ABC Inventors - electrical safety device

[Franc Zabkar]

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
--
Please remove one 's' from my address when replying by email.

 

[Dave Goldfinch]

On Thu, 05 May 2005 08:45:01 +1000, Franc Zabkar
<fzabkar@optussnet.com.au> wrote:

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

Hi Franc

Yes I saw the show and was going to post almost exactly what you have
said.

He also claimed it was pretty cheap ie around a dollar to build.

Frankly, I am a bit sceptical of claims that it would do anything more
than an RCD and/or a sensitive circuit breaker, especially as you got
virtually no information as to how the thing works at all. I would be
happy to be proved wrong.

Dave Goldfinch

 

[John G]

"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:agji71lifbikg844o1l3osik3rb28aphsf@4ax.com...

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

In the text Wayne said "It works" but the description is very vague on
details and seems to not understand 'Double Insulated'.
He says it can be built into the device. Well if the switch is in the
hair dryer in the water how does it keep the EXCESS electricity out of
the water?
--
John G

Wot's Your Real Problem?

- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

 

[KLR]

On Thu, 05 May 2005 08:45:01 +1000, Franc Zabkar
<fzabkar@optussnet.com.au> wrote:

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)

 

[Phil Allison]

"KLR"

also, how many cases would there be of people accidentally coming into
contact with both active and neutral connections *simultaneously* in
domestic situations ?

** Imagine a small kiddie picking up one of those mini two pin female plugs
as used on many items like shavers, small audio and VCRs and DVDs. The
kiddie then decides to put the plug in its mouth while the other end is
plugged in and live.

The RCD will not trip.

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)

** Not at all - when standing on a wood or carpet floor there is not
enough earth leakage to trip an RCD.

One has be in contact with an earthed object to do that.


BTW

I agree with your other comments about the Inventors device.


............ Phil

 

[Phil Allison]

"Franc Zabkar"

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

** My two cents worth is this:

The Protex device trips a normally closed latching solenoid switch upon
detection of a significant AC voltage appearing on the metal case or
internal metal ( non live) parts of the particular Class 2 appliance - as
measured relative to the neutral wire. Pretty much, this makes it a
submersion detector.

Such AC voltage detection - if applied to external metal parts would have to
be via a low value Y2 rated capacitor so not to breach Class 2 requirements.





.............. Phil

 

[Terry Collins]

KLR wrote:

If this is the case, (its in the appliance) then surely it would
provide no protection for the cord, plug etc

Correct, he said such on the show when asked.

 

[Franc Zabkar]

On Thu, 05 May 2005 11:24:01 +1000, KLR <kenreed@yahoo.com> put finger
to keyboard and composed:

On Thu, 05 May 2005 08:45:01 +1000, Franc Zabkar
fzabkar@optussnet.com.au> wrote:

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.

But how do you make a device like that for $1? And how could you
distinguish leakage from the load changes that result from normal
usage? Furthermore, the ABC URL states that "Protex is an electrical
safety switch that can be installed ... into a home’s electrical power
box or switch board". The inventor also agreed that it could be fitted
inside a GPO. This means that one device could be protecting several
appliances.

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.

Unfortunately the panel were not knowledgeable in this particular
field, so they were unable to ask pertinent questions. The inventor's
website is annoying in that it requires you to log in, and is heavily
reliant on flash. Whenever I see a Macromedia intro, I am immediately
suspicious of the quality of the content.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

 

[Franc Zabkar]

On Thu, 05 May 2005 13:51:18 +1000, Terry Collins
<terrycbongo@woa.com.au> put finger to keyboard and composed:

KLR wrote:

If this is the case, (its in the appliance) then surely it would
provide no protection for the cord, plug etc

Correct, he said such on the show when asked.

Then why go to the trouble of building it into your appliances when
you could mould it into a universal plug? In fact the inventor agreed
that the device could be incorporated into the GPO. The ABC URL goes
on to say that "Protex is an electrical safety switch that can be
installed at the manufacturing level into new household appliances
(toasters, kettles, hair dryers) or into a home’s electrical power box
or switch board." This says to me that it's a two-wire device
(remember the toaster demo), and that it's probably nothing more than
an automatically resettable RCD, despite the inventor's statement that
it senses voltage. The switching element would be mechanical, as it is
claimed that "it does not use power until a fault is detected, meaning
it does not generate heat". A triac would get quite hot if it were
asked to deliver 2000W to a kettle, for example. I suspect that
latching could be provided by an SCR or a transistor pair. Maybe one
end of the solenoid coil is connected to neutral and the other end to
the gate of an SCR via a zener diode. Perhaps that's what the inventor
meant by "sensing voltage". You'd probably need a diode bridge and a
capacitor as well. But can all that be made for a dollar?


