Procedure and optical device receptor of great sensitivity with reproduction of manually gradually acoustic tones (Machine-translation by Google Translate, not legally binding)

摘要

Sound player apparatus, modulated at frequency by an optical capture. The luminous signal received by a phototransistor (11) is initially amplified by a sender follower (13) and subsequently by a differential amplifier (22), so that this signal will module frequently to that of the audio or oscillator generator (40), obtaining to the output (45) of this a new signal that goes through a filter (48), to be finally amplified in a monitor circuit (52) and reproduced in its speaker (59). (Machine-translation by Google Translate, not legally binding)