LED Blinking Circuit using BC547 NPN Transistor

This is a LED blinking circuit with minimal components and connections. You can easily build this circuit in a bread board or a PCB. The components using in this LED blinking circuit is a single LED, BC 547 NPN transistor and a 1000uf/63b electrolytic capacitor.

The circuit will not works on 3v or 9v battery it needs at least 12v DC to start the light to blink. The proper connection circuit diagram and connection video is also attached with this article.

Table of Contents

LED Blinking Circuit Diagram

Blinking led circuit using bc547 Npn transistor circuit diagram

Connection

The BC547 transistor collector pin is connected to the positive pin of your LED light.
The Negative pin of the LED light is connected to the 100UF/63v Capacitor negative pin. These pins are directly connecting to the negative voltage to the 12v battery or power supply.
The positive polarity of the electrolytic capacitor is connected to the emitter pin of the BC 547 transistor. Then the pin is connected to a 1K ohm resistor.
The Base pin of BC 547 is leaving free. Their is no connection to it.
The battery positive voltage is connecting to the one end of the 1k ohm resistor. Now the circuit will start to works, the LED light will get turn on and off at an interval of timing.