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

 

[Franc Zabkar]

On Thu, 5 May 2005 10:54:14 +1000, "John G" <Greentest@ozemail.com.au>
put finger to keyboard and composed:

"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:agji71lifbikg844o1l3osik3rb28aphsf@4ax.com...
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

In the text Wayne said "It works" but the description is very vague on
details and seems to not understand 'Double Insulated'.

My impression of the man was that he was either short on
understanding, overawed by the occasion, or just deliberately vague.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

 

[Franc Zabkar]

On Thu, 5 May 2005 10:54:14 +1000, "John G" <Greentest@ozemail.com.au>
put finger to keyboard and composed:

"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:agji71lifbikg844o1l3osik3rb28aphsf@4ax.com...
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

In the text Wayne said "It works" but the description is very vague on
details and seems to not understand 'Double Insulated'.
He says it can be built into the device. Well if the switch is in the
hair dryer in the water how does it keep the EXCESS electricity out of
the water?

The ABC URL states that the device could be made waterproof by
encapsulating it. Assuming there are no exposed parts upstream of the
safety device, then the hair dryer should not "leak" electricity.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

 

[Phil Allison]

"Franc Zabkar"

Then why go to the trouble of building it into your appliances when
you could mould it into a universal plug?

** See my "two cents worth" .

Doing that does not allow connection to metalwork in a Class 2 appliance.

In fact the inventor agreed
that the device could be incorporated into the GPO.

** But it looks like he has not tried it.

The ABC URL goes
on to say that "Protex is an electrical safety switch that can be
installed at the manufacturing level into new household appliances
(toasters, kettles, hair dryers) or into a home's electrical power box
or switch board." This says to me that it's a two-wire device
(remember the toaster demo), and that it's probably nothing more than
an automatically resettable RCD, despite the inventor's statement that
it senses voltage.

** I prefer not to assume the inventor is a liar.




............ Phil

 

[Phil Allison]

"Franc Zabkar"

The ABC URL states that the device could be made waterproof by
encapsulating it. Assuming there are no exposed parts upstream of the
safety device, then the hair dryer should not "leak" electricity.

** Exactly - the inspiration and whole idea of the invention is to
instantly isolate a Class 2 hair dryer or shaver that lands in the bath tub
or wash basin.





............... Phil

 

[Heywood Jablome]

I reckon its all a croc of shit. The only way to get electrocuted to death
if you have an RCD, is if you grab a neutral cable in one hand and an active
cable in another while standing on an insulated floor. The current has to
pass through the heart or through the brain to kill you. If you read some
stories with regard to electric chairs, you will find that it is actually
quite difficult to kill someone with electricity.

Even a baby that sticks a live two pin plug in its mouth will be ok. Might
just get a big shock but certainly not death. Even then the child will have
to be insulated from earth.


Same goes with a dryer in a bath tub. A bath tub is often connected with
metal drain pipes to earth. So the RCD will go off if the current is not
balanced between active and neutral. If it is balanced enough to not set the
RCD off, then there is little risk to the occupant in the bath tub.

 

[Phil Allison]

"Heywood Jablome"

I reckon its all a croc of shit. The only way to get electrocuted to death
if you have an RCD, is if you grab a neutral cable in one hand and an
active
cable in another while standing on an insulated floor. The current has to
pass through the heart or through the brain to kill you.

If you read some
stories with regard to electric chairs, you will find that it is actually
quite difficult to kill someone with electricity.

** If you read accounts of accidental electrocutions - you will find it is
absurdly easy to die.

Do you remember the one where the 3 y.o girl died when using a hairdryer
while sitting on the back step - when her older brother threw small bucket
of water onto her ???

Even a baby that sticks a live two pin plug in its mouth will be ok.

** You have proof of this ????

Might just get a big shock but certainly not death.

** You have proof of this ????

Even then the child will have to be insulated from earth.

** A carpet floor will do that.

Same goes with a dryer in a bath tub. A bath tub is often connected with
metal drain pipes to earth. So the RCD will go off if the current is not
balanced between active and neutral. If it is balanced enough to not set
the
RCD off, then there is little risk to the occupant in the bath tub.

** This last one has GOT to be a subject for the Mythbusters .



............ Phil

 

[Dave Goldfinch]

On Thu, 5 May 2005 13:45:48 +1000, "Phil Allison"
<philallison@tpg.com.au> wrote:

"Franc Zabkar"
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


** My two cents worth is this:

The Protex device trips a normally closed latching solenoid switch upon
detection of a significant AC voltage appearing on the metal case or
internal metal ( non live) parts of the particular Class 2 appliance - as
measured relative to the neutral wire. Pretty much, this makes it a
submersion detector.

Such AC voltage detection - if applied to external metal parts would have to
be via a low value Y2 rated capacitor so not to breach Class 2 requirements.





