[sdiy] PSU ripple/hum testing

[harrybissell]

oopsie...

watch out. Twenty or thirty amps will not kill you, it will cook you to death.

The amount of current available is not usually an issue for killing people...
its
how much current you can get them to draw.

The human body (skin) resistance is usually around 10K ohms... so a 12 volt
supply will only give you 1.2mA.  In most cases you might not even feel that at
such a low voltage.  You can't usually feel a 9V battery unless you stick it on
your
tongue, with is MUCH lower resistance.  Worst case for the human body is usually

specified at 1K ohms. (we're hot and sweaty and maybe standing barefoot...)

I agree, it could easily kill the speakers.

I'd imagine that if the locked rotor test kicked you @ss... there was something
else
involved, such as some inductive kick or the like... MUCH higher than 12V

In most cases, voltage is an ...er.... voltage source. Your body resistance will
take all
the current that it wants to, according to the law (of Ohm's :^)

H^) harry

Peter Grenader wrote:

> Lincoln Fong wrote:
>
> > The initial spike when attaching the probe could kill my amp/speaker/ears
> though. Any ideas or should I get a better scope?
>
> The initial spike could kill you, screw the amp/speakers.  Be very careful.
> 30 amps will hurt like a dickens.  I once got 12 volts at about 20 or amps
> through my hand only during a UL locked rotor test on a DC motor and it felt
> as if I dropped a safe on it for about a week. Had the current crossed my
> heart,  it would have been a whole other story