CD4093BE Circuit

In class we have been exploring the affordances of the CD4093BE micro chip. Through the use of NAND gates, we can create a voltage oscillation which vibrates a membrane in a speaker or other device to create a tone. When a photoresistor is introduced to the circuit, it adds resistance to the loop created between the second input and the output. When the light-sensitive head of the photoresistor is exposed to higher luminosity, its resistance decreases. The resistance adjustment influences the speed of oscillation, which changes the pitch produced. In the video below, my phone’s flash is on, so that when the phone gets closer to and farther from the photoresistor poking out of the circuit, the pitch changes.

In my circuit I use a piezo disc in place of a speaker. I was inspired by the buzzing sounds being created and the ease of changing the pitch. In my upcoming instrument project, I look forward to utilizing this circuit and expanding it to several pitches to create chords and even melodies.