Re: [CAD_CAM_EDM_DRO] How much current for encoder LED?

onecooltoolfool wrote:

> How much current does the average LED need for operation in a
> quadrature encoder? With an unknown encoder I should start with 5V
> and what size resistor? Very important not to fry this encoder.

IF the encoder is supposed to run from a voltage source, it already has
the circuits inside to control LED current. 20 mA is a good guess,
but it could be all over the place. Some encoders use more than one
LED.

If you are just going to hook power to leads at random, you will likely destroy
the encoder anyway, as they have a chip in there to amplify and square
the photodetector signals.

Jon