FUN DAMENTALS FOR THE BEGINNER
HOW A SPEAKER WORKS
A speaker is an electromechanical device. It has
a coil, a magnet, and a paper cone. These three
parts are mechanically connected in such a way
that when current is increasing or decreasing in
the coil, the paper cone moves which causes
sound. So, the function of a speaker is to convert
electrical energy into sound.
You can order parts for this
experiment from their
website as follows:
10 ohm Resistor
Speaker with Wires
1. Build the Circuit.
Using the schematic along with the pictorial
diagram, place the components on a solderless
breadboard as shown. Verify that your wiring is
2. Do the Experiment.
Theory: In this circuit, the electrons flow from
the battery through the resistor, through the
speaker, and back to the battery. To make sound,
the coil requires a constant change in current. The
speaker will only emit sound when you first touch
the wire to the resistor, and when you disconnect
the wire from the resistor.
Procedure: Connect a nine-volt battery to the
battery snap and tap the probe lead to the 10 ohm
resistor. (Do not leave the wire touching the 10
ohm resistor or it will burn out the battery and ruin
the speaker.) Reverse the battery leads and do the
procedure again. Observe how the cone moves in
the opposite direction.
A kit to go with these
experiments can be
purchased from the
Nuts & Volts Webstore
at www.nutsvolts.com or
call us at 800-783-4624.
Order online at:
Development Tools for PIC® MCUs
microEngineering Labs, Inc.
Phone: (719) 520-5323
Fax: (719) 520-1867
Colorado Springs, CO 80960
With Accessories for $119.95:
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