Noise Meter
Noise pollution is tends to many non-communicable diseases and. Safe level of noise is considered up to 30 dB. Here is a interesting circuit by dreamlover technology, "Noise Meter" used to measure the level of noise indicting by LED and in addition it give warning when noise crosses the safe level of 30 dB by beeping sound.
Circuit description of Noise meter
The entire circuit of noise meter has been designed and fabricated using sound intensity sensor and display unit. Here condenser microphone is used as sensor of noise meter with operational amplifier (IC2) and corresponding passive components. The inverting and non-inverting input is given to operational amplifier IC (IC2) from pin 2 and pin 3 respectively. Where output from pin 6 of IC2 is connected to the inverting input for negative feedback through resistor R5. The controlling sound ac signal from potentiometer VR1 is first rectified by diode (D1 and D2) and maintains it at the output level of IC2.
The display unit is designed around monolithic IC LM3914 (IC3). It drives ten LEDs by sensing analog voltage. Each LED is connected to output of IC3 represents the sound level of 3 dB in descending order from 18 to 10. The glowing all ten LEDs indicate sound intensity is 30dB.
The PNP transistor get base bias when output at pin 10 of IC3 goes low to drive the piezo buzzer in order to give sound. This indicates noise crosses the safe level of 30 dB.
PARTS LIST
Resistors (all ¼-watt, ± 5% Carbon)
R1, R3, R4, R7 = 10 KΩ
R2 = 12 KΩ
R5 = 10 MΩ
R6 = 27 KΩ
R8 = 4.7 KΩ
R9 = 1 KΩ
R10 = 5 KΩ
VR1 = 1 KΩ
Capacitors
C1 = 1000 µF/25V
C2, C3 = 0.1 µF
C4 = 0.22 µF
C5 = 4.7 µF/16V
C6 = 1 µF/16V
C7 = 2.2 µF/16V
Semiconductors
IC1 = 7809 (voltage regulator)
IC2 = CA3130 (operational amplifier)
IC3 = LM3914 (monolithic IC)
D1, D2 = 1N4148
D3 = 1N4001
T1 = BC558 (PNP)
Miscellaneous
LED1 – LED4 = Green
LED5 – LED7 = Yellow
LED8 – LED10 = RED
MIC1 = Condenser microphone
PZ1 = Piezo buzzer
Related Project
- Versatile Digital Tester digital tester for detection of condition of the components as well as nature of defect
- Ohm Meter measuring the low resistance range form 0 to 1 and and 0 to 10.
- Test a Diode | Zener Diode tests the diode as well as zener diode
- IC tester tester for timer IC 555 And Op-Amp IC 741
- Timer IC Tester check IC NE555 whether it have fault or not
if IC2 = CA3130 (operational amplifier) is out in the market or any merchandise, can i use CA3140? or any compatible or substitute for this operational amplifier?
IC2 = CA3130 is a 15MHz BiMOS Microprocessor Operational Amplifiers with MOSFET Input/CMOS Output.
And CA3140 is a 4.5MHz BiMOS Operational Amplifier with MOSFET Input/Bipolar Output.
Theoretically CA3140 should also work with the circuit. Another replacement option can also be HCA10014 it is a 15MHz BiMOS Operational Amplifier with MOSFET Input/CMOS Output.
tnx…but can i use other op amp other than that, that is most available?
Yes sure ; Theoretically you can use any operational amplifier but with the change in op-amp you might also want to change the values of R2 ; R5 and C4 correspondingly by using the Hit and Trial method and analyzing the output.
pls suggest if theres other ic we can place to ca3130..other than HCA10014….for more option…. thank u so much!
As I said earlier you can also use any Op-Amp but but with necessary adjustments in the circuits.
I would also like to hear to your experience of using Op-Amps other than CA3130 if you do so.
i use this noise meter for my proposal to my electronic final term…i cant start cause IC2 is not available….and im an electrical engr. thats why i dont know what to do or what alternative should i buy…to start immediately to my project…
oh! See this link :
http://www.intersil.com/en/products/amplifiers-and-buffers/all-amplifiers/amplifiers/CA3130.html#00.html
You can buy from this link if you have access to online shopping and don’t care about the shipping time.
or , you can also use other op-amps with similar properties like CA3140 , CA3240.
so CA3140 can be replacement for CA3130 in this noise meter? thank you ^_^ ssoooo mmmmuuccchhh…
I dont find the configuration of VR1.Can you please give it
The part list is now updated with the value for VR1.
pls tell me what should be the input voltage??
Because we are using a voltage regulator here voltage input from anywhere in the range 10-24 voltage should be ok.
ur circuits really applicable with our projects…we want to use it but theres a problem we need to apply it in amplifier..what should we can u help us…how can we apply it with amli we have already circuit for ampli with 3watts output how can we we fit ur design..tnx
saale yeise project dalta hei ki jo chalte bhi nahi aur ter ko kuch sharam hey ki nahi ,….
Ek to sem chota hey.. Guide pagal jaisi mili hey,,, aur tere bharose project choda tha …. aur padhai kar rahe the,,,aur abhi project chal nahi raha ///
im having a problem with the proteus simulation of this circuit. the leds are lit inspite of the fact that the battery is removed. can you help me with it please
good project… and its working we made it. This is my project for MSc physics.
what will happen if I replace the microphne by LDR but i keep the same circuit ?
The normal range of conversational sound is between 45 to 60,so is that possible to change the level represented by each LED from 3db to 10db or something so as to make it useful in a wide range.
Can I get a bread board diagram of this circuit ?
guys can we use instead lm3914 a lm3915 or lm3916? pls answer me
give design of noise meter with neat explaination
Sir, can we use LED displays instead of LED’s ?
If so then the components which are using are enough or we may need some other components?
if i wnt to use 40db then
i want to use 40db sound then what should i do
which ic shoud i use for 40db??
dd this work properly
I want to use this circuit to detect the noise of students in class .. Can i increase the sound range from 30db to like 90db? Please help?
what is the maximum level of the noise to be measured by this circuit ? in decibals.
what should be add to the circuit if i want to set the zero & span of the noise level?
if i want to measure the slight change in the noise level continously upto 120 decibals, then what should be done.
i made the circuit. but it detects voice level of 50 db and above.what would be the reason?