| Author |
 Topic  |
|
|
Justinkais
New Member
2 Posts |
 Posted - Dec 22 2009 : 01:15:18 AM
|
I built this circuit in Multisim just to see if my schooling has done any good. Maybe it hasn't. I cannot seem to get it to count up. The switches are NC, NO, and NO respectively. The space bare is supposed to start the count, the plus sign is supposed to stop the count and the minus sign is supposed to reset the counter (by opening and closing the respective switches). please look at the design and let me know what I am doing wrong. I am sure it is going to be something realy simple that I will kick myself for not seeing. Thanks.
Download Attachment:  7 Segment Counter.JPG
203.65 KB
 |
|
|
eliza
New Member
1 Posts |
Posted - Jan 08 2010 : 06:42:46 AM
|
| Great post........ |
 |
|
|
wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Jan 08 2010 : 08:47:24 AM
|
I am not that knowledgeable on the discrete ICs that you are using because I moved onto micro controllers many years ago. I wouldn't have done it the way you have, instead I would have used a single micro controller. To solve your problem you must use the "elimination technique". What I mean is (in the case of your circuit) start at top of the schematic and check if the 7 segments actually are displaying the correct numbers - they don't in your case. Check the inputs going into the 7 seg decoders, if they don't appear correct then the problem could be with the counters, and so on...
A similar example.
If you go to bed and turn on the bedside lamp to help you read a book and then notice that the lamp didn't turn on, you don't strain your eyes to see if the filament is broken first. Instead you check if the lamp is plugged in first!
Of course I assume that you have the power connected. My point is the "elimination method" makes problem solving a lot quicker and you avoid countless hours of frustration. It will help you out in the future if yo ever work yourself up to really complicated projects.
Next time you ask for help, why don't you tell us what does, and doesn't work already in your design and then the solution can be found a lot quicker. It's no good us telling you where you went wrong, especially in a circuit of this small size. You won't learn as much if we told you that wire doesn't go here it actually goes over there. You want to learn right?
->Common sense<-
Is it not? |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
|
|
|
Justinkais
New Member
2 Posts |
Posted - Jan 30 2010 : 7:29:18 PM
|
Thank you for the information. I have built the circuit in multisim. I have tried to take readings with the test equipment provided in the program and I am not able to find the problem. The readings seem to all be acurate. I appreciate your comments, but I would not have posted this if I was able to find the problem. I would realy be greatful if some one could take a look at it and see if they can figure out what I did wrong, or point me in the right direction. There is no hurry It is just for my own gratification if I can get it to work.
Thanks.
quote:
Originally posted by wasssup1990
I am not that knowledgeable on the discrete ICs that you are using because I moved onto micro controllers many years ago. I wouldn't have done it the way you have, instead I would have used a single micro controller. To solve your problem you must use the "elimination technique". What I mean is (in the case of your circuit) start at top of the schematic and check if the 7 segments actually are displaying the correct numbers - they don't in your case. Check the inputs going into the 7 seg decoders, if they don't appear correct then the problem could be with the counters, and so on...
A similar example.
If you go to bed and turn on the bedside lamp to help you read a book and then notice that the lamp didn't turn on, you don't strain your eyes to see if the filament is broken first. Instead you check if the lamp is plugged in first!
Of course I assume that you have the power connected. My point is the "elimination method" makes problem solving a lot quicker and you avoid countless hours of frustration. It will help you out in the future if yo ever work yourself up to really complicated projects.
Next time you ask for help, why don't you tell us what does, and doesn't work already in your design and then the solution can be found a lot quicker. It's no good us telling you where you went wrong, especially in a circuit of this small size. You won't learn as much if we told you that wire doesn't go here it actually goes over there. You want to learn right?
->Common sense<-
Is it not?
|
|
|
|
wasssup1990
Nobel Prize Winner
A Land Down Under
2261 Posts |
Posted - Jan 30 2010 : 9:32:58 PM
|
| I'm pretty busy but I'll take some time out to fix your design. Just send me your multisim file as an attatchment and I'll scan over it and find your problem. U1 & U2 don't seem to be connected to a power supply. Are you sure they are being fed the right supply voltages? I think multisim hides those pins to make it less cluttered. Also U1 & U2 might be connected to a seperate ground reference. |
When one person suffers from a delusion it is called insanity.
When many people suffer from a delusion it is called religion. |
|
|
| |
Topic |
|
7 Segment Counter Uncooperative.
