Phototransistor cap filter supplier?

[eecook]

Hi All,

I am trying to build an LED light detector (Classify between LED and non-LED light). Given it's typical spectral footprint I was planning on measuring the 2 peaks and the valley (450, 480, 620nm) and do something like peak to valley ratio. In any case, I found that photodiodes are to expensive, and I didn't find any IC that does the job (particularly at the lower wavelengths). So I was planning to use wide spectrum phototransistors with cap filters to do the measurements. Now the problem is cannot find any company that sells off-the-shelf cap filters, everything I found so far, is either not for phototransistors or custom made.

Any suggestions?

Thanx,

Simon.

[Zero999]

How about a prism to split the light into a rainbow, then position the sensors at the correct positions for the wavelengths?

[eecook]

I am open to suggestions, but I need to buy the stuff and needs to be small enough to fit in an enclosure!

[Zero999]

I am open to suggestions, but I need to buy the stuff and needs to be small enough to fit in an enclosure!

That's pretty vague.

What size is the enclosure?

Do you have to make do with what you have on hand? If so, what do you have?

If you can buy stuff, what's your budget?

[eecook]

That's pretty vague.

What size is the enclosure?

10cm x 10cm x 5cm(height)

Do you have to make do with what you have on hand? If so, what do you have?

Nothing at this point. I was going to order some parts

If you can buy stuff, what's your budget?

100usd