Electrical code Compliance - HUMplug-e product

Author

HUMplug-e product

Tomi Holger Engdahl

2007-05-14, 1:25 pm

Anyone has experience on this HUMplug-e product ?

Web page
http://www.21best.com/21_best/elect.../for_sale_.html says:
" Simply plug your equipment through this, to cure it of Ground
Loops. Filters out unwanted voltage and current in the ground line
that cause ground loop hum while simultaneously maintaining a solid,
safe ground."

I have experience on many different way on solving ground loop
loop problems in audio/vidoe systems. Practically every other
types of products listed on that page are known to me in details
(I have used similar produicts, know what is inside such items,
even manufactured some quite simlar products). I have written
some material on ground loop solving to
http://www.epanorama.net/documents/...loop/index.html

How this HUMplug-e product works makes me wonder.
Given the specifications (15A current) and a small
size it can't be an isolation transformer.
According the description it keeps the solid
ground connection it just can't be a "cheater" plugs
that just simply cuts ground connection (dangerous
peactice that is not recommended).

My quess that it does some magic on ground connection
so that it stops/reduces the current that can flow on
normal ground loop case, but still lets the ground
connection to be good enough for electrical safely.
I am just wondering how this is done in such what that it
works and meets the electrical code safey requirements.
Anyone has experience on how this is implemented ?
Some of my quesses would be those impklementation
possibilities:
- some common mode coil type construction over all wires
- two parallel diodes (on different directions) wired
between input and output ground connections
(stops current when voltage difference is low but
will pass hort circuitfualt currents at low voltage drop)

Anyone commenting my quesses how this device works ?
Anyone has experience on this ?

--
Tomi Engdahl (http://www.iki.fi/then/)
Take a look at my electronics web links and documents at
http://www.epanorama.net/

Mr.T

2007-05-15, 3:25 am

"Tomi Holger Engdahl" <then@pippuri.niksula.hut.fi> wrote in message
news:lajbqgncp43.fsf@pippuri.niksula.hut.fi...
> Some of my quesses would be those impklementation
> possibilities:
> - some common mode coil type construction over all wires

Not very effective at mains frequencies in such a small device.

> - two parallel diodes (on different directions) wired
> between input and output ground connections
> (stops current when voltage difference is low but
> will pass hort circuitfualt currents at low voltage drop)

Probably, that technique has been used many years ago.

The other possibility is that it's simply bullshit, either way it would be a
total rip off at that price.

MrT.

Arny Krueger

2007-05-15, 9:25 am

"Mr.T" <MrT@home> wrote in message
news:464941c6$0$16033$afc38c87@news.optusnet.com.au

> "Tomi Holger Engdahl" <then@pippuri.niksula.hut.fi> wrote
> in message news:lajbqgncp43.fsf@pippuri.niksula.hut.fi...

[color=darkred]
> Not very effective at mains frequencies in such a small
> device.

>
> Probably, that technique has been used many years ago.
>
> The other possibility is that it's simply bullshit,
> either way it would be a total rip off at that price.

Either that, or a safety hazard.

yea

2007-05-15, 9:25 am

Tomi Holger Engdahl wrote:
>
> Anyone has experience on this HUMplug-e product ?
>
> Web page
> http://www.21best.com/21_best/elect.../for_sale_.html says:
> " Simply plug your equipment through this, to cure it of Ground
> Loops. Filters out unwanted voltage and current in the ground line
> that cause ground loop hum while simultaneously maintaining a solid,

brrrrr.

> (stops current when voltage difference is low but
> will pass hort circuitfualt currents at low voltage drop)
>
> Anyone commenting my quesses how this device works ?
> Anyone has experience on this ?
>
>

A 10 Ohms resistor inserted somewhere in the ground loop will
almost always cure a hum.
Inserting this in the safety-ground at the mains connection
could give a hazardous situation.
But in the ground connection of the audio connection-cables
will do fine.

and

absolutely no "loss of volume, tone or both."

Andre

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