>I prefer to use an op-amp circuit as shown to convert the
>current into a voltage (1 volt per microamp using a 1 Megohm
>feedback resistor). This arrangement forces the voltage across
>the LED to be zero volts. One nice side effect of this is that
>the response time of the LED receiver is greatly improved. It
>also helps linearize the input/output characteristics of the
>LED.

I don't know why this isn't done more often.
Some transducers output voltage (relative to input) and some output current.
If you treat a current transducer like a voltage transducer, you will be
sad. :)


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