............. Phil

Phil

That would seem to be a plausable explanation but what about if it was
built into a GPO ? There would be no way to sense the voltage on the
case or internal metal without an extra wire back to the GPO.

Perhaps this is why he claims that it 'could' be built into a GPO but
he hasn't done it yet - because it is impractical ?

BTW could you use a triac instead of a solenoid switch or would this
cause problems with some appliances ?

Dave Goldfinch

 

[T.T.]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:3du48nF6eu4U1@individual.net...

"Heywood Jablome"

I reckon its all a croc of shit. The only way to get electrocuted to
death
if you have an RCD, is if you grab a neutral cable in one hand and an
active
cable in another while standing on an insulated floor. The current has to
pass through the heart or through the brain to kill you.

If you read some
stories with regard to electric chairs, you will find that it is actually
quite difficult to kill someone with electricity.



** If you read accounts of accidental electrocutions - you will find it
is absurdly easy to die.

Do you remember the one where the 3 y.o girl died when using a hairdryer
while sitting on the back step - when her older brother threw small
bucket of water onto her ???


Even a baby that sticks a live two pin plug in its mouth will be ok.


** You have proof of this ????


Might just get a big shock but certainly not death.


** You have proof of this ????


Even then the child will have to be insulated from earth.


** A carpet floor will do that.


Same goes with a dryer in a bath tub. A bath tub is often connected with
metal drain pipes to earth. So the RCD will go off if the current is not
balanced between active and neutral. If it is balanced enough to not set
the
RCD off, then there is little risk to the occupant in the bath tub.


** This last one has GOT to be a subject for the Mythbusters .



........... Phil

Yes. But how do you get both of them into a bath?

 

[Phil Allison]

"Dave Goldfinch"
"Phil Allison"

//www.abc.net.au/newinventors/txt/s1356442.htm


** My two cents worth is this:

The Protex device trips a normally closed latching solenoid switch upon
detection of a significant AC voltage appearing on the metal case or
internal metal ( non live) parts of the particular Class 2 appliance - as
measured relative to the neutral wire. Pretty much, this makes it a
submersion detector.

Such AC voltage detection - if applied to external metal parts would have
to
be via a low value Y2 rated capacitor so not to breach Class 2
requirements.


That would seem to be a plausable explanation but what about if it was
built into a GPO ? There would be no way to sense the voltage on the
case or internal metal without an extra wire back to the GPO.

** AFAIK that is a purely hypothetical product. It would need to sense
voltage on the appliance earth wire - so breaking the rules about earth
continuity.

Perhaps this is why he claims that it 'could' be built into a GPO but
he hasn't done it yet - because it is impractical ?

** IMO, 100% yes.

BTW could you use a triac instead of a solenoid switch or would this
cause problems with some appliances ?

** The safety trip MUST break both the active and neutral conductors ( in
case of A-N reversal) and provide galvanic isolation - ie an air gap or
solid insulation. A triac is just not on.




............ Phil

 

[Brad Hogan]

"

The Protex device trips a normally closed latching solenoid switch upon
detection of a significant AC voltage appearing on the metal case or
internal metal ( non live) parts of the particular Class 2 appliance - as
measured relative to the neutral wire. Pretty much, this makes it a
submersion detector.

significant AC voltage means the person is well and truely shocked !!!

An electrocuted person can be electrocuted by leaks that dont cause such
signficant voltage.

That would seem to be a plausable explanation but what about if it was
built into a GPO ? There would be no way to sense the voltage on the
case or internal metal without an extra wire back to the GPO.

The case of a fridge or heater has to be connected to earth.

Perhaps this is why he claims that it 'could' be built into a GPO but
he hasn't done it yet - because it is impractical ?

I think he just means its impractical to put such a stupid device in there.

Mabye you could only tolerate the stupid thing in a hair dryer.

BTW could you use a triac instead of a solenoid switch or would this
cause problems with some appliances ?

triacs cant be used as a safety device - they dont work well enough - not
reliable, and their reliable performance as as with isnt good enough for
safety.

 

[Brad Hogan]

"John G" <Greentest@ozemail.com.au> wrote in message
news:Y8eee.46$sb6.969@nnrp1.ozemail.com.au...

"Franc Zabkar" <fzabkar@optussnet.com.au> wrote in message
news:agji71lifbikg844o1l3osik3rb28aphsf@4ax.com...
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

In the text Wayne said "It works" but the description is very vague on
details and seems to not understand 'Double Insulated'.
He says it can be built into the device. Well if the switch is in the hair
dryer in the water how does it keep the EXCESS electricity out of the
water?

double insulated .. well the level of insulation isnt relevant, he was
probably trying to think of what doubling the insulation could do....

(my wires are double insulated - two layers of cling wrap !)