Sound Level Meter
Monday, March 26, 2012 by skemarangkaian
This is circuit can be used to check the sound levels.The sound pressure meter is vey useful in setting up home theater systems , if you need to test the sound pressure of each channels on different positions in the room.
The circuit is nothing but a non- inverting amplifier based on op-amp CA 3140. The sound picked by the condenser mic will be amplified by the IC1 and rectified by the bridge D1 to drive the meter M1. The deflection on the meter will be proportional to the pressure of the sound falling on the mic.The switch S1 can be used as an ON/OFF switch.
The circuit is nothing but a non- inverting amplifier based on op-amp CA 3140. The sound picked by the condenser mic will be amplified by the IC1 and rectified by the bridge D1 to drive the meter M1. The deflection on the meter will be proportional to the pressure of the sound falling on the mic.The switch S1 can be used as an ON/OFF switch.
Note:
- The bridge D1 can be a 1A bridge.If 1A bridge is note available,make one using four 1N4007 diodes.
- The circuit ca be powered by using a 9V PP3 battery.
Pin IC CA3140
The IC CA3140 is integrated circuit operational amplifiers that combine the advantages of high voltage PMOS transistors with high voltage bipolar transistors on a single monolithic chip.
Features
- Very High Input Impedance (ZIN) -1.5TΩ (Typ)
- Very Low Input Current (Il) -10pA (Typ) at ±15V
- Wide Common Mode Input Voltage Range (VlCR) - Can be Swung 0.5V Below Negative Supply Voltage Rail
- Output Swing Complements Input Common Mode Range
- Directly Replaces Industry Type 741 in Most Applications
- Pb-Free Plus Anneal Available (RoHS Compliant).
