The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: Kevin McMurtrie
Subject: Re: Wall wart with two blade polarized plug,,,Why?
User-Agent: MT-NewsWatcher/3.2 (PPC Mac OS X)
Date: Wed, 02 Oct 2002 17:31:46 GMT
NNTP-Posting-Date: Wed, 02 Oct 2002 10:31:46 PDT
In article <3D9A856D.99A017C7@110.net>, Jeff Wisnia
>I'm trying to think of a realistic reason why my little TV's 120 vac -
>12 vdc 1.0 amp simple xformer/bridge rectifier wall wart needs one of
>its two input blades wider than the other so that it won't insert into
>an duplex outlet in a convenient direction. (i.e. so its body doesn't
>interfere with a right angle cord plug already in the other half of the
>I've got half a drawer full of wall warts from various now-discarded
>devices, and all but one have equal width plug blades and can be
>pluggged into a receptical "either way".
>Before I file down that wide blade, did I overlook anything? Maybe the
>designer of this wall wart has the wide blade connected to the end of
>the transformer primary nearest the secondary so that an insulation
>breakdown there doesn't connect the hot side of the line to the low
>voltage circuitry? That seems a stretch to me.
>Anybody know for sure?
There's likely a resistor between the DC negative and the AC neutral.
TV's throw off some electricity from the high voltage they use. All TVs
powered off AC either have a hot chassis or a partial connection to the
AC neutral. A fully insulated chassis would eventually result in
something arcing over.
Your .sig needs a space after the dashes.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup