How to turn on appliances using Raspberry PI2?

Question

Raspberry Pi

I want to teach the raspberry to turn on the music center. I found the contacts where the power button is soldered - is it possible to put them in the GPIO on the Raspberry and close them programmatically, without using transistors and other relays? Basically, I just want to close the circuit for a second.

Answer 1

For many reasons (prevention of a common ground, protection against stray currents, etc.) it is better to separate the electrical circuits of the RPi from the circuits of the center using a relay.

Answer 2

For these purposes, any optocoupler with a small input pickup current should be suitable. Unlike a relay, an optocoupler is not so bulky and does not click