IR and Photo Transistor

K

Klitzie

New Member

• Mar 5, 2008

• #1

Just wanna ask if an IR & Photransistor works well in scanning 2 colors red and blue and can differentiate it from one another, i tried using LDR together with a RGB leds, but the data is unstable it changes everytime we make a movement to the box. Maybe an IR would make it simpler it doing the same job as the LDR based sensor.

 

Norlin

New Member

• Mar 6, 2008

• #2

Question is, do the red and blue surfaces reflect different amount of Ir? I'm not sure myself...

 

ronsimpson

Well-Known Member

Most Helpful Member

• Mar 6, 2008

• #3

Why IR?
Give us more information on your RGB LED design that does not work. I think it can work.

 

Hero999

Banned

• Mar 7, 2008

• #4

Norlin said:

Question is, do the red and blue surfaces reflect different amount of Ir? I'm not sure myself...

Click to expand...

The amount of visible light it refects makes no difference as far as IR is concerned.

An object might look white at visible wavelengths but black at IR and vice-versa.

 

Norlin

New Member

• Mar 7, 2008

• #5

Hero,
Is what I figured, meaning that Ir would be useless for the OPs project

 

jpanhalt

Well-Known Member

Most Helpful Member

• Mar 7, 2008

• #6

Try splitting your incident beam* and using the "split"portion as a reference. Variations in the emission intensity may be what's screwing you up. John

*Edmund's Scientific used to sell such splitters. They are basically just front-surface mirrors.