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= TIMER =

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I R Haynes

New Member
I am having trouble designing a circuit using a 555 timer and a 4017 chip and making lights go on sequentially. I would like to have a variable resistor also, so then the time between the light changes can vary.

Please help.
 

I R Haynes

New Member
bloody heck how am I spposed to read that, don't you guys have crocodile clips or anything
 

darowland711

New Member
help

if you would email me at [email protected], i may be able to help you with a detailed process... We made this circuit a few weeks into school in my electronics class.... It takes alot of testing, readjusting and when its all done, its a fun thing to show people :)


DARowland711
 

Roff

Well-Known Member
I made a few changes. The "???" means that I don't know why these are here. They do nothing.
The CD4017 wll not drive LEDs very well. I added 2N3904 emitter followers. You can try it without them, but you may not get much light from the LEDs. With the transistors added, you could change the 330 ohm resistor to 180 ohms for added intensity.
I changed your variable resistor to 100k, and added a 1k resistor in series. You should get a better frequency range with these changes. You might want to change the timing capacitor from 100uF to 10uF.
 

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jcaluma

New Member
software

furrycow,
i just want to ask what software did you use to draw the schematic?...

thanks!...
 

jcaluma

New Member
thanks!

but too bad i still have to purchase a copy....
there's a demo for download but i'm not sure if there will be more restrictions and the time limit.....
maybe you have a copy of the installer of this software, maybe you could lend it to me.....hehehehehehe :lol:
 
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