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HalurTest1 (talk | contribs) m →Mechanical analog computers: misspelling |
Em3rgent0rdr (talk | contribs) m Minor hyperlnks. More than just Adders and multipliers...add log converters. Tags: Visual edit Mobile edit Mobile web edit Advanced mobile edit |
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Electronic analog computers are especially well-suited to representing situations described by differential equations. Historically, they were often used when a system of differential equations proved very difficult to solve by traditional means. As a simple example, the dynamics of a [[harmonic oscillator|spring-mass system]] can be described by the equation <math>m \ddot y + d \dot y +cy = mg</math>, with <math>y</math> as the vertical position of a mass <math>m</math>, <math>d</math> the [[damping coefficient]], <math>c</math> the [[Hooke's law|spring constant]] and <math>g</math> the [[gravity of Earth]]. For analog computing, the equation is programmed as <math>\ddot y = - \tfrac{d}{m} \dot y - \tfrac{c}{m} y - g</math>. The equivalent analog circuit consists of two integrators for the state variables <math>-\dot y</math> (speed) and <math>y</math> (position), one inverter, and three potentiometers.
Electronic analog computers have drawbacks: the value of the circuit's supply voltage limits the range over which the variables may vary (since the value of a variable is represented by a voltage on a particular wire). Therefore, each problem must be scaled so its parameters and dimensions can be represented using voltages that the circuit can supply —e.g., the expected magnitudes of the velocity and the position of a [[spring pendulum]]. Improperly scaled variables can have their values "clamped" by the limits of the supply voltage. Or if scaled too small, they can suffer from higher [[noise (physics)|noise levels]]. Either problem can cause the circuit to produce an incorrect simulation of the physical system. (Modern digital simulations are much more robust to widely varying values of their variables, but are still not entirely immune to these concerns: [[Floating-point arithmetic|floating-point digital calculations]] support a huge [[dynamic range]], but can suffer from imprecision if tiny differences of huge values lead to [[numerical stability|numerical instability]].)
[[File:Federpendel als Analogrechenschaltung.png|thumb|Analog circuit for the dynamics of a spring-mass system (without scaling factors)|alt=|260x260px]]
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*'''[[Filter (signal processing)|Filter]]s:''' Filters are used to modify the spectrum of signals by suppressing or amplifying specific frequencies. They allow the isolation or suppression of certain signal components depending on the computational requirements.
*'''[[Modulator]]s and [[demodulator]]s:''' Modulators convert information into analog signals that can be transmitted through a communication channel, and demodulators perform the reverse transformation, recovering the original data from modulated signals.
*'''[[Adder (electronics)|Adder]]s
*'''Storage and [[memory]]:''' Analog computing machines can use various forms of information storage, such as capacitors or inductors, to store intermediate results and memory.
*'''Feedback and control:''' Feedback and control blocks are used to maintain the stability and accuracy of the analog computing machine. They may include regulation systems and error correction.
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