"Just Another Theremin Fan" wrote in message
oups.com...

Ron(UK) wrote:
mikercana1 wrote:
Where do you get the idea that a switch is a safety device????


Many manufacturers list the mains switch as a 'critical safety
component' which means it should only be replaced by the manufactureres
part number.

Which is what I said.

Many generic mains switches can be found to fit and be utilised, that`s
against the advice of the manufacturer, but it`s up to the engineer who
fits it to make sure that it leaves his workshop in a safe condition.

Any "engineer" doing so would leave himself wide open to legal action.
Possibly criminal legal action if things went badly wrong.

"Real" engineers might remember the Sony TV switch fiasco a few years
back
which resulted in several fires.

A repaired plastic part shoudn`t constitute a safety hazard,

"Shouldn't". These jokers are sticking lumps of copper wire up the
middle of plastic shafts. What happens if the shaft snaps again and the
wire is exposed?


Ron(UK)

Can you imagine the fuss these people would kick up if they put their
Ford car in a garage and got it back with a Vauxhall engine stitched
in it?

You're getting this out of all proportion, and trying to liken apples to
oranges. And yes, I am a fully qualified electronics engineer, and have been
for more years than I care to remember. The Sony debacle was due to the
switch itself failing as I recall. This had nothing to do with its plastic
shaft. Your point about a " low voltage fire " is pure and utter nonsense.
Perhaps you'd like to explain to us all, with your obviously superior
knowledge of these things, just exactly how a repaired plastic shaft is
going to catch fire - especially one on a switch with a seriously current
limited 5v supply on it. Perhaps you think that the mains voltage is
magically going to jump across to the floating piece of copper wire inside
that 5mm square shaft. The place at which these switch shafts break, is at
least a cm from where any actual power carrying contacts are located, and
usually where the external metal clip and return spring is placed - perhaps
you're suggesting that the manufacturers don't know what they are doing
either when they fit a lump of metal to the outside of the switch. Likewise,
when they fit another dirty great lump of metal to the switch body itself to
make a mounting bracket.

As I said before, in an ideal world, the switch should be replaced, and yes,
I agree that it is usually a designated safety part, but by the same token,
it is often impossible to obtain manufacturer's replacement parts, and a
generic from one of the main component suppliers, has to be used. Are you
seriously suggesting that these are dangerous devices and, if an original
part cannot be obtained, that the piece of equipment should be dumped in the
nearest landfill ?

To examine your car analogy a bit further. We are not talking here about
grafting an IBM chassis into a Dell monitor. We are talking about repairing
one part within the existing chassis. If you took your Rover to the garage
with a braking problem, and they told you that it was a wheel cylinder
problem, but that the original part was no longer available, when they
suggested to you that they could repair your original wheel cylinder, by
redressing its surface, and fitting new seals from a manufacturer of
replacement brake parts, would you tell them no, better tow the whole car to
the nearest scrapyard ? No, of course you wouldn't. You'd have it repaired
and trust that the garage were doing something that was considered safe.

The OP is not a professional repairer, and is not laying himself open to
prosecution for doing something improper to a customer's unit - he is merely
trying to repair a personal item. His house is not going to burn down as a
result - even if the shaft breaks again, and the piece of wire does become
exposed - and how that is going to have any effect is beyond me anyway. You
really are just being pedantic about this.

Arfa