activation switch controlling with 5v dc voltage

Hello,I have basic circuit project and it has a small problem in this project.You can think a basic switch.First,switch in open case.If 5v dc voltage comes to switch,Then,The switch should close.How can i do it?Thanks.

1 Like

You describe a relay.
Use a 5vdc relay, an fet or bi-polar npn transistor.
Can you draw a picture of circuit in and out?
Source current available and load current needed.
Also if you need isolation, or both circuits use the same common “ground”.

Yeah, a picture or graph would be nice to describe or suggest.

Such a broad request. Is it a real project or a general question?

2 in one:
5v controlling 12v
12v controlling 9v

Looking solid and reliable. Thanks!