If you are looking for an Acoustic-guitar-pickup circuit that cheap and you can build with yourself. Suitable for the show enjoy of the party at home or in a group of friends. This project is a good answer. For people like to play surely acoustic guitar with no pickup in it.
Known piezo speaker
The piezo speaker mostly is used as the driver for the audio signals. Such as in a digital watch or a warning voice types. As the structure of the piezo is crystal with special properties that can generate a voltage from the pressure of crystallization. We can use it instead of the general microphone by By which it can respond to vibrations and high sensitivity.
When considering the structure of the acoustic guitar. Guitar body is wood and is designed to be hollow. When players strum guitar strings which is designed to the size and tension of the lines are different. by patterns of the sound of music.
In science, When an object vibrates at a any frequency. Would become a sound wave. That sound wave will travel through the structure of the wood body guitar. When we put the piezo speaker set up on the structure of guitar body is made ??of piezo crystals have better string vibration of the guitar itself. The piezo will generate a small voltage to which we can put to use in the future.
The working of circuit
As shown Figure 1 We start from the strum the guitar. Guitar string vibrates, causing sound to come out. Body vibration on the acoustic guitar could be passed to the piezo. Resulting electrical signal out.
The electrical signals that are sent through the C1-capacitor into pin 3 of IC1. Which the op-amp IC serves to amplify the small signal to large increase by rate with a gain that is determined by the ratio between R5-resistor and R3-resistor.
The gain of the circuit is 3.2 time. Then the signal through the expansion to a large. Then be passed to the C4-capacitor, and through a potentiometer to adjust the volume before send to J1. Which is Which is jack for connecting the input signal to the amplifier is available.
Process of building.
Because this project, have less parts. If you do not want to build a typical PCB. You can use as a Universal PCB Board. By soldering and placement itself. Which can build in short time. But need to check the wiring carefully.
But if you like tidiness so can build the copper-based model in Figure 2 as easy. When done, it should check deficiency and short-circuited by copper. Inspection at all times. Will help prevent problems. The does not work of this project.
The next step is to assemble various electronic components on the PCB, as in Figure 3. Then the wiring between the PCB and other devices such as The switch, volume, battery terminals and output jacks.
List of the parts
The resistor ¼ watts +-1%
R1, R2__2.2M______________2 pcs.
VR1__10K (B) _potentiometer__1 pcs.
C1______0.1uF 63V Polyester Capacitor___1 pcs.
C2, C3___10uF 50V Electrolytic Capacitors____2 pcs.
LED1____size 5 mm._____1 pcs.
B1— Battery 9V within Pole___1 sets.
PZ1_____peizo speaker______1 pcs.
S1____Switch ON/OFF__________1 pcs.
J1____Mono jack socket size 6.3mm___1 pcs.
Testing and implementation.
A very easy to use, just put the piezo plate attached to the guitar body. and the output has to enter into the guitar amplifier circuit. or others amplifier that we use.
Adjustment of the volume to the minimum position before. Turn ON switch the power supply to this projects will see LED1 glow light.
Then accelerated volue modest position. Then the guitar’s sound output to the power amplifier are active or not? When it came out, then adjust the volume to suit the actual use next.
For this project. Shown to have fun with friends. Various festive party. But it is not suitable for Showing or recording professional high quality.
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