Relät problems (total beginners)

Hello, 1..Är total beginner Do not know if it is the right setting to post this on Is there a kind soul who can help me with a relay Want to make it work together with a ledlist powered by 12 volts But will it not work, it is lit all the time so it seems that the relay does not break or turn on, the little kod I have is to turn on the green light, I assume that then ought relay function But do I not ledlisten with 12 volts so it shines all the time how much I plug it in Need the relay more power because now the only current from arduinon 5v


Sorry for my english


Pic from Original Post

I can’t figure out the connections from the photo.
Please make a pencil drawing showing the connections, including any for the LEDs you mention, and post a photo of the drawing.

Also post a link to the datasheet for the relay.

And, most importantly, post your code.
Please use the code button </> so your code looks like this and is easy to copy to a text editor


Found only this, but there is such I have But the fact is that it requires 12 volts to operate properly ???? The code gets the green light to go on and off and I thought that it was enough there to relay to react As you understand, I'm totally lost in space :-)

int outPin = 8;

void setup()
     pinMode(outPin, OUTPUT);

void loop()
     digitalWrite(outPin, HIGH);
     digitalWrite(outPin, LOW);

12V is 12V ;) It will never work on 5V or 3.3V unless you add an additional power supply to get the 12V. Do you have a schematic of the relay board?

i only have this side on ebay

You need a transistor between the Arduino and the relay. The Arduino can control the transistor and the transistor can control the 12v.

You can buy relays that work on 5v but beware that an Arduino I/O pin cannot provide enough current for the relay coil so you will still need a transistor in that case.

The Arduino Circuits on this website may help.

You can also get solid state relays that can be directly controlled by an Arduino


Robin2 Many thanks for your help, will check and continue with my little project