Turn on LEDs one after another?


I want to make a circuit where I can connect 5-10 LEDs. When I turn it on first LED should turn on for a moment and then turn off, after that the next LED does the same and so on. So that it has an appearance of 'flowing light' throughout the circuit.

The problem is that I don't know the name of this circuit or anything so I am unable to search anything on the internet regarding it. Any help would be much appreciated.


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dansing lights !!

mscott273 years ago

The name of the circuit MAY be a Larson Scanner, assuming you want something like the knight rider hood light that appears to be "flowing" back and forth. It doesn't actually turn on and off LEDs one at a time, it dims them (or reduces pulses) so that several are actually lit at the same time, to give a sensation of a sliding light motion.

Otherwise, the name is something like a "chaser light system" for the kind of thing you see in christmas lights that do one light at a time on the string, "chasing" down the line. I don't know the name of the circuit that does the same thing but with only every third light lit at a time, to give the directional chase on a string where the lights are separated.

iceng3 years ago
Like Rickharris says use a 555 clock and a 4017 sequential counter.

Any modern micro processor can also perform this task for you.

rickharris3 years ago

will do what you want with a 4017 and a 555 timer.
framistan3 years ago
It is called a "ring" counter.. and I believe the IC number to make it is an LM317. The circuit will need a 555 timer IC also to give it the clock pulses. If you feed it clock pulses very fast... it will look like all the LED's are lit constantly.... or slow down the clock, and the led's can pulse one after another very slowly. I believe the LM317 has ability to flash about 12 LED's in this fashion. I am in the middle of moving, or I could upload the schematic for you. You could also do this with an arduino.
Check out the URL below for a more in-depth guide, but the basic parts you need are a 555 timer and a decade counter.