The article is being published in collaboration with JLCPCB. They supply high quality PCBs at a very reasonable price. They also can provide SMT circuit assembly.

We thanks to our sponsor JLCPCB https://jlcpcb.com/RTA for sponsoring us PCBs for this project circuit.

Thanks To JLCPCB.

$2 for 1-4 Layer PCBs.

Get SMT Coupons: https://jlcpcb.com/RTA

In this project, we’ll teach you making music activated LED light circuit. This sound-activated light is designed to change its LEDs' color and orientation based on sounds picked up by an internal microphone. Based on the music, the lighting systems will determine the speed and color of the lights, and flash and strobe accordingly.

This circuit is using 50 LEDs they will blink one by one when there is music. The circuit is built around a CD4017 decade counter IC, the output of the first IC is received at the clock input of this IC. This IC is very useful and beginner-friendly it provides 10 outputs in a circuit.

Applications and Uses -

  •  Decorative Pieces
  •  Toys
  •  Advertisement Hoardings
  •  Visual Sign Indications

Component List -

To make this wireless power transfer circuit, we might need some electronics component.

All components list have been given below –



Component List –

  •  Transistor – BC 557
  •  IC – LM 3914
  •  Resistor – 1.5 KΩ 33 KΩ • LED – 50 Pieces
  •  Power Source – DC 3.7 volt

Transistor Pin Out -

A transistor is a miniature semiconductor that regulates or controls current or voltage flow in addition amplifying and generating these electrical signals and acting as a switch/gate for them.

In a simple word a transistor is a solid-state electronic device that is used to control the flow of electricity in electronic equipment and usually consists of a small block of a semiconductor.

Its 3 legs pin-out can be seen above.

  •  Collector
  •  Base
  •  Emitter

Transistor Feature -

Part No – BC 557

  •  High Collector Current.(IC= 500mA)
  •  Power dissipation - (PC=300mW)
  •  Collector-Base Voltage – 40 volt
  •  Collector-Emitter Voltage – 25 volt
  •  Emitter-Base Voltage – 5 volt
  •  Collector Current –Continuous – 500 mA
  •  Collector Dissipation – 300 mW
  •  Junction and Storage Temperature – 55~150 C


CD 4017 Features -

  •  High speed 16 pin CMOS Decade counter
  •  Supports 10 decoded outputs
  •  Wide supply voltage range from 3V to 15V, typically +5V
  •  TTL compatible
  •  Maximum Clock Frequency: 5.5Mhz
  •  Available in 16-pin PDIP, GDIP, PDSO packages

Hardware of SMT Project Circuit - 

To make this mini flip-flop circuit, we might need some electronics component. JLCPCB has its own parts library. JLCPCB has 200k+ in stock components, 24 hours rapid SMT assembly.

You can check SMT parts library here - https://jlcpcb.com/parts

Circuit Connection – Step 1 

To make this music activated light circuit, 1st we connect CD4017 IC with PCB board. We connect 2no, 4no and 8no leg of IC and connect 3no and 9no leg of IC. Then we connect 33 KΩ resistor with 3 no leg of IC and then connect its other terminal with 6no leg of IC.

Now we connect 1.5 KΩ resistor with 7no leg of IC and then connect its other terminal with 8no leg of IC. We utilize JLCPCB (https://jlcpcb.com/RTA) to printout our PCB.

Circuit Connection – Step 2

To make this circuit we are using 50 pieces LED light. We divide this led by 10 and then each side got 5 led. We make parallel connection in this 10 side led and connect all LED negative legs with 8no leg of IC.

We connect all transistor emitter leg and connect this emitter leg with 9no leg of IC.

Circuit Connection – Step 3

If we count this transistor in 1 to 10, then we connect its 1no transistor “Base” leg with 1no leg of IC, 2no transistor “Base” leg with 18no leg of IC, 3no transistor “Base” leg with 17no leg of IC, 4no transistor “Base” leg with 16no leg of IC, 5no transistor “Base” leg with...

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