Friday, July 23, 2010

LM386 Based Low Power Audio Amplifier

About LM386

LM386 is a low power audio amplifier IC designed for use in low voltage consumer applications. You can use this 8-pin IC to amplify the output signal from your mp3 player or computer audio output. The inputs are ground referenced while the output automatically biases to one-half the supply voltage. The quiescent power drain is only 24 milliwatts when operating from a 6 volt supply, making the LM386 ideal for battery operation.

Applications of LM386
  • AM-FM radio amplifiers
  • Portable cassette player amplifiers
  • Intercoms
  • TV sound systems
  • Line drivers
  • Ultrasonic drivers
  • Small servo drivers, etc.

The circuit below shows a simple audio amplifier using LM386 with a gain of 200. If the 10uF capacitor connected between pins 1 and 8 is taken off, the gain would be 20.  The gain can be adjusted between 20-200 by placing an appropriate resisor in series with this 10uF capacitor.


Source: http://www.eleccircuit.com/wp-content/uploads/2008/02/simple-lm386-audio-amplifier.jpg


You can test this circuit with your mp3 player or ipod. The varying 10K resistor at the input is to control the volume of output audio.

1 comments:

Bren ECX said...

Hello May I ask a question?
for my project , Is it possible that the input of amplifier is contain 220 volt ac and the output of it is 3 volt using multitester, can you help for the schematic diagram,, can you help for what is the best thing i can do with my project?
thanks send me an email :))

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