I didn't design this particular part of the circuit, the other member of our group did. I don't know how to answer your question but i did think it was funny a pin was not being used on the 555! And i do agree that the way he has the 7490 hooked up is obviously done poorly but i can't fix that right now. I'm just trying to make a simple yet good circuit for starting and stopping the ENTIRE circuit on a whim, and of course a reset switch to reset the ENTIRE circuit.

But if this is a group project then the intent is for you to work on it as a group -- meaning that you do not have this person design that part and everyone else just has to live with it. You need to split up your tasks and NOT go off into a vacuum and then throw everything together at the end. You split up the tasks and decide what the interfaces are between those tasks. Then you design your part. Then you have the people that need to interface with your part of the project sign off on it. It's not uncommon to find things that have been overlooked or that weren't taken sufficiently into account. But saying that your partners did a poor job doesn't cut it -- it was YOUR TEAM that did a poor job.

 

I'm not asking for a solution Dude so please don't accuse me of being lazy, I didn't know where else to put my question as you guys don't have a "College Project help" Section.

I have been taking everything you guys have suggested and i am currently in multisim trying out the ideas, so unless you are willing to be helpful then please just don't waste either of our time!

Not trying to be rude!

Frankly, so far we're not seeing a whole lot of effort on your part. As near as I can tell, what we are seeing is, "Here's a circuit that my teammates have designed. Here's a circuit I found on the internet that does something like what I need to do. I don't know how to take that person's work and apply it to my teammates' work. Please tell me what to do."

Instead of "trying out ideas" in Multisim, how about "designing" a circuit that will do what you want. The first approach is known as "a happening" in which you just "try out ideas" hoping that, at some point, you find something that just "happens" to work. The second is the practice of applying what you know to a problem to arrive at a solution by intent.

 

I just thought i would ask for help because of my difficulty in this subject but i guess im better off not trying to...

This is the right place, but you are expected to show YOUR efforts to solve YOUR problem. We will point things out to you to guide you toward a solution, we will not just hand you one.

 

The first responder gave you a solution that you're trying to implement. Though it is unlikely a solution that someone of your level would have come up with on their own.

I'd hate to see you if you were trying to be rude. You don't know me well enough to call me "Dude". Have a little respect for your elders. Were you taught that as a child???

If you'll answer my questions, I'll help guide you to a solution. But, as this sounds like a homework assignment, I won't give you an answer without you showing what you've attempted and what you understand.

And that's what i have been trying to do, but the sheer aggressiveness has turned me off from wanting anyone's help here. I'll just keep doing this on my own till i get it right, it's a shame. And to notice that you are flinging personal attacks at my upbringing says it all, i don't want your help.

I said Dude out of frustration because only one person has been truly helpful, if you must know i have a learning disability so this entire subject is a monumental challenge to me.

Someone of my Level, Care to Explain? Another insult?

 

This is the right place, but you are expected to show YOUR efforts to solve YOUR problem. We will point things out to you to guide you toward a solution, we will not just hand you one.

I haven't had a chance to do anything but to defend myself from the rudeness of the responders and the sheer aggressiveness i have faced.

 

Just forget it guys

To those who have tried to help me and not turn this into an aggressive witch hunt i thank you, to the rest...

When i pass this class i am throwing away my books for it, you have turned me away from wanting to enjoy this subject!

I was just about to post a new picture of my progress but i guess i'll email it to my group instead!

 

I haven't had a chance to do anything but to defend myself from the rudeness of the responders and the sheer aggressiveness i have faced.

Well, then go away and DO something and then come back and show what you have done and explain how it was supposed to work and the degree to which it did work and in what ways it didn't work.

 

And that's what i have been trying to do, but the sheer aggressiveness has turned me off from wanting anyone's help here. I'll just keep doing this on my own till i get it right, it's a shame. And to notice that you are flinging personal attacks at my upbringing says it all, i don't want your help.

I said Dude out of frustration because only one person has been truly helpful, if you must know i have a learning disability so this entire subject is a monumental challenge to me.

Someone of my Level, Care to Explain? Another insult?

I believe it was you who started it by questioning my ability to read... Someone who attacks someone personally should expect similar treatment. That's what Society expects.

