Electronics Really Cool Idea...Have the entire circuit designed...

Ok i got my 4017 IC's and 555 timers. Here are links to the technical docs so that it might be able to answer some of the dumb quesitons i am goign to ask.

4017 Clock

555 timer

First off, the +5V next to the U$1, where does the negative end of that connect, and then (this question may sound really dumb but i am sorry i must ask to figure out) if I hook up the LEDs with 12V like you guys suggested then won't i need to have 12V go into the +5V line near the U$1 instead of just 5 volts?

Second, what does the circle around the 4 line coming out the 555 timer stand for?

Third, what is the thing that is just to the right of the potentiometer?

Fourth, what are the three things that have 3 leads coming off of them, they are in the Q3 space and not labeled?

That about wraps up all the questions I have, Thank you for giving me some of your time!!!!!!!!

 

1. They go to the transistors. They're NPN, so a negative (in respect to the base) voltage is going between the emitter (tied to ground) and the collector (tied to the LED). You should run the LEDs off of +12v, as indicated at the bottom of the post I made that first included the schem.

2. It means that's it is an active low input. By tying it to Vcc (+5v in this case), it means that its function (reset, which swings the timer's output low IIRC) does not occur ever.

3. Polarized capacitor. Not sure if the polarity matters or not, but at the farad range you need for the appropriate effect, it'll probably be polarized.

4. NPN transistors. A 2n2222 would be beeft enough to run all those LEDs provided to follow the advice in #1.

 

I don't mean to be asking so many questions, but i just am not that great with working with electronics.

A couple of more questions:

1. When you(whypick1) Hz, do you mean mHz or do I need to convert, because all of the data sheets list information in mHz?

2. How will the capacitence of the capacitor effect the rest of the circuit? (such as; increase speed of blinking....)

3. The potentiometer on the left side of the schematic just adjusts the brightness of the LEDs or does it adjust the speed that the LEDs cycle through?

Thanks Again!!!!!!

much thanks go out to whypick1!!!!!!!!!!!!!

 

1. I mean Hertz. I don't think the 555 can go into the Megahertz ranged, plus I take it you want to be able to see a change in states as opposed to appearing to be solid.

2. The capacitor only affects the output of the frequency of the 555.

3. Also affects the frequency. Brightness is determined by the resistors hanging off of the LEDs.

 

For the LED's you (whypick1) suggested that i put them in series-parallel. Then you suggested the use of 240ohm resistors, the thing is that i can't find 240 ohm resistors at most electronic sites.....mainly jameco. Do you know of a site that has a large variety of resistors?

Also i had a question about the power sources again, sorry...
Ok you said that i should run the LED's off of a 12V+ source. does this mean that i plug that into the 4017 timer or where do i hook that up, near the U$1 thing that i have asked so much about there is a power input but i can't figure out how this is run through the circuit to give proper timing?

I will post some cool pictures soon of the setup....they are getting developed.

Thank you@@@@@@

 

1. Those were approximate values. IIRC, 270 is the closest standard value, so go with that. You won't notice the difference in brightness.

2. +12v goes to the positive end of your string of LEDs. That power source is unchanging, it's the ground source that gets switched on an off by the transistors connected to the 4017 connected to the 555.

 

Ok i am still a little confused about the power.

This is what i have come up with on how it works. There are 3 power sources coming into the circuit in all. One that connects to the 555 timer through pins 1 and 8. Then there is one that goes into the 4017 clock that connects to pins 8 and 16, those don't supply power to the LEDs at all.....correct, so they can be a lower voltage?

Now this is where i get confused. On one side of the LED's there is the positve end of a 12V power source and then the other end of the LEDs connects to the transistors which in turn are connected to the 4017 clock and then the 555 timer. Then where does the negative side of the 12V power source connect to?

THANKS FOR ALL THE HELP!!!!!!

 

First of all - you understand that the "negative side of the 12v power source" is just a ground - either of the black wires on the Molex plug. Looking at the schematic that whypick1 was nice enough to draw for you - the emmitter of each transistor is grounded - so they connect through that. Hope this helps.

 

Another quick question.

If I increase the capsitance of the capcitor then the frequency of the 555 timer will increase or decrease?

 

Increase. Formula for astable output is:

F = .693*C*(R1+2R2)

R2 in this case would be the pot.

