Electronics project just because of the name must not, always be complicated and advance level projects. Small projects play vital role in the field of electronics. Here is a similar basic project which is named as, ‘Grasshopper Sound Generator Using 555’. The project will surely entertain children and for electronics beginners, this project is best option to start with. Especially at night times, we do often hear the shrill sound of grasshopper or cockroach. This project also produces similar sound (PI-PI sound like grasshopper) and for this reason is named so.
Circuit Description of Grasshopper Sound Generator
A pair of timer IC (NE555) acts as the building block of this circuit which is accompanied by few passive components (i.e. resistor and capacitor). In this particular project, both the timer IC (IC1 and IC2) are used here as astable multivibrator. The frequency of IC1 is used to modulate the frequency of IC2. Thus modulated frequency is further supplied to speaker from pin 3 of IC2 through capacitor C4. The frequency of IC1 used for modulation is obtained as saw tooth voltage at pin 6. It is then given to control pin 5 of IC2 in order to control frequency of IC2 as stated above. Here, IC1 serves as a low frequency oscillator where as IC2 acts as a high frequency oscillator. The saw tooth voltage at control pin 5 of IC2 is used to drive output audio frequency (3 – 30 KHz) high and low. Because of this we hear something like shrill sound of insect (pi-pi sound of grasshopper).
PARTS LIST OF GRASSHOPPER SOUND GENERATOR
|Resistor (all ¼-watt, ± 5% Carbon)|
|R1 = 3.3 KΩ
R2, R4, R5 = 10 KΩ
R3 = 8.2 KΩ
|C1 = 0.01 µF/50V
C2 = 4.7 µF/10V
C3 = 0.033 µF/50 µF
C4 = 220 µF/25V
|IC1, IC2 = NE555|
|L.S. = 8 Ω speaker|