a device in which an input signal controls a local source of power in such a way as to produce an output which bears some desired relationship to, and is generally greater than,the input excitation
... Optical reader for reading alphanumeric dot-matrix printing characters and converting them into electrical signals, comprising a read head containing an optical detector, an amplifier, a focusing lens and two lamps, linked by one or two flat cables to a central module the dimensions of which do not exceed 200 x 220 mm, comprisng a printed circuit board on which are mounted a microprocessor, an image recognition circuit and an analogue-to-digital converter ...