 

Ok another quick question. I have recieved all the necessary parts....i think and i am workign on the circuit on a bread board. But do to my lack of knowledge i didn't realize what size diode i should get so i ended buying these huge ones, that i can obviosuly tell...are way bigger then necessary.

(for all those whoe don't speak my launguage, gibberish, here is a link to the diodes I purchased)

Massive Diode

Here are links to the other things i purchased and i will also fill you in on the values of resistors i plan on using.

First off we have the Potentiometer:

Potentiometer

This also I am afraid is too big, but by using this in combination with some of the resistors i get a good astable output from the 555 timer.

Then there is the capacitor that i will be using:

Capacitor

And then there are the transistors:

Transistors

The resistors that I plan on using....at least for the resistors that don't yet have suggested values are as follows:

Resistor 1- 5.6K ohm
Resistor 2- The POT whic is 1Kohm
Capacitor 1- 470uf

This produces a astable output bewteen 2.5 and 3.0. I chose to have the astable output here for the reason that 3 mhz is as much as the 555 timer can handle.

Thanks for all the help, pictures of the progress to come soon!!!!!

 

So my question is: Are the diodes i bought too big? Should i get different ones that can' handle such high amperage?

 

The only problem should be the physical size of the diodes themselves. I'm no expert, but I'm pretty sure it should be fine, but if space is an issue smaller diodes would be good.

 

I think you may need base resistors between the 4017 and the transistors, unless you put the leds+resistors on the emitter side...but then the 2222a will run much hotter...the diodes can be small signal types like 1N4148, they only need to carry a few mA, the transistor is doing the grunt work.

 

Link to diode's cpemma was talking about. If my memory serves, the size of that diode is about the size of a typical 1/4w resistor, but significantly shorter.

Unless you think you're going to be changing the 555's frequency a lot, you should probably get a small trimmer pot like so. Make it a lot easier to breadboard with, as you can actually put it on the breadboard.

Using a base transistor like cpemma said would be a good idea (I wasn't sure if one was needed or not). I *think* 5-10k is what you should use, but I can't be totally certain.

One last note: If you're going to get the stuff above and only the stuff above, it's probably not worth it going through Jameco, $2 order w/ $6 shipping. On the other hand, you could go to Futurlec, pick up the stuff you need cheaper (1n4148 under Diodes->General Purpose->General Purpose, trimmer pots under Potentiometers->Trimpots->Vertical), and if you're going to do other electronics projects, some of the component packs they offer as well (personally, I've got the 1/4w resistor, both cap, and transistor packs), and shipping is only $3 for <$30 orders. Granted, it's USPS, but sometimes cheap won't bite you in the ass like it normally would with other things.

 

The 2222A gain is guaranteed 100min, so worst case 6mA in will get you 600 out. With the diodes dropping 0.7v and the tranny dropping 0.7 Vbe and a bit less than 12v to start with, I'd use around 1k5, which will make sure the transistor is hard on at highish load without pulling more than about 7mA out of the 4017.

5k would work fine at lighter loads, say to 200mA, I've forgotten what it ended up at.

 

All right well I haven't tried the circuit out yet I am just setting it up and I finally have some pictures of my progress. But I think I may have to restart because I am going to get those other electronics that everyone was suggesting. I just need to convince my parents to let me use their credit card.....argh!!!!

Well here are the pictures:


<4017's and 555's>


<capacitors>


<diodes>


<jumper kit>


<POT>


<resistor kit>


<transitors>


<placing the circuit on the bread board, the wires that are comign off of the bread board either go to the POT or to the LED's>


<and finaly my beutiful work space that i am ....working in>

Thank You Everyone!!!!!!!

 

Allright i ordered some parts from futurlec.com, diodes...smaller ones and then some 1K trimPOTs.

So i am trying to hook up the trim pots...but i can't figure out how to hook them up. I can't figure out which of the leads i am supposed to hook up.

this is kind of what they look like:



so i was just wondering if someone could tell me which of the leads to hook up to the circuit.

Thank You

 

Only 2 leads? They usually have 3. Can't realy imagine why would a 2 lead trimpot better than a normal.

Do you have a multimeter? Measure the resistance across the 2 leads, and turn the turnable part.

 

hahaha....i am very sorry...i just noticed that i mislabled the diagram....it has three leads in all...thank you for bringing that to my attention LukR.

Again...CORRECTION TO DIAGRAM: 3 LEADS IN ALL