Did anybody see the New Inventors last night? Can anyone guess how
"Protex Switching Technology" works? The inventor said something about
detecting voltage changes, and using the neutral as the reference.
See
http://www.abc.net.au/newinventors/txt/s1356442.htm
- Franc Zabkar
It seems to be a device to be built into or retrofitted into an
appliance, as is implied in the video, and as such, the only way I can
think it would work is to "learn" the typical current/voltage usage
patterns of the device its connected to - and if there is any sudden
change in these patterns- (that 'looks' consistent with human contact
or "hazardous" leakage for example?) that seems suss, then it shuts
off the power.
If this is the case, (its in the appliance) then surely it would
provide no protection for the cord, plug etc of that appliance, and
these probably need to be protected a lot more than the innards of the
appliance, as cords are so easily damaged, and often touched by the
consumer ? for that matter - if his magic device is INSIDE the
hairdryer - and the dryer is then thrown into the bathwater - it might
very well do a great job of cutting the power to the dryer's
internals, but how is it going to stop the current still flowing down
the cord and into his device ?
(Put a massive short across the active/neutral to make the house fuse
blow maybe ?
I also find it strange his implication that appliances with 2 pin
plugs "seem to be unable to work effectively with an RCD compared to 3
pin ones". As I see it - an RCD will work just as well with 2 pin as
3 to protect a human body from electric shock, as long as you have an
earth connection, (ie: the ground you are standing on) and if you
didnt have a ground connection to your body when you touched the
active lead, you aren't going to get a shock anyway, unless you grab
both active and neutral.
I didn't see the process where the panel interviewed him on the device
- and there are no details even remotely on how it works, either on
his website or the URL you gave above. In fact the whole site seems
to totally avoid the theory of operation and instead give tons of
vague"consumer' type information about how wonderful it is - and will
save the world etc etc.
also, how many cases would there be of people accidentally coming into
contact with both active and neutral connections *simultaneously* in
domestic situations ? remember that unless you grab both of them at
the same time, (within the trip time of the RCD) then the one you
touch first - will set the RCD off and stop the current flow anyway)