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LED's

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LED's (Light Emitting Diodes) are tiny crystals of a semiconductor, which give off light when an electric current passes through. They are very efficient devices, as almost no heat is generated in the process, leading to much longer battery life.

'Standard' LED's are low current devices, which produce relatively low levels of illumination, and are used as indicators rather than light sources.

You can use a standard LED:

as a 'power-on' indicator to show that a system is currently connected to a power supply; as an 'armed' indicator to show that some function of the system is active; as a sequence indicator, to show which stage of a sequence of operations is currently under way; as a simple test instrument to show whether an output of the system under development is at a high or low voltage, (logic 1 or logic 0,) during the testing stage. LED's are available in a wide range of formats, from pin-point sized single LED's, to arrays of ultra-bright LED's, used in message display panels, and traffic lights.

<^< Adding Outputs | Course index | Using LED's >^>