I have a question about “Current Switches” I think they are called, or at least the concept and how to calculate creating my own.
Basically, I want to detect when current is running through a wire by wrapping/clamping something around it without interfering with the circuit, and use that detection to trigger a separate device.
I’m assuming a wire winding of some kind around the wire, attach the leads from the winding to a transistor, and use the transistor to trigger a separate load? Sounds simple, but are there any examples I can look at?
What you are looking for is a current sensor. It depends on the kind of current (alternating or direct current) how that signal can be translated into a switch action. Please provide more details on the type of the current, and the strength of it that must be detected. AC currents induce an also alternating voltage and current inside a coil of wire. Which can be rectified to produce a dc voltage that can drive a transistor or other electrical switch.
Dc currents produce a magnetic field around the wire, but would need a halleffect sensor to detect it. A reedswitch could also detect this, but it depends on how strong the magnetic field gets. The hall-effect switch usually provides a nice 5 volt signal to activate a more stronger electrical switch.
While you are at it, tell more about the thing that must be switched. Are we talking about a low voltage LED, a vacuum cleaner, or a nuclear powerplant.