Correct wiring using multiple voltages

Projects General Guidance
1

OK, I’m using an esp8266, A 5 V relay, And IR receiver, And a 12 V LED bulb. The power source I’m using is the battery bank that has a 5 V USB output, as well as a 12 V output. I’m fairly new to this and haven’t found a specific video that would address using the same power source for both voltages which is what created this question. So here’s the question– the negative coming off of the LED which I would then tie to the negative wire coming off the 12 V output, ChatGPT is telling me to twist those together and then run that negative to the Arduino. In my mind that would fry the Arduino, when I posed this question it response was that it just uses the negative as a reference voltage and then it would not hurt the Arduino. Is this correct? I tried to simplify very long question

Open Skeleton Hand Lantern Wiring Diagram
Open Skeleton Hand Lantern Wiring Diagram971×731 254 KB

2

ALL grounds should be connected back to the power supply.

3
  • First things first, don't use ChatGPT.
    :grimacing:

  • The ESP8266 will need a 3V3 to 5V driver to control the relay.

  • Give us a link to the LED, you should be able to control it with a MOSFET.

4

Why do you think that? (It's not true, but without knowing why you think that I can't really tell you why it's wrong).

This might help:

This is fundamental to all electrical circuits:

5

I use Red for +5, Orange for +12 and black for ground. I cannot always do this but I tend to follow this pattern. Be sure all grounds are connected.

6

You need to be careful the 5v and 12v connections from the power supply may not have a common ground .
Are you sure the 12v isn’t just the charger socket ….,,
( often the internal switched mode 5v circuit inverts the signal , producing -5v relative to the input ground ).
Check first by seeing if there is a voltage between 0v on the 5v and ( if it exists ) the 0v on the 12v .

7

You don't have to connect the 5V and the 12V grounds.
The esp8266 ( which is powered by the 5V ) is isolated from the 12V by the relay.
If both grounds are connected inside the power bank, no need to add an additional connection, and the 5V and 12V will share the same ground.
If the grounds are not connected inside the power bank ( which I don't think ), the 5V and 12V will be isolated