Arduino 4 speed fan assistance, help please :O

[Iain]

Hello everyone,

I am trying to make a four state automatic electronic control with manual bypass (4 speed variable resistor) for a fan control which is digital temperature controlled, and am not sure what parts to use.
I was hoping to code with arduino, and have it standalone afterwards. It also displays temp and humidity from two locations, and wasn't sure how to interface this either.

I am new to arduino though.

Most relays require 5 volts and above the recommended voltage for arduono, and the mains fan is 240VAC 5A :/

I realized I will need relays, opto isolators and transistors not sure on logic circuit, but thats where I am at the moment.

It is very much like an ac circuit

0=off
1=low 17C
2=med 22C
3=high 28C

These temps seem a bit high to you?

thanks

Iain

 

[donkey]

http://arduino.cc/en/Tutorial/HomePage
there is a start for the programming. a few things in there to look at are analog I/O as you could possibly control the fan down to 1% if you wanted to.
http://arduino.cc/en/Tutorial/AnalogInOutSerial
as for controlling the speed use the PWM area of the board.
remeber that arduino goes from 0 (off) up to 255 (full on) as shown http://arduino.cc/en/Tutorial/PWM
if you want the code written out for you give me a holler in bout a week I might be able to google something for you.

as for being temperature controlled there are a few ways to go. there are parts for that too. some are connected directly to the item you wish to know the temp of and there are the IR ones too.

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

I got those links from typing "arduino temperature controlled fan" into google.