Dual LED Flasher by 2N2907

This circuit calls more Free Running Multivibrator work resemble Flip Flop. Which encourage itself repeatedly. The Q1 and Q2 be Transistor PNP be usable general (2N3906,2N2907, etc.) The R1 and R2 limit current that flow through LED the bilateral. If enhance the value C1 and C2 the rate something Flasher slow down. Request friends have fun LED Flasher , this please sir.


This circuit is working well on breadboard. below..

I desined the PCB layout for You easy to builds this circuit as Figure below.

The components layout of Dual LED Flasher by BC556

And An actual-size of Single-sided Copper PCB layout.

Simple flashing light by transistor BC548

This circuit basically the base of LED Flashing circuit, the character generally be have Transistor stay 2 work alternate be be like the automatic switch that alternate work. if wasp output at C pin of Q1 or Q2 as a result get Frequency signal.
Operation of the circuit assume the Q1 run before LED1 will be lit, so the current flows through LED1, R1 through pin C out of leg E of Q1 at the same current will flow through LED2, R4 and the charge on C2 left delete right B positive stand out through the leg C of Q1, but the current lines are not enough to make light LED2 when C2 charges to the voltage BE value of less than 0.7V, resulting in downtime LED1 off Q1 and Q2. LED2 C1 bright start running positive charge left and right negative Q1 Q2 stopped off LED2 will start running again. The work is part of the circuit so indefinitely.
Simple flashing light by transistor BC548

The bicycle tail light flashing for my son.
The principle of this circuit, I built the bicycle tail light flashing for my son.At first he was very appreciate. But he embarrassed every time, friends to tease. Because it’s funny. I used a hot food box, because prevent water heat resistant and very economical. And more importantly, it increases the safety of the children. When riding a bicycle in the evening.



My son want to builds simple LED flasher. I choose this circuit because easy we assemble all parts on the bread board and use 3V AA battery, use BC549 and not need Resistor limit current to LEDs as Figure below.


3V dual LED flasher circuit diagram

and He test it as video below

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  1. Raghuvarma November 1, 2016

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