Use a 100nF ceramic capacitor at the encoder from GND to +5VDC. Place it as
close to the encoder as you possibly can (0.25" or 5mm lead lengths). Parallel
it with a 10uF Aluminum electrolytic.

Mariss


--- In geckodrive@yahoogroups.com, "vrsculptor" <vrsculptor@...> wrote:
>
> Don't the USDigital encoders use HEDs optical heads? I am have been using
older ones successfully in my machine. Do you have a specific capacitor
recommendation for decoupling? I recently switched cables on two axis and only
one of my axis still has a capacitor.
>
> Roger
>
> > There is a problem with some of the newer HEDS encoder optical heads. The
specifications show an OK 8mA sink current but a pathetic 40uA (that's right, 40
millionths of an Amp) source current. That makes the head unsuitable for driving
a cable.
>