Mini Mic Pre-Amplifier Circuit based IC LM358



Simple Audio Pre-Amp circuit
Designed based on single Transistor 2N3904, this circuit will provide good gain for weak audio signals such as electret microphone. Easy to build and really simple for pre-amp circuit

Condenser Mic preamplifier
This is a very simple preamplifier circuit for condenser microphone. This mic preamplifier also can be used for dynamic microphone.

You can replace the BC549 with BC109C. For bette ....etc

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In the output stages of most broadcastreceivers and some amplifiers,there is a limit up to which maximumpower can be developed withoutdistortion. In the widely acceptedoutput circuit, two output transistorsare connected in series between thepositive and ground and biasing is adjustedso that each transistor gets halfthe supply voltage.The circuit presented here is asimple audio amplifier for a personalstereo system. In this, supply voltageto each transistor can be enhanced toproduce a larger output. The audiodriver transformer drives the transis ....etc

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I need circuit diagram of electronics stethoscope because of my project..i have an challenge to build a instrument that caunt our heart beat and send to digital display plz give me circuit diagram ....etc

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Abstract:

A digital audio broadcasting system that is capable of providing a large number of high quality stereophonic channels to mobile receivers in an environment with severe multipath delay and fading. Optimum combination of frequency and time diversity to guarantee robust performance in the mobile channel, with its multipath delay and frequency-selective fading effects. The system is based upon a dynamic single channel per carrier assignment of each stereo channel to many carriers. Inter symbol interference degradations caused by multipat ....etc

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i want heart beat sensor using ldr and lm358.its my major project.can u plss send it as soon as possible ....etc

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Audio Amplifier Circuit



In the first part of lab#1 you will construct a low-power audio amplifier/speaker driver based
on the LM386 IC from National Semiconductor. The audio amplifier will be a selfcontained, battery-operated component. In the second part of the lab you will construct a
microphone circuit using a compact electret condenser microphone cartridge. These circuit
modules are important building blocks of many audio communications systems, and will be
used in our ultrasonic transceiver system. ....etc

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It looks like an ordinary radio with a headset. Spy Ear is actually a powerful secret sound amplifier with a built-in highly sensitive microphone.

With this sound amplifier, you can now hear things crystal clear that you could never not before. Spy ear is very easy to use, just put the ear buds in your ears - aim the Spy Ear towards what you want to hear and listen-in. Spy Ear has adjustable volume control, which amplifies sound up to 50 decibels.

You can listen to conversations across a room, and gather all the gossip!! Spy ear is also great ....etc

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Digital Audio's Final Frontier-Class D Amplifier

Digital technology continues its march from media like CDs and DVDs toward your audio speakers. Today, amplifiers based on digital principles are already having a profound effect on equipment efficiency and size. They are also beginning to set the standard for sound quality.

An old idea, the Class D amplifier has taken on new life as equipment manufacturers and consumers redefine the musical experience to be as likely to occur in a car, on a personal stereo, or on an a ....etc

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Circuit of an automatic switch for audio power amplifier stage is presented here. The circuit uses stereo
preamplifier output to detect the presence of audio to switch the audio power amplifier on only when
audio is present. The circuit thus helps curtail power wastage. IC1 is used as an inverting adder. The
input signals from left and right channels are combined to form a common signal for IC2, which is used
as an open loop comparator. IC3 (NE556) is a dual timer. Its second section, i.e., IC3(b), is configured
as mono ....etc

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to get information about the topic digital audio s final frontier class d amplifier full report ppt and related topic refer the page link bellow

http://seminarsprojects.net/Thread-digital-audio-s-final-frontier-class-d-amplifier--2028

http://seminarsprojects.net/Thread-class-d-amplifiers ....etc

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