Simple electronic 555 timer keyboard

Description

The Simple electronic 555 timer keyboard 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. By choosing the capacitor values well, the tones produced may mimic those of an toy organ. The number of ‘keys’ in this toy organ may be increased by adding more switches and capacitors.

555 Pocket Keyboard is the main component of this circuit is the 555, configured as an astable multivibrator. A 555 TIMER IC configured as such outputs an oscillating signal with a frequency determined by the values of variable resistance PR1, 10k resistance (R8).In this circuit, every time one of the switches is pressed, a capacitor of a certain value is connected to the 555, causing it to deliver a signal of corresponding frequency to the speaker, thereby producing a tone specific to the switch pressed.