What kind of IC is this

Roy J. Tellason rtellason at verizon.net
Fri Jan 9 05:05:52 CST 2009


On Thursday 08 January 2009 11:54:38 am Philip Pemberton wrote:
> Roy J. Tellason wrote:
> > "One of the celebrated things Widlar did was to put a "hassler" in his
> > office.2 When a person came in to his office and spoke loudly, this
> > circuit would detect the audio, convert the audio to a very high audio
> > frequency, and play back this converted sound.
>
> [snip]
>
> > I *want* one of these...!
>
> It was published in Electronic Design magazine:
>
> "What's All This Hassler Stuff, Anyhow?" (Pease Porridge)
> Pease, Bob
> Electronic Design, May 15, 1995
>
> I've got a (signed!) copy of the article here. Five op-amps (1x LMC6484,
> LM837 or similar + 1x LM301A), two transistors (jellybeans), a handful of
> Rs and Cs, half a dozen 1N914 diodes, a tweeter (Radioshack 40-1383 or
> similar -- 2x6" piezo horn tweeter) and a microphone (Radioshack 270-090 or
> similar -- basically a cheap PCB-mount electret element).

Yeah,  I started browsing through his other articles after reading that one,  
and ran across a link to that device somewhere in the process.  Saved the 
page with the smallish diargam on it (I couldn't really see it on my screen),  
and will look into it one of these days...

-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"
-
Information is more dangerous than cannon to a society ruled by lies. --James 
M Dakin



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