Hello! I am looking to build 3 simple clock dividers to cram into a single module, I am mostly looking to use them as subharmonic generators for oscillators (but for rhythm as well, of course). I made this stripboard layout with help from Hagiwo’s clock divider schematic, but used a 4017 instead of 4040 to get odd harmonics. I already have a binary clock divider, as well as a sub oscillator for sub-octaves on my synth.
I would like some second opinions while I wait for some parts to come in the mail. How does this layout look? Will it work with oscillators? I am still very new and this is only my 3rd stripboard design. Thanks in advance!
As you had suspected this doesnt work in the same way as wity the 4040 circuit, the common connection of the switch needs to be returned to the reset pin on the 4017
Also it is generally good practice to take the output from Q0 (pin 3) of the 4017 as this way the output pulse will be reasonably long whereas if taken from the common of the switch the pulse will be very short and may not trigger certain modules reliably. The transistor buffer at the output prevents excess loading at the output from interfering with the functioning circuit also it means the output can trigger multiple modules as it can output more current than the 4017 could itself.
The input circuit uses an opamp wired as a comparator this should ensure proper triggering of the 4017 even if the input is a non rectangular shape, say a triagle, sine or saw wave.
Thank you for the helpful response. I had a feeling there was more to the chip when looking at the pinout, but I’m a glutton for extremely simple circuits because I’m lazy and just want to make music. I will stripboardize your schematic tonight. I wish I could warrant purchasing a subharmonicon but it’s just too expensive for what it does, so this will be a fun addition to the modular.
Am I correct in my understanding that the thought behind your schematic is ‘only trigger output 1 if IC4017 once every X clock input pulses’? And so for additional clock divisions you add more of these?
Here is a mockup based on your schematic. How does this look? I’m exhausted
I think the 1815 transistor has a different pinout than what I’m used to, Could I use 2n304-6 instead? Also no ground on pin 8 of 4017??
You need to add cuts under the ICs. Also, a few additional cuts and some shifting of the jumpers could make the layout much more compact. Even 1/4 of its current size. I know some people like their stripboards layouts very spaced out though.
If you required outputs that are divuded by a different amount, you would need additional 4017s and switches.
However the other outputs in the circuit I posted would still be divided by n but in relatively different positions. Note that only the outputs up until n-1 would be valid as the counter returns to zero on the Nth clock pulse.
I presume you are basing this on the 2sc1815 having a E-B-C pinout, Ive noticed variations of this online, some say E-C-B, do you know for sure that the 2sc1815 you will be using have the E-B-C pinout?
Otherwise it looks good, remember to add track cuts under the IC’s.
As you are relatively new to this, bigger layouts might be best, as it is easier to correct any construction errors on a more spacious layout. It took me a while to get good enough to succesfully build much more compact layouts, even now I still make some mistakes.
EDIT: I just noticed youve got the output of the unused half of the tl072 connected to ground , it should be the (+) input connected to ground.
2N3046 is a discontinued dual transistor, did you mean 2N3906? That is EBC.
2SC1815 I guess was originally from Toshiba, now is supplied by Central Semiconductor and Lumimax. The datasheets I find say ECB.
I can’t imagine a 2N3906 wouldn’t work. But I also can’t imagine soldering up an untested circuit, I’d breadboard it first and verify whether the 2N3906 works.
Surely pin 8 must indeed connect to ground. It can’t just float like that.
You are absolutely right, that bottom rail is all supposed to be connected to ground. Thanks for spotting that!
I take it you meant 2n3904, as 2n3906 is PNP. I agree though 2n3904 should work and also 2n2222 (the to92 version not the metal can ones) should also work.
I meant 2N3904 NPN. I will test it’s functionality before soldering up everything. Glad my intuition was right about the pin 8 rail being tied to ground. Thanks for the insight!
Thanks! I was way too tired to be finishing the layout last night. I plan on making the clock input normalled (sp?) to the second (maybe third) clock divider circuit in the module so that different odd subdivisions can be made from a single source. Thanks again for your help and good luck on your build.
I forgot what they are calling it, but who knows when it will be released. I’ve been eyeing their DFAM clone for a bit, but I don’t think it can do much that my big synth can’t do.
You might have seen these, but they may help others too.
A couple of interesting links about CD4017 dividers.
An article by Mid Century Modular. CMOS Clock Dividers
