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How do I adapt a laser trip wire alarm. to work in reverse? Answered

I need a schematic of a circuit that provides a 12v output when a laser is picked up on a phototransistor.  Essentially working in reverse of the laser trip wire alarm.

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user
lemonie (author)2011-04-05


What have you come up with so far & what bits do you have?

L

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user
mightywetfoot (author)lemonie2011-04-05

A friend recommended this http://www.optekinc.com/pdf/App%20Bulletin%20213-Opto%20Assemblies.pdf Figure 1 but the resistor R2 moved to V out. I am new to all of this so I am not really sure what I am looking at.

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user
lemonie (author)mightywetfoot2011-04-05


You want figure 2, that's the opposite function.
That looks like good stuff, do you need high current output?

L

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user
mightywetfoot (author)lemonie2011-04-06

Nope, high current is not needed. Just something to trigger an Arduino Uno or similar microcontroller.

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user
iceng (author)lemonie2011-04-05


You are going for 999 ? :-)

A

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