Build a LED Mini Audio Analyzer circuit Diagram

This analyst is, a sensitive instrument, in the frequency changes   and width of a acoustic signal. Thus the brightness of LED that turns on each moment of is proportional signal width, while the colour of proportionally frequency.

Mini Audio Analyzer Circuit Diagram

 

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The circuit input sensitivity is regulated with R2, in order that in powerful signals they turn on the red LED, in the middle the yellow LED and in the low green LED. The display unit, is constituted by 3 lines of 10 LED the every, what is checked by a counter decoder (IC2). Two gates ICa-b, function as the IC2, with the R6 regulate the frequency.

When does not exist signal in the input, then no one LED does not turn on. As soon as it will be applied signal, then the LED will begin to blink depending on the rythm and the intensity of signal. Can experiment with the prices of resistances R4, R5, so that you find the value that suits in like your. Initially it can they are placed trimmer 1KO, in the place of R4, R5 and after is found the suitable value, they are replaced with permanent resistances.

What it wants it can it adds also other LED, adding other a completed same press with the IC2. The particular circuit does not have the claim, the precision of measurement  input signal.

Part List

R1= 1K8Kohm    
R2= 100Kohm trimmer    
R3= 1Kohm    
R4= 100 ohm.....1Kohm    
R5= 100 ohm.....1Kohm
R6= 100Kohm trimmer
C1= 100nF 100V
D1....10= RED LED    
D11....20= YELLOW LED    
D21....30= GREEN LED    
IC1= LM3915
IC2= 4017
IC3= 4011