
SPARKFUN IS AWESOME
microchoc 5 months ago
excuse my ignorance im i to understand that this is 3 leds in 1 with a common ground and i could simply plug the shared ground to -5v then take 3 variacs from +5v to each of the led terminals to control the brightness?
prankmypants 1 year ago
@prankmypants Yep, the three LEDs are in one plastic lens with a common ground, so it has 4 pins in total. The voltage/current characteristic of LEDs is very nonlinear, and so variacs would sort of work, but not that great. For brightness control, Pulse Width Modulation is the best way to go with LEDs, or you can also use a variable current source. A variable voltage source or variac won't work so well.
precosky 1 year ago
@precosky
wow thanks for speedy response. yeah really all im looking to do is replace all the LEDs in my computer fans and have a colour switch and possibly a colour pulse mode depending on how hard this is. what would you recommend?
prankmypants 1 year ago
Comment removed
alexwarrior1 1 year ago
@prankmypants Cool, that'd look pretty neat. The ultimate solution would be a microcontroller with PWM outputs, but you could probably get started quicker using an LM317 and a potentiometer as a variable current source
precosky 1 year ago
@precosky
thanks again, i looked up the LM317 and feel confused. do you possibly have a link to picture or something that shows the circuit you had in mind so I may understand what im doing better?
prankmypants 1 year ago
GOOD CONTROLLER Z16F
HolgerHartenstein 2 years ago
Very nice!
AustinSalgat 3 years ago
nice
hiatuszero 3 years ago
omg lawl
IcyMidnight 3 years ago