THE TELEPHONE - How it works. Ladybird series 654 (1981). скачать в хорошем качестве

THE TELEPHONE - How it works. Ladybird series 654 (1981).

THE TELEPHONE - 'How it works' series 654 Published by Ladybird Books, Loughborough, England. How telephones began pp 4-6 How Edison improved on the early telephone p 8 How the sound of your voice travels p 10 Sound waves into electric currents p 12 The Transmitter p 14 The Receiver p16 Telephone exchanges p 18 How manual exchanges worked p 20 Automatic exchanges p 22 How the selectors work p 24 Automanual switchboards p 26 Dialling codes p 28 Exchange systems p 30 Long distance telephoning p 32 Helping the electric currents over long distances p 34 International services p 36 Radio-telephones p 38 London Telecom Tower p 40 Telephoning by Satellite p 42 Special services p 44-45 Emergency services p 46 Public services p 48 Learning more about the telephone p 50