question about LEDs ... if i had a 3.7 volt (20ma) LED connected to a pot (and say the line powering the led is 5v) the pot is resisting around 75 ohms ... how much more resistance will i be able to add before the LED goes out? or does it just get dimmer and dimmer and never truely go out? i figure if i was going to seriously do this, i'd have the 5volt line | | | | 75ohm resistor | pot | Led | | | gnd i just want to be able to control the brightness of the LED(s) i know its basic, but i'm in a rush and you guys know your stuff, so i feel that i can't go wrong asking here first edit: and i'm asking so i can find out what resistance pot to buy.
The led will still be on but very dim at around 250uA, so you could use a 10k pot, try with a fixed resistor or two first. It won't be a nice smooth dim, though.
I am tryig to do the same thing, could some one help me out and show me on either here www.dse.com.au or here www.jaycar.com.au what Potentiometer i would need, there are so many at different ratings i am unsure what to get. I'm a bit of a noob when it comes to electronics.
I'd try it TheAnimus way with a 10k log, like JCar's Code: STOCK-CODE: RP7610 RRP: $1.75 Qty 1+ $1.75 Qty 10+ $1.45 Qty 50+ $1.20 10K 16mm Potentiometer Log Single Gang (A) Don't forget to use the resistor as well, to limit current when the pot is turned right down to zero.
