ic 4027 wave form

[colum]

The circuit is a divide by 2. With the current wiring the output pulse is all over the place fast slow large small The input signal is from a 555 and is stable . could someone suggest a repair or different wiring
Thanks...colum

 

[Nanren888]

For CMOS random-like misbehaviour could mean a disconnected input. Check the connections are good to all the pins?
.
Any load on the outputs?
.
Is the supply voltage stable, regulated?
Any capacitor on the supply near it?
.
Is the 555 on the same supply?
pin 14 should probably show inverted compared to 15, rather than in suynch as illustrated.

 

[Harald Kapp]

The circuit is a divide by 2.

It is not. It is 2 × divide by 2 effectively divide by 4. Each flipflop divides by 2.

the output pulse is all over the place fast slow large small

What do you mean by this? Please explain.

 

[bertus]

Hello,

As shown it is a divide by 4 circuit.
The divide by 2 will be on the pins 1 and 2:



Bertus

 

[colum]

Thanks bertus that answera alot. Wonder what happens to the jumper from 13 to 1 in my circuit

 

[Harald Kapp]

Wonder what happens to the jumper from 13 to 1 in my circuit

That makes for the second /2 divider.

 

[Nanren888]

Pin 1 to pins 2 or 1 gives you divide by 2.
Pin 13 to pins 14 & 15 are another divide by 2.
.
The division is in frequency.
.
Did you get anywhere on the strange output?

 

[bertus]

Hello,

What is the supply voltage of the 555?
Is that also connected to the 9 Volts?

How do you check the output voltage?
If you look at the output with a scope, post a picture.
If not, can you make a drawing of the output voltage you see?

Bertus

 

[colum]

Thanks for all of the replies
I built this circuit from an old Astronomy magazine which was a mistake and never verified
I give up on this and try to find verified circuits for my bucket list.
Many thanks to all the great folks in these forums....colum

 

[bertus]

Hello,

Could you scan or make a photo of the page and post it here?
Then we can have a look at the circuit.

Bertus

 

[Nanren888]

From the circuit posted & your info, it appears that this should work as a divide by 4, or slightly modified as a divide by 2.
This points to perhaps assembly technique letting you down.
.
This may not be helped with a new circuit.
Your choice, of course, to post more info, as in the questions above, or go a different direction.
Enjoy

We'd be interested to see the original circuit. Posting it might help others too.

 

[colum]

 

[Nanren888]

Many thanks. Interesting.
3055's Yep, an older circuit.

At first look there seem no reason that this cuircuit won't work.
The joystick adjusts frequency to the motor: the purpose of which is not obvious to me.
.

 

[bertus]

Hello,

One of the problems that I see is that the outputs of the 4049 can not go higher than the base/emittor voltage of the output transsitors.
I also wonder if the 4049 can pull down against the 270 Ohms.
It is also not clear what the transformer voltage is.
Also there is no data for the output transformer.
Maybe that information is given in the text from the article.

I would use mosfets on the transformer:



Bertus

 

[colum]

Thanks Bertus for your well thought information. The only info I have for the transformer is 40v unreg to A of the CT output transformer but I will check to see if I can find the magazine for more info.
I am going to try to use the 1and 2 as outputs if I don't wreck the whole thing
before personal computers I built a circuit which wouldn't work as it turned out circuits were copied on a Xerox machine and it reversed the numbering some how probably too many chefs...Thanks...colum

 

[colum]

For CMOS random-like misbehaviour could mean a disconnected input. Check the connections are good to all the pins?
.
Any load on the outputs?
.
Is the supply voltage stable, regulated?
Any capacitor on the supply near it?
.
Is the 555 on the same supply?
pin 14 should probably show inverted compared to 15, rather than in suynch as illustrated.

Thanks for your advice

Hello,

One of the problems that I see is that the outputs of the 4049 can not go higher than the base/emittor voltage of the output transsitors.
I also wonder if the 4049 can pull down against the 270 Ohms.
It is also not clear what the transformer voltage is.
Also there is no data for the output transformer.
Maybe that information is given in the text from the article.

I would use mosfets on the transformer:

View attachment 49759

Bertus