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From: Jeroen Belleman <jeroen@nospam.please>
Newsgroups: sci.electronics.design
Subject: Re: Electrostatic actuators to move robots legs...
Date: Sat, 14 Sep 2024 21:49:39 +0200
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On 9/14/24 20:21, john larkin wrote:
> On Sat, 14 Sep 2024 05:55:41 GMT, Jan Panteltje <alien@comet.invalid>
> wrote:
> 
>> On a sunny day (Fri, 13 Sep 2024 20:40:55 +0200) it happened Jeroen Belleman
>> <jeroen@nospam.please> wrote in <vc20pt$10e68$1@dont-email.me>:
>>
>>> On 9/13/24 13:38, Jan Panteltje wrote:
>>>> On a sunny day (Fri, 13 Sep 2024 20:55:09 +1000) it happened Chris Jones
>>>> <lugnut808@spam.yahoo.com> wrote in <jSUEO.167440$QvZa.5887@fx08.ams4>:
>>>>
>>>>> On 13/09/2024 2:49 pm, Jan Panteltje wrote:
>>>>>> On a sunny day (Thu, 12 Sep 2024 14:43:02 +0200) it happened Jeroen Belleman
>>>>>> <jeroen@nospam.please> wrote in <vbuneq$8hap$1@dont-email.me>:
>>>>>>
>>>>>>> On 9/12/24 12:34, Jeff Layman wrote:
>>>>>>>> On 12/09/2024 10:45, Cursitor Doom wrote:
>>>>>>>>> On Thu, 12 Sep 2024 05:00:38 GMT, Jan Panteltje wrote:
>>>>>>>>>
>>>>>>>>>> Artificial muscles propel a robotic leg to walk and jump:
>>>>>>>>>>      https://www.sciencedaily.com/releases/2024/09/240909113111.htm
>>>>>>>>>>
>>>>>>>>>> quote:
>>>>>>>>>>      "
>>>>>>>>>>      The actuators are oil-filled plastic bags, similar to those used to
>>>>>>>>>>      make ice cubes.
>>>>>>>>>>      About half of each bag is coated on either side with a black electrode
>>>>>>>>>>      made of a conductive material.
>>>>>>>>>>      Buchner explains that "as soon as we apply a voltage to the
>>>>>>>>>> electrodes,
>>>>>>>>>>      they are attracted to each other due to static electricity.
>>>>>>>>>>      ...
>>>>>>>>>>      "
>>>>>>>>>> And press the fluid out....
>>>>>>>>>> So electrostatic actuators!
>>>>>>>>>
>>>>>>>>> How does that not violate thermodynamics? You seem to be getting useful
>>>>>>>>> power from zero energy.
>>>>>>>>
>>>>>>>> How do little pieces of paper defy gravity when you put a charged comb
>>>>>>>> near them? Isn't the energy supplied by rubbing the comb against some
>>>>>>>> material to give it the charge to attract the paper? Where does the
>>>>>>>> voltage come from which is applied to the bag electrodes?
>>>>>>>>
>>>>>>>> Didn't we discuss something like this not too long ago, or was it in
>>>>>>>> another NG?
>>>>>>>> <https://en.wikipedia.org/wiki/Electrostatic_motor>
>>>>>>>>
>>>>>>>
>>>>>>> That was right here in s.e.d in July. And no, thermodynamics, or
>>>>>>> rather conservation of energy is not violated. It never is.
>>>>>>>
>>>>>>> I don't think that they can get useful amounts of work out of these
>>>>>>> things. The Science Daily article is useless, as always, and I did
>>>>>>> not bother to read the paper.
>>>>>>>
>>>>>>> Jeroen Belleman
>>>>>>
>>>>>> At least they made something that works,
>>>>>> unlike the trillions spend at CERN that never do anything for anybody.
>>>>>> I would cancel all funding to CERN if they did not come up with something revolutionary and practical useful in a year.
>>>>>> He who does not want to see is practically blind.
>>>>>>
>>>>>
>>>>> Kicad and web browsers are quite useful, even if the physics is of no
>>>>> interest to you.
>>>>
>>>> html was invented long ago by somebody from CERN
>>>>    https://nl.m.wikipedia.org/wiki/Tim_Berners-Lee
>>>> quote in Dutch:
>>>>    " Timothy John (Tim) Berners-Lee (Londen, 8 juni 1955) is samen met zijn toenmalig manager, de Belg Robert Cailliau,
>>>>    de bedenker en grondlegger van de technologie en het protocol, die het world wide web of wereldwijde web, afgekort tot www,
>>>>    mogelijk maakten. Hieraan werkte hij toen hij consultant-software-engineer in dienst bij het CERN in Zwitserland was,
>>>>    van juni tot en met december 1990"
>>>>
>>>> Timothy John (Tim) Berners-Lee  only worked at CERN from june to december 1990
>>>> So basicaly nothing to do with CERN or elementary particles etc.
>>>> There is old html server code I had somewhere from a CERN website that I once used.
>>>> Modern browsers are hopelessly bloated with other stuff, mostly for enabling more advertizing :-)
>>>>
>>>> Without CERN he likely would have invented it anyways, maybe earlier :-)
>>>>
>>>
>>> I think Berners-Lee spent more time at CERN than that. He was a software
>>> engineer involved in data acquisition software for physics experiments.
>>> We were in the same department. I've been in meetings with him present.
>>> This was in the 1980s. We were young. The subject at the time was
>>> FastBus software libraries. FastBus was used in the LEP experiments,
>>> but it was expensive and cumbersome and never lived up to expectations.
>>> It died with the end of LEP.
>> Here is the English wikipedia site, more info, says the same thing about hiistime at CERN though
>> https://en.wikipedia.org/wiki/Tim_Berners-Lee
>> You can correct stuff on wikipedia if you want.
>>
> 
> Fastbus was an even stranger version of CAMAC.
> 
> We used to sell CAMAC modules and crates but passed on Fastbus, went
> to VME instead.
> 
> There are still a couple of people making CAMAC, I think.  VME is
> still a sizable market.
> 

Good decision. Fastbus was a monster. It wasn't all that fast
either, depite being all ECL. Near the end of the 1980s, physicists
had understood that too, and they embarked on the design of another
monster: The Scalable Coherent Interconnect, or SCI. Thankfully,
that never went anywhere, as far as I can tell. I left that department
around that time and concentrated on accelerator instrumentation
instead.

Jeroen Belleman