What I am trying to do today is control one circuit using another, with no common ground or voltage between the two circuits. Basically what I am looking for is some way to have my Arduino, powered off of its own battery, control a 24V led circuit without using a voltage regulator.
It seems like I am looking for somewhat of a hybrid between a relay and a transistor, the relay providing the ability to control current in a circuit from a separate setup, and the transistor providing a solid-state variable current setup (in this case, hopefully also with signal amplification. If need be, though, I could always just use BJTs)
I apologize if there is something like this already on the forum but I could not think of what I should search for, and my searches turned up nothing.
Thanks in advance,
Trevor
Best Answer
First, if the controller is running from its own battery, then you can connect its ground and the 24 V ground together (or any one point on each one, but the grounds is usually what you'd connect).
Second, you don't need this device to have amplification on its own. You need to get the signal from one circuit to the other, but the receiving circuit can amplify that as it needs to.
If you really need isolation, then a mechanical relay, solid state relay, or opto-coupler is what you want. If you don't actually need isolation, and it sounds like this is the case, then have a digital signal control a transistor as usual.