Hello!, I need to control a brushed DC motor (speed is regulated by voltage, 3.3v 0.2A), through PWM, I don't have any idea to which transistor I should use and the resistor value too.
I power the Arduino UNO and the motor with the same battery, 5V DC.
Can you explain me which method I should use for find the right one?
Thanks.
A brushless motor normally needs a lot more complex circuit than that to drive it. Can you provide details of exactly what motor it is that you want to drive? Are you certain it is brushless?
Steve
Is brushed, I wrote bad. Sorry.
You need to know the stall current of your motor before choosing a transistor.
Rather than go through that effort (which generally requires study of electronic engineering), why not just build a circuit that has well chosen parts (Q3 and Q4) and is known to work, like the following?
For NPN and PNP, just about any bipolar transistor will work, but 2N3904 and 2N3906 are old favorites, respectively.
I tried with 2N3904 but the voltage in the motor is at 0.7V, and isn't enough for run it 
I used a resistor with 220Ohm and others values, but nothing changed. I set the PWM first to 52 then to 120, but nothing append.
I need to add something or remove something and where in the circuit?
I'm very noob in electronics, I don't need change of direction or others complicated things, I need only to control the speed of this simple motor, in the simplest way.
The circuit I posted does not show a 2N3904 transistor directly controlling a motor.
A 2N3904 can't support the motor stall current, which you have yet to tell us, but is probably greater than 1 Ampere.
Google "arduino motor control" for other examples, but avoid Instructables.
In the datasheet of the motor there isn't any voice "stall current", but I think is about 0.2A, because is the only current data on it.
Is a very small and low power motor.
jremington:
Google "arduino motor control" for other examples, but avoid Instructables.
I seen a device called "L9110", Can it work?
(sorry for bad english)
To estimate the stall current, measure the motor winding resistance R with your multimeter, then divide that value in Ohms into the motor supply voltage V. I = V/R.
V = 3 V
R = 10 Ohm
I = 0,3 A
Otherwise, the "L9110" can be used with 3V DC motor? And it can control the speed through PWM?
The L9110 is a motor driver, not a transistor. Google will show you how to use it, like this page.
But I need a motor driver, I can use it instead of the circuit with transistor?.
