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VU meter using LM3914 ic

DIY VU meter using LM3914 ic

This things are required to make this amplifier.........

1. 10×5mm/3mm Led.........

2. 1×LM3914N-1 ic..........

3. 1×1.5k resistor 1/4w.........

4. 1×100k resistor 1/4w.........

5. 1×560Ω resistor 1/4w.........

6. 1×4.7uf capacitor..........

7. 1×4k7 preset........

8. 1×SPST push button..........

Watch this video for better understanding

circuit diagram

In this post I make Led VU muter. Now watch the circuit diagram and follow my steps for make this 
VU muter. First you need LM3914N-1 ic. Connect 10 pieces led's cathode (-) pin to ic,s 1,18,17,16,15,14,13,12,11,10 no pin. frequency start 1 no pin and end 10 no pin. Then short ic's 2,4,8 no pin by a wire for gnd. Then connect a 1.5k resistor with ic's 7 no pin to gnd. Then connect a 560 Ω resistor with ic's 5 no pin. Then connect a 100k resistor with the 560 Ω resistor. And then connect this 100k resistor with gnd. Then connect 4.7uf capacitor (+) between 560 Ω resistor and 100k resistor, and capacitor (-) connect with gnd. Then connect a IN4148 zener diode(-) with 4.7uf capacitor(+), and zener diode (+) pin is audio input signal. Then you need a 4.7k preset for frequency gain control. Connect this 4.7k preset's output pin with ic's 6 no pin. Then short all Led's anode (+) pin by a wire. Then connect this wire with preset right side pin and ic's 3 no pin,. And preset left side pin connect with gnd. Then you ned a SPST push button for Dot and Bar mode. Connect this SPST push button with ic's 3 no pin and ic's 9 no pin. Now your circuit is ready.

*ic's 3 no pin is power supply pin. for power supply 9 - 12 volt DC.

*zener diode (+) pin for audio input signal. audio input signal upto 3.7 volt.

Thank you,

Technical Mriganka.........

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  1. I need pcb layout this diagram.. Please give us pcb layout

  2. yes please give us pcb layout