I'm new to this community so I apologize if this isn't posted correctly.
I am looking for a circuit that could switch between two low voltage (1v or less) DC inputs to a single output. Oxygen sensors such as the type used for car engines use a chemical element that generates a small voltage dependent on the amount of oxygen present. While the engine computer for my application only has one o2 sensor channel, I need to supply computer with the signal/voltage from two o2 sensors; switching between the two at least twice per second.
Since even a small variance in the signal output would cause an issue, there would need to be minimum resistance/voltage loss in the circuit. Is this possible, and if so what could the circuit look like?
Best Answer
You could use an analog(ue) switch - these are basically open/closed contacts in silicon controlled from a logic signal: -
There are sub-1ohm varieties but you can buffer the signal (in or out) with a high impedance op-amp circuit.
Functionally they look like this (DG273): -
But can be much more complicated offering the ability to multiplex several signals to one line. Here is a guide from Texas Instruments.