What is the remote control of a television set?

          The remote control is a small hand-held device used by a viewer to control the television without touching its controls. It is an opto-electronic device which makes use of optical and electronic techniques and hardware.

           The remote control device emits a beam of light which is detected by a, “light control” built into the television. In an optical remote controller, a multivator (1) produces pulses (2) from push button controls (3). The pulses are amplified (4) and modulate a beam of light in the form of saw tooth pulses (5) These pulses are received by a photo transistor (6) fitted in the television set, amplified (7) and used as a trigger to recreate the pulse shape (8) The resulting signals are used to change volume and channels.

          The volume, contrast and channel can be altered by remote control. If the television is connected to a video cassette recorder, programmes can be recorded and replayed by remote control. A remote control prevents the wear and tear of switch buttons.