No mosfets to control fans?

Other Hardware Motors, Mechanics, Power and CNC
1

Hello, Normally I use a N-channel But I ran out of them and I do not have any P-channel either. I have 2 of the 12v fans 3w 3pin fans. Is there anything else I can use to control the fan itself? I need to control two of them but they do not need to be connected together to be controlled together in arduino.

Joseph

2

If PWM is "0" then aren't they Off?

3

Hi,
Define control?

Turn ON and OFF?
OR
Control Speed?

Tom... :grinning: :+1: :coffee: :australia:

4

Use the fire fighting aids and calm down from the panic..
Read this link to understand what forum helpers prefer.

Link: Arduino Forum

5

I'm sorry let me rephrase this question. I need to control two fans that are 3Pin using PWM. Normally I use a N-Channel mosfet. But for some odd reason I ran out of them. And I tried to see If i have any P-channel mosfets but I do not have any of them either. I'm looking for something to replace with so I can Pwm fan speeds to make them go high or low speed. These fans are 3watts each at 12v.

Joseph

6

The 3rd pin is PWM input, isn't it?
Don't they stop with 0% Duty?

7

Hello, No it is a tackometer to read the speed of the fan not for controlling the fan.

Joseph

8

Well, in that event, it's not happening without a transistor.

9

Forget about using P channel MOSFETs for 12 volt and 5/3.3 volt controllers. Transistors are needed.
Buy logic N channel MOSFETa.

10

Only tansistors I have currently at the moment are the 2n222 transistors.

Joseph

11

2N2222 should work as low side switch don't forget kickback diode in parallel with fan.

12

2n222 I do have.

Joseph

13

Which Arduino, you may need 20mA base current.

14

I'm using the arduino zero board. which has a 3.3v logic level.

Joseph

15

I doubt that would work, not enough output pin current, how about a Darlington like TIP120?

16

Nothing else I have at the moment. I can not order anything either for a while.

Joseph

17

Any opto couplers like PC817?

18

Matter a fact I do. 3 of them.

Joseph

19

Maybe;
MCU output to opto input through 390 or 470Ω resistor(about 5mA), Opto collector to +12V through 390 or 470Ω, opto emitter to 2N2222 base (about 25mA)?

20

I can give it a try I do have them resistors values. I hope I don't let the smoke out. I need to look online for the collectors and emitters I do not know which one are they for the opto and the 2n222. I hope I can draw this out before I try it. Thank you

Joseph