Hello all,
I have almost zero knowledge in electronics and this is my first Arduino project.
I want my Arduino Mega to control 8 power outlets (on\off).
I guess it's important to mention that my home electricity is 220v.
My questions (for now ;)) related to "power center" I need to create.
I read a lot about this, and I understood I will need somekind of realy.
My questions are:
Can I buy 2 relays like this 4 Channel Relay Board and connect them to my Arduino? How can I do that? Do I need any more parts?
This relay has separate power supply, does it mean that I just need to connect it to any power outlet in the wall, and control it usiing Arduino?
Please help me understand these things, and remember I'm very (very) new , so if you think I need to but something else, it will be great if you could explain
The easiest things to use for mains control are SSRs (Solid State Relay) They usually have 2 conections to the arduino - ground and a digital pin set to output. No problems with reverse voltages or extra power supllies, and the low voltage arduino side is completely isolated from the mains part. The only possible downside is that they leak a small amount of current in the off state, which isn't usually a problem but you can get a shock if there isn't a load on it.
Can you please explain me why it's simpler then the 4 relay board?
If we are talking about cost: 8 SSR like this 10A Solid State Relay Technical Data will cost about 80$ while 2 boards like I posted earlier will cost 30$.
Can you please explain me how to connect the SSR's to the Arduino and to the power outlet?
On your illustrated SSR, Pin 3 is arduino Ground, Pin 4 is to arduino digital pin. Pin 1 is Live in, Pin 2 is live out. Neutral and earth are connected direct to the outlet. When the digital pin is programmed high, the mains is 'on' and when its low its 'off'.
You don't need a seperate power supply to feed the relay board with SSRs. If cost is an issue you can get them much cheaper from Ebay vendors in China......
For an inexperienced DIY project, I suggest a relay based board like below. Simple and inexpensive. As to powering it, just use the same power source as the arduino that controls it.
That is looking a bit like something I would like to try too, just with vertical blinds instead. That would be something with attaching an external pot instead of the one inside the servo, and make it a full rotation one, so it could measure how far the blinds are tilted. (takes quite a few rotations from one side to the other)
That is looking a bit like something I would like to try too, just with vertical blinds instead. That would be something with attaching an external pot instead of the one inside the servo, and make it a full rotation one, so it could measure how far the blinds are tilted. (takes quite a few rotations from one side to the other)
If the individual slats in the blind rotate less than 180 deg, modify the servo for continous rotation and connect to the actuator, remove the pot, and connect the pot to one of the slats.
My final project is reef controller that will control 8 power outlets (pumps, heater etc.).
If I understood correctly, the best way is to buy the following:
8 SSR like this one: 10A Solid State Relay Technical Data
8 outlets
power cable
a box
And to create my own "power center", right?
And when I say to "create" I mean to connect each outlet to single relay and each relay both to current and to the Arduino digital pins.
Another approach (which needs no wires) is to use an Arduino with an added RF transmitter. This can then control RF power sockets. There is example code hosted on google code project arduinoha - go google search for 'arduinoha google code' to see how it is done.
I really appreciate your help and honesty, and you are right, I do have as little experience as it appears.
This is why I don't do anything without first consulting you.
This picture was taken from the Internet, I just googled for the Hebrew word of Relay and this is what I found.
I think that eventually I will buy 8 SSR's from futurlec (10A Solid State Relay Technical Data) and wire them to 8 power outlet, It will be the easiest solution - this is how I will not have to handle many electronics.
Not that I recommend buying anything from futurlec unless you don't mind waiting weeks. But all you need is 2 of these boards.
You simply wire a digital output from the Arduino to the input of the optocoupler for each position (8 digital outs) then tie the other end of the optocoupler input to ground. I believe this board already includes the current limiting resistors for the opto's.. If not you need to also include a resistor in series to limit the current to the internal opto LED to 20mA. Then simply take your power cord to your 220Vac device and cut the hot lead (without it plugged in obviously) stick one end of the cut wire into the "C" terminal block and the other into the "NO" terminal block. When you write the digital pin high you turn on the LED in the opto which energizes the relay and creates continuity between C and NO (just like taking the wire you just cut and putting it back together) DONE.
I'd recommend playing with simply using the relays to turn on an LED at low voltage first..then when you know what you are doing switch to AC.
Disclaimer...Line voltage is dangerous.. This writer of this reply assumes no responsibility if you die or get shocked or any other damage you may create by playing where you shouldn't.
Just small question: What should be connected to the SSR, is it the live or neutral?
I mean, one line will be connected directly to the device while the other will be connected to the SSR.
It's more expensive, but what I did was use an X10 transceiver-arduino to switch on/off some X10 outlets. It's very expandable and you don't have to have all your outlets in one spot.
It is traditional to switch the live side of the circuit. It (slightly) reduces some risk factors.
Sorry for brining it back up, but can you please explain what are the pros and cons of each way?
I asking because I saw few postes (not here) which I saw that the blue wire (the neutral) was connected to the SSR while the brown wire (the live) was connectet directly to the device.
