I believe this caused damage to my LMNC breadboard breakout thingy!
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At the request of a new community member.
CD4024 - Simple Frequency Divider and Sub Oscillator.
The schematic is not mine, I just made the layout.
Link to author and original schematic:
CD4024 - Simple Frequency Divider and Sub Oscillator
I’ve used this project a few times in the past as a simple bench circuit to test sub oscillator outputs for my VCOs. I had a paper layout and digitally redrawn it.
The layout here is the same as the one on paper, I just added the decoupler capacitor on the opamp and the 10uf capacitor on the supply input. I think everything will be fine.
Note: I believe that the output diodes are for divide clock, gate or trigger signals, I have never used the project for this purpose, so if you are going to use it as a sub oscillator you can exclude these diodes.
In the layout there is a note about the switch configuration, take a look.
If anyone ever builds it let me know so I can change the layout to VERIFIED status.
Any questions you can call me here.
Edit 1: Fixed the position of R3 (47K) in layout.
Fixed Switch type in B.O.M (SPDT on-off-on)
Diode D2 placed on the board.
Edit 2: Removed trace cut under TL072 between pins 4 and 5, this is necessary to
connect pin 4 to GND.
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Fantastic, thank you! I believe I don’t have any 47k resistors on hand, so I’ll start laying this out tonight or tomorrow and will finish as soon as I can get across town to the electronics store!
The 47k isn’t critical either, is it? Isn’t it just a pulldown to send the output to ground if none of the diodes are in conduction? And the diodes are said to be optional, too.
Hmm, in Peter’s layout it looks like the 47k is on the other side of the diodes, in which case it’s NOT functioning as a pulldown. And it connects only to one of the 4024 outputs. So I’m puzzled.
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That’s right, it’s not critical and has the function you described.
And thanks for noticing my mistake. I will fix this now.
By the way: I’m your fan 
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Alright, so I could use more or less anything?
I’ve got 100 ohm, 470 ohm, 1k, 15k, and 100k. I’m very new to this and don’t get what impact it will have.
You can leave empty and replace with a jumper, or create your board without it.
If you want to put it anyway, it could be 100k, when you get the 47k you replace it.
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Here you’ll find me asking virtually the same question a year ago. You’ll get there.
Uh, no, you don’t want a jumper from the 4024 output to ground!
If you leave out the diodes, then you don’t need that resistor at all — just leave it out. With the diodes, you should have a resistor from the jack tip (not the 4024 pin) to ground. Of the ones you mentioned I’d say use the 100k.
In Belver’s version the diodes are acting as logic gates. In Peter’s version they aren’t, and normally don’t do much, I think, although they do serve to protect the 4024 against inadvertently connecting the output to a negative voltage source. So I’d leave them in, and use the resistor.
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@analogoutput Thanks for the precious tip.
What do you recommend? A layout with diodes and resistors and another without any of that?
I’d do it exactly as you had it, except move the resistor!
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Okay, I’m fixing the layout now and I’ll update it here in a minute.
Thank you so much!
I missed this post, you went on a tear! Well done!
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Alright, I can verify that the sub osc is half working! Not sure if the mistake is on my end or the layout. I’ve looked it over a few times and I’m pretty confident that I’ve done it properly according to the layout, but with my extremely limited knowledge and looking at the pin out for the chip, I think this should be working… My down position and middle wires are bare and close together so maybe it’s shorting but I believe I tested that. I finished up at about 6am this morning though so it’s quite possible I missed something silly (like those wires touching and me not noticing). Anybody seeing any glaring issues from the top here?
I racked it anyway for right now so I could play around with it before work. Tomorrow is a holiday so I’ll probably leave it and keep playing with it tonight then pull it out tomorrow. On the rack it’s the white one between the oscillator and mixer. My laser cutting guy is shut down until Tuesday - was going to get a new panel done but it worked fine in the panel I had made for the slew limiter, which he gave me two of.
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What happens when in operation? Any sound?
By the image, apparently it’s correct. I just think those wires on the switch terminals could be insulated from each other.
I’m a little confused to understand the connection between the output connectors, is the diode connected to GND? Or is it just me?
What happens when in operation? Any sound?
The 0 oct output works as expected. For the sub out, up position on the switch gives an octave down, middle position is the played octave, down position is also the played octave.
I’m a little confused to understand the connection between the output connectors, is the diode connected to GND? Or is it just me?
Ah - this is just the angle of the photo. Lower jack (sub out) ground is connected to the jack above it jack (0 oct out) ground. Diode is connected to 0 out hot signal. I’ll double check this after work to make sure I didn’t solder them together like it looks in the photo, but pretty confident it’s just a weird picture.
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I understand, in this case the ideal is to use a switch without the center position.
(SPDT on-on)
The shape is the same, but it doesn’t stop in the middle.
I forgot this.
So if I’m understanding correctly, the stripboard layout should be correct, but I’m using the wrong switch - an ON-OFF-ON where I should have an ON-OFF? If so, is there a way to wire my switch to get this to work or do I need to pick up an ON-OFF?
edit: I had messaged but to save effort, or for anyone else, these are the switches I’ve got - https://www.taydaelectronics.com/mini-toggle-switch-spdt-on-off-on.html
The switch you need has the same format as the one you’re using (SPDT on-off-on). Looking at them will be the same.
However, the switch you need (SPDT on-on) the lever don’t stop at the center, it only moves in two positions, up and down.