Sine wave amplifier

Bela Kaltenekker

Other Parts Discussed in Thread: LM386

Hello:

I am working on a project where I need to amplify a sine wave. Sine wave is generated with a Arduino, voltage is 1 volt PP and 1 cycle / second. I need to amplify to 7.5 volt pp. The voltage source is a 14.8 volt Lithium battery. I tried with an LM386N-4 but the output voltage goes to about 7 volts even with no input voltage and never drops below that. Would an LM741J work better?

I appreciate any help, thank you.

Bela

over 11 years ago

0 Don Dapkus over 11 years ago

TI__Guru**** 189401 points

Hi, Bela,

It sounds like the LM386 was working correctly.

Using a single-supply, you should measure VDD/2 at the output.

You need to use a DC-blocking cap at the output to get rid of the DC offset, and get your desired signal. At 1 Hz, dependign on your load, you might need a very large cap: f=1/(2*pi*RL*C)

-d2

0 Bela Kaltenekker over 11 years ago in reply to Don Dapkus

Prodigy 50 points

Hi Don:

Thank you for your reply. I had a 250microfarad cap on the output, Ill try something bigger.

Bela

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Sine wave amplifier