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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
Audio files: 3
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Posted: Thu Jun 28, 2018 10:27 am Post subject:
Using a momentary push to trigger timed actions Subject description: Need a bit of help figuring this one out! |
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Hello guys
My 4017 based sequencer build is almost finished, but I wanted to have a momentaty push button to trigger an effect.
My idea is to trigger an action for 4 or 8 steps of the sequencer then revert back to normal.
The idea was to use a 4015 and tie either 4 or 8 outputs together to send a high signal to a 4066 switch. The switch stays open for the number of steps tied together, then closes again afterwards. The 4015 uses the same clock as the 4017, and the data input to the shift register keeps the effect going.
The problem is that the momentary needs to be held down whilst the clock cycles through one whole step, making it less "reactive". Sometimes it even takes holding down for slightly longer (not sure why)
Are there any other ways to achieve a signal to the 4066 for a set number of steps that i can activate with one momentary switch closure?
I can upload a schematic if that helps
Cheers
Chris |
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piedwagtail
Joined: Apr 15, 2006 Posts: 297 Location: shoreditch
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Posted: Thu Jun 28, 2018 10:50 am Post subject:
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making it less "reactive"
hmmm, smells like a flip-flop
(better have a schematic for when the cavalry arrive; I'm only reconaissance)
R |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
Audio files: 3
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Posted: Thu Jun 28, 2018 11:12 am Post subject:
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Wow that was fast! Thanks guys
I'll get a schematic up soon - never had to draw one up before so it might take a while
Will investigate flip flop latches in the meantime |
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piedwagtail
Joined: Apr 15, 2006 Posts: 297 Location: shoreditch
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Posted: Thu Jun 28, 2018 12:34 pm Post subject:
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Quote: | reaches the number of steps you want.
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typical mission creep
R |
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
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Posted: Sat Jun 30, 2018 10:26 am Post subject:
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Got it working used an RC circuit to trigger a momentary clock pulse into a JK flip flop, which latched until a 4017 counted 4 beats then reset.
Just tied the flip flop latch to a 4066 to keep the switch closed for the 4 beats.
Thanks for your help. Mission success |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
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Posted: Sun Jul 01, 2018 4:31 am Post subject:
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I swear it's on the way!
Was going to wait til I'd finished the whole project and then upload one, but the whole thing has just grown organically as I've learned new things. There are 24 breadboards and over 60 ic's.
The thought of drawing a schematic for the whole thing terrifies me |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24079 Location: The Netherlands, Enschede
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Posted: Sun Jul 01, 2018 7:13 am Post subject:
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W W |
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Steveg
Joined: Apr 23, 2015 Posts: 182 Location: Perth, Australia
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Posted: Tue Jul 03, 2018 2:31 pm Post subject:
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I had to print out that block diagram to fully appreciate what you are building.
I notice a lot of 4046 / 4017 combinations. To save on board space it might be worthwhile to look at this circuit: http://electro-music.com/forum/topic-28799.html for your VCOs. You can feed the control voltage from an XOR / resistor / capacitor type comparator but you will need 50% duty cycles to compare. Get them by using the 4018 instead of the 4017. Because of the extra glue logic you might find this doesn't save much but it could be worth checking. |
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
Audio files: 3
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Posted: Tue Jul 03, 2018 3:57 pm Post subject:
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Cheers for the suggestion Steve. I need any help I can get saving on space. This is my first build and it's bound to be made it in an inefficient way. I read the thread you linked but I"m a bit unsure how to apply it (will give it a few reads to make sure)
Those 4046/4017 combos are just frequency multipliers to get 3rds and 5ths etc.
I love the sound of the 4046's the only drawback is you can still hear the internal VCO whirring during any dead time - i.e notes switched off in the sequence |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
Audio files: 705
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Steveg
Joined: Apr 23, 2015 Posts: 182 Location: Perth, Australia
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Posted: Tue Jul 03, 2018 4:25 pm Post subject:
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So the circuit is a poor man's VCO. Ignore Q2 and its downstream circuitry and take the 4018 clock directly from "b". Ignore Q3 and its associated circuitry unless you want to use that as your VCO output. Ignore R1 and R10 because you are not using manual control.
Connect the 4018 output and a reference clock as inputs to an XOR. Output from the XOR goes to a resistor / capacitor low pass filter and the output from that goes to CV In on the diagram.
There is your phase locked loop with 1/6 of a 40106, 1/4 of a 4070 and a 4018.
You could tune all your VCOs to the same base frequency like the drones on a bagpipe. |
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
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Posted: Wed Jul 04, 2018 3:52 am Post subject:
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Thank you for the help and suggestions guys I appreciate it.
Phobos - that idea looks awesome and simple! I'll definitely give that a go
Steve - cheers for explaining the VCO idea. Gonna keep this one handy for my next project I think |
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
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Posted: Fri Jul 13, 2018 9:49 am Post subject:
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Hang on, the 100k from pin 5 of the 4066 should be tied to Vcc |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5591 Location: Moon Base
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Posted: Mon Jul 16, 2018 9:38 am Post subject:
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Using the transistor is actually a rather crude method, a comparator would function better. What you're doing with some extra switches
is a more standard approach and much more versatile. However there is an easier way to do it if you use the Inhibit pin (pin 5) of the
4046. Making this pin high wil shut it up so you can attach the switches (with some diodes) directly to it.
Thanks for the schematic _________________ "My perf, it's full of holes!"
http://phobos.000space.com/
SoundCloud BandCamp MixCloud Stickney Synthyards Captain Collider Twitch YouTube |
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stolenfat
Joined: Apr 17, 2008 Posts: 476 Location: Sunny Oakland California
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Posted: Wed Jul 18, 2018 5:44 pm Post subject:
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Mind explaining your 358 filter section? Curious if it's similar to the WSG filter which uses the 471. got a schematic? (hoping it's relatively simple) _________________ home made noise and electronic ill-logic |
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
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stolenfat
Joined: Apr 17, 2008 Posts: 476 Location: Sunny Oakland California
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Posted: Tue Jul 24, 2018 7:14 pm Post subject:
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Thanks for this, I'll give it save. Looks similar to some other designs I've seen but that diode section in the lower part seems unique, I'll have to build it up. How do you get the v- for the opamp? Is your project on a dual supply or did you create a voltage reference ladder with some resistors? _________________ home made noise and electronic ill-logic |
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CHRISKELLY
Joined: Apr 08, 2018 Posts: 103 Location: England
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Posted: Wed Jul 25, 2018 2:49 am Post subject:
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From what I can gather the diodes help prevent the op amp running into wild oscillation, but someone who knows what they're on about might be able to explain better!
I used GND for -V as my build is single supply 0 - +9V. Still sounds nice.
One thing worth trying is different dual pot values. My first try was with 500k pot. The LP and HP filters really squealed at the top end which gave it loads of character. In the end I swapped for a 200k so that the sweep made better use of the range available (i.e with 500k there was alot of wasted range where nothing happened) since doing that i can only get the mad squealing on the LP. Might have something to do with the resistance matching in the dual gang pot.
Again, someone else can probably explain why |
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