The relay is this one: http://mexico.newark.com/te-connectivity-potter-brumfield/t90s1d12-5/power-relay-spst-no-5vdc-30a-pc/dp/46F3610
I downloaded the pdf that comes with It and still I have no idea how to make It work, I'm new at this and I just don't understand the schematics, It has 5 connectors that have to be soldered, I already did It.The relay is POTTER & BRUMFIELD T90S1D12-5, I read a bit and It's just a switch for great currents, so It can be activated with a single code like LED blink, I also would like to know which terminals go to arduino and what to do with the rest of the terminals in order to turn on a common lightbulb. I tried every single combination but I don't hear the "click" sound that must be triggered.
Thank you so much for your cooperation.
The bare Arduino can't drive that relay directly. It takes too much current. The Arduino is limited to an absolute maximum of 40mA per output pin and that relay requires 180mA.
You need a transistor to drive that relay.
[u]Here[/u] is a link to the actual datasheet.
[u]Here[/u] is an example of a solenoid driver circuit which can also be used to drive a relay coil.
I also would like to know which terminals go to arduino and what to do with the rest of the terminals in order to turn on a common lightbulb.
Looking at the datasheet, there are 3 terminals almost in a row. Those go to the relay coil (driven by a transistor with the transistor driven by the Arduino).
The other two terminals are the switched contacts for controlling your light bulb or whatever you connect.
thank you so much, another question If I buy an arduino module will I still need the transsitors and stuff?
A ready-made relay module will eliminate almost all of your problems. Such modules can carry one to eight relays, if you need more than one. Also check that the relay is powerful enough for your specific load. Some loads require high (mains) voltage proof contacts, other (low voltage) loads require high current contacts. Switching audio or other low level signals again requires different contacts - that's a whole science of its own. But for now I think that the upper limits (voltage and current) are sufficient for a selection of the proper relay module.
Careful when you buy a module though, I bought one and it simply had four 5 volt relays driven by the digital pins of the arduino. (No relay driver) If I was lucky I could switch two of the four relays before I overloaded the arduino. This was an example where cheap from china wasn't the good way to go.