[BC] Hot and grounded chassis

[nakayle@gmail.com]

Well I saw it both ways- some switched the hot side, some the chassis side.
I can think of no logic to switching the chassis side.   Using a polarized
plug to insure the chassis was on the cold side and then switching the hot
side would be the sensible thing to do.  I don't know why they didn't since
even the old 2-prong outlets were polarized- with one slot wider than the
other.

Later transformerless equipment used a floating ground which was somewhat
safer.  Here the circuit ground was floated and connected to the chassis
only through a capacitor/resister combo.  This put the chassis pretty much
at RF ground- but not AC ground.   Still, the cap would pass enough AC that
you could get a bite from it.

Now a days most everything comes with polarized plugs and many with
grounding plugs as well.  And GFI breakers are required for anything used
around water.

One change which I think is over-kill is the current UL requirement that
even small household appliances now must use SPT2 cords.  These seem
unnecessarily bulky for small light-duty appliances such as a table lamp or
clock radio.

    - Nat

On 8/10/06, Harold Hallikainen <harold at hallikainen.com> wrote:
>
>
> As I recall, one side of the line went through the power switch to the
> chassis. If the plug was in one way, the chassis was at zero volts (or
> thereabouts, it was connected to neutral) when the unit was on, but at
> 120VAC when the unit was off. Reverse the plug and the chassis was at zero
> volts when the unit was off, but at 120VAC when the unit was on. It also
> two RCA phono plug inputs with the shells grounded, so your record player
> ALSO got to have a hot chassis.
>
> Harold
>
>