ok, im a noob at electronics, so i need some help with this. I have a crapload of LEDs that i want hooked up. All from the same molex connector. And each led will be turned on by a switch, and will fade out. I was going to hook them all up in parallel with a switch before each resistor and LED. Im not sure how to draw some of the symbols, so if you can't tell the V is the LED, /\/\/ is the resistor, and the S stands for switch. Would this design work? Code: _ ----V--/\/\/---S--- | _ | ----V--/\/\/---S--- | _ | ----V--/\/\/---S--- | _ | ----V--/\/\/---S--- | _ | ----V--/\/\/---S--- | | Ground| |+5v And if it can work, where would I throw the capacitor s in to give them the fading out effect? BTW, how many LEDs would you be able to have on at the same time running off of one Molex connector? Thanks a lot guys.
For future reference, I use |>| for diodes, _/ _ for switches and v^v^v for resistors. Anyway, onto your question. I can't think of any simple way to get a simple fade out effect. A typical RC circuit will have a fade in and fade out effect. If you want to pursue that method, then 1 LED circuit should look like this Code: R C +5v - - _/ _- -v^v^v- - -||- - - - - - - GND |- -v^v^v- - -|>|- - | R-LED LED should begin to illuminate after about 1 time constant (R*C), while it will be at full-brightness after 5 time constants.
I've a bench psu with a led "on" indicator that has a fairly slow fade out from the smoothing cap, so that would have Code: /S R LED 12v--o o--+---\/\/\/----->|----+ |+ | === cap | -+- | | | 0v---------+--------------------+ The fade may work better from a 12v supply than from 5v, try it with a 470uF 16v cap and 2k resistor and see how it goes. 2k is not a typo.
