IR slotted switch sensor

It appears that you are using AdBlocking software. The cost of running this website is covered by advertisements. If you like it please feel free to a small amount of money to secure the future of this website.

There is a type of detector known as a “slotted switch” that consists of a phototransistor/LED pair mounted on a solid frame with a small air gap between the two elements. A typical circuit might be:

               o +5v     o +5v 
               |         | 
               |         | 
               \         \ 
    220 ohms   /         / 4.7K 
               \         \ 
               /         / 
               |         | 
               |         +-------> Vout 
              _|_        / 
              \ /      |/ 
             -----     |\ NPN 
               |         \ 
               |          | 
               |          | 
               |          | 
              GND        GND 
                | air gap | 
  

When the air gap is unobstructed, the transistor saturates, pulling Vout to ground; when the gap is blocked, the transistor cuts off and Vout is +5 volts.

Sources

  • Paul Hitchcock

Category:InfraRed

 

© 1998-2017 – Nicola Asuni - Tecnick.com - All rights reserved.
about - disclaimer - privacy