Regardless of your treating me with unwelcomed familiarity, I am willing to help guide you through the process of finding a solution. None of us were born knowing this stuff, but you won't learn if people just give you the answers. It doesn't help you in the long run.

 

Just forget it guys

To those who have tried to help me and not turn this into an aggressive witch hunt i thank you, to the rest...

When i pass this class i am throwing away my books for it, you have turned me away from wanting to enjoy this subject!

I was just about to post a new picture of my progress but i guess i'll email it to my group instead!

If you wear your feelings on your shirtsleeves that is on you. If a hour or two's interaction on the internet with strangers is enough to turn you away from wanting to enjoy a subject, then you didn't have much chance of enjoying it long before you came here.

 

Hello, Jacob Heckman:

Returning to the theme.

You have many opportunities to improve the design that you enclose your original message.
1)- The decoder 7448 requires 7-Segments Display's with Common Cathode (CK) and not Common Anode (CA) like you have in your design.
2)- The current limiting resistors for the segments of the display's have a value too low.
The Displays in Multisim required, to turn on, 5 mAmp.
So, regardless of the voltage drop in the segments, it would be: Vcc / IF = R = 5 / 0.005 = 1000 Ohms.

Now, when you assemble the circuit in reality you will require data sheets of the Display's to use.
In these sheets are the electrical characteristics of the display's; The formula for calculating the limiting resistors would be: (Vcc - VF) / IF = R.

Another things you have not mentioned:
A)- That circuit is going to count what:
Milliseconds??. . . 00-99.
Seconds ??. . . 00-60.
Minutes ??. . . 00-60.
Hours ??. . . 00-12 or 00-24.
Or What. . . ??

B)- What to do You design when it reach the highest number: stop, reset to zero and continue counting ??

Could You, please, provide this information. ??

Now Well: What you must do for the "Start - Stop" function is somehow interrupt pulses exiting the 555 and arriving to the units counter.
Note that the Clk(14 or 1) inputs are very sensitive to negative transitions of pulses applied.
If you use a mechanical device (switch or button) you must add a circuit called de-bounce to eliminate this condition.
That kind of devices produce the effect rebounds.
You can find these types of circuits on Google.com.

To reset to zero use the R0 inputs, 2 and 3 PIN’s and the other inputs, R9 6 and 7 PIN’s connect them to ground.

I hope I have helped you to continue your project.

 

The problem with this suggestion is it is very susceptible to switch bounce. You pretty much always have to assume that whenever you activate a switch that it will actually open and close a few dozen times. You need debounce circuitry.

In general, using gated clocks is a bad idea unless you have a damn good reason (and damn good reasons DO exist).

I agree which is why I mentioned:

The CLK into the flip flop is a single push button with switch debounce.

Since this is school work I kept my suggestion as light as possible not for example providing a gate circuit. I also agree as to gated clocks but for a basic school project to get the idea across I don't see a problem with gating the clock as I suggested. Anyway and overall when it comes to school assignments I believe the idea is to get the students to think. Get them to clearly see their objective and then find a path to that objective.

Ron

 

Hi Ron,

An alternate action switch made with a push button is an elegant solution, but probably unnecessary for what the student needed. A very simple solution exists and the student needed to be guided to it. Simply giving him/her the answer is like feeding a hungry person by giving them food. As the saying goes, "give a man food and you feed him for a day, teach a man to fish and you feed him for a lifetime". My goal was to teach him/her to fish. It takes longer, but will be more rewarding to all in the end.

Even though the OP was taking cheap shots at me, I was still willing to help. But I will only take so much before going on offense.

I hope the instructor takes neatness into consideration. That schematic was drawn horribly with no pride in workmanship. It's been a long while since I was in school, but my instructors also placed an emphasis on neatness and readability. The counter placement leaves a lot to be desired. As for the displays, I'll just say cut and paste.

 

I hope I have helped you to continue your project.

This is homework and the student needs to show their work and be guided to a solution; with or without their cooperation. You gave him the answer and he won't learn as much from the experience. His only contribution to the project was start/stop and reset. He'll get a grade without doing any (technical) work...