In this experiment, we will use the Arbitrary Waveform Generator (AWG) on the Analog Discovery™ to apply sinusoidal and swept sinusoidal voltages to a speaker. Sinusoidal signals are a special type of periodic signal which varies according to the mathematics of sine and cosine functions. Human perceptions are often geared toward sinusoidal signals—sinusoidal pressure waves are heard as “tones”, and sinusoidal light waves have a particular “color”.
Sinusoidal sweeps are signals which are composed of sinusoids of varying frequency—in particular, the signals we will use here have frequencies which increase with time. Sinusoidal sweeps are described in slightly more detail in the Swept Sines link associated with this experiment.
Our goal in this experiment is to obtain an intuitive feeling for the properties of sinusoids and swept sinusoids and to understand the more abstract representations of these signals as they were presented in the Sinusoids and Swept Sines links. This experiment also introduces the “Sweep” tab on the Analog Discovery's arbitrary waveform generator instrument.
|Qty||Description||Typical Image||Schematic Symbol||Breadboard Image|
|The Buzzer/Speaker in the analog parts kit has two terminals. If a time-varying voltage is applied between the terminals a film in the speaker vibrates, converting the voltage waveform to a pressure waveform with a similar “shape”. Note: The speaker in your parts kit may have different markings than the one pictured.|
Connect one terminal of the speaker to the W1 terminal of your Analog Discovery.
Insert the terminals of the speaker into your breadboard so that they are in different rows.
Connect W1 (the yellow wire) to one terminal of the speaker.
Open WaveForms™ to view the main window.
*Make sure symmetry is set to 50%
You should hear a tone from your speaker.
Change the lower and upper frequencies and the sweep time. Do these controls have the effect you would expect?