How to Make an LED Blinker Circuit

A LED blinker is a circuit or device that causes a Light Emitting Diode (LED) to flash or blink at a regular interval. The blinking effect is achieved by turning the LED on and off quickly and repeatedly.

The basic LED blinker circuit consists of a power source, a resistor, a capacitor, and an LED. When power is applied to the circuit, the capacitor begins to charge through the resistor. As the voltage across the capacitor increases, it eventually reaches a threshold voltage that is sufficient to turn on the LED.

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.

The final circuit diagram and design can be seen above. We also thank to our sponsor JLCPCB https://jlcpcb.com/RTA for sponsoring us PCB for this project.

Thanks to JLCPCB.

$2 for 1-4 layer PCBs.

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

To make this LED blinker circuit, we might need some electronics component. Those component lists have to been given below.

Component list -

• PCB by JLCPCB
• Transistor - BC 547 *6
• Capacitor - 1µf/ 50v *6
• Resistor - 100 KΩ *6
• LED - 5mm *6
• Power Source - DC 12v

There are different types of LED blinker circuit. Each circuit have it's own unique design. As a like -

• Stable Multi vibrator Circuit
• 555 Timer Circuit
• Johnson Counter Circuit
• Microcontroller-Based Circuit
• Integrated LED Blinker Circuit

The BC547 is widely used general-purpose NPN bipolar junction transistor.

• Suitable for use in low-noise amplification circuit
• DC current gain ranging from 110 to 800
• Low voltage drop, typically around 0.7v
• Maximum collector current rating of 100mA
• Maximum collector-emitter voltage rating of 45V
• BC547 is also available in TO-92, SOT-23 and SOT-223 package.

The BC547 is a general-purpose NPN bipolar junction transistor commonly used in electronic circuits. The pinout of the BC547 transistor is as follows:

• Collector (C)
• Base (B)
• Emitter (E)

The design of led blinker circuit along with the PCB layout can be seen above. We don't include power supply circuit with the circuit. You can use any 12v battery or 12v adaptor for this LED blinker circuit.

To make this LED blinker circuit, we are using 6 pieces BC-547 transistor. We make a parallel connection in these 6 transistors. We connect these 6 transistor "Collector" leg with each all other. Now we connect capacitor with the circuit.

We connect 1µf/ 50v capacitor positive leg with "Emitter" leg of one BC-547 transistor and connect the same capacitor negative leg with "Base" leg of another transistor. We follow the same process for all transistors and all capacitors.

Now we'll connect 100 KΩ resistor with the circuit. We connect all resistor with "Emitter" leg of all transistor. This time we need to connect 5mm-LED with the circuit. We will connect all LED negative leg with each other.

We utilize JLCPCB https://jlcpcb.com/RTA to printout our PCB.

This time we need to connect all LED positive leg with the circuit. We connect all LED positive leg with "Emitter" leg of transistor and connect LED negative leg with "Collector" leg of transistor.

Now we need to connect power source with the circuit. For power source we are using DC-12v.

Connect DC-12v negative cable with "Collector" leg of transistor and DC-12v positive cable with 100 KΩ resistor.

Neat and perfect soldering is an important part for all kind of PCBs. Since soldering, you should remember that, there should not be any kind of short circuit connection. After soldering all leg, we cut-off the extra leg of all electronics component.

We also can use liquid PCB cleaner to clean the PCB board.

Again thanks to JLCPCB for best quality PCBs.

Our circuit is now completely ready for use. Now just plug-in power and enjoy the awesome effect of LED blinking circuit.

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