I think you need to start at the beginning and go on the 'Electronics 101' course. You're in it up to your neck and are clutching at straws.
I remember when I went to college we learnt about the theory and loads of seemingly boring mathematical stuff first. The circuit you are trying to build probably wouldn't have been until year 2.

Also I hate breadboards. Buy some veroboard and solder the components in.
Good luck.

 

Thanks to everyone for their interest in helping me. I've got it working properly now. I'll attempt to upload a video.

 

Hi David,

I suppose the errors are only in the values of some resistors.

Why not try this identical circuit with different resistor values?

http://www.instructables.com/id/Turn-signal-using-555-timer/

Good luck!

Regards,

Nandu.

Special thanks to you, sir. I used the circuit diagram in that page and, even though they are almost identical circuits, I guess a circuit diagram that is organized differently helped me solve my problem.

 

They are identical, except for R3, and the lower value makes more sense to me.

But I doubt that makes all the difference. Maybe you just had a loose connection, or a backwards diode?

 

Even though that class is now over, I'd still like to learn what some of you were (seemingly condescendently) suggesting I do: build it and test it step by step rather than blindly building the entire thing and then trying to figure out what's wrong.

I don't know entirely what the purpose of transistors and diodes is. Also, I don't know why all the different pins on the ne555 timer are shorted the way they are or why everything else is wired the way it is... Please go easy on me if you're willing to help.

Maybe someone can direct me to a useful resource for learning how to wire curcuits. Like I said, this is a relatively advanced "circuits" class, but I have never had experience with electronics before or building a circuit. I guess it's like trying to learn calculus without knowing algebra or trigonometry. I feel absolutely terrible because I will very likely end up failing this class...

 

Here is a short recording of the final working project, for those interested. Although I'm sure many of you already knew what this would look like. FULL HD!

 

Someone asked me what I thought the problem was and I thought I'd post what I replied to him/her here...

I'm still probably going to fail the class.

But, I actually found a few things that were wrong. This is where the circuit diagrams from one website to the other differed. The "inaccurate" diagram showed two 10k resitors connected to the left-most transistor while the "accurate" diagram showed only one resistor per transistor.

Another thing is that about 3 different pins required to be shorted either through a resistor or directly with a cable. I already had most of these done, but I believe I took care of another.

One last thing was that the higher resistance resistors (47k ohm) that were connected to 1) pin 8 and pin 7 and 2) pin7 and pin 6 were somehow placed incorrectly. I can't recall exactly now, but I'm almost certain that the resistors were shifted one pin down, if that makes sense.

Once I finally got the circuit working, there was about a 15 second period between alternating states (Low to high and high to low)! I used the formula, t=0.7(Ra+Rb)*C to determine that I needed about a 5k ohm resistor to achieve about a 2 second period. So I replaced two 47 k ohm resistors with two 4.7 k ohm resitors and voila, my circuit worked flawlessly.

Don't worry. I'm one of the few students whose main goal is to learn the material rather than getting a good grade. I enjoy learning and always try to learn from past mistakes.

Thanks for following up! (I typed this on mobile, so I might have a few grammar/spelling mistakes)

 

Congrats on getting it working, and learning lots along the way!

I've been following this whole thread, but didn't chime in sooner cause I'm way too new at this to have had anything helpful to add. Hopefully I'll eventually understand enough of this to really contribute to these forums, but for now I'm just glad they're here. Good luck on future projects!

 

Even though that class is now over, I'd still like to learn what some of you were (seemingly condescendently) suggesting I do: build it and test it step by step rather than blindly building the entire thing and then trying to figure out what's wrong.

I don't know entirely what the purpose of transistors and diodes is. Also, I don't know why all the different pins on the ne555 timer are shorted the way they are or why everything else is wired the way it is... Please go easy on me if you're willing to help.

Maybe someone can direct me to a useful resource for learning how to wire curcuits. Like I said, this is a relatively advanced "circuits" class, but I have never had experience with electronics before or building a circuit. I guess it's like trying to learn calculus without knowing algebra or trigonometry. I feel absolutely terrible because I will very likely end up failing this class...

