Comprehensive Guide to Public Address Equipments Public address (PA) systems are typically encountered in various projects such as office complex, residential complexes, industrial office buildings, schools, healthcare facilities, railway stations, flight terminals, bus stations, financial in

 New York City streets in 1890. Besides telegraph lines, a number of electric lines had been required for every class of product necessitating diverse voltages. Business electric powered power was to begin with transmitted within the same voltage employed by lighting and mechanical hundreds.