chirp

life-like bird song circuit by kelly heaton

This simple circuit sings like a bird, even with chirp variation! This effect is caused by various discrete non-linear components in a breadboard. I tried to build a soldered version and, while it sings, I haven’t been able to reproduce the life-like quality of this circuit (hence my theory that parasitic capacitance is at play).

In the front half of the breadboard, you see three astable multivibrators that create an irregular tempo. These are connected back to various locations in a “chirp generator” circuit (based on the classic doorbell canary design with an audio transformer).

Cricket PCB by kelly heaton

My first cricket circuit board arrived today and it chirps!

Astable multivibrator circuit built with discrete transistors. The circuit generates a waveform that sounds like a cricket when applied to a piezo electric buzzer. Kelly Heaton, 2018

Astable multivibrator circuit built with discrete transistors. The circuit generates a waveform that sounds like a cricket when applied to a piezo electric buzzer. Kelly Heaton, 2018

I did make one error in my schematic, which involved the reversal of the PNP transistor (3906). Thankfully, the wiring worked perfectly when I turned the PNP in the opposite direction.

Unafraid field cricket by kelly heaton

Unafraid Field Cricket, 2018. Analog electronics, watercolor, and graphite on paper. This little analog electronic cricket painting is "unafraid" because its sensor is pretty insensitive. The speaker element is a deconstructed RadioShack piezo electronic buzzer (with some blue paint to knock down the white rubber ring - see detail on right).