Most Useless Machine

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jwax
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Most Useless Machine

Post by jwax » Sun Jan 31, 2010 7:57 pm

May have seen this:
http://www.youtube.com/watch?v=Z86V_ICUCD4
I'm wondering what the simplest circuit/actuator would be to get the machine to function this way.
Would several switches alone perform the function? A microcontroller seems like overkill. The existing design uses a 555 timer to activate a servo.
I'm wondering what the forums design gurus can come up with to function this way, with the simplest circuitry.
Bear in mind the servo used needs pulses to activate it. Maybe a servo-less design would be the simplest circuitry? Motor? Solenoids?

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Externet
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Re: Most Useless Machine

Post by Externet » Sun Jan 31, 2010 8:23 pm

- Abolish the deciBel ! -

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Re: Most Useless Machine

Post by CeaSaR » Sun Jan 31, 2010 10:35 pm

Saw that on Instructables.com when I joined last year. As a matter of fact, you can find the link for it
under the info section of the video you posted Jwax. It's a great "idiot box".

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Re: Most Useless Machine

Post by haklesup » Mon Feb 01, 2010 1:08 pm

Seems like a variation on a piggy bank or maybe a halloween gag with a skeletal hand that comes out when someone reaches for the candy. However, this one is dumbed down to the least common denominator. I can see this as an interesting pet toy too (with alternate pressure switch used)

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Re: Most Useless Machine

Post by dacflyer » Mon Feb 01, 2010 4:05 pm

wow,, i could finally find a good use for that servo exerciser, change the pot out for a certain value resistor on each side of the switch..

otherway if you use a geared motor is have a forward/reverse switch with 2 limit switches.
Hmmmmm
looks fun either way..

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Bob Scott
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Re: Most Useless Machine

Post by Bob Scott » Tue Feb 02, 2010 10:33 am

It would be interesting to see a version with two arms and one switch, each arm toggling the switch in the opposite direction as the other. It would never stop moving....

This brings up even more ideas. :grin: Building a toy crane or bulldozer with the "operator's hands" constantly moving the hook left, right, up , down, or the bulldozer moving sand in random directions much like a Roomba out of control. :smile:
-=VA7KOR=- My solar system includes Pluto.

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Re: Most Useless Machine

Post by CeaSaR » Tue Feb 02, 2010 10:46 am

Bob Scott wrote:... Roomba out of control...
ROOMBOTICA!

:razz: :mrgreen:

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Re: Most Useless Machine

Post by dacflyer » Tue Feb 02, 2010 3:43 pm

hey bob, your idea with the two arms fighting it out.. that would be a good switch tester, to see how long it last til it wore out..

kinda would be like 2 kids fighting over who has control..lol

curious what the servo circuit version look like.. actually the part where it has a auto turn off switch until you turn it on.. when the servo goes in the box, it rest on a switch to turn the unit off, until you hit the switch ,

switched and no electronics version is the simplest tho..

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jwax
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Re: Most Useless Machine

Post by jwax » Thu Feb 04, 2010 5:08 am

Here's the servo version:
Image

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Re: Most Useless Machine

Post by dacflyer » Thu Feb 04, 2010 4:39 pm

great ! thanks... :D

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jwax
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Re: Most Useless Machine

Post by jwax » Thu Feb 04, 2010 4:54 pm

And the circuit description, courtesy of instructables.com:
Inside the box is a very simple circuit controlling a standard RC servo. It's powered by four double A batteries. When idle, the circuitry is fully powered down. Inside the box is a secondary power switch that is held in the off position by the servo arm.

The main switch (the switch on top of the box) is a Dual Pole, Dual Throw (DPDT) toggle switch. This type of switch is actually a pair of switches which operate together (Dual Pole) and both are On-On (Dual Throw).

One pole of the switch supplies power to the circuit. The other pole switches the servo arm back and forth.

When the toggle switch is turned on, it provides power to the circuit (using one pole of the switch) and sets the servo arm to rotate towards turning the toggle switch off (using the other pole of the switch).

As the servo arm moves away from it's off position it allows the secondary power switch to turn on supplying redundant power to the circuit.

When the servo arm reaches the toggle switch and turns it off, power is still supplied by the secondary switch. At this point the circuit now signals the servo to return to it's 'OFF' position.

The servo arm reverses direction returning to it's 'OFF' position and switches off the secondary power.

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Re: Most Useless Machine

Post by dacflyer » Thu Feb 04, 2010 5:36 pm

the term DEAD BUGGING in the circuit description... not sure what that means..can someone clairify please.. thanks.

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Re: Most Useless Machine

Post by Robert Reed » Thu Feb 04, 2010 5:46 pm

Well from what I have always seen. DEADBUG circuits use no platform (circuit bd.,breadboard,whatever). the components are all soldered direct with as few wires as possible. The end result looks like a "dead Bug" especially with DIP ICs lying on their back.

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jwax
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Re: Most Useless Machine

Post by jwax » Thu Feb 04, 2010 5:53 pm

Correct Robert. No board, terminal block, or other supporting structure- just the components hanging in the breeze by their leads. In this case, resistors wired right at the switch terminals.
One point not clear is the servo has three leads- ground, power, and signal. The power goes to the Pin 8 of the IC, not directly to the battery pack.

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Lenp
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Re: Most Useless Machine

Post by Lenp » Fri Feb 05, 2010 7:56 am

Dead Bugging?..
A lifetime of electronics and that's the first I've heard that term.
Great description, never too old or smart to learn!
Len
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"I must be on the way to success since I already have the junk". (Me)

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