How to Design a Printed Circuit Board – Voice Modulator Circuit

This tutorial will construct a Voice Modulated signal circuit with a self-designed PCB in this construction process. We have designed a PCB using the online PCB prototype & designer EASYEDA in this construction process. It’s a fun project designed primarily to change or alter the voice.

We usually hear the same voice when we speak in a MIC. And so we will listen to just a robot in this construction process when we talk in the MIC. This can be used to play or to celebrate with your friends, or as a robot voice.

Hardware Component

The following components are required to make Voice Modulator Circuit

S.no	Component	Value	Qty
1.	Bergsticks	–	1
2.	Jumper	–	3
3.	Speaker	–	1
4.	LED	–	1
5.	Supply	–	1
6.	MIC	–	1
7.	IC	LM386, LM358	1, 1
8.	Audio Jack male/female	–	1
9.	Fabricated PCB	–	1
10.	Potentiometer	50K, 2K	2, 1
11.	Resistor	1K, 10K, 22K, 47K, 15K, 68K, 100K, 10R	1, 2, 1, 1, 1, 1, 3, 1
12.	Capacitor	10uF, 100uF, 220uF, 4.7nF, 100nF	3, 2, 1, 1, 7

LM358 Pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of LM358

LM386 Pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of LM386

Voice Modulator Circuit

Circuit Operation

The LM358 and the LM386 audio-amplifier IC serve this Voice Modulator Circuit. The user can operate this circuit from 3 volts to 9 volts.

On this circuit, we changed our voice through the use of a band-pass filter that is made with op-amp IC and the MIC pre-amp circuit gain is altered with an R10 pot. Besides voice-modulator signal amplification, IC LM386 is used. In the output, we have two options: the speaker and the headphones jack 3.5 mm to listen to the modulated voice. Also, for volume control, Pot R5 is used. For mostly audio amplifier gain, jumper J2 is used.

Applications and Uses

Scans equipment: x-ray screens, CT scanners, and UL scans all use electrical equipment to function. Some of the typical applications of PCBs include Monitors: All healthcare monitors have electrical equipment inside, also including blood glucose monitors, heart rate, and blood pressure monitors.