Bench Amplifier

Description: A small 325mW amplifier with a voltage gain of 200 that can be used as a bench amplifier, signal tracer or used to amplify the output from personal radios, etc. Circuit diagram Notes: The circuit is based on the National Semiconductor LM386 amplifier. In the diagram above, the LM386 forms a complete non-inverting amplifier with voltage gain of x200. A datasheet in PDF format can be downloaded from the National Semiconductor website....

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Low impedance microphone amplifier

Description The circuit is a microphone amplifier for use with low impedance (~200 ohm) microphones. It will work with stabilized voltages between 6-30VDC. If you don't build the impedance adapter part with T1, you get a micamp for higher impedance microphones. In this case, you should directly connect the signal to C7. Schematic diagram...

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Amplifier of acoustic frequencies with preamplifier

Technical characteristics:Tendency of catering: 15V Force of expense: 4,2Wrms in the 4W Minimal signal of entry: 94mVp-p with preamplifier, 0,65Vp-p without the preamplifier. Circuit diagram...

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Three-Level Audio Power Indicator

Battery-operated 3 LED display Simply connect it to loudspeaker output Circuit diagram...

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Audio Perimeter Monitor

Circuit diagram Notes: Using a single cable such as speaker wire or doorbell cable, this circuit can be remotely positioned, for example, at the bottom of a garden or garage, and used to detect all sound in that area. The cable can be buried in a hosepipe or duct and is concealed out of sight. The mic is an ordinary dynamic mic insert and should be housed in a waterproof enclosure with the rest of the circuit. The mic output is amplified by the...

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