DC Fan

Hello
I would like to control 4 DC 12 V Fans with the Arduino. There is only a black and red cable on the Fan, so it will be not as easy as with a servo.

I guess I also have to use an external power supplier, but I might just buy smaller fans.

Does anyone know a tutorial on Arduino and Fans?

all the best
Krisztian

my guess is you could use about every tutorial on dc motors matching your specs. As far as I know, the third cable (if it was there in your case) is only for reading RPM anyways, not for setting them (might be wrong though...)

So just have a look for how to control dc motors (should work with a mosfet or something like that, but don't hook the motor directly to an arduino output pin!)

my guess is you could use about every tutorial on dc motors matching your specs

...but probably won't do what you want.

There have been a number of threads on this in the last couple of months, and I think most of them were answered very well by Grumpy Mike.

Here is an example of controlling 12V PC fans using an Arduino.

http://www.uchobby.com/index.php/2007/09/23/arduino-temperature-controlled-pc-fan/

Hello all
Thank you, now I wonder...
the plan is to control 4 servos and 4 fans from Max/MSP.

4 x 5g Servo (Operating voltage 4.0 V - 7.0 V)

I am thinking about to buy:

4 x 5V 40mm x 40mm x 10mm COOLING FAN
Voltage:- 5 volts DC
Rated Current:- 0.11A
Actual Current:- 0.11A

  1. Could I use this 8 tools just with the Arduino's power (5V)?

  2. If yes, is it possible to use the MegaServo libary to control all of them with the dig pins?

  3. What is the different between the Fans with 2 and 3 cables?
    Thank you!

Krisztian

Could I use this 8 tools just with the Arduino's power (5V)?

No. Too much current.

What is the different between the Fans with 2 and 3 cables?

That was mention earlier. It is a pulse signal that is generated once every motor rotation so you can measure how fast it is going.

thank you for the replies.

yet, I only tried 3 servos and a really small fan (only connected to 5V and Ground), and all works.

could anyone tell me how (or where to find info) about how to calculate how many items I could use with 5V?
thank you,
Krisztian

Its not something that is easy to calculate because you don't have information on how much current the servos will draw (this is dependant on the servo and the torque and is almost never accurately specified).

If you have a meter that measures current then you could run some tests to see how much current your components draw. If your 5 volts is provided by a USB hub, most will supply up to 500ma although some may be less.

I did it as a temp controller and a pic go to youtube and type temp controller visual basic or try this link

or search aqua excel. I used a relay

hello,
my basic math:

max current from 5V usb: 500 mA

4 small servos 4 * 0.11A = 0.44A = 440mA

1 small 5V Fan with 0.9W, 0.18A = 180mA

(P=UI - 0.9=5I > I=0.18 )

all together it would be 660mA if all servos are working hard.
what actually happens, could I damage my Arduino or my Computer with this circuit?

thank you for the replies.
K

I don't think you will damage anything but you probably won't get reliable operation powered from USB. 0.11 amp is low for a servo (if there is any significant mechanical load the current drain will be higher). And you need to add the current to drive the Arduino board.

I suggest you try a good quality 5v 1amp regulated DC power supply. These are often used to power computer peripherals so should not be difficult to find.

I found one AC to DC regulator on the shelf.

Current: 1000 mA Max

I think it has to be and old one from Europe. It has a (1) POLARITY SWITCH (2) VOLT CHANGE SWITCH.

the (2) has only 1.5 - 3 - 4.5 - 6 - 7.5 - 9 - 12 V

The servos operating voltage is 4.0V ~ 7.0V

I guess I should adjust my adapter to 6V. My question is:
What would happen if I had the adapter on 7.5 or even on 9V? Would the servos burn down?

If it is not regulated (and its probably not) then the voltage will peak higher then the switch markings. If you have a multimeter you can measure the voltage to see what it actually is producing. I would not recommend running most servos on anything higher than 6 volts.

Whoah had the same prob. helps me out all right

Hello
I bought an AC/DC power supply. I did not try it yet.
I have got the Arduino Duemilanove, I just went trough the hardware details on the website, but could not understand everything.

The AC/DC can provide me with 1200mA which is enough to power the
4 x 5V servos and
1=2 x 5V fan

After I plug the regulated P supply in, shall I use the Vin or the 5V pin the get the current? The USB is still going to be connected as I control the tools from the computer.

Shall I use the 6V from the P supply? (there is 4.5 and 7 as close alternatives)

Thank you,
krisztian

Your fan is rated at 5 volts but your power supply does not provide this. You can try running the fans and servos from 4.5 volts and see if they have enough power.

To try this, you connect the +4.5 volts from the external power supply to the fan +5v line and the servo power line (the center pin of the servo connector). Connect the ground line from the external power supply to Arduino Gnd. That way the external power supply will drive the fan and servos, the USB will drive the Arduino board.

You could also try the 6v line but if that is not too much for the fans.

This means (sorry for English),

1, I do not connect the power supply to the Arduino instead I use PCB mounting socket and connect it to the breadboard.

2, from the breadboard I connect the power supplies current (4.5 V) with the servos and the fans.

3, from the breadboard I connect the power supplies ground the the Arduino's ground

4, the servos and the fans ground is going to be connected with the Arduino's ground or with the ground on the breadboard (power supply), or this does not matter, it works in either way?

best, K

1 , I do not connect the power supply to the Arduino...
only the ground from the external power supply is connected to arduino

2, from the breadboard I connect the power supplies current (4.5 V) with the servos and the fans.
yes, the +4.5 volts from the supply goes to the +voltage lines on the fans and servos

3, from the breadboard I connect the power supplies ground the the Arduino's ground
all the grounds must be connect together

4, the servos and the fans ground is going to be connected with the Arduino's ground
all the grounds - power supply, arduino, fan and servo must be connected together

thank you.