Decibel Level Detector Project Chris Lombardo IME 458
description
Transcript of Decibel Level Detector Project Chris Lombardo IME 458
Decibel Level Detector Project
Chris LombardoIME 458
• Produce a decibel level detector with a range of 0-50 decibels
• Use a LM3915 integrated chip to drive a series of ten groups of LEDs
Objective
Circuit Diagram
BOMCount Ref Value Description Size Part # MFR
1 R1 10k Resistor Std Std
6 R2, R3,R5, R7,R8, R10
100k Resistor Std Std
1 R4 47k Resistor Std Std
1 R6 1k Resistor Std Std
1 R9 56k Resistor Std Std
1 R11 4.7k Resistor Std Std
2 R12,R14 100 Resistor Std Std
1 R13 330k Resistor Std Std
1 R15 220k Resistor Std Std
1 R16 10 Resistor Std Std
2 R17, R19 390 Resistor Std Std
1 R18 22k Resistor Std Std
1 P1 10k Log Potentiometer Std Std
3 C1, C4, C8 330nF Capacitor
1 C2 47uF/10V Capacitor
2 C3, C9 100uF/10V Capacitor
1 C5 100nF Capacitor
1 C6 470uF/16V Capacitor
1 C7 10uF/16V Capacitor
1 IC1 MC33172P
1 IC2
1 5V Reg Voltage Regulator LM2931AZ5 TXS
20 LED Red LEDS MV8191 Everlight
1 Mic Electret microphone CEM-C9745JAD462P2.54R
Challenge Electronics
1 Bat 9V Battery Std Std
1 Switch SPST switch 2FA5373TABS CARLING TECHNOLOGIES
Project Description• Omnidirectional electret microphone
serving as the input• Two amplifiers with the first
amplifying the signal and the second serving as a rectifier driver
• The Q2 transistor charges capacitor C8 and then discharges it across R13 to make a peak detector
• The Q3 transistor changes the sensitivity of the LM3915 chip giving the system an extra 20db of range
• The main component of the system is the LM3915 itself which controls the currents through the LEDs while also measuring the input voltage line SIG logarithmically with a range of 0-50db
Description Continued
After completing this project I have a fully functioning sound level reader with a range between 0-50db with steps of roughly 5db between each LED
Overall success but a board with dual LM3915s would be more useful.
Conclusion