Trigger Several Relay modules with only 1 Digital or Analog output

Using Arduino Project Guidance
1

Hello all.

I have a project that has 2 relay modules. The relay modules are 12V. There is a 12V source that powers both relay modules and the Arduino. To trigger the modules, they have a signal pin, and they get triggered when that signal is low or high.

In this project, both relays turn on or off at the same time. So they are either both OFF or both on. My question is, in order to save pins and wiring, can I connect the signal pins from both relays to the same Arduino Analog or digital pin so when that pin goes high or low all the relays turn ON or OFF?

If yes, is there any limit in how many modules I can connect?

Thank you in advance.

2

MY answer is for you to try it! AS for how many modules. Same answer: try it!

3

You can read the datasheets for the relay current draw and compare it with 20 mA available for many Arduinos, 10 mA for some.

4

Thank you for your answer.

I found that the trigger current is 2-4 mA so as far as I only do 2 relays together I I would be below the 10mA in the worst case, I could do 4 relays if the arduino gives 20 mA per pin.

5

Well I am trying not to fry anything and do the things right. Thats why I ask first. It looks like it can be done. See above.

Thank you.

6

As long as You keep it a secret which Arduino You use nobody can tell. There are some 20 different Arduinos....
Tha datasheet of "Your Arduino" will tell.

7

I will check, I am using a common Arduino nano.

Thanks again

8

Some Arduinos exist in different version, all the same common. Nano as well?

9

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