This circuit is called the Room Noise Detector, which is intended to signal, through a flashing LED, which exceeds the threshold specified in the room noise, chosen from three fixed levels, namely 50, 70 & 85 dB.
This circuit diagram using two Op-amps, which provides the circuits required to obtain a voice-picked by a miniature electric microphone to drive a LED. SW1 to the first position in the circuit is not active. Second, third and fourth position in the power circuit and set the input sensitivity threshold to 85, 70 & 50 dB respectively.
Part :
R1 = 10K
R2,R3 = 22K
R4 = 100K
R5,R9,R10 = 56K
R6 = 5K6
R7 = 560R
R8 = 2K2
R11 = 1K
R12 = 33K
R13 = 330R
C1 = 100nF
C2 = 10µF 25V
C3 = 470µF 25V
C4 = 47µF 25V
D1 = Red LED
IC1 = LM358
Q1 = BC327
MIC1 = Miniature electret microphone
B1 = 9V Battery
This circuit diagram using two Op-amps, which provides the circuits required to obtain a voice-picked by a miniature electric microphone to drive a LED. SW1 to the first position in the circuit is not active. Second, third and fourth position in the power circuit and set the input sensitivity threshold to 85, 70 & 50 dB respectively.
Part :
R1 = 10K
R2,R3 = 22K
R4 = 100K
R5,R9,R10 = 56K
R6 = 5K6
R7 = 560R
R8 = 2K2
R11 = 1K
R12 = 33K
R13 = 330R
C1 = 100nF
C2 = 10µF 25V
C3 = 470µF 25V
C4 = 47µF 25V
D1 = Red LED
IC1 = LM358
Q1 = BC327
MIC1 = Miniature electret microphone
B1 = 9V Battery
punda tell me the hw the switch sw2 works? fucker.
ReplyDeleteThe sw2 switch it's used to turn off the circuit, as you can see, there are two cases, one: the battery is connected, the other, the battery is not connected.!
ReplyDeleteBut I also have a question:
ReplyDeleteHow is the Op-amp V- pin connected? As I see is floating; where should I connect that pin?
Best regards!
Done, this project is working;) look for more details on http://www.electro-tech-online.com/electronic-projects-design-ideas-reviews/96054-noise-detector.html
ReplyDeleteBye!