the absolute beginners thread

[tjookum]

Totally awesome! I really like the idea of a wearable lunetta band, Stanley Lunetta must be proud.

I can totally recommend the slacker melodygenerator as a good next project. But really the best thing to do is to get a breadboard and experiment. Build a few circuits, get familiar with the cmos ic's and the lunetta way of thinking and just go from there.

Maybe this might work well as a hat?
http://www.youtube.com/watch?v=AXO6gzsD6xo

[Draal]

You've brought my Sid And Marty Krofft nightmares to life. I will never be the same again! You're H.R. Puffnsynth

Keep up the great work!

[Tomoroh Hidari]

wow, finally made it trhough this thread!
very helpful and inspirational. thanks!
so far i've tried a few lunetta circuits on breadboard... working on getting something built...

found an old joystick and working on building a quad 40106 osc in it.
two oscs controlled by the x+y axis of the joystick (both 100k slide-potis), two oscs by two pots I plan to place in the space of two pusbuttons and vol. by a third (allready built-in) pot...
i'm thinking of using the pushbuttons on the joystick (2) for the following -
1 switches off the gating of oscs 2+4 by 1+3 (yeah, that's part of the plan too)
2 switches off audio-out

since these are normal off switches, though, i'll have to do the switching via 4066s and inverters, though, which I yet have to figure out fully how to.

any ideas/criticism/peer-review?
cheers, th

[PHOBoS]

[tjookum]

Just had someone on youtube ask for a more detailed schematic of the 4069 LFO since there is some confusion surrounding the parts involved. Please feel free to spread this around, just let me know if you made any cool stuff with it!

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[elmegil]

I see it has to be a particular model of 4069...any idea if it works with other forms of inverters (dual connected NANDs, things with Schmitt Triggers in them?)

[tjookum]

I've only seen 4069 and 4049 being used in linear applications, I don't think other cmos ic's will work.

My entire experience with cmos is based on trial and error, maybe some of the other forum members is willing to explain why it has to be the 4069UBE?

[Psyingo]

you can use any non-buffered (and depending on the situation, buffered) non-schmitt trigger inverting logic for linear operation. that means 4001, 4011, 4009 etc. of course you can also use the 'building block' ic the 4007.

4001 and 4011 are pretty interchangeable when i was building analog drums i swapped between the 4011 and 4001 with no problem.

maybe this would be of help understanding the difference:
http://www.ti.com/lit/an/scha004/scha004.pdf

basically buffered has extra inverters buffering somewhere in the circuit, where as unbuffered has just the gate. so for a 4011 buffered will have the NAND gate and some buffering on the input or output, depending on the manufacturer. an unbuffered 4011 will only have the NAND.

that TI link is an interesting read, i would suggest it if you want to get serious about this stuff..

[elmegil]

Cool, thank you for the reference.

[RingMad]

I'm not exactly a beginner any more, but with this famous 4069 circuit, I feel like one. I've tried to build it several times. Now I finally got some actual CD4069UBE's, but they don't seem to work any better than the particular model I had before. I built the circuit exactly as in the one posted above by tjookum. The triangle is not smooth, there are glitches where the wave falls or rises vertically, which is audible as a click at lower frequencies.

In the scope shot below, the bottom horizontal trace is just to show where the actual ground is (notice the approx. +3.5 V DC offset!).

Ultimately, I'm looking for a cheap (low-parts count) triangular very LFO I can feed some "vactrols" (opto-isolators) with.

James.

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[Psyingo]

[RingMad]

[Psyingo]

well, it does 'work' but not the way it should.

[Psyingo]

heres the 9v one, or 12v. R8 may need to be adjusted a bit. but its pretty good as is.

the output will never quite be rail to rail, it'll always float above ground and below +v. you would have to remove the offset and run it into an amp to get it to be full swing.

if you want this to be an LFO C1 should be larger.

[tjookum]

Thank you psyingo for providing a lot of additional info.

I did notice in my limited experiments that the R8 and R9 resistance ratio is crucial when working with different voltages. That's why I altered the original by scott gravenhorst to my preferred 5v.

And thanks RingMad, I think that scope image shows very clearly the problem some are having with this circuit. I've used it on several drone type circuits and I've discovered it's very hard to make a pure triangle wave with linear cmos. But as everything wich involves the lunetta way of thinking, I considder it a feature .

I hope psyingo's schematic works for you(and others who need it at 9v).

[RingMad]

Thanks a lot, Psyingo! I finally get a nice triangle out of the 4069 on 9V!

This also works quite well as a VLFO (Very Low Frequency Oscillator). With an approx. 4700uF cap in there, I get around 17 minutes per cycle (approx. 0.001 Hz), which is what I was aiming for! And it's quite smooth. With a bit of DC shifting, this should work quite well for my application.

James.

[Psyingo]

Nice.glad it worked. And yeah it handles low frequency pretty well