Elenco 130-in-1 Electronics Playground - Manual (Page 87)

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This circuit has a multivibrator connected to a pulse
type oscillator. Rather than turning the oscillator
completely on and off, the multivibrator provides a
tremolo effect (a wavering tone).
After you build the circuit, use the control to vary the
base current supplied to the NPN transistor. This
changes the charge/discharge rate of the 0.1
μF and
0.05
μF capacitors, as well the frequency of the pulse
oscillator.
The key works to turn the whole circuit on and off.
You can substitute it with the slide switch. By
changing the 10
μF and 3.3μF capacitor values, you
can change the tonal range.
Try using the switch or the key to add additional
components to the circuit (like an extra capacitor in
parallel with the 10
μF or 3.3μF), so you can alter
from one tonal range to another, quickly. These
changes will make a more complete organ from this
experiment. Be sure to make notes on what you do.
Notes:
EXPERIMENT #69: ELECTRONIC ORGAN OSCILLATOR
Wiring Sequence:
1-29
2-30
3-47-106
4-74-45-42-119
5-105-109
27-46-110
28-86
40-111-80
41-114-78
43-113-82
44-112-87-76
77-75-81-79-48-138
73-85-88
120-137
Schematic