Hey guys, so we were asked to follow this circuit design:
https://app.box.com/s/nuqszc1dts3sm6l9hoi2noud6704eicv

Now I've followed the given paper to me as best as I could but I still have 2 problems with
my design right now:
>When it's powered on, the ones digit counter has to start from zero instead of one
>The circuit has to reset after it reaches 60.

Check this video for reference and feel free to point out any more problems~

Some pictures of what I made:

Any help would be greatly appreciated!

Also, if any of you have any more questions, I'll do my best to give a reply as soon as possible.

Thanks!

 

Nice. Your prototyping work on breadboard looks very neat. Lot of wires you have there. Easy to get a couple wrong. So you have 7 chips for a circuit that counts to 60 then resets? Did you design the circuit? I mean can we eliminate the schematic from errors and say that you basically have a couple of wires wrong on the proto? I notice that the schematic in that link that you posted has no pin numbers.

 

Need pin numbers on chips, looks like ,the reset pins are tied to ground....

 

Nice. Your prototyping work on breadboard looks very neat. Lot of wires you have there. Easy to get a couple wrong. So you have 7 chips for a circuit that counts to 60 then resets? Did you design the circuit? I mean can we eliminate the schematic from errors and say that you basically have a couple of wires wrong on the proto? I notice that the schematic in that link that you posted has no pin numbers.

Well all ICs used in my circuit have their notches at the left.

I'll try editing the PDF so it'll show the pin numbers for every IC.

 

Have you thought about using IC CD4026? 7 chips for an circuit that counts from 0 to 60 is just so 70's Better still use an microcontroller to do the job, and providing it is an flash memory type, this will bring you into this century. If you use the PIC 16F628 then this will equate to like 2001.

 

Have you thought about using IC CD4026? 7 chips for an circuit that counts from 0 to 60 is just so 70's Better still use an microcontroller to do the job, and providing it is an flash memory type, this will bring you into this century. If you use the PIC 16F628 then this will equate to like 2001.

We aren't allowed to do so.. I need to just use what's on the diagram. It's frustrating, I know.

 

We aren't allowed to do so.. I need to just use what's on the diagram. It's frustrating, I know.

Well your man to help you out is going to be Bertus (our administrator) -- his profile states that he loves old TTL logic chips. I'll go about as far back as an CD4026 (modern CMOS device)

 

Well your man to help you out is going to be Bertus (our administrator) -- his profile states that he loves old TTL logic chips. I'll go about as far back as an CD4026 (modern CMOS device)

Thanks for the suggestion.

@bertus

 

It may be that your are getting an extra pulse at the very start as you insert the wires into the board. It is extremely difficult to do that cleanly (i.e., not get extra pulses). Generically, it is called switch bounce. Here's a nicely written discussion of it: http://www.ganssle.com/debouncing.pdf

For a start, I would put a genuine switch in the circuit. With that, you may see it start on zero some times start at one other times. If that happens, then it is almost certainly switch bounce, but even if that doesn't happen, you might want to try a simple debounced switch, i.e., somethng with just a resistor and capacitor.

John

 

It may be that your are getting an extra pulse at the very start as you insert the wires into the board. It is extremely difficult to do that cleanly (i.e., not get extra pulses). Generically, it is called switch bounce. Here's a nicely written discussion of it: http://www.ganssle.com/debouncing.pdf

For a start, I would put a genuine switch in the circuit. With that, you may see it start on zero some times start at one other times. If that happens, then it is almost certainly switch bounce, but even if that doesn't happen, you might want to try a simple debounced switch, i.e., somethng with just a resistor and capacitor.

John

Ok I'll try.

Link for PDF with pin configurations:
https://app.box.com/s/oibou1rsrfmqfuuxhpuoc4zsw1jzpvm1

 

Hello,

If you want to let the counter start at 01 , you can use the load function of the 192:



You can use the data pins ( 9,10,1,15 ) to set the wanted value:



For reset to 01 again, use the load function again.

Bertus

 

Hello,

If you want to let the counter start at 01 , you can use the load function of the 192:

View attachment 83032

You can use the data pins ( 9,10,1,15 ) to set the wanted value:

View attachment 83033

For reset to 01 again, use the load function again.

Bertus

Thanks, however I need it to start at 00 and have it reset back to that after it reaches 60.

 

as i said earlier, your reset pin on the 10S counter and units are tied to ground and wont work properly, they need to go to the and output of the 7400.

 

Hello,

If you want to start at 00, you can use a startup reset circuit.
This can be combined with the reset at 60.

Bertus

 

as i said earlier, your reset pin on the 10S counter and units are tied to ground and wont work properly, they need to go to the and output of the 7400.

I'm sorry but I can't really reconfigure it without a visual reference or very precise instructions(like pin x to pin y)... Is it possible for you to at least edit a picture on paint to show what you're trying to tell me? (But you don't have to if you don't want to...)

I have very limited knowledge as to this circuit to be completely honest.
I'm still trying to grasp the basics of every IC..

Hello,

If you want to start at 00, you can use a startup reset circuit.
This can be combined with the reset at 60.

Bertus

Can you tell me in a step by step basis? Only if you have the time...

 

Hello,

You could try the following circuit:



The capacitor will give a delay to create a reset-pulse for power-on.

Bertus

 

pin 14 on the 74162 chips are tied to gnd, they need to go to the output of one of the And gates from the 7400 chip, so when the Tens counter gets to 6, it resets the 74162 chips back to zero,.

 

Hello,

You could try the following circuit:

View attachment 83036

The capacitor will give a delay to create a reset-pulse for power-on.

Bertus

I really appreciate your help..
However, I don't have a 74132 IC at the moment. Is it really not possible to fix this without adding additional ICs?
Also, that circuit is supposed to fix both of my problems or just one?

pin 14 on the 74162 chips are tied to gnd, they need to go to the output of one of the And gates from the 7400 chip, so when the Tens counter gets to 6, it resets the 74162 chips back to zero,.

Understood, I'll give this a go.

 

Hello,

The 74132 is like an 7400 with build in schmitt triggers.
This will provide a fixed switching point.

Can you give a real schematic in stead of the connection diagram?
I have no time to find out how the schematic looks like from the connection diagram.
Schematics are the language for electronics.

You can use the "Upload a File" button, to upload the schematic.

Bertus

 

pin 14 on the 74162 chips are tied to gnd, they need to go to the output of one of the And gates from the 7400 chip, so when the Tens counter gets to 6, it resets the 74162 chips back to zero,.

Okay so the problem now is that when it reaches 59, the tens digit goes directly to 0 instead of 6, and then when the ones digit resets to zero, the tens digit becomes 1..

Hello,

The 74132 is like an 7400 with build in schmitt triggers.
This will provide a fixed switching point.

Can you give a real schematic in stead of the connection diagram?
I have no time to find out how the schematic looks like from the connection diagram.
Schematics are the language for electronics.

You can use the "Upload a File" button, to upload the schematic.

Bertus

I don't have a copy of it, but I'll try to make one..