Hello.

I'm trying a project that involves a coin operation mechanism. I've decided to make my own mechanism; coin rejection will be done mechanically (according to Canadian coinage dimensions,) while the desired coin will trip a TIL159 opto slot sensor, mounted on the top of the coin slot's track.

My problem is that I'm unable to find any specification sheet for the TIL159 opto slot sensor. If anyone has a copy, can you point me to the right direction? And if not, can anyone tell me if a resistor is required to protect the optical receiver as well as the transmitter from excessive current (like a standard LED)?

If a resistor is needed, I already have a good idea as to the resistor's value (168 Ohms should be enough for 20 mA & 3.3 V).

To get an idea of what I'm talking about, here's a diagram:

http://www.rohm.com/products/o...nsor/images/faq_01.gif

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Technology: something that's hated & cursed at by all engineers, technologists & technicians!

( Lousy modern technology! )

I think you need a resistor in series with the IR LED emitter and some resistance in series with the emitter or collector of the detector transistor.

I can't find a datasheet for the TIL159 but it might help to have a look at:

http://quarndon.co.uk/index.ph...info&products_id=7477

then compare with:

http://www.nteinc.com/specs/3100to3199/pdf/nte3102.pdf

http://www.evercolors.com/Uplo...le/file/itr-20403.pdf

and see:

http://www.nteinc.com/Web_pgs/photointerrupt.html
http://www.everlight.com/index...ype&Itemid=268&lang=en

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Andy Fierman

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http://signality.co.uk
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Hmm... Interesting. It seems like the documents you've given here prove that the detector needs a protective resistor (& especially with respect to my application, as it would constantly be fed a steady 3.3 V & 20 mA). Thank you for the help; I'm sure my resistor value will work.

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Technology: something that's hated & cursed at by all engineers, technologists & technicians!

( Lousy modern technology! )