Amplifier device for internal communication in a loud voice. (Machine-translation by Google Translate, not legally binding)

摘要

Because, in general, it is an amplification device based on dynamic loudspeakers with permanent magnet excitation and a rectifier lamp by two amplifiers for each equipment, being able to be instead of three lamps, one rectifier and another amplifier of multiple services. (Machine-translation by Google Translate, not legally binding)