Presentation 2

1.

Комитет общего и профессионального образования
Ленинградской области
государственное бюджетное профессиональное образовательное
учреждение Ленинградской области
«Сланцевский индустриальный техникум»
Автор
Студент группы 24-ЭП-85
Специальности 13.02.13.85
А.А.МЕЛЬНИК
Проверил
Т.А.СМИРНОВА
2025-2026 уч. год

2.

• Alexander Graham Bell
(1847 – 1922)
• Scientist, Inventor, and
Engineer
• The Pioneer of Telephony

3.

His story before the telephone:
• He was a teacher for deaf people. He loved
sound and speech.
• His mother and wife were deaf. He really
wanted to help people hear and
communicate.
• He was trying to improve the telegraph
(which sent beeps, not voice). He had a big
idea: "What if we could send the human
voice through a wire?"
• Main goal: Make a machine that can carry
your voice to another city.

4.

Inventing the Telephone
• He got the official patent (the rights) for the telephone on March 7, 1876.
• Just three days later, the first call in history happened.
• Bell spilled some acid in his lab and said into his machine: "Mr. Watson,
come here. I need you!" His assistant in the next room heard it perfectly
through the telephone!
How it worked:
• Your voice shakes a small plate (diaphragm).
• These shakes become an electrical signal.
• The signal travels very fast through a wire.
• On the other side, the signal shakes another plate and becomes sound
again.

5.

He was more than just the telephone!
• He started the famous Bell Telephone Company (which later became AT&T).
• Photophone: Sending sound on a beam of light (like an old wireless
phone!).
• Aviation: He built big kites and early airplane
• Helping the deaf: This was his life's passion. He founded schools and
associations.
We remember him every day:
• Every time we make a phone call.
• The unit of sound loudness is named after him: the Bel and decibel (dB).
His famous quote:
"Great discoveries need the help of many minds."