### Author Topic: ina126 gain question  (Read 2125 times)

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#### Its_Friday

• Jr. Member
• Posts: 31
##### ina126 gain question
« on: March 12, 2009, 04:36:39 PM »
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

• Supreme Robot
• Posts: 4,672
##### Re: ina126 gain question
« Reply #1 on: March 12, 2009, 11:40:35 PM »
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.
Regards,
SÃ¸ren

A rather fast and fairly heavy robot with quite large wheels needs what? A lot of power?
Engineering is based on numbers - not adjectives

• Jr. Member
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