it is not done with component type electronics.
??? what does that mean?
Something like this has to have at least two inputs. 1. The sensor input 2. the reference input. With out those your comparing oranges to apples.
I get what the sensor input it, it's the tach wire, what is the reference input?
A tachometer out put is just a signal from a sensor, nothing more, nothing less.
in it's simplest form power is sent to a coil/transformer, power flows through that coil and to the negative post. that post is grounded either by points or a module charging the coil. when the ground is broken the charge collapses and sends power out the secondary side.
so the tach wire would read 12v (or 14.2) then would show a short to ground and back to 12v cycling at a frequency linear with the engine RPM, correct?
The opening of the throttle/addition of more air and fuel is what makes a engine go faster. Not the signal/voltage from the tach output.
who ever said such a thing? not me... unless you can intercept the wire from the points/module before it reaches the coil and modify it's timing...