Toy Organ 2012-09-17

This circuit produces a tone according to the button being pressed. Only 1 button can be pressed at a time, that's why it is called a monophonic organ. You can change the 1k resistors to produce a more-accurate scale.

Schematic



Parts

R1-4 -1k Resistor
R5 - 4.7k Resistor
P1 - 10k Trimpot (Potentiometer)
S1-5 - Switch
C1 - 100n Capacitor
C2 - 10 Electrolytic Capacitor
SP1 - 8ohm Speaker
555 - NE555