2B-REMOTE AUDIO LEVEL INDICATOR
The audio level indicators available in the market have to be attached to the output of sound producing apparatus. At times it creates problems. The present project avoids all these problems. You can keep this project near any sound producing device without making any connections. The L.E.Ds connected to the circuit will indicate the audio level.
TECHNICAL DESCRIPTION AND WORKING
This project has been developed and tested O.K. in our TV Engineers Technical Lab. The components and PCB used in the projects published in our books are available for sale at resonable price.
The project is based on two ICs LM324. The IC LM324 is an operational amplifier IC. The IC incoperates four operational amplifier in its internal configuration. The first amplifier is non-inverting while the rest work as inverter. The signal received by the condenser mike is 1st amplified by the pre-amplifier and applied to the inverters of the IC through the 1st Non-inverter of the IC. The second IC LM324 works as a comparator. Basing on the output of 1st non-inverting amplifier, the L.E.Ds connected to the rest of inverting amplifiers (7nos) glow and indicate the audio level.
PRECAUTIONS WHILE ASSEMBLING THE PROJECT:-
*Check polarity of condenser mike while mounting.
*First of all check all the components as per circuit.
*Check short circuit , while soldering.
*Please use resistance of the exact value as given in the circuit.
*Check +ve & -ve terminal of L.E.D. while mounting on PCB.
*Use IC base for mounting of the ICs otherwise IC may damage due to current leakage of soldering iron.
IC LM324 = 2
CON. MIKE = 1
BC148 = 1
.1 = 2
1K = 7
10K = 2
4.7K = 2
820K = 1
220E = 7
1MEG = 1
220K = 1
LED = 7