I got to build me one of those.
A YouTube video of "The Most Useless Machine EVER!" is proving popular among those who'd like to have a robotic box whose only purpose is to turn itself off: This entertaining device is a version of the "Ultimate Machine" built by US electronic engineer Claude Shannon, based on an idea by Marvin Minsky, the co-founder of …
..when I saw the video. I was gutless with laughter (and, 'outside' means -20 Celcius at the moment - in a t-shirt). Outside, because, being on the Dole I couldn't afford to buy the pub. yet another keyboard.
Thanks for that! Joviality, gathering nuts and may, etc. Could even get a wry smile from Eeyore.
Actually, you guys are missing the point, this is actually pretty interesting, if you think, there isnt any actual invention that can turn itself completely off ready to be powered on without an external intervention, here is the description of the box that ben posted (the grand illusion one):
"I believe I am right in saying this machine was actually always "on", with an electromagnet holding the spring-loaded piston (with a doll's hand on) in place until the switch was operated; the hand then shot out, turned the switch "off", re-energised the solenoid, and retracted. "
Its exatly the inverse mechanism, which means that by mixing the two techniquies with some adaptations, we can actually create perpetual motion by constantly switching between on and off states...
Paris Hilton, because genius iam not
Apart from the banks from the 60's (I had one that was called the Schmeckenbeckerschnitzelbank), I also remember an Apple prank from the pre-OS X days: there was a little AppleScript with an icon of a switch that, when clicked, shut the computer down (devised, I guess, as a minor convenience). Putting this item (surreptitiously) in the Startup Items folder turned the Mac into a similarly useless machine, with the added value of driving the victim nuts...
Grief, it was - er -funny. Yet some of you have been lambasted.
As an aside I'm glad Moderatrix is back as a moderator. I've had some IMHO incongruous posts rejected by the new jobcentre retrainee yoof numpties that El Reg is now giving the BOFH's cattle-prod training course, one of whom who e-mailed me to tell me he didn't respect my opinion. Can't remember hs name - "Ding, Dang, Ding-a-l-ling-a Dong, Dung" or something like that....
Muppet. Bet he's less than 50 years old. Why do children moderate my comments???
I'm not your friend and protector, McCoatover. I would nix all of your comments as soon as look at them. And if you bother my esteemed colleague again then you will be in a world of poop.
Either that or I'll just go on living my life, as will he. It's always an option. I tend to forget.
He bothered me. Personally. Write the reason for the distaste of the comment on this 'wall', NOT my personal e-mail. (As you did about my comment earlier - fair play to that). E-mail was unprofessional. Me? I don't need to be professional - I'm not in a profession, unless 'drawing the dole' is becoming one nowadays - which IS a 'world of poop'. Hope you never try it.
As my mother used to say "Andus, you're big enough and ugly enough not to let it bother you". (Nor, I might add, to need a 'friend and protector')
Wassat? "Life on line 1, Andus"
I first saw one of these on http://www.hackaday.com a while ago and had that "I've so got to make one of those" thoughts, a little digging round YouTube revealed these things have been around forever, originating in those cute mechanical coin banks where you place the coin on a pad and a hand or something reaches out of the box and pulls it in.
However this one is my favourite useless machine so far: http://www.youtube.com/watch?v=2F_BKe-XWo4
"if you think, there isnt any actual invention that can turn itself completely off ready to be powered on without an external intervention."
Of course there is. The original novelty "black box" toy of the 1950s, upon which this less interesting knockoff is based, contained a mechanism powered by an electric motor. Power to the motor was gated through the top-mounted switch. When the switch was turned on, the motor ran for several seconds while the box rocked and jerked mysteriously (thanks to a cam-actuated lever on the underside); then the hand came out of the lid, flipped the switch, and retracted as the motor shut off. At that point the cycle could be repeated ad lib.
Point is, while the black box was off, it was truly and completely off--it wasn't drawing any current until the switch was thrown by the user. I believe that meets your definition, "Paris."
As for Ben's statement that "I believe I am right in saying this machine was actually always 'on', with an electromagnet holding the spring-loaded piston..." well, Ben guessed wrong. At least, none of the boxes of this type that I saw in the 50s and 60s worked that way. Think about it: if they had, they would have drained their batteries very quickly supplying current to Ben's imagined solenoid. It may be hard to believe, but even fifty years ago, engineers were smart enough not to do that. ;-)
They had commercially available versions of this very toy when I was a kid. The only difference was that it was a modified version of the "coin grabbing hand" box and so had a convincing monster hand that threw the switch instead of the wooden hook this one has.
I call shenanigans!
I just looked at the schematic. It uses a 555 timer as a monstable. Retro sure, but a relay would work as well, or a windscreen wiper motor switch.
If you think about it, a single stroke windsceen wiper does exactly the same thing: push the switch and release it, and the wiper does one wipe then switches itself off. This just uses the arm to reset the switch instead of a spring.
Very good workfriend of mine, who was turned to dust in a crematorium (G3TFM, anyone?) in the Autumn of 2007, had a mini.
I had a Ford Anglia*. Neither of us had a delay wiper, so, I designed and built on Veroboard - one for each. Used a UJT (Unijunction transistor) as the 'timer', with a cheap relay to fire the wipers off. About 5 components in total. This was about 1978.
*This was an Anglia 105E (registration 989 FOJ - clue on it's age. Never let me down, even tho' it only cost me £50 then), not the previous version 995E. The previous version had a vacuum wiper mechanism linked to the intake. In short, the more you put your foot down, the slower the wipers got. Yep, doing 70 in heavy rain, it was better to stick your head out of the window. If you REALLY needed to see, take foot off accelerator, and wait...wait...wait for the vacuum to build up.
This concept has been around for forty years that I personally know of; probably even longer. Back then, however, the machines were a it more entertaining, as a skeletal hand would creep out and *pull* the switch to turn the device off.
I suppose that when enough people forget about something, it gets "reinvented" and is considered new by a new generation. I await the (re)discovery of the Slinky, the Frisbee (previously known as the "Pluto Platter"), and the Hula Hoop.
Paris Hilton, because El Reg doesn't do IT, but they do Paris...