Improvements in electronic laboratories for teaching. (Machine-translation by Google Translate, not legally binding)

摘要

Improvements in electronic laboratories for teaching, especially for language teaching, typing and shorthand, characterized because each laboratory comprises a first source of power with its means of transformation, rectification, regulation and stabilization, which feeds at least one tape recorder and an amplifier; a second power source with its transformation, rectification and regulation means, which feed a preamplifier, this preamplifier having a great feedback between its first two stages, to perform the automatic sensitivity control according to the input impedance; means of amplification of the signal sent by the teacher, means of adapting the impedance of the load to the amplifier; switching means for the different possibilities of use of the laboratory; means of sound reinforcement, preferably loudspeakers and headphones, recording and reproduction media and security means. (Machine-translation by Google Translate, not legally binding)