2 LED Flasher Circuit

Introduction

One can find numerous 2 LED flasher circuit designs using transistors alone or IC based on the internet. All of them use LEDs from single numbers to multi numbers for flashing purposes. Also, they just blink or give a psychedelic effect. However, these flasher circuits are easier to build even by newbies as electronics projects. These circuits are the favorite ones among electronics enthusiasts and hobbyists. Students invariably attempt to build these 2 LED flasher circuits for their projects. 

As the working principles of these circuits are somewhat similar based on the design configuration, it is easier to understand the circuit setup. Since most of the circuits operate with dry cells, the construction setups become easier. Also, low component count and low-cost ICs and transistors are invariably used in these types of circuit designs. Most of the circuits drive the flasher LEDs directly or with a driver circuit. If the number of LEDs counts is more, relay-type outputs are employed.    

2 LED flasher circuit schematic

In this post famous timer, IC 555 based 2 LED flasher circuit is described for ease of assembling. The circuit is very simple and can be wired on any general-purpose PCB. DIL 8 pin IC is used here and the output is directly coupled to LEDs for flashing purposes. AS the output pin 3 goes high and low alternatively depending upon the duty cycle determined by RC network namely R2C1 combination. Both the LEDs 1 and 2 Red in color flash alternately as pin 3 goes to battery potential or zero.  

The flashing rate of LEDs can be changed or varied by simply changing the value of electrolytic capacitor C1. Alternatively one can replace the resistor R2 with a 1M ohm preset and it can be adjusted to the required flashing rate of LEDs. 

R3 and R4 are the limiting resistors for the LEDs since a 6V DC power supply is used here. In this circuit, only 2 LEDs are connected. The number of LEDs can be increased by increasing the supply voltage as well as reducing the limiting resistor values, such that the circuit is set for proper operation design to that voltage. For 6V operation, 2 more LEDs may be added.  

Parts List

IC 555 -1

LED1, LED2 = Red LEDs

R1, R3, R4 = 1K ohm Resistors

R2 = 270K ohm Resistor

C1 =4.7 MFD electrolytic capacitor

C2 =10KPF capacitor

VCC = 6V Battery

PCB = Author's PCB design 

Assembling 

As discussed earlier this flasher circuit can be assembled on a general-purpose PCB. However, for ease of assembling and simplicity and compactness, a readymade PCB design is given here for your use. Especially novice and beginners in electronics prefer this ready-made PCB design for their assembling work. Hence full PCB design along with component placement picture and the copper track to be etched are given here. 

PCB design full view

PCB design - copper track

PCB component layout

PCB with copper pour

To sum up

A simple easy to build 2 LED flasher circuit using timer IC 555 is fully described here with the aim of electronics enthusiasts and students to find it beneficial to build a successful project of their own. Please give your esteemed comments over this post for their values and utility. Please share these post details with your friends and relatives.