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 for sponsoring us PCBs for this project circuit.

Thanks To JLCPCB.

$2 for 1-4 Layer PCBs.

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In this project, we’ll teach you making a led flip-flop circuit. A Flip-Flop LED flashing circuit is a basic circuit that produces a continuous square wave blinking output. In this project, we are going to design a simple Flip-Flop LED Flashing Circuit Using a stable multi vibrator. The heart of this circuit is S-9013 transistor.

This difference causes one transistor to turn on fast than the other when power is switched on for the first time. The flashing period is approximately the product of this resistance and the capacitance which is about 1 sec. The 560Ω resistors set the LED current and may be reduced for lower battery voltage.

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 – S9013

• Resistor – 560 Ω

                     10 KΩ

• Capacitor - 100µf/ 25v

• LED (Red, Green, Blue) – 3 volt

• Power Source – DC 12 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 - 

  •  Gate
  •  Drain
  •  Source

Transistor Feature -

Part No – S9013


  • 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

Circuit Connection – Step 1

To make this flip-flop circuit, 1st we connect 3 pieces 10 KΩ resistor with “Base” leg of transistor. Then we connect 100µf/25v capacitor negative leg with “Base” leg of transistor and its positive leg with other transistor “Collector” leg.

We follow this process with the rest capacitor also and connect its empty terminal with 3 legs of 10 KΩ resistor. We utilize JLCPCB to printout our PCB.

Circuit Connection – Step 2

To make this flip-flop circuit we are using 3 different color LED light, as a like red, green and blue. For this 3 different color we make different set led light and we connect all LED negative leg with each other. 

Then we connect all red color led positive leg, blue color led positive leg and green color led positive leg. Connect red color led positive leg with each other, blue color led positive leg with each other and green color led positive leg with each other.

Circuit Connection – Step 3

Now we connect this 3 different color LED positive leg with 3 different transistor. Our circuit is now completely ready for use. You can use this circuit to decorate your home, office and can use any cultural program.

To operate this circuit, we need DC power source. We are using DC-12v power supply to operate this circuit. We connect dc 12v positive cable with that place, where 10 kΩ and 560 Ω resistor make series connection. The last connection is to connect dc 12v power supply negative cable. Just connect this cable with all transistor “Emitter” leg.

Our circuit is now completely ready for use. Just plug-in power and decorate your residential places. Thanks to JLCPCB for offering us, this SMT...

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