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rossics
Joined: Nov 23, 2013 Posts: 12 Location: Australia
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analog_backlash

Joined: Sep 04, 2012 Posts: 393 Location: Aldershot, UK
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Posted: Thu Dec 26, 2013 4:35 pm Post subject:
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Hi rossics.
This is a radio frequency (RF) circuit, designed to work in the megahertz region (or above, possibly). I know little about RF circuits, but I know that usually there is a problem with converting an RF circuit to an audio frequency circuit. The inductors need to have impossibly high values for practical use. Normally, inductors come in microhenrys or the low millihenrys, but my guess is that much larger values would be required (if it would work at all at audio frequencies).
If I'm wrong, someone will soon post about it
Gary |
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rossics
Joined: Nov 23, 2013 Posts: 12 Location: Australia
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PHOBoS

Joined: Jan 14, 2010 Posts: 5906 Location: Moon Base
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Posted: Fri Dec 27, 2013 7:01 am Post subject:
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To function correctly that circuit needs a 50/50 squarewave which it will turn into a pulsewave with 2x the frequency. If you try to multply that again using
the same circuit you'll probably end up with a very narrow pulsewave with varying pulsewidth. Could be a fun experiment though. (You'll probably need
to use smaller caps on the second multiplier). _________________ "My perf, it's full of holes!"
http://phobos.000space.com/
SoundCloud BandCamp MixCloud Stickney Synthyards Captain Collider Twitch YouTube |
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rossics
Joined: Nov 23, 2013 Posts: 12 Location: Australia
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Posted: Sat Dec 28, 2013 6:45 am Post subject:
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| Cheers for the help, I'm waiting on a new batch of chips to come in, will report back when its on the breadboard |
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analog_backlash

Joined: Sep 04, 2012 Posts: 393 Location: Aldershot, UK
Audio files: 21
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Posted: Sat Dec 28, 2013 9:19 am Post subject:
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I've tried that circuit and it definitely works, but all that PHOBoS said is true. I was thinking of how to widen the pulses again. If you pass them into half a 4013, you get 50:50 out again, but it divides the frequency by 2, which puts you back at square one . You could use a monostable to widen the pulses, but this would have to be varied with frequency or else the "highs" will overlap.
Anyway, good luck trying it out.
Gary |
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inlifeindeath

Joined: Apr 02, 2010 Posts: 316 Location: Albuquerque, NM
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analog_backlash

Joined: Sep 04, 2012 Posts: 393 Location: Aldershot, UK
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Posted: Mon Jan 13, 2014 6:27 am Post subject:
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| inlifeindeath wrote: | | couldn't you resquare the waveforms to 50/50 pw with 2 - 40106 schmitt trigger gates? |
I hadn't ignored this, I was just thinking about it for rather a long time . The output of the doubler circuit actually gives very wide pulses (i.e. a large duty cycle). The only way that I could think of using 2 40106 gates here, is to use an edge detector (or "half monostable" as it says in the CMOS Coookbook). I've tried this out (see circuit and scope traces below). I've managed to get a 50% duty cycle output, but the circuit still needs to be tweaked every time you change frequency. Am I missing something (I probably am...)?
BTW, the second gate here is optional, as it just re-inverts the signal (which may not be necessary). Also, due to the capacitor having to charge, there is a phase lag between the two waveforms, which gets worse at higher frequencies.
Gary
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DUBmatze

Joined: Feb 18, 2013 Posts: 150 Location: south Germaica (schwabilon)
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Posted: Thu Jan 23, 2014 12:27 pm Post subject:
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the german wikipedia article show this Image (xor):
the needles shud have the length of the RC-time. |
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L´Andratté

Joined: Sep 23, 2012 Posts: 153 Location: Hamburg, Germany
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