Phototransistors/LED's/PNP Transistors

Other Hardware General Electronics
1

Hello!
I would like to know:

  1. How do you tell a phototransistor from an LED?
  2. How might I wire a phototransistor to my Uno?
  3. I recently bought two new PNP transistors, for some reason the base pin behaves in the exact opposite fashion of my other two PNP's. Why is that?
2
  1. How do you tell a phototransistor from an LED?

a) Look at the part number.
b) wire it up to 5V through a 1K resistor (both ways round) and if it lights up it's an LED.

  1. How might I wire a phototransistor to my Uno?

Emitter to ground, collector to an analogue input plus 100K from analogue input to +5V.

for some reason the base pin behaves in the exact opposite fashion of my other two PNP's.

What on earth do you mean by opposite fashion? Not all transistor pinouts are the same are you sure it is the base on this transistor.

3

Ah, I looked up the datasheets for my old Transistors. They're NPN. Thank you for the help!