trouble with 555/4017

[bruems]

i am having some serious trouble with my design. i am trying to get a 4017 to count 4 inputs, (q7-q15) and then trigger(q2) a 555(on the reset of the 4017 so i get the (-)edge) set up for 20-25s(2200uF and 10k) ouput (q3). i am using a 5vdc regulator for the 555 (q8 pos-q1 gnd) and for the 4017 (q8 pos -q16 gnd). i can get the 555 set up to trigger when i connect pin 2 from vcc to gnd and i can get the 4017 to count and reset. i cannot get the two to play together. any suggestions?

 

[BrownOut]

I have a suggestion, make and post an accurate, well constructed schematic of your circuit. That's how we communicate our ideas on this forum. You're probaly not going to get much of a response until you do.

 

[bruems]

sorry, dont have a schematic software. will try and find something. was hoping ppl here would know what i was talking about.

 

[ljcox]

You could draw it on paper and post a scan.

If you don't have a scanner, you could download a programme such as Circuit Maker.
Alternatively, use PowerPoint, MS Paint or other drawing package.

Attached is an example (when helping someone else on this forum) I did using PowerPoint.

I save it initially as a .ppt then, when ready, save as a .gif and post.

The point is that we are all busy people and we don't have the time to unscramble your verbal description.

Besides, a picture is worth a 1000 words.

 

[Boncuk]

sorry, dont have a schematic software. will try and find something. was hoping ppl here would know what i was talking about.

Try CadSoft Online: EAGLE Layout Editor and download a free (light) version of the latest EAGLE version.

It has everything to create a neat and clean schematic - and contains a PCB-editor as well.

Boncuk

 

[audioguru]

I copy and paste pieces from schematics and datasheets into Microsoft Paint program then hold down the shift ket to draw straight lines between them.

An ordinary 555 has a very high output current that causes a 400mA spike on its power line. The spike upsets the CD4017 counter.
Two bypass capacitors are recommended on the datasheet of the LM555 to reduce the spike.

You should use a Cmos oscillator made with Cmos inverters or gates or use a Cmos 555 since the counter is Cmos.

 

[BrownOut]

I copy and paste pieces from schematics and datasheets into Microsoft Paint program then hold down the shift ket to draw straight lines between them.

Leave it to you LOL! Now that's a poor man's schematic editor

 

[Hero999]

I don't think audioguru is poor, he's probably too much of a scrounge to buy some schematic software.

 

[audioguru]

I laugh at some of the schematics made by simulation software (Multisim is one) that are covered with chicken pox dots, have ground lines and other lines all over the place and have the parts much too far apart so a simple schematic needs two or three pages.

 

[BrownOut]

Actually, I thought it to be ingenious. I've made lots of schematics in Paint, though I find Power Point to be easier. But I never thought of pasting IC outlines from data sheets. I'm going to give it a try. Just another tool for my belt, courtesy of ETO!

 

[Hero999]

I use Paint but only when modifying other people's schematics or improving schematics created by CAD programs.

 

[shokjok]

I've used this 555/ 4017 combination in two projects previously. I am proud to say that neither project board ( Christmas light chaser, name-in-lights), has failed or have been changed from its original design.
Both are free-running projects unaffected by weather.