AEC chase circuit wont work

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
I am new to the forum today....so let me see what I can do....also since I bought three of these...I will build another and see if that one works
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
Here is the circuit I am working with. So far I have built two and neither works as expected. Going to pick up a fresh battery and see if that helps at all.
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
Will also post pics with my cell phone shortly, so you can see the finished product. Thanks for the help. I am trying to get this working so I can use it with fiber optic threads on an HO scale drive in marquee sign.
 

Dodgydave

Joined Jun 22, 2012
8,359
Will also post pics with my cell phone shortly, so you can see the finished product. Thanks for the help. I am trying to get this working so I can use it with fiber optic threads on an HO scale drive in marquee sign.
That's a pcb print not a circuit diagram,, i'm guessing it's a 555 and Cd4017 chip...
 

JohnInTX

Joined Jun 26, 2012
3,796
Welcome to AAC!
@Dodgydave is correct about the 555/4017 according to the spec sheet available here:

No schematic that I can find but a clear photo of the completed board top AND bottom will help a lot. Maybe that fresh battery will fix it.

Good luck!
 

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Reloadron

Joined Jan 15, 2015
4,498
My only thoughts are polarity. Make sure the chips are correctly installed observing the notch on the chips for correct orientation. Next make sure all of the LEDs are installed correct polarity and finally C1 is a polarized electrolytic capacitor and must be installed correctly. Everything should look like this when assembled. There really is not much to the circuit and with all parts correctly placed it should work just fine.

Ron
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
Here are the pics. I have followed directions exactly as far as I can tell and it still doesn't work. Polarity on capacitor is as required. all leds are cathode anode correct. The notches are on the left according to their directions although my pic is upside down. I have one more that I can build, but I have to figure out why its not working.
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
Welcome to AAC!
@Dodgydave is correct about the 555/4017 according to the spec sheet available here:

No schematic that I can find but a clear photo of the completed board top AND bottom will help a lot. Maybe that fresh battery will fix it.

Good luck! Thanks dodgy, I put in some pics. and completed two of them. neither works.
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
My only thoughts are polarity. Make sure the chips are correctly installed observing the notch on the chips for correct orientation. Next make sure all of the LEDs are installed correct polarity and finally C1 is a polarized electrolytic capacitor and must be installed correctly. Everything should look like this when assembled. There really is not much to the circuit and with all parts correctly placed it should work just fine.

Ron
Thanks, check the pics and you can see they are correct as far as I can tell. the 555 has a dot on the left and no notch at all. is it possible its reversed?
 

Dodgydave

Joined Jun 22, 2012
8,359
If you have a Dvm you can check the 555 timer for clocking pulses on pin 3, then check pin 15 on the 4017 for clocking, check the supply on both the chips,...
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
This is the best pic of what I have. If you can look closely, I think everything is done correctly. I don't have a digital volt meter, all I have is a regular multimeter. Thanks for the help.
 

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