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.