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Can anyone help?

Posted: Sun Mar 13, 2005 10:06 am
by terri
I want to make noise with electricity. Can anyone help?

Re: Can anyone help?

Posted: Sun Mar 13, 2005 4:59 pm
by jimandy
What kind of noise - white noise? pink noise?<p>A banging noise? :) <p>Whats your application?

Re: Can anyone help?

Posted: Sun Mar 13, 2005 5:27 pm
by pboese
Oooh, interesting topic! All sorts of ways to make noise. Semiconductores in avalanche mode; digital random noise generators; analog circuts that ocillate, ring, etc. Noise! The problem most engieers try their darndest to eliminate from their designs 8P<p>I've got Popular Electronics Magazines from the 70's full of interesting audio projects. One in particular that comes to mind is a drum machine. Very cool, all discrete parts; ring-counters; diode keying, and all sorts of circuitry to make the various percussive instrument sounds. Of course a PC with a soundcard and the appropriate software makes things a whole lot easier these days. But I assume you are looking for a circuit to build.

Re: Can anyone help?

Posted: Sun Mar 13, 2005 5:52 pm
by jwax
Wire a cat to an outlet?

Re: Can anyone help?

Posted: Sun Mar 13, 2005 5:57 pm
by philba
I remember my dad once made noise with electricity. Funny though, it was mostly swearing... <p>You know how to make a cat go woof?<p>[ March 13, 2005: Message edited by: philba ]</p>

Re: Can anyone help?

Posted: Sun Mar 13, 2005 7:22 pm
by jimandy
<blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr> You know how to make a cat go woof?<hr></blockquote><p>I'm poised for a rimshot,

Re: Can anyone help?

Posted: Sun Mar 13, 2005 9:11 pm
by philba
a little gasoline and a match ... WOOF!

Re: Can anyone help?

Posted: Mon Mar 14, 2005 5:02 am
by Dean Huster
When I originally made my Tesla coil from the July 1967 issue of Popular Electronics, I found that it made noise. The spark gap alone had enough audio noise to wake up the dead. Then I discovered that it totally destroyed all radio and TV reception (these were the days before cable) for blocks.<p>Dean

Re: Can anyone help?

Posted: Mon Mar 14, 2005 12:44 pm
by zotdoc
take a double a battery and run wires from it to a speaker, with a momentary switch. Each time you press the switch you should hear a click.

Re: Can anyone help?

Posted: Mon Mar 14, 2005 6:13 pm
by jwax
12 volt air horns for truckers make a "noise".
Big "noise". Whatcha after terri? :confused:

Re: Can anyone help?

Posted: Mon Mar 14, 2005 11:23 pm
by John Abel
Check out the section on the "singing arc" at this link: <p>http://www.richieburnett.co.uk/cwsstc.html<p>be sure to download the video.

Re: Can anyone help?

Posted: Tue Mar 15, 2005 4:43 am
by Bernius1
I think the industry standard is an avalanched E-B junction of a bi-polar x-istor. Of course, omitting all those .01uf power supply bypass cap's will yield tons of RF noise as well.
I think an interesting project ( college essay topic searchers' hint..) would be to sample noise off an AM radio ( audio file ), and analyze the file numerically for range and domain variances in the parallel bit stream. Then see if you can mathematically predict the various noise 'colors', and write a program to generate that sequence. A closed-loop repetitive sample will make a good test benchmark. Especially if the same circuit can be subjected to a catalog of generated noise profiles, with the intent of determining max/min tolerances and device failure rates. Is there a 'golden ratio' for noise ?

Re: Can anyone help?

Posted: Tue Mar 15, 2005 6:13 am
by terri
Yes, there is a golden ratio for noise. It's 2.0898 dB.<p>---------
Additional info/search terms:<p>Fibonacci
phi
golden ratio
greek architecture
decibel
<p>[ March 15, 2005: Message edited by: terri ]</p>

Re: Can anyone help?

Posted: Tue Mar 15, 2005 9:13 am
by Bernius1
Please clarify.....

Re: Can anyone help?

Posted: Tue Mar 15, 2005 3:39 pm
by terri
In brevis:<p>In buildings, index cards, and Greek Architecture, the "Golden Ratio" was that proportion between the length of the face of a building and its height which was most pleasing to the eye. This "most pleasing ratio" was considered to be about 5 to 3. That is, if a building had a length of 5 units and a height of 3 units, it was judged to be more pleasing to look at than another building without these proportions. So the proportion 5 : 3 got to be called the "Golden Ratio." A 3 x 5 index card has these proportions.<p>The mathematical "Golden Ratio" is the result of something called the "Fibonacci Series," and is a mathematical constant called "phi." This constant is 1.618..... and if you divide 5 by 3, you get a number close to phi, that is,
5 / 3 = 1.666...<p>So the two sorta got linked in peoples' minds.<p>("Phi" in this sense has nothing to do with electrical phase angle.)<p>When the question arose, "was there a 'golden ratio' for noise?" I immediately thought of phi, or 1.618... as a "golden" signal-to-noise power ratio, and figured that would be fitting for this supposed "golden ratio for noise."<p>And since this number, phi, is actually a ratio (see "Fibonacci Series" on your search engine), and we can express any power ratio in terms of deciBels, I converted it to dB:<p>10 X log (1.618...) = 2.0897851... deciBels.<p>I rounded it to 2.0898 dB<p>[ March 16, 2005: Message edited by: terri ]</p>