Re: Circuits for Dummies

[Bernard Cleyet <anngeorg@PACBELL.NET>]

Here's one I found in a book since thrown out by a de-clutterer.

I pray it's not a repeat. You'll have to improvise too.    on the lid of a cigar
box fasten with bare heavy Cu wire two carbon rods from #6 cells (~ six inch X one
diam.  D cell one's'll prob. do) about an inch apart.  before you do that, cut a v
groove in each for a mechanical pencil "lead";   wire it up in series with a P/S,
consisting of one cell, and earphones.  The book claimed that one can hear a fly
walking on the lid.  I don't remember if I coaxed one on to the lid, but it was
damn sensitive.

bc  I did this while still in Palo Alto, so it was before '48.


Brian Whatcott wrote:

> At 08:04 AM 2/14/02, you wrote:
> > Hi
> > Does anyone know a good basic electronics reference book?   I need so=
> > me more background info on electronic circuits.
> >
> > I also need some more practical practice.  I can do the theory but watchin
> > me wire one of these things is distressing.
> >
> > Tina
> >
> > Tina Fanetti
>
> When I was a kid, I had a science kit with a battery, some wire and a
> trembler bell,
> a  light bulb holder and several small bulbs.
>   Before long,  I was wiring up commutator motors stripped from vacuum
> cleaners.
>
> On one memorable occasion, I wanted to step down the house supply for some
> low voltage component - and I worked out the appropriate resistance which
> would drop the
> necessary volts. It might have been a supply for a 12 volt one amp device.
> I set up the appropriate resistance on an audio taper potentiometer, but I
> was quite surprised when I switched the mains supply on though this dropper.
> It disassembled in smoke with a startling blue flash.
>
> It was about then that I found that a desired resistance value is not
> enough of a specification - sometimes the power dissipation rating matters too.
>
> Brian Whatcott
>    Altus OK                      Eureka!