phototransistor vs photointerruptor

[Mark Haase]

What is the difference between these two items? I accidentally burned
out one of these little units (the kind with the sensor and LED mounted
right next to each other inside a small package) and went to digikey to
replace it. I ordered a phototransistor from the catalog only to notice
later that what I had use previously was *actually* a photointerruptor.
(It came out of a CDROM drive head, paired with an optical encoder
disc.) I noticed the difference because one package has a beveled corner
and the other is totally square.

I suspect that a photointerruptor outputs discrete 0 or 5V logic levels,
where as the phototransistor varies continuously. Correct? Please comment

 

[CWatters]

I suspect that a photointerruptor outputs discrete 0 or 5V logic levels,
where as the phototransistor varies continuously. Correct? Please comment

A phototransistor is usually just a light detector (eg it needs a seperate
light source).

A photointerrupter is usually a phototransistor or diode AND a light
source/LED.

Try some of the links on this page...

http://sharp-world.com/products/device/lineup/opto/index.html