Many Electronic circuit projects in simple ways of learning

Donkey sound effect Circuit using IC-555

This is a donkey sound effect project that easy to builds because use simple components include three IC-555 and LM386 and more little parts. Although at present we use Micro controller IC because small. But some times it is hard to find, so this circuit is suitable for everyone.

How it works
In Figure 1 the schematic diagram of this projects.
schematic diagram

When press switch S1 to apply power to this project. The operation of IC1 will be 2 ranges.
– First the high voltage is shown at pin 3 until full time (about 2 second), Then switch to the low voltage automatically. This times is controlled by R1,R2 and C1, C2

This high and low voltage from pin 3 of IC1. We will take it to controlled IC2 and IC3 again, by through diode D1 and VR1 to pin 5 of both IC. Which D1 act as protect external voltage backward to IC1

While IC2 and IC3 are connected to others parts that controlled it generate the high and low frequency as voltage from pin 5.

If high voltage IC will generate high frequency and if low voltage the frequency is low.

Both IC2 and IC3 same work. Because we want realistic sound, Create a two frequency range with a frequency similar to simultaneously make it sound like a chorus.

The IC4 acts amplifier IC2 and IC3 frequency of the speaker, the VR3 as a control signal voltage level before expanding.


The parts you will need.
Resistors 0.25W 5%
R1___________100K
R2___________6.8M
R3,R4,R6_____ 10K
R5___________ 270 ohms
R7___________ 27K
R8___________ 27 ohms
Electrolytic Capacitors
C4,C7_________10uF 16V
C8___________220uF 16V

Mylar capacitors
C1,C2__________0.22uF 50V
C3____________0.056uF 50V
C5____________0.047uF 50V
C6____________0.047uF 50V

Variable Resistors
VR1,VR2_______4.7K
VR3___________100K

Semiconductors
IC1,IC2,IC3_____NE555 Timer
IC4____________LM386 Amplifiers

SP1- 8 ohms speaker
PCB and more

How to builds
First you need to make a PCB as Figure 2 then assemble all parts on it as Figure 3 , next connect more wire and speaker. Next check for error. Then apply power to the circuit.

PCB layout
Figure 2 the PCB layout

the components layout
Figure 3 the components layout

This Post Has 3 Comments

  1. Interessante.

  2. In the electric schema there are VR1 and VR2 = 47k and in yhe list of parts is noted 4,7k. In the same situation C6 = 0,47 in schema and 0,047 in the list parts.
    Which of this value are true ?

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