Inverter - ghost dance not dancing !

Started by LightSoundGeometry, April 17, 2016, 10:22:15 PM

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LightSoundGeometry

Is there an opamp inverter in the 8 pin size or do you always use a hex inverter for circuits? thought i would try this since I am messing with fundamentals of opamps right now - I believe this is cmos logic though?

http://www.ece.mtu.edu/labs/EElabs/EE2304/EE2304_website_2008/Stepper%20Motor%20Resources/CD4069.pdf

the ghos dance sounds like a trebly filter with a slight boost in gain , nothing else. I swapped some components around to no avail ..any ideas where to start next? I omitted the Fet current limiter or is it essential to circuit somehow?

https://www.google.com/search?q=escobedo%27s+ghost+dance&biw=1360&bih=614&source=lnms&tbm=isch&sa=X&ved=0ahUKEwimo87ekJfMAhVBuoMKHfmpDaQQ_AUICCgD


bluebunny

Quote from: LightSoundGeometry on April 17, 2016, 10:22:15 PM
Is there an opamp inverter in the 8 pin size1 or do you always use a hex inverter for circuits2? thought i would try this since I am messing with fundamentals of opamps right now - I believe this is cmos logic though?

1No and 2yes.  This is indeed CMOS.  They come in 14- and 16-pin packages.  Try not to mix "opamp" and "CMOS" in your head: they're different things.  Understand them separately.  But mix them in a circuit, by all means...   :)
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Ohm's Law - much like Coles Law, but with less cabbage...

anotherjim

Although it's still a 14pin, have a look at the CD4007 if you only want 1, 2 or 3 inverters. As the Mosfets in it are, almost, separately pinned, some of those not used to make inverters can be used for other purposes, such as millennium bypass.

The inverters made with a 4007 are similar to those in the 4069UB but not the 4049UB. I have something on the breadboard now that uses 1x N channel common source amp, 1x P channel source follower buffer and 1x inverter amp - all from the one 4007 chip.



anotherjim

As to the Ghost dance, try working it up starting just with the inverter with the 2 feedback resistors - input after the 500k//680p. Then add the 680p in the feedback... keep building it up.
I would fit the 10uF supply smoothing capacitor to pin14-0v - I don't see it in the picture.

Do you need the current limit? Actually, you might, it could be part of the sound. You can probably get away with a 100R series resistor in the power feed instead of the JFET, but don't forget a smoothing capacitor.