Definition
An analog computer processes analog data. It requires a physical input of the problem to be solved, either mechanical, electrical or hydraulic quantities. These computers were commonly used in the 20th century for engineering and scientific calculations, but digital computers have replaced them for major tasks.
History of Analog Computer
Most analog computers were created in the early 20th century. The differential analyzer by Vannevar Bush developed at MIT, is one of the earliest examples of analog computers. It used mechanical shafts and gears to solve differential equations.
Other examples are the analog computer with electro-mechanical integrators developed by British engineer Douglas Hartee and the hydraulic analog computer by French engineer Georges R. de Sarrio.
These early inventions laid the foundation for developing modern analog computers and computing techniques.
Features of Analog Computers
- Real-time processing: These computers can perform real-time computations, making them useful in applications like control systems and scientific simulations.
- Non-programmable: Analogue computers are designed to perform specific types of computations, meaning they cannot be configured to perform extra tasks.
- Uninterrupted signal usage: Analogue computers use continuous signals, which are physical quantities like current or voltage, to represent data and perform tasks.
- Accuracy: Analogue computers can perform computations with high accuracy, but the components of the system limit their exactness.
Types of Analog Computers
- Differential analyzers: It is a popular mechanical analogue computer capable of solving differential equations. Massive improvements were made to the differential analyzer in the 1930s. Unlike modern computers, differential analyzer computers are huge.
- Slide rules: This is the most basic and classic mechanical analogue computer used for creating rough estimations for simple mathematical tasks. Users adjust the rod to align a hashed rod with different marks on another rod. Moreover, they can read the device using a series of various hash marks.
- The castle clock: It showcases the broad spectrum of applications for mechanical analog computers. Al-Jarazi developed this computer and it can store programming code.
- Electronic analog computers: These computers employ electrical signals that travel through different capacitors and resistors. They do not depend on the mechanical interaction of parts, and the signal’s voltage offers the displays.
Limitation of Analog Computer
- Limited accuracy of the outcomes: Analogue systems are prone to errors in complex calculations due to tolerance restrictions and noise.
- Sensitivity to environmental adjustments: The reliance on analogue circuits may be disrupted by changes like humidity swings and temperature.
- Costly maintenance: Analogue computers require regular maintenance and calibration due to sensitive circuitry and mechanical components.
- Lacks adaptability: These computers are more difficult to update and modify than digital systems.