Editing User Adaptor (section)

== Reflective opto switch ==

[[File:Circuit-Reflective-Opto-Switch.svg|frame|left|Fig. 3]]

Figure 3 shows how a reflective opto switch can be connected to the adaptor.
The device contains an infrared transmitter and receiver.
The infrared beam is directed outwards and when a reflective surface is placed near the end of the device a change in voltage will occur on the line connected to the input socket.
When the detector receives only a small amount of reflected light the voltage produced will be low and will rise as the detector picks up more infrared light.
Typical uses of this type of sensor include:

* Sensing the ‘colour’ of various objects by measuring the amount of infrared light they reflect.
* Measuring short distances as a reflective surface moves within the sensor’s range.
* Reading ‘bar codes’ by detecting if the sensor is over a black (non-reflecting) surface or white (reflecting) surface.

The adaptor also allows the reflective opto switch to be used as a digital sensor.
Unplug the lead from the ‘input’ socket on the adaptor, and plug it into the yellow socket of one of the digital sensor inputs on the Smart Box.
The leads plugged into the ‘0V’ and ‘5V’ sockets on the adaptor remain connected.

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[[Category:Sensors]]