Analog Signals Fundamentals

What is an Analog Signal?

• An analog signal is a continuous signal that changes to represent a time-varying quantity.
• Example: an analog spring scale that weighs objects by pointing to a number representing the weight.

Characteristics of Analog Signals

• Can take any value on the dial, indicating a continuous signal.
• Can vary in air density, such as sound waves carrying speech or music.

Analog Signal Conversion

• Can be converted from one form of energy to another, such as AM and FM radios converting sound signals into electrical signals and then into electromagnetic waves.
• Can also be converted back, such as receiving electromagnetic waves and converting them into electrical signals and then into sound signals.

Analog Signal Storage

• Can be stored and retrieved using technologies such as chart recorders, vinyl records, and magnetic recording tapes.

Analog Applications

• Examples include rotary watches and clocks, spring scales, car speedometers, thermometers, pressure gauges, seismographs, phonographs, and AM and FM radio.

Benefits of Analog Technology

• Often simple to make, such as a spring scale.
• Can be easy to broadcast, such as AM and FM radio or TV.
• Can be easy to figure out, with visible wave patterns on vinyl records.

Drawbacks of Analog Technology

• Noise and interference can ruin the signal, especially over long distances.
• Limited bandwidth, requiring frequency separation to prevent overlap.
• Privacy issues, making it difficult to keep transmissions and recordings private.
• Space issues, with analog recording media taking up a lot of space.
• Damage issues, with analog recording media being easily damaged and time-consuming to copy.

Transition from Analog to Digital

• Despite drawbacks, analog technology enabled communication, entertainment, and scientific measurements for much of the 20th century.
• Led to the development of digital technology, driven by the need to speed up mathematical calculations during World War II.