Audio Amplifier Circuit
An amplifier also shorted as amp is generally used to increase the amplitude of the signal given as input. In audio systems, amplifiers run the loudspeakers to increase the volume of a human voice or any other audio signal or it can also be used to play recorded sounds. Small audio amplifiers to drive small speakers can be built in a number of ways. The circuit of an amplifier is a little complicated.
Simple LM836 Audio Amplifier Circuit
* The LM836 configuration is a high gain configuration. For a maximum gain of 20, connect the 10F capacitor to pin 1 to 8. A 10k potentiometer can give the amplifier a variable gain.
* A computer audio amplifier circuit will change the volume from low level audio cards to high level.
Transistor Audio Amplifier Circuit
These types of circuit have a 4-transistor utility amplifier suitable for a variety of projects including microphones, receiver, telephone pick-up coils, intercoms and general audio monitoring. The amplifier has a power isolation circuit and bandwidth limiting to reduce oscillations and “motor boating”. Three cell battery packs giving about 4 to 5 volts are recommended for most transformerless audio amplifiers running a small 8 ohm speaker. The amplifier may be modified to work with a 9 volt battery if desired by moving the output transistors’ bias point. Lowering the 33k resistor connected from the second transistor’s base to ground to about 10k will move the voltage on the output electrolytic capacitor to about 1/2 the supply voltage. This bias change gives more signal swing before clipping occurs and this change is not necessary if the volume is adequate. As before, the two 4.7 ohm resistors may be replaced with a single 10 ohm resistor in series with either emitter.
In these types the amplifier will provide room-filling volume from an ordinary crystal radio outfitted with a long-wire antenna and good ground. The audio amplifier circuit is similar in complexity to a one-transistor radio but the performance is far better. This audio amplifier circuit is available in a TO-92 package and it looks like an ordinary transistor so your friends will be impressed by the volume you are getting with only one transistor and the amplifier may be used for other projects, too. Higher impedance headphones and speakers may also be used. An earphone from an old telephone will give ear-splitting volume and great sensitivity! The 68 ohm resistor may be increased to several hundred ohms when using high impedance earphones to save battery power
Audio Amplifier Circuit
An amplifier also shorted as amp is generally used to increase the amplitude of the signal given as input. In audio systems, amplifiers run the loudspeakers to increase the volume of a human voice or any other audio signal or it can also be used to play recorded sounds. Small audio amplifiers to drive small speakers can be built in a number of ways. The circuit of an amplifier is a little complicated.
Simple LM836 Audio Amplifier Circuit
* The LM836 configuration is a high gain configuration. For a maximum gain of 20, connect the 10F capacitor to pin 1 to 8. A 10k potentiometer can give the amplifier a variable gain.
* A computer audio amplifier circuit will change the volume from low level audio cards to high level.
Transistor Audio Amplifier Circuit
These types of circuit have a 4-transistor utility amplifier suitable for a variety of projects including microphones, receiver, telephone pick-up coils, intercoms and general audio monitoring. The amplifier has a power isolation circuit and bandwidth limiting to reduce oscillations and “motor boating”. Three cell battery packs giving about 4 to 5 volts are recommended for most transformerless audio amplifiers running a small 8 ohm speaker. The amplifier may be modified to work with a 9 volt battery if desired by moving the output transistors’ bias point. Lowering the 33k resistor connected from the second transistor’s base to ground to about 10k will move the voltage on the output electrolytic capacitor to about 1/2 the supply voltage. This bias change gives more signal swing before clipping occurs and this change is not necessary if the volume is adequate. As before, the two 4.7 ohm resistors may be replaced with a single 10 ohm resistor in series with either emitter.
In these types the amplifier will provide room-filling volume from an ordinary crystal radio outfitted with a long-wire antenna and good ground. The audio amplifier circuit is similar in complexity to a one-transistor radio but the performance is far better. This audio amplifier circuit is available in a TO-92 package and it looks like an ordinary transistor so your friends will be impressed by the volume you are getting with only one transistor and the amplifier may be used for other projects, too. Higher impedance headphones and speakers may also be used. An earphone from an old telephone will give ear-splitting volume and great sensitivity! The 68 ohm resistor may be increased to several hundred ohms when using high impedance earphones to save battery power.