please help simple circuit design needed

Hi there, I need some help designing a simple ciruit.

when a power source up to 12v is applied to the ciruit, the voltage is sequentially switched between 3 globes.. from one to the next and then back to the first. It would be nice If it wqas expandable for N number of globes so that the light seems to jump from one bulb to the other.

I guess this is sort of a light chaser type circuit or some such other thing.

any help appreciated.

cheers, Mitch.

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Look up the "astable multivibrator" - then add another section.


Reply to
Frithiof Andreas Jensen


You don't mention much about the power requirements but I think the easiest way to do that would be with a PIC or other micro. The following link...

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shows an LED chaser based on a PIC and has some source code to go with it that you could probably manipulate. You would need a regulator for the PIC and would have to drive the globe's via transistors to drive them at the full 12V. Probably not the cheapest option but it would allow room for expansion and you would be able to adjust the timing of everything via code changes rather than component changes.



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In message , dated Fri, 4 Aug 2006, Frithiof Andreas Jensen writes

You aren't supposed to tell newbies about the tri-vibrator. We need to keep some arcane lore! (;-)

OOO - Own Opinions Only. Try and
2006 is YMMVI- Your mileage may vary immensely.
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Reply to
John Woodgate

May i ask what you are going to do with this circuit??

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first you need a clock generator-- a 74hc14 , a resistor and a capacitor will do the job.

Then you need a stepper= a 4017 is exactly what you need. It counts up to 10 raising a differnt line each count. You can feed back any of the output lines to the reset pin so it starts over at any desired count.

You can hang small LED's directly off the 4017 pins. If you want to drive heftier lights, you'll need some fets or transistors as current amplifiers.

How does this sound?

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You am want.

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Wiv a datasheet

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What you am have read lots.

Then you am need to werk out how to interface to glob lits wiv transistory stuff.

Plus you am need clock thing frum..

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Wiv a data shit

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Which you am have read lotz.

Also am all RoHS complaint so plants dont die from led posning. Plus work off lotz ov volts. No brane requid.

Do not listen to peeps who say PIC coz then you am hav progrimm in Ooobject C++ and watchdog timmer plus oscillator never werk anyway. Also need TPIP stack for phone home.... Pluz data shit am 14 million pages long. Shite.


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You didn't say how much current the globes take.

Since no-one else suggested it, I'll suggest a 555 for each globe.

The first globe in the chain needs a different circuit from the others but forunately, the difference is minor enough that you could make all of them have the same circuit and make the change by how things plug together. Each unit would have two three pin connectors on it:

Input side +12V Output side O----------+-----------+--------------+------------+---O ! ! ! ! \\ ! Olamp, ! / ! !-- \\ \\ ! --! N MOSFET / ! ---------- ! !--GND \\ -----+-+-----!THR ! ! ! ! ! ! Q!---+-+--------!!------+---O ! / ! ! ! ! \\ ! ! ! ! / ! ! ! ! ! ! ! ! O---------+-------!TR ! ! ! ---------- ! ! ! +---!!---\\/\\---- ! --- --- ! GND


With a little more stuff, you can make it so that as you add stages, the first stage slows down so that the last one always blinks before the first one starts the string off again.

--   forging knowledge
Reply to
Ken Smith

You could get the below LED chaser kit and connect the outputs to the LEDs to the below relay board to do the power switching for the lights.

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Reply to
Si Ballenger

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