When using an optocoupler ... The circuit in Figure 1 accomplishes that task by using a differential amplifier with the drift treated as a common-mode signal. In operation, it is interesting to apply ...

And while simple on-off control of a device through an optocoupler ... circuit is required, there’s one more missing ingredient: the amount of light the LED puts out per milliamp of input ...

Here is a useful circuit for Arduino lovers and experimenters. It is a simple digital voltmeter, which can safely measure input dc voltages in 0 to 30V range. The Arduino board can be powered from a ...