There was nothing condescending about suggesting that you build up the circuit bit by bit, testing as you go. Quite the opposite, this is how most real engineering is done. As a poor analogy, consider designing and building an entire car from scratch. Would you really want to build the entire car before seeing if anything worked? And what would you do if you turned the key and nothing happened? Where would you even start the troubleshooting process? Was it the key switch? The wiring from the switch to the engine? The starter? The ignition circuit? Is the engine bound up? Or any of a thousand other things? But if you had built the engine and tested it, then you could at least start off by assuming that the engine worked. The same for all the other subsystems. You would focus on the interfaces between the systems that were connected together in the most recent iteration. And you would have used this process from the start. So you would have built and tested one brake assembly as well as the master cylinder before integrating them into the brake system and testing that. You would have built up the engine in many stages, doing appropriate tests as you go.

It is even more the case with circuits. You design, build, and test things in small stages so that when you connect them together you can focus on the interfaces.

 

There was nothing condescending about suggesting that you build up the circuit bit by bit, testing as you go. Quite the opposite, this is how most real engineering is done. As a poor analogy, consider designing and building an entire car from scratch. Would you really want to build the entire car before seeing if anything worked? And what would you do if you turned the key and nothing happened? Where would you even start the troubleshooting process? Was it the key switch? The wiring from the switch to the engine? The starter? The ignition circuit? Is the engine bound up? Or any of a thousand other things? But if you had built the engine and tested it, then you could at least start off by assuming that the engine worked. The same for all the other subsystems. You would focus on the interfaces between the systems that were connected together in the most recent iteration. And you would have used this process from the start. So you would have built and tested one brake assembly as well as the master cylinder before integrating them into the brake system and testing that. You would have built up the engine in many stages, doing appropriate tests as you go.

It is even more the case with circuits. You design, build, and test things in small stages so that when you connect them together you can focus on the interfaces.

Yes, I understand completely and it makes perfect sense. However, like I said in a previous post, I don't really know what certain components of the circuit do and why they are shorted the way they are. The most confusing part for me is understanding why the pins around the ne555 timer are connected the way they are and also why the trnsistors are there. If you could help me out, that would be great.

Hi David,

Good you made it. But your job would have been easier had you just taken the resistor values from the other diagram I referred to you (4.7K instead of 47K for R1 & R2 and 2K instead of 47K for R3)!

Regards,

Nandu.

If you were the person who posted the link to instructables.com, then I did use your advice. That circuit is the one that allowed me to complete the circuit properly- whether it was identical to the previous one or not.

About choosing the resistors: even though I don't remember a single class or lecture in which we were taught how to wire circuits or how altering certain component values would change the outcome of the circuit, my professor made me alter my circuit so that the pulsation was quicker (higher frequency, smaller period). So, I recalled the formula I posted and used simple logic/mathematics to know that as the resistance and/or capacitance decresed, the period between low and high states would decrease as it is a linear formula.

 

Even though it is a simple project and is probably laughable to most of you, it felt great when I finally got my circuit to work. All the time and effort I had invested into it finally paid off.

 

"The file cannot be opened because the file is corrupted or damaged"

"This document is not a valid PDF"

Errors from two different apps.

Will try to look for the same book elsewhere, I guess.

I've always tried to avoid reading these series of book because I don't want to be labeled a "dummy" lol.

 

... it felt great when I finally got my circuit to work.

And that is the lesson you will likely remember for a lifetime.

Hopefully you have also begun to learn the value of building in stages, checking as you go, and the payoff from paying great attention to detail. There are so many things that can cause a circuit to malfunction - you have to fight against them at every step. Check, re-check. Assume it is wrong and check again. That's how a pro does it. The beginner charges ahead.

Don't assume you will fail the class! This attitude will be self-fulfilling. You built this circuit.

BTW, I'm an Illini alum. Which school in Illinois are you attending now? (If you don't mind divulging that.)

 

And that is the lesson you will likely remember for a lifetime.

Hopefully you have also begun to learn the value of building in stages, checking as you go, and the payoff from paying great attention to detail. There are so many things that can cause a circuit to malfunction - you have to fight against them at every step. Check, re-check. Assume it is wrong and check again. That's how a pro does it. The beginner charges ahead.

Don't assume you will fail the class! This attitude will be self-fulfilling. You built this circuit.

BTW, I'm an Illini alum. Which school in Illinois are you attending now? (If you don't mind divulging that.)

