Part 3. In this post, we modulate the oscillator we previously built from a Quad NAND CMOS chip. We use another gate from this CD4093 chip to achieve this. All we need to add is another capacitor and resistor to modulate the second NAND operator by the first one.
In the previous post, we built a single oscillator with a Quad NAND Logic chip. But what if we took the output of this oscillator and used it as one of the inputs of a new NAND gate oscillator? Enter modulation madness…
Modulate the oscillator
The image below shows how the output of NAND logic oscillator Y1 is used as an input to NAND operator A2. As explained in an earlier post, the NAND operation always sets the output Y to HIGH except when both inputs A and B are HIGH.
For maximum effect, we use a different value for the capacitor, resistor or both. Fiddle around and try what works best for you. The result on the second output B is a rhythmic or sometimes chaotic pulse.
Next up, we employ all four NAND operators in a feedback loop to create an even more exciting modulated sound source.