Hello there. I am very noob in this, I am sorry in advance for the stupid questions. This is my second project ever. The first one involved the classic blue relay you can find in all starter kits, but I can't use it since it is too big to fit inside the intercom's case. And, I found this smaller relay.
I have a 50ohm 0.5W speaker inside my apartment intercom device (tcs ISH3022). That speaker is connected to the intercom's board with two wires: red and black. The intercom device itself is pretty basic, only two small wires from the wall are connected to it.
I want to insert a switch so that I can turn on/off the speaker. My idea is to cut the red wire, insert a relay and then control that relay with Arduino.
Now, I have Arduino UNO and Omron G5V-1 (5VDC). How can I wire up those 3 things to turn on/off the speaker? I will provide external power to Arduino of course.
I made a "schematic" so if someone could draw wires on top of this image?
Your relay coil using the 5 volt coil has a 30 mA current draw. Not good for an Arduino or sort of pushing the limits. While 40 mA is kicked around most will tell you do not exceed 20 mA. That said you want to use a transistor to drive your relay coil as was already mentioned. You also as mentioned want a flyback diode across your relay coil.
Using a uC like an Arduino is really super overkill unless you have a reason for doing this. I could make a schematic and sorry I don't do Fritzing images. All you need is a simple common switch to turn your speaker On / Off. Again, don't drive the relay directly with an Arduino.
It is not at all hard to learn, then you will be able to speak a universal language that has served the world very well, for over a century. Have some respect for your own abilities!