LM3915组成的音量电平指示器电路图

音量电平指示器电路图
This nifty sound level meter is a perfect one chip replacement for the standard analog meters. It is completely solid state and will never wear out. The whole circuit is based on the LM3915 audio level IC and uses only a few external components.

Schematic


Corrected schematic by Eplanet



Original Schematic

Parts

Part
Total Qty.
Description
C1
1
2.2uF 25V Electrolytic Capacitor
R1
1
1K 1/4W Resistor
D1
1
1N4002 Silicon Diode
LED1-LED10
10
Standard LED or LED Array
U1
1
LM3915 Audio Level IC
MISC
1
Board, Wire, Socket For U1

Notes
1. V+ can be anywhere from 3V to 20V.
2. The input is designed for standard audio line voltage (1V P-P) and has a maximum input voltage of 1.3V.
3. Pin 9 can be disconnected from ground to make the circuit use a moving dot display instead of a bar graph display.