Question about voltage and current

My reference is this tutorial. http://arduino-for-beginners.blogspot.com/2011/04/controlling-12v-fan-speed-with-pwm.html

My concern is can I use the Vin pin of Arduino to be the 12v input of the fan. Because it is said in the blog. That I should use different 12V input. Is using the Vin of my Arduino can damage it?

By the way. I'm using a Universal AC/DC adaptor as my external input of my arduino. The voltage that it can produce is range froum 1.5V to 12V. Input: 220V~60Hz Output: 1.5-12V ("I don't know what is the symbol after this, but it is a line on top and three dots in the bottom" after that symbol..)500mA.

Thanks for helping me :)

I didn't see that in the blog, but there's no reason not to use the same 12v for both VIN and the fan.

line on top and three dots in the bottom

DC or pulsed DC.


Rob

Graynomad: I didn't see that in the blog, but there's no reason not to use the same 12v for both VIN and the fan.

line on top and three dots in the bottom

DC or pulsed DC.


Rob

It can't damage my Arduino? Thanks :) because I already done it with different input. And I'm afraid to try i with the same input. I thought it might damage my Arduino because i'm not using an IC like stepper driver in my stepper motor.

It can't damage my Arduino?

Not putting 12v into VIN no, but this worries me...

because I already done it with different input.

And this

And I'm afraid to try i with the same input. I thought it might damage my Arduino because i'm not using an IC like stepper driver in my stepper motor

If you are trying to drive a motor directly from the Arduino we're going to have a problem :)


Rob

Graynomad:

It can't damage my Arduino?

Not putting 12v into VIN no, but this worries me...

because I already done it with different input.

And this

And I'm afraid to try i with the same input. I thought it might damage my Arduino because i'm not using an IC like stepper driver in my stepper motor

If you are trying to drive a motor directly from the Arduino we're going to have a problem :)


Rob

So it does damage my Arduino?

I just copy the schematic in the blog that i post here. I use a 12v Fan.

No that schematic looks ok, but you said

i'm not using an IC like stepper driver in my stepper motor

So I had thoughts of you connecting a motor directly to the Arduino. That circuit uses a transistor so it's OK.


Rob