That's awesome! I'm at OCC right now and planning to go to either U of I or UIC (probably UIC) after completing my ASE. What's your major at U of I?

The thing is: I don't know what each component in the circuit does, so how can I test a "stage" if I don't know what it's supposed to do and much less how to test it? If I knew exactly what each component and each section of the circuit does, I would have probably spent significantly less time completing the circuit because, as you and others say, I could test each section because I would know how to test it and what it's supposed to do.

But seriously, I turned in about 6-9 lab reports to my professor yesterday (it is allowed). I think he was angry or something because I had made very little mistakes in each lab report, but got 4's, 6's out of 10 and only about two of all received a 7/10 or above. When I asked him why I hadn't received a 10/10, he said to re-check my results and that he couldn't explain further because he had a class elsewhere and had to leave. He has a pretty bad reputation of being a bad teacher. I will probably have to retake the class and the F will probably stay on my transcript.

 

Even though it is a simple project and is probably laughable to most of you, it felt great when I finally got my circuit to work. All the time and effort I had invested into it finally paid off.

David,
If you look at the MAkE beginner electronics book, they basically write that you will feel very good once you figure out how to wire up a 555 and make an LED flash. But they advise not to show it to your friends and family because they will just look at it and day, "so what, it's a flashing light." It is a burden you will have to live with. It is projects like this that convince you that a DIY iPhone is unlikely.

 

[QUOTGopherT, post: 794820, member: 185531"]David,
If you look at the MAkE beginner electronics book, they basically write that you will feel very good once you figure out how to wire up a 555 and make an LED flash. But they advise not to show it to your friends and family because they will just look at it and day, "so what, it's a flashing light." It uA a burden you will have to live with. It is projects like this that convince you that a DIY iPhone is unlikely.[/QUOTE]
Lol! Exactly what I thought and the reason I won't show anyone who has never taken a similar class! I'll look into the book you mentioned to see if it's any good.

 

Yes, I understand completely and it makes perfect sense. However, like I said in a previous post, I don't really know what certain components of the circuit do and why they are shorted the way they are. The most confusing part for me is understanding why the pins around the ne555 timer are connected the way they are and also why the trnsistors are there. If you could help me out, that would be great.

There is a whole section of the E-Book here devoted to the 555:

http://www.allaboutcircuits.com/vol_6/chpt_8/1.html

There are also lots of similar materials out on the web -- some better and some worse. You can also download some of the datasheets for the 555 from some of the manufacturers (there are a number of companies that fab this particular IC) and most of them will have reference circuits that include descriptions of how they work.

The 555 is actually a pretty simple circuit. Basically you have a latch that gets set when the voltage at the 'trigger' input rises above 1/3 of the supply voltage and gets reset when the 'threshold' input rises above 2/3 of the supply voltage (in addition to being reset whenever the 'reset' input is asserted). The latch, in addition to coming out to the 'output' pin, it also closes a switch between the 'discharge' pin and ground when the latch is HI. That's about it. By connecting resistors and capacitors in certain ways you create a voltage that changes at the 'trigger' and 'threshold' pins as the capacitor charges and discharges. This changing voltage in turn causes the latch to set and/or reset which, in turn, can be used (via the 'discharge' pin, usually) to change whether the capacitor is currently charging or discharging.

 

Today I just attempted my first 555 circuit. Thought it would be pretty straightforward, but couldn't get it to work for a long time. Eventually realized I had connected everything perfectly... except no ground at all to the 555! I kept looking for hard stuff and overlooking the most basic possible problem. Live and learn...

 

Today I just attempted my first 555 circuit. Thought it would be pretty straightforward, but couldn't get it to work for a long time. Eventually realized I had connected everything perfectly... except no ground at all to the 555! I kept looking for hard stuff and overlooking the most basic possible problem. Live and learn...

With experience you will soon learn to always check the simple things and never assume that they can't be the problem -- precisely because experience will teach you that the simple things are usually the problem.

 

Hi David,

I thought as much!

The title implies that the presentation enables even dummies to comprehend.

By the way, the 'Dummies' series covers a whole range of subjects.

Regards,

Nandu.

Yes, I am aware of that. That was supposed to be joke (lol?)...