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# What Is a Sine Wave Generator?

Article Details
• Originally Written By: C. Greason
• Revised By: C. Mitchell
• Edited By: Angela B.
2003-2019
Conjecture Corporation
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A sine wave generator is a type of electronic equipment that generates an oscillating frequency in a sinusoidal pattern. Most are relatively small, with the vast majority being hand-held. There are a couple of different reasons why these sorts of tools are important, but most have to do with measuring either sound or electric frequency, both of which typically take on a sine pattern. A sinusoid function goes up and down and up and down in a consistent, smooth, rolling pattern of hills and valleys. In mathematics these curves are often plotted and measured, and in natural environments they often tell a lot about speed, volume, and other questions of amplification. A sine wave generator produces these waves, usually as a means of comparing or measuring waves existing elsewhere. Sometimes generated waves are also used for calibrating measurement equipment and generating sound effects.

#### Understanding Sine Waves Generally

A sine wave is characterized by even, unbroken oscillation that can be plotted as a series of perfectly proportioned “hills” and “valleys,” or ups and downs. Light waves and sound waves take this form naturally, as do many other natural phenomena such as ocean waves. Most electrical outputs follow this pattern, too.

Plotting and identifying the sine functions of these outputs can be instructive, but there are also instances where actually generating artificial imitations or mimics can also be useful. This is where sine wave generators come in. Most of the time, these devices are used by people who are looking either to calibrate a device or to fix something that isn’t working properly. Generators emit frequencies equal to what they detect, which can allow engineers to see the exact patterns being emitted naturally; most devices can also emit waves of pre-programmed specifics, which can help recalibrate things like sensitive sound equipment or amplifiers.

#### Audio and Electrical Uses

A sine wave generator can drive audio speakers if the wave generated is in the range of human hearing. Technicians first measure the wave velocity being emitted, then regenerate that with their devices to synch and usually also amplify the sounds being produced.

The same technique can be applied to electronics and electrical appliances more generally. Electrical alternating current (AC), which is available from wall outlets in most places, alternates in a sine wave pattern at 60 cycles per second (Hertz). A turbine or electrical generator producing AC current is a kind of sine wave generator. Some electrical circuits, specifically resonant circuits, oscillate in the pattern of a sine wave and, thus, are used in sine wave generators. Sine waves are produced by a resonant circuit when the voltage across the output rises and falls in a sinusoidal pattern.

#### Function Generators

Function generators can typically produce both sine waves and other wave shapes, such as square waves and triangular waves, by adding together several different waves. Any periodic or oscillating function can be described as a weighted sum of multiples of the base frequency. A Fourier transform, for instance, is a mathematical function that describes which sine waves added together will make the desired wave.

#### Square Waves and Other Variants

Oscillators can often generate waves of different shapes by generating multiple overlapping sine and cosine waves. Common examples include square waves that go up and maintain a level for a time, and then drop to the inverse of the original level and maintain that for a time, and then oscillate back up again, repeatedly. Square waves are used in digital electronics to produce an on/off signal at consistent intervals to drive digital logic, thus serving as internal timing clocks that regulate actions in computers. The speed of a computer processor chip is described by the frequency of its internal clock in a unit called Hertz. A computer is described as working at a speed of a certain number of gigahertz (GHz). One cycle per second equals 1 Hertz.