Take one soft iron rod and place inside a coiled wire. Pass current through the wire and, inductance being what it is, the iron rod will shoot out of one end of the coil of wire. Put something on the rod to stop it going all the way out of the coil and you have something which is a bit like a spring - any attempt to push the rod back into the coil will (back emf, etc.) be resisted proportionally to the strength of the current in the coil.
Now replace all the pocketed springs in a mattress (about 1500 in the mattress I just bought...) with these, turn on, and you've got a nice springy mattress.

- Adjustable firmness - just turn up the power for a firmer mattress

- Massage - Microprocessor control of the current being supplied to individual 'springs' can be used to gently massage you to sleep

- Bed Hog counter-measures - if your partner takes command of the centre of the bed, forcing you to the edge, a travelling 'Mexican Wave' can be passed through the mattress to nudge them back over to their side. Alternatively, this can be reversed if you're feeling amorous.

- In cold climates the heat lost from the coils as you toss and turn will gently warm you


Halfbaked or what?
-- hippo, Apr 23 2001

(?) Earnshaw's theorem http://www.sci.kun....ation-possible.html
Coils being dipoles, Earnshaw's theorem says that you will need some sort of horizontal stabilization or feedback. You will also need some damping, as "springs" will be near perfect and thus oscillate for a long time (one of the reasons some people don't like waterbeds). The later quite easy to do electromechanically using eddy currents. [rmutt, Apr 23 2001, last modified Oct 21 2004]

Diamagnetic Levitation http://www.physics.ucla.edu/marty/diamag/
Rmutt now knows what Earnshaw didn't: diagmagnetic effects can produce real magnetic levitation without motion, current, or superconductivity. [rmutt, Apr 23 2001, last modified Oct 21 2004]

Maglev sleep chamber http://www.halfbake...v_20sleep_20chamber
[phoenix, Apr 15 2002, last modified Oct 05 2004]

Is a travelling 'Mexican Wave' equivalent to fanned farts reaching the other side of the bed? <rimshot> My only concern is what magnetic properties do outside the construction itself.
-- thumbwax, Apr 23 2001


:applause: Halfbaked indeed, I'd say. But, how much would it *weigh*? No more flipping the mattress every other season, unless you rent a crane. ('course, also, no more wearing out of springs, either)
-- absterge, Apr 23 2001


Oh yes - And if we assume the 'springs' are arranged in a matrix and are individually addressable, then Braille readers could lie in bed reading books as they scroll past their whole body...
-- hippo, Apr 24 2001


[waugsqueke] A low hum can be arranged
[UnaBubba] Yes. (Hmmm - risk of electrocution...)
-- hippo, Apr 24 2001


...and it will have an alarm clock function - gentle at first, then increasingly violent 'spring' activity...
-- hippo, Apr 25 2001, last modified Apr 26 2001


Attach further magnets to the edges of blankets, sheets, quilts etc and the fight for an equal share of the covers could be ended peacefully.
-- sirrobin, Apr 26 2001


Loudspeaker drive units could be used as the 'springs' too.
-- hippo, Apr 26 2001


[hippo]: Can the spring activity have a Richter scale?
-- angel, Apr 26 2001


I don't know. I'd probably wake up from a quick nap perfectly refreshed and ready to face the world... until I realized that I erased every credit card in my wallet and that my watch no longer worked.

On the other hand, for the sexually adventurous, there's no more of a risk of lost handcuff keys. Just unplug the bed and take off the bracelets.
-- III, Apr 27 2001


How do you unplug the bed when you're handcuffed to it?
-- sirrobin, Apr 28 2001


Note that these 'springs', if individually addressable, can be fored to oscillate either in phase or out of phase with sexual activity, depending on preference...
-- hippo, Jul 06 2001


This all sounds like a bit of a disaster for us bed wetters.
-- DrBob, Jul 06 2001


Electromagnetic bed?

The old man said.

Not the place to lay MY head.

Nor do I want to go off in,

An electromagnetic coffin.
-- rayfo, Jul 06 2001


Just imagine, people having sex on the bed could generate enough power for the entire neighborhood.
-- Rico419, Jul 06 2001


WARNING: Hippo Mattress Corp. accepts no liability for misuse of this product. This product should not be used by people with braces, pacemakers, metal bone pins, metal hips or back braces. It is recommended that all metallic objects within 10' of this product be removed. This includes (but is not limited to) radios, eyeglasses, ceiling fans, crutches, lamps, silverware, wheelchairs, watches, computers or computer accessories, candle holders, remote controls and sexual aids. Do not allow food or drink in the vicinity of this product. FAILURE TO FOLLOW THESE INSTRUCTIONS MAY RESULT IN SERIOUS INJURY. Please refer to the Owner's manual for operating instructions. Do not attempt to open or repair this product as there are no user servicable parts inside.
-- phoenix, Jan 21 2002


I think the humming sound that electromagnets produce under stress would keep you awake.
-- iansmith, Jun 06 2002


Sounds dangerous if the power went out in the middle of the night.. And then, came back on with a big power spike. cool.
-- blowfish, Jun 06 2002


Many believe that the North Pole of magnets have therapeutic value, curing everything from Arthritis to Cancer.
-- KindlyRat, Jun 06 2002


I think there needs to be an uninterruptable power supply, or at least something that, in case of power failure, simply lowers the magnets slowly to the bottom so you aren't jolted into a serious backproblem during a thunderstorm.

Maybe combine it with that levitating bed idea and have some real fun. And when you wake up, you'll be in Japan!
-- adamsmith, Sep 29 2003


it sounds like the prep for an MRI[phoenix]
-- toomer34, Jun 26 2005


I like. [+]. Imaginary [++].

'Want to really scare your enemies? Buy our new, patented electromagnet desruptor! Simply point the device at your enemies bed to fire them up to six feet in the air! (We take no responsibility for any damage, accidental or purposefull, caused by use of this device.)'
-- dbmag9, Jun 26 2005


You bugger [hippo]! I was just checking that no one had done the anti bed-hogging mattress using walking wave motion and I find that not only have you done it but you've concieved an entire electromagnectic mutlifunction intelligent ultra-mattress. [++]
-- wagster, Jan 25 2006


[wagster] That's the trouble with the HalfBakery. All the really obvious ideas like anti bed-hogging measures using walking waves in mattress springs have been done now.
-- hippo, Jan 25 2006


What about using this bed with a defibrillator? Will the magnetic field interfere with it?
-- Jscotty, Jan 25 2006


Yeah [21], this idea came before yours by like 5 years.
-- MikeOxbig, Jan 27 2006


Make* $$ as you sleep.

*'Make' in the little known meaning of 'burn', here.
-- loonquawl, Mar 23 2009



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