Re: Linear Encoder Question

This is a very wild guess but it sounds like you have a photo interrupter
(or possibly a reflective optosensor)
If there is a slot for a tab on the table to break the beam between the LED
and optosensor, then it is a photo interrupter,
If OTOH it only has a diode on one face that reflects off a close surface,
that would be a reflective type sensor.

If it is such a device, then it would be the equivalent of a LED and
phototransistor probably sharing a common ground
With one lead being the 2v / 20mA supply to the LED and the other being the
collector of the phototransistor.
(If it is such a device it is very unusual not to have a pair of leads for
each instead of a common)

Depending on what the case looks like, it may already have the necessary
signal conditioning and LED resistor on board
in which case the leads would be power and signal.

Please describe it some more, is it in a case that opens or is it a moulded
unit?

Regards
Mo

> And does any body know how to hook up a SHARP 3A39 limit sensor?
> It has a 3 pin connector and is some form of diode xmitter/reciever in a

nice

> little case, if you know or would like one to play with and let me know

how

> to hook it up drop me a line, I have several, and was hoping to use them

for

> limit/home switches, I can't find any specs on them though.