Lets get right to buisness. This device is installed to the doornob of your door and a place where it hits if pushed into the wall. both of these are magnetic, but the thing that makes this halfbaked idea is that the polarity on the place where the doornob hits the wall can be changed because it is an electrig magnet. If you can have a magnet strong enough to do this, when charged positively, the doornob magnet would attract towards this spot, therefore, opening the door. The polarity can be charged negatively to repel the door closed. The doors magnet would have a power switch so bugulars would not use a powerful magnet to repel it. The doornob being two-sided, could have a positive flow on the outside and negative on the inside. or vica versa. And that's it!-- Chickenbreadthe1st, Jul 16 2005 Electromagnetic Door Release http://www.sargentl...il.php?line_id=232&Electromagnetic door releases are commonly installed on normally open fire doors in office and commercial buildings. You don't see many powerful enough to automatically pull a door open, though. [jurist, Jul 17 2005] knob! believe me...-- po, Jul 16 2005 If we get started on spelling and punctuation with this one, we'll be here all night. At least this one has a few capital letters, often in the right place.-- Basepair, Jul 16 2005 It would be scarier to see magnetic objects flying from any peoples standing near the door, or indeed people with pacemakers apparently spontaneously collapsing.-- pooduck, Jul 16 2005 This idea is knobtastic --- DenholmRicshaw, Jul 16 2005 Mr. Google has just given me 312,000 hits for "automatic door opener" and 595,000 for "automatic door closer". So I'm not sure that having a magnetic knob is essential, interesting though it would be.-- Basepair, Jul 16 2005 Yeah yeah yeah. So what if I have trouble with spelling and punctuation. So maybe it's impractical, but you can put up a sign...
"GOOD CARDIAC ENTRANCE ONLY"-- Chickenbreadthe1st, Jul 16 2005 //So what if I have trouble with spelling and punctuation.// You mean "So what if I have trouble with spelling and punctuation?", surely?-- Basepair, Jul 17 2005 Magnetic fields do not operate over the distance you are implying here (2 feet minimum between closed door knob and wall) unless they are VERY strong. This error was also made in the Bond film "Live and Let Die"-- Minimal, Jul 18 2005 I think the point that [po] was making was that, as you spelled it, it may mean something else entirely.-- david_scothern, Jul 18 2005 sorry, this wouldn't really work for 2 reasons #1- the magnets would be too far away #2 every time you walked through this door, if you had a cell phone or whatever all the phone book contacts may be erased! (i doubt it would damage the phone but that could cause problems-and then you may take your frustration out on the door by kicking it really hard-and then the door out of anger for unneccesary abuse, would fly back at you quickly and strike you, repeating until you run away screaming or are K-Od-- Dickcheney6, Oct 09 2009 Actually, it probably wouldn't erase anything. Phones store data in memory or flash memory, not on disc, I think. And, in any case, some of the most powerful magnets you're likely to encounter in everyday use are already a part of your disc drive. Still wouldn't work, though, for reasons that you and Minimal pointed out. (Not such a bad idea, though, apart from this.)-- MaxwellBuchanan, Oct 10 2009 random, halfbakery