Gunner Asch kom med følgende:
On Mon, 13 Jan 2014 14:01:44 +0100, Leif Neland
wrote:

DaveC sendte dette med sin computer:


Yes, we all know about "during a power failure" but many times this won't
be an issue (actually the friend would appreciate the saw continuing the
cut after power comes back!), but the "auto turn-on" feature )c: is one I
hadn't thought of.


Why on earth would frind want the saw to turn on after a power failure?

In most cases...if the saw is running WHEN the power goes off....it
comes back on when the power returns.

With a contactor..it stays OFF if properly wired until you turn off
the switch..then turn it back on.

I agree, but my question is

"Why on earth would frind want the saw to turn on after a power
failure"

which OP claims "the friend would appreciate".

When the power is turned off, the material being sawed, tools, fingers
etc. could block the saw. I very much prefer the saw does *not* start
by itself.

In the circuits I've seen, the ON is a "no", normal open pushbutton,
which energizes the contactor. An on-switch on the contactor in
parallel with this provides current to the contactor.
The OFF is a "NC", normal closed pushbutton, removing the voltage to
the contactor. All kinds of safety switches could be wired in series,
all required to be closed for the saw to run.

Leif

--
Husk kørelys bagpå, hvis din bilfabrikant har taget den idiotiske
beslutning at undlade det.