Controlling AC fan

Question

Hello I found these project online its called vent a garage. It has 2 ac fans the LINK DEPOT 120mm AC Cooling Fan (AC-FAN-1238B) and its controlled by a thermostate. What I have plan is to use the arduino and a temperature sensor to turn on the fans when for example reaches 70 degrees. what I dont know is what to use to link the 2 ac fans to the arduino to communicate.

mcb1 · Answer

I hate it when tutorials provide advise that is less than SAFE . The above is WRONG . 1. It needs to be fastened and NOT floating around. 2. The wires should not be soldered before entry into a compression style connection, as if there is any heating the solder retract and the connection become poor. it either makes it worse or potentially hazardous. 3. they don't show any form of cable clamp to stop it getting pulled out the box. 4. The board design leaves a lot to be desired. They are relying on a clearance across the pcb of slightly under 2mm ... it should have a physical cut between the track carrying mains voltage and the relay coil. (they have put the low voltage side on the other side of the pcb which is wise) I agree with the other replies. If you are unfamiliar with this then remain unfamiliar and buy something like this which can be controlled remotely from an Arduino. Easy Off Sockets Mark

mcb1 · Answer

Peter As I said in the PM, having the link in place helps others if they follow it, and given the warning I provided could be made safe. In many cases the person is ignorant because they don't know, so understanding the reasons and things to look for is part of learning. I'm less worried about people playing with mains voltages and killing themselves, than I am for them to leave a death trap for someone else. Most electrocutions aren't because someone intentionally touched the mains, its the un-intentional contact that causes problems. Besides the electricity being able to kill you, the force of the shock can cause physical injuries as you are thrown across the room, or off the ladder, etc. RCD's do provide some help in removing the power (after you've gotten the shock), but not all circuits are required to have them, so treating all mains as deadly is far better. Bernardo Is there a reason why you can't just add a manual thermostat set at 70 deg to turn the fans ON. I applaud you wanting to learn, but I suggest using the arduino to measure the temperature and maybe warn you. You could follow this article we did to give you a high and low setting (sorry we used celcius) http://www.theshedmag.co.nz/online/images/stories/downloads/arduino/arduino-101-part4.pdf The sketches are just to the right, and the LCD isn't required if you don't want it. Mark