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Electronics => Electronics => Topic started by: s2kwak on March 26, 2008, 01:48:52 PM

Title: What is the difference between a color sensor and an IR sensor?
Post by: s2kwak on March 26, 2008, 01:48:52 PM

Hello,

I am just starting new, and I need to make a sensor to differentiate the colors of bubble gums (I am making a bubble gum sorter, 5 different colours).

I noticed that the color sensor uses a normal LED and a photoresistor, whereas the IR sensor uses a IR LED and a phototransistor.

Can the IR LED and phototransistor also differentiate color?

Also, can you use a 'visible light' LED (non IR) with a phototransistor?

Title: Re: What is the difference between a color sensor and an IR sensor?
Post by: AndrewM on March 26, 2008, 03:06:36 PM

"Color" is part of the visible light spectrum, while IR (and UV) is outside that range and thus have no "color" to detect (actually IR is a color, just not visible to the human eye and not available from crayola).  IR LEDs and sensors work in the IR range of light and ignore the visible color range, so you could not use one reliably to determine different types of bubble gum.

It would depend on the type of phototransistor as to whether you can use a visible light LED with it.  If the phototransistor is geared for the visible light spectrum, then yes, if it is geared for IR, then no.