How to Power and Control a 12V Danfoss Solenoid Valve via Arduino Uno and Wireless Sensor

Hello

I'd like to put an electro-valve in my house, which will cut off the water supply to my boiler if the temperature of the circulating water drops below 50 degrees C. I would like to put the whole thing on an arduino, which would receive the temperature measurement via radio from another arduino already mounted, then convert the 5V voltage into the 12V necessary to control the electro-valve.

Can it be done this way, or is it necessary to use what additional power supplies?

I have decided on a solenoid valve like this:
http://valveselector.danfoss.com/showresult.aspx?v=pl&system=Heating&medium=Water&function=NO&size=G34&coilvoltage=DC_12V

Inverter (I don't want to make an advertisement here, just the first image from the internet)
http://www.bro.net.pl/Obrazki/2AB88EC1-0B42-4770-A373-D93B4FCDD75F.JPEG

Have you checked the wattage of the 5V power supply to power this valve? The solenoid is 18W which at 5V gives you over 3A not counting the losses on the inverter, which also has to withstand continuous operation to hold the solenoid of the valve closed.
If you pulled up 12V to power the valve you could easily drop down to 5V for the other circuits.

Relays missing ?

The relay is a good solution, but I have a few doubts:

1) I receive the temperature measurement via radio, that is, when I receive a temperature lower than 50 degrees, I put a high state on a given pin which is connected to the relay and it activates the circuit with the coil ?

2) which relay should I choose?

3) this is more or less how it should look like ?


So I then quietly use the power supply to turn on the valve, yes?

PawelP930 wrote:

3) this is more or less how it should look like

This diagram of yours sorry, scares you Relay dedicated to Arduino, 5V, with protection, some pennies.....Temperature too high, you set ,,0'' on output µC, relay lets go and disconnects solenoid valve or this ,,something''. Is that so difficult? By the way, familiarise yourself with the symbols of the electrical and electronic components, because from this it hurts your eyes

It's not difficult, but I wanted to make sure I understood everything correctly, rest assured ;P

Image quickly converted from Wikipedia, I know I didn't follow the applicable symbols, sorry, but it was all about ideas.

I hope it will be good:
http://botland.com.pl/przekazniki/2723-modul-przekaznika-rm0-5v-10a125vac.html

Yes, that's the transmitter.

Are you assuming that the 12 V coil of the central heating valve will be controlled by 5 V?

So what should it look like in the end?
I thought the relay solves everything, the valve would be powered by a 12V supply with one wire going to the relay and the relay would be controlled by this 5V?
Is there anything else I'm missing from this circuit?

And so for hours this valve will draw ~20W from the grid? A very uneconomical solution.
Maybe look for another solenoid valve that only draws power when closing/opening.

Andrew55, thanks for the valid observation.
Thank you all for your help, do you have any suggestions? anything else I should pay attention to?