I'm trying to make a simple op-amp inverting amplifier. If I assume I have a split-supply, everything works fine, but I'm very confused about how split supply designs can actually work in the real world.
Let me show a simplified schematic for what I'm trying to make:
In this circuit, VGND is the virtual ground, giving me a split supply generated by R1 and R2 with an op-amp buffer.
It seems to me this would work fine if I was building an entirely self-contained circuit, but it seems like this type of split supply (where VGND is actually 15V off GND) limits what I can connect the output to.
For example, if the power supply (USB power supply) was mains referenced, wouldn't that mean I couldn't probe it with an oscilloscope as shown in the diagram, because the oscilloscope would be shorting 15V?
If it's powered by USB (and therefore 15V off USB ground,) wouldn't that mean I also couldn't connect the output to an Arduino, because when I tried to connect to the grounds I would again be shorting 15V?
It seems to me like this type of virtual ground circuit can never be connected to other circuits, so this sine wave amplifier could never be connected to an Arduino, right?
Is there a term for kind of problem?
Googling terms like "grounded split supply" doesn't seem to lead me to any more information about this problem or potential solutions.
Ideally, I would love to figure out how to get a split supply that makes VGND = GND, instead of making VGND = V/2, but I can't seem to find anything on the internet about this problem, so even just some terms to search would be helpful.