Cricket Chirping Generator

Funny gadget for props and jokes

5 - 12V Battery operation

Circuit diagram:

Cricket Chirping Generator


R1_____________330K  1/4W Resistor
R2_____________220K  1/4W Resistor
R3,R6__________100K  1/4W Resistors
R4_____________Photo resistor (any type) (Optional, see text)
R5,R7___________22K  1/4W Resistors
R8______________10K  1/4W Resistor
R9_____________470R  1/2W Trimmer Cermet or Carbon
R10_____________22R  1/4W Resistor

C1,C2,C3________47µF  25V Electrolytic Capacitors
C4______________10µF  25V Electrolytic Capacitor
C5_______________1µF  50V Electrolytic Capacitor
C6______________10nF  63V Polyester Capacitor

D1,D2,D3,D4__1N4148   75V 150mA Diodes

Q1____________BC547   45V 100mA NPN Transistor

IC1____________4093   Quad 2 input Schmitt NAND Gate IC
IC2____________4060   14 stage ripple counter and oscillator IC

SPKR______________8 Ohm Small Loudspeaker

SW1____________SPST Toggle or Slide Switch

B1_______________9V  PP3 Battery (See Notes)

Clip for PP3 Battery


This circuit generates an astonishingly real imitation of the chirping of the cricket. A suitable audio wave form is generated by IC2 and related components, driving the loudspeaker through Q1.
To allow a more real-life behavior, the chirp is interrupted in a pseudo-casual way by two timers built around IC1C and IC1D, whose outputs are mixed into IC1B and further time-delayed by IC1A, driving the reset pin of IC2.
An optional Photo resistor can be wired across this pin and positive supply, allowing circuit starting in the dark and stopping when light is coming, thus imitating the cricket's behavior even more closely.
R9 acts as volume control and can be a preset trimmer or a small potentiometer.