MayukhSobo

modified 10 years ago

3 led chaser

410

04:39:31

The LEDs in this circuit produce a chasing pattern similar the running LEDs display in video shops. 
In fact the effect is called: "Running Hole." All transistors will try to come on at the same time when the power is applied, but some will be faster due to their internal characteristics and some will get a different turn-on current due to the exact value of the 22u electrolytics. The last 923u will delay the voltage-rise to the base of the first transistor and make the circuit start reliably. It is very difficult to see where the hole starts and that's why you should build the circuit and investigate it yourself. The circuit can be extended to any number of odd numbers of transistors.

published 10 years ago

Sine_eyed

10 years ago

These circuits actually are really neat for a real life build- but this example is needlessly over-complicated. Where is somebody gonna find a 923uF capacitor anyway?..

MayukhSobo

10 years ago

Well you can use 22u. Read the article properly. It is mentioned that the capacitor is used for delay. So it 's a common sense that if you use a 22u capacitor, that is only going to alter the the delay period not the operation..

Sine_eyed

10 years ago

I'm curious, did someone teach you this? Or was it learned from a book it maybe something you read on the net? Or is this your own account of operation as you understand it?..

MayukhSobo

10 years ago

I did it

MayukhSobo

10 years ago

I did it when i was in high school and my teacher explained this. I later designed the same with 32 leds on PCB.

Sine_eyed

10 years ago

Ok. Well, I don't know what you're teacher said about it so I can't say he was wrong. And I don't want to sit here and point my finger and tell you you're wrong either. But it has always bothered me when someone makes statemens that they believe to be true, but simply aren't. I don't get mad or irritated about it but, I feel compelled to enlighten them. I have a lot to learn myself about electronics, but I can tell you a few things about this circuit, if you'd ike..

wyoelk

10 years ago

There have been a GIGAMILLIONs of these blinkies posted overtime cuz there are so cool and we all love them. Not to be mean, but most of the component values listed could never be found. For a better explanation click on the examples section and scroll down to the Astable Multivibrator it helps explain.

Sine_eyed

10 years ago

Ouch! Hey, that was my toe!.. >X^°

wyoelk

10 years ago

Dear Sine_eyed, Can you pull my foot out of my mouth or at least off my ^*&() keyboard. Sorry I meant his explanation. Just wish folks would look at the Examples section to learn more before posting blinkies or a lot of stuff, but NOT copy it all to the public section. Or at least search for yours cuz you posted one a bit ago it seems that explained the timing of the cap and resistor. Sorry again, you are awesome.

wyoelk

10 years ago

@Sine_eyed , I actually copied from another comment I posted called "dual led flasher" that would not work. Can't say sorry enough for being stupid and unintentionally stepping on toes. Please ask Igor for a bandaid

Sine_eyed

10 years ago

Lol- easy now @wyoelk. No need to get all blubbery like ya just broke a nail! But I do appreciate the display of respect and recognition, as well as keeping the humor rolling. A bit of sass with a touch of honor- that's a good style. I've noticed you becoming more assertive in comment threads and in offering help to others- I think that's great. One thing though- be sure that what you offer as fact in your advice or explanation is indeed a fact. I've caught an error or two on your part, albeit minor. Other than that, I can tell you're a good guy over all, and I'm glad to have you onboard...

MayukhSobo

10 years ago

Please give your suggestion.. You are most welcome. I am a computer programmer or os developer guy.. I am actually designing an electronic emulator like Eagle or Geda on linux and this is just my test circuit to check if my dll files works properly.

MayukhSobo

10 years ago

The reason because the values of these components are odd because this are the values my project partner use while debugging my code and i just copied it... When i made it on PCB, made a better circuit...

Sine_eyed

10 years ago

Ok- when you made it on pcb, that's probably when you used the 22uF capacitors- am I right? These little circuits, whether built in simulation or in real life will operate much happier with more common (and more sensible) values..

MayukhSobo

10 years ago

That's true

Sine_eyed

10 years ago

Ok, I'm getting a clearer picture. So your friend, helping you debug you're new code, purposefully gave crazy values to the capacitors in an attempt to at least push your program to it's limits, if not crash it altogether- correct?..

MayukhSobo

10 years ago

Yes...as a developer i must cover all the possibilities of my software. At least we don't behave like Microsoft who intentionally release softwares with bugs and glitches and fix those in future to emulate their customer support.

MayukhSobo

10 years ago

But i shouldn't have out a schematic without my eye on it once. Next time, i will be more weary

Sine_eyed

10 years ago

Sounds fair enough- ok well, keep at it and have fun- c ya around..

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