Trying to figure out Dividers

acidblue · Joined: Jun 26, 2009 Posts: 226 Location: The Darkside

Could some one please explain to me Dividers, specifically the cd4040 divider.

Should I put the reset to ground, (thru a resistor perhaps).
What goes into the clock pin? Is a VCO ok? or does it have to be pulse, like an LFO??

My understanding is it will divide the signal, (VCO?) by 2,4,6,8 and so on
thru Q1-Q12.

How do I connect the outs, (Q1-Q12)?
Can I put them into a mixer?
Will it give me a sequence??

Please forgive my ignorance, I've been looking at data sheets, but
the ones I've looked at dont give an example circuit.
Which is what I need, a few schems would be great.

commathe · Posted: Tue Feb 04, 2014 6:16 pm Post subject:

The 4040 and 4060 are just chained flip flops. From the fairchild semiconductor datasheet:

The counters are advanced one count on the
negative transition of each clock pulse. The counters are
reset to the zero state by a logical “1” at the reset input
independent of clock.

This means that every time the input (clock pulse) goes from high to low the output from at least one pin will change. Think of it like this:

acidblue · Joined: Jun 26, 2009 Posts: 226 Location: The Darkside

Was thinking of outputting the 4040 into a simple R2R ladder.
Then into a VCO so I get a sort of step sequence. i think

I have some 47k and 100k r's for the ladder, should work.
Was looking at Phobo's triple ladder here:
http://electro-music.com/forum/phpbb-files/modlunetta_tripler2r_v2_528.gif

But i dont think I need one that complex, for now.
Time to do some breadboarding, I'll be back Wink

commathe · Posted: Wed Feb 05, 2014 5:14 pm Post subject:

I would say build the r2r ladder as a separate module as they are very useful. If you do what you are saying then you will get some sort of sequence, but if you don't solder them together, and leave it patchable, then you have a huge variety of sequences you can make.

Also, if you use a fast enough square wave you can use a divider and an r2r ladder to make stepped waveforms

acidblue · Joined: Jun 26, 2009 Posts: 226 Location: The Darkside

commathe · Posted: Wed Feb 05, 2014 6:13 pm Post subject:

Of course you can try it! Can't tell you how it's going to sound though Razz

JingleJoe · Posted: Thu Feb 06, 2014 5:43 am Post subject:

I've done this quite a lot and I feel I need to clarify that logic/digital circuits can usually only accept pulse/square waves as thier input, what you're talking about in the first post kinda confuses the concept: you just need a pulse wave, the frequency doesn't matter Smile

only the voltage.

the 4040 itself will really give you octaves below the input. (e.g. input frequency divided by 8, if output "3" is selected) so if you put in a frequency of 100 Hz you get frequencies of 50, 25, 12.5, 6.25, 3.15 and so on, halving with each successive division. commanthe gives a great example with textual waveforms Smile

some inputs of cmos ICs require a pull up or pull down resistor depending on other parts of the circuit, but rarely ever a resistor in series. However, make sure you allways connect your inputs ot something, even if they are not used, or your circuit will malfunction because the high impedence inputs pick up random electromagnetic fields in the air!

Your suggested circuit yeilds some great and very fun results. Very Happy

commathe · Posted: Thu Feb 06, 2014 7:35 am Post subject:

Thanks Jingle Joe! I guess I maybe wasn't clear about the fact that it had to be a pulse input (digital logic). I also had no idea problems coming from not tying unused pins to ground caused problems because of that!