I have been working on a four bit by four bit multiplier/divider circuit (it's actually three bit point 1 bit by three bit point 1 bit multiplier/divider circuit). I have used ICs from the 74LS series, namely: 7400, 7408, 7485, 7486, 74283 and 74147. The multiplier part works just fine, but the divider part kept on flickering. For example if I divide 0000 by 0001 it sometimes gives 0088 and sometimes 0041. I felt that there was something wrong with the decimal part of the division perhaps? But I couldn't figure it out. I used two 2A, 5V DC connected in parallel to power the circuit. How do I troubleshoot this? I've attached the actual connection in the pictures. I would want to attach the logisim file as well but .circ files were not allowed. I'd send it to anyone who's interested. Thanks

 

Yeah, sure, someone is going to look at those photos and tell you what is wrong.

 

Yeah, sure, someone is going to look at those photos and tell you what is wrong.

It's just for context, see if the error is due to the physical arrangement of the components

 

That is not usually a problem with logic circuits unless you are pushing the limit in frequency.

 

It's just for context, see if the error is due to the physical arrangement of the components

There are these magic things called decoupling and bypass capacitors you use with digital logic.

https://www.renesas.com/us/en/document/apn/an1325-choosing-and-using-bypass-capacitors

 

That is not usually a problem with logic circuits unless you are pushing the limit in frequency.

I'm new

There are these magic things called decoupling and bypass capacitors you use with digital logic.

https://www.renesas.com/us/en/document/apn/an1325-choosing-and-using-bypass-capacitors

Thanks!

 

Yeah, sure, someone is going to look at those photos and tell you what is wrong.

Yes, they can.

 

I'm impressed with the neat layout of that BB circuit.

 

I'm impressed with the neat layout of that BB circuit.

Looks like something a programmer would build. Likely full and proper logic design and layout but missing some of the basic needs of actual working electronics.

 

Yes, they can.

Oh? The problem is fixed? I must have missed that.

 

Oh? The problem is fixed? I must have missed that.

Yes, you did miss that with your original answer.

THE problem? Who knows if it was THE problem.

So, well, yes, at least one problem with be fixed from just looking at his pictures. I've seen this many times before with flaky circuits that were connected perfectly and logically but were intermittent in actual operation on a perf or breadboard.

It's a classic beginner circuit builder error.

 

Some IC's are not reliable in breadboards because the legs are not long and not as wide as other components that have previously "stretched" the contacts. Try using DIP Sockets, in the Breadboard, with round legs. eg Digikey dip socket

 

Yes, you did miss that with your original answer.

THE problem? Who knows if it was THE problem.

So, well, yes, at least one problem with be fixed from just looking at his pictures. I've seen this many times before with flaky circuits that were connected perfectly and logically but were intermittent in actual operation on a perf or breadboard.

It's a classic beginner circuit builder error.

Some IC's are not reliable in breadboards because the legs are not long and not as wide as other components that have previously "stretched" the contacts. Try using DIP Sockets, in the Breadboard, with round legs. eg Digikey dip socket

Thank you, I will do that.

 

Yes, you did miss that with your original answer.

THE problem? Who knows if it was THE problem.

So, well, yes, at least one problem with be fixed from just looking at his pictures. I've seen this many times before with flaky circuits that were connected perfectly and logically but were intermittent in actual operation on a perf or breadboard.

It's a classic beginner circuit builder error.

Yes you're right, I think that this is just because I'm new to the project. But I'll look into it, see if the mistake really was just the wiring, but thanks guys, the forum was really helpful

 

Yes, you did miss that with your original answer.

THE problem? Who knows if it was THE problem.

So, well, yes, at least one problem with be fixed from just looking at his pictures. I've seen this many times before with flaky circuits that were connected perfectly and logically but were intermittent in actual operation on a perf or breadboard.

It's a classic beginner circuit builder error.

Yes, I saw your answer. I just doubt that it is the cause of the problem.

 

I'm impressed with the neat layout of that BB circuit.

I am also very impressed that someone has that much patience to build -very neatly- something as large and complex on a protoboard.

 

Yes, I saw your answer. I just doubt that it is the cause of the problem.

I'm not a mind or remote reader over the internet but I can tell a lot of effort and planning (unlike a lot of help wanted requests we see here) has been put into making this so I gave it a look and noticed something I've seen many times before that's caused problems in the past.

I think your original answer was not useful at all for any solutions to potential problems.