Which one of these do you think is a better circuit to control/limit current to an LED? The 5V line with a 330 Ohm resistor on it, represents the arduino output pin. When I ran the circuit number 1 on a simulator, it did not work. I used Every Circuit on android. But circuits number 2 and 3 did work on the simulator.
Transistor in question is 2N2222. I put its data into the sim and still, circuit 1 did not work.
jremington:
What do you mean by "circuit 1 did not work"?
It will work fine if the components are properly chosen.
Well, the simulator I'm using is very realistic. That schematic did not work in that simulator. That is why I was asking.
To be specific: I'm goind to be using arduino output pins wired to the base of that right transistor through a 330 ohm resistor.
I will be individually controlling high power LEDs (1W, 3.2V, 350ma) through NPN transistors. OK, lets say I will use that schematic that was posted before. So I will be using two 2N2222 transistors. The resistor downstream of the right transistor will be 2 Ohm. And I will have corresponding power supply. Will this circuit work in a way that it would control the current?