Microphone Preamplifier – Sound Sensor

  • Rajkumar Sharma
  • 878
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  • easy
  • Tested

This is an easy to construct dual-stage microphone pre-amplifier. The project can be used as a sound sensor or microphone pre-amplifier. The 1st op-amp pre-amplify the very low-level signal coming from the condenser microphone and 2nd op-amp provides more boost to the audio signal. The pre-amplifier is an important building block for many audio communication systems and sound sensors.  The circuit has been built around OPAMP LM358. The output signal level is dependent on the input sound level. The maximum peak to peak output is 2Vpp.

Connections: CN1 Pin1 = VCC, Pin 2 = Low level audio signal, Pin 3 = NC, Pin 4= High level Audio Signal (it can be used for microcontroller interface)

Features

  • Power supply: 5V DC @ 10 mA
  • On-Board electret condenser microphone
  • Dual Stage Amplification using OPAMP LM358
  • PCB dimensions: 47.31 x 14.76 mm

Schematic

Parts List

NO.QNTY.REF.DESC.MANUFACTURERSUPPLIERSUPPLIER PART NO
11CN25 PIN MALE HEADER PITCH 2.54MMWURTHDIGIKEY732-5318-ND
22C2,C44.7uF/25VNICHICONDIGIKEY493-11353-3-ND
33C3,C6,C7,C10.1uF/50V SMD SIZE 0805MURATA/YAGEODIGIKEY
41C510uF/25V SMD SIZE 1206MURATA/YAGEODIGIKEY
57D1,U2,D2,R7,C8,R9,R10DNP
61MK1MICSOBERTON INCDIGIKEY433-1088-ND
72R1,R5100K 5% SMD SIZE 0805MURATA/YAGEO
82R2,R810K 5% SMD SIZE 0805MURATA/YAGEO
92R3,R41K 5% SMD SIZE 0805MURATA/YAGEO
101R624K 1% SMD SIZE 0805MURATA/YAGEO
111U1LM358 SOIC8TIDIGIKEYLM358MX/NOPBCT-ND

Connections

Gerber View

Photos

Video

LM358 Datasheet

lm158-n

PCB

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chic

Supply Voltage?

chic

Thnx.

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