AEC chase circuit wont work

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
OK, here's what I got from your photographs: This is an x-ray view through the board. I've slightly modified the traces to present it more as a schematic. Black is ground, Red is power, Orange and Salmon are control and Blue is clock. Green are the outputs. Parts count: Capacitors (2), Resistors (1), Potentiometers (1), LED's (10), 555 timer (1), CD401 7 (1).View attachment 189554
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
Thanks Tony, this actually helps a LOT. As I look at yours, its exactly what I believe they send as far as the CB. You mentioned that, it's missing a resistor, and the package only comes with one. Using the photo, you showed me...where would I attach a second resistor and what ohm output.
 

Bernard

Joined Aug 7, 2008
5,788
Looking at CB back side with 0114 at top, on 555 there are 2 pads from pin 8 & + lead; cut a small gap on each side of pads. Drill a small hole to right of pads just below + lead & connect a 1k R
from lower pad to +lead. Add a jumper from pin 8 to + lead. Operate on 6 V.
 

Dodgydave

Joined Jun 22, 2012
10,087
Looking at CB back side with 0114 at top, on 555 there are 2 pads from pin 8 & + lead; cut a small gap on each side of pads. Drill a small hole to right of pads just below + lead & connect a 1k R
from lower pad to +lead. Add a jumper from pin 8 to + lead. Operate on 6 V.

Or just put the 1K in series with the wiper pin...
 

Audioguru again

Joined Oct 21, 2019
3,833
We looked at the pcb you showed and it looks fine except for the missing resistors and capacitors.
The problem is either the poor soldering or overheated defective ICs.

Look at the reviews for the kit. A few of them mentioned that their ICs were destroyed by an overheated soldering iron or wrong kind of solder.
 

SamR

Joined Mar 19, 2019
3,607
In the future, use chip sockets. They not only prevent overheating the IC during soldering but also allow easy later replacement of the IC if failed. Do not solder them in with the chip mounted. Solder, check continuity, insert IC chip and be sure to orient the socket correctly before soldering it in (most are notched same as the chip). Very inexpensive parts.
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
Thanks Sam, if I had thought of it, I would have ordered sockets when I ordered extra IC chips. Live and learn I guess. The good part is that I have one chase circuit working and now used fiber optic strands to make it light up a Drive In Theater Marquee in HO scale. Still working on a second one, since I have 18 holes for lights.
 

Thread Starter

electricgeezer

Joined Oct 22, 2019
37
Your diagram is exactly what I saw...Now let me ask a question. I have two 4017 ICS, and three 555 timers, in addition to, the fact that I have three more complete chaser kits that should be delivered today or tomorrow. That means I have 3 of these circuit boards, 5 4017 ic units, and also 6 555 timers. Based on the pic you sent which is correct, and forgive me for being a newbie, can you give me an idea of how, when I say how, I need to know step by step, the connections to be made, or any easy way to combine two of these chasers in order to run 20 LEDS. I have one chaser that is up and running, and it works well in using fiber optic strands to light a drive in movie theater marquee. The problem I have now, is to get 2 of these running so I can chase 20 LEDS. The marquee has room for 20 leds. Thanks. Any help is appreciated. Since I got one running and I have three kits coming, I am going to try installing all components without soldering the IC and the timer, and try testing it first. Thanks
 

Audioguru again

Joined Oct 21, 2019
3,833
The Texas Instruments datasheet for the CD4017 shows how to cascade additional 4017 ICs with additional AND gates to get 9 outputs on the 1st CD4017 and 8 more outputs on each additional CD4017 and AND gate.
I have a circuit that uses two CD4017 ICs and some diodes make "Mickey Mouse" AND gates for a total of 18 outputs:
 

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Thread Starter

electricgeezer

Joined Oct 22, 2019
37
Thanks to everyone for all the help. It took bit and building 5 chasers but I now have two that are actually working and that should take care of this marquee. Thanks again!! And audioguru, I am using 63/37 solder and a weller adjustable soldering iron set at 25 watts. But I also know how to sweat copper pipe and use plumbers solder. LOL
 
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