Infra-Red LED and Photo-Transistor

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Mastahh

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How could you arrange a circuit so that there is an Infra-Red LED and Photo-Transistor, which when the connection between is broken, gives an output?

Thanks
 
So what do you know about LEDs and photo-transistors? If you Google them, you should be able to determine the answer to your question.

Just giving you a solution to your question, doesn't help you learn.
 
Hey

The reason I asked is because i connected it up within a circuit, but it seems to me that the output is always high.

If you wish to see, below is a diagram of my circuit
 

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The circuit you show should turn on the output LED when you interrupt the beam. But you also have to prevent any ambient light from being seen by the photo-transistor.To do that you may have to add a tube around the transistor and/or add a dark red filter.

You have over 60mA going through the IR LED which seems like a lot. Is that how much you want?
 
Honestly, i am sorry but i am not good at the technical details.
In the end, it will not be 60mA because there will be other, more complicated, sections added to this foundation.
All i need right now is to make it so that when the beam is interrupted, an output is high, as opposed to a constant high output, which i am getting right now
 
If your 9V is a brand new 9V battery then the current in the 1.3V IR LED is (9.0V - 1.3V)/270 ohms= 28.5mA which might be high enough to burn it out. If your IR LED survives such a high current then the phototransistor should be turned on shorting the red LED turning it off.
When the IR beam is interrupted then the red LED turns on and has a voltage of about 1.8V.
 
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