Analog signals use a continuous stream of electromagnetic waves to transmit data. They are the most basic of computers, and pure applications of analog signals are often special purpose rather than general purpose computers.
Analog signals are best for transmitting data from physical phenomena like temperature, weight, pressure, speed, etc. Hence, their applications are quite widespread. Some of such devices that transmit analog signals include:
1. Analog clocks
Analog clocks are still quite common in modern times. From alarm clocks to wall clocks and analog wristwatches, we still use them almost as well as their digital counterparts.
The regular analog clocks have quartz crystals that vibrate in response to voltage (analog signals) from the built-in battery. The crystals vibrate 32,768 times per pulse, equivalent to a second. This effect is called the piezoelectric effect.
2. Thermometer
The mercury-in-glass thermometers are one of the simplest applications of analog signals in use today. Mercury expands in response to heat from the body. The heat emission is an analog signal, which you can read on the graduation on the thermometer.
3. Flying simulator
Before pilots take off, they often run through the extreme conditions they might experience during flight. It helps them, so they don’t panic in such situations.
The simulator brings together audio and visual signals to create the scenario in a cockpit. It uses sound systems, hydraulic pumps, image generators, etc., to simulate the experience.
4. Seismometer
Seismometers measure the intensity of earthquakes using vibrations from the Earth’s surface. They are placed in direct contact with the Earth, and when the Earth vibrates, so do they. The vibrations from the Earth are seismic waves, which the seismometer picks and records. They are analog signals that the instrument plots on a graph. The seismologists study the graph to understand the intensity of the earthquake.
5. Tide predicting devices
Tide predicting devices use water waves, which are analog signals, to predict high and low sea and ocean tides. The gravitational pull of the Earth, moon, and sun contributes to the water tides’ intensity daily. Since the position of these bodies is known, it is easy to use a machine to calculate and predict the level of the tides.
6. Car speedometers
The speedometers on most cars are analog devices. They receive analog signals from the motor system to indicate how fast the car is going with the aid of the needle on the dashboard.
The speedometer cable attaches to the gear system on one end and a permanent magnet on the other end. The magnet is placed close to metallic speed cups, with an inductor rod linking them to the speedometer cable. When the vehicle moves, the speed of the gear system rotates the magnet, which attracts the speed cups. The speed cups then cause a deflection of the speedometer needle, indicating the vehicle’s speed.
Analog computers have been replaced functionally by digital computers. However, there are some benefits to analog circuits and their applications, especially when detecting physical quantities like speed, weight, temperature, etc. You can find analog circuits within some digital devices, especially in communication technology.