P1f

P1f

1. Analogue signals have a continuously variable value.

2. Digital signals are either on (1) or off (0).

   • We are switching to digital TV and radio because the sound quality and picture is better. Digital signals don't suffer from the same degradation as an analogue signal.
   • The advantages of using digital signals include: that it is easier to remove noise and you can use multiplexing.
     • It is easier to remove noise from digital signals as digital signals only have two values, and, therefore any small difference in the signal value (noise) will be noticed and can be removed.

3. Everyday uses of infrared radiation include:remote controls and short distance data links.

   • Infrared signals send a coded digital signal from a remote controller to the device.

4. Multiplexing is when you send more than one signal on a carrier wave.

5. Infrared sensors detect body heat.