Elenco PK101 w/ Computer Interface - Manual (Page 24)

Build the circuit and connect the Winscope PC-interface cable as shown. There are 4 resistors and 4
capacitors connected to the 3.3k
Ω
resistor (we are using the (+) row of holes at the bottom to make
the connections easier) and 2 loose wires connected to the transformer. Connect the transformer to
one resistor and one capacitor at a time, then press the switch.
Use Winscope to view the waveforms in oscilloscope mode and the frequency spectrum using spec-
trum analyzer mode just like in project PC1. You may need to adjust the horizontal (time/frequency)
scale depending on which resistor-capacitor combination you select. If continuing from the previous
experiment then you may want to close the Winscope program and run it again, to reset the settings.
All the combinations are listed below, you don’t need to try all of them but try some and see if there is
a pattern in the frequency or pitch (a term used in music) of the sound. Record a few comments about
the sounds you hear and the waveforms that correspond to them.
10k
Ω
33k
Ω
100k
Ω
1M
Ω
0.005
µ
F
0.047
µ
F
10
µ
F
100
µ
F
You will see that the frequency increases when you lower the resistance or capacitance. It also
increases if you lower the inductance, but you don’t have any other inductors you can substitute.
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