FUN DAMENTALS FOR THE BEGINNER
A kit for these experiments can be purchased from the Nuts & Volts Webstore at www.nutsvolts.com or call us at 800-783-4624.
Build an
Electronic Metronome
This circuit lets you adjust it to keep time to music, just like
you would do with a standard mechanical metronome.
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 correct.
2. Do the Experiment.
Theory: This is a two-transistor oscillator set up to make a tick-tick
sound in the speaker. The potentiometer adjusts the bias on
transistor Q1; this controls the speed of the turning on and off of
transistors Q1 and Q2. The full musical tempo range should be
attainable by adjusting the potentiometer from one extreme to the
other.
Procedure: Connect a nine-volt battery to the battery snap. You should hear a
tick-tick sound in the speaker. If you only hear one tick from the speaker, twist the
potentiometer shaft from one extreme to the other until you hear the tick-tick
sound. The speed of the
ticks can be adjusted
using the 100K
potentiometer.
SCHEMATIC
R1
PICTORIAL
DIAGRAM
These
experiments
are provided
by GSSTechEd at
www.gssteched.com
You can order parts
for this experiment
from their website
as follows:
GK01077 3,300 ohm 1/2K watt
resistor
GK18001 NPN bipolar transistor
GK18002 PNP bipolar transistor
GK33008W 100K potentiometer
GK35002 Nine volt Battery Snap
GK05005 100 mfd radial
electrolytic capacitor
GK27002 8 ohm speaker
with wires
GK45008 Four 4” solid wires
56
September 2011
