LED Flasher using Transistor

This simple Transistor LED flasher circuit it is a simple practical circuit or project for electronic hubbies especially the beginners in the electronic world. It is interesting for those who are learning building electronic projects or circuits.

There are many different simple Light Emitting Diode (LED) flasher circuits out there which use transistors as this one does. But, what makes this circuit different is; it can efficiently flash brighter LEDs and the flashing rate or frequency is not fixed.  This means that, you can tune to the rate or frequency you wish the LEDs to flash. You can do this by adjusting the level of the variable resistor or pot to the desired level.

The Bipolar Junction Transistors BJTs Q1 and Q2 are wired as oscillator or Astable Multivibrator.

The components you need to build this circuit are as follows:

The values of the components
  • Q1 and Q2 = C1815
  • R1 and R2 = 390 Ohms
  • R3 =2.2 Kilo Ohms
  • R4 = 0.12 Ohms
  • R5 = 100 Ohms
  • VR = 50 Kilo Ohms
  • C1 and C2 = 100uF, 16V
  • LED = 3V White LED

Below is the simple Transistor LED flasher circuit diagram

LED flasher Transistor


Meanwhile, you can use more than one LED in parallel with protection resistor each for this circuit. The LEDs should be of the same characteristics: colour, voltage, internal resistance, size, and manufacturer.

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