Hardware Hacking - Nicolas Collins

Hardware Hacking 79

Chapter 21: Even More Oscillators

You will need:

• A breadboard.


• 1 CMOS Hex Schmitt Trigger Integrated Circuit (74C14) or CMOS
  Quad NAND Gate Schmitt Trigger Integrated Circuit (#4093)


• 1 CMOS Binary Counter/Divider (#4040)


• Assorted resistors, capacitors, pots & photocells.


• Some solid hookup wire.


• A jack to match your amp.


• A 9 volt battery and connector.


• A Piezo disk


• An amplifier.


• Hand tools.

Dividers

The musical applications of digital logic circuits go well beyond simple
oscillators. For example, a chip that performs the arithmetic function of dividing
a number can be used to generate several harmonically related pitches from a
single master oscillator.

4040

Breadboard the circuit shown below. Ground (battery -) connects to pin 8, +9
volts to pin 16. The master oscillator is connected to pin 10, the clock input of the
divider circuit (#4040). The chip has 12 cascaded stages, each of which divides
its input frequency by 2 (ie, outputs are provided for the input signal divided by
2, 4, 8, 16, etc, all the way to 4096.)