ina126 gain question

[Its_Friday]

I'm building 2 encoders using 2 IR LEDs, 2 optical switches, and an ina126 dual amplifier. My main question is "what is gain?" It says i can set the gain anywhere from 5V/V to 10000V/V but i don't know how much gain (ballpark range) i need for a normal axon microcontroller to read the signal.

[Soeren]

Hi,

Gain is the amplification factor.
5V/V means you get 5V out for every 1V in which means that the gain (Av) is 5.
10000V/V is simply a gain of 10,000 (times).

The amount of gain needed can be calculated by: Uo/Uin
(Where Uo = output voltage needed and Uin = input voltage available).
You probably want Uo=5V, but without knowing the schematic of your circuit, I cannot tell you what gain you need.

[Its_Friday]

Thank you. That cleared things up for me.

My schematic uses an IR LED and an optical switch, it looks similar to this one. The only big difference is that mine uses a different IC.