Monthly Archives: July 2016

volume indicator

Volume indicator Indicates the level of audio signal.(this project is under construction.. will update soon )

INPUT devices: microphone                                                                                                         OUTPUT: LED bar graph                                                                                                               processing: AVR (ATmega32A)

My construction:

volume unit meter version1


microphone pickup’s the audio signal and BC546 preamp amplifies the signal to the level 1.8Vpp max, so that ADC can read.  BC546 collector feedback bias circuit.



audio fed to the ADC pin of ATmega32A

aaded voltage regulator (2sc1383 + 5V6 zener), we can also use LM7805 regulator.

volume indicatorpic1.jpg







AM transmitter

I am always interested in building radio circuits. am transmitter, for construction, I used copper clad boards and really like the construction, not neat though, I do remember that I sprayed thicke…

Source: AM transmitter