Author Topic: Fun for nerds  (Read 24093 times)

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Offline RoGeorge

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Re: Fun for nerds
« Reply #100 on: March 03, 2020, 07:43:12 am »
[attachimg=1]

What value is that?   :o
 
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Offline bsfeechannel

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Re: Fun for nerds
« Reply #101 on: March 03, 2020, 10:52:07 pm »
What value is that?   :o

I don't know, but R3 is 470Ω.

 

Offline RoGeorge

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Re: Fun for nerds
« Reply #102 on: March 22, 2020, 05:06:41 am »
(no Catgirls anime, Mousegirls for real)  :D
The making of Mouse computer advertising:


Offline RoGeorge

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Re: Fun for nerds
« Reply #103 on: March 24, 2020, 08:12:00 pm »


 :o

Offline RoGeorge

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Re: Fun for nerds
« Reply #104 on: April 09, 2020, 09:46:56 pm »
Without a Smith chart or a computer, can you do impedance matching and controlled attenuation in your head?   :o



 ;D
 
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Offline RoGeorge

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Re: Fun for nerds
« Reply #105 on: April 10, 2020, 09:12:38 am »
Terahertz Geometric Diode   8)

https://phys.org/news/2020-04-one-way-street-electrons.html

Ratcheting quasi-ballistic electrons in silicongeometric diodes at room temperature
Science  10 Apr 2020:
Vol. 368, Issue 6487, pp. 177-180
DOI: 10.1126/science.aay8663

[attachimg=1]

Offline RoGeorge

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Re: Fun for nerds
« Reply #106 on: April 17, 2020, 08:45:36 pm »
 :wtf:  Do Gods read Holy Books?



Quanta Magazine:  The Computer Scientist Who Can’t Stop Telling Stories
 
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Offline Alphaprot

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Re: Fun for nerds
« Reply #107 on: April 18, 2020, 01:54:05 pm »
Yet another idiot (me!) who tried to get the password from the scripts.  |O
 

Offline RoGeorge

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Re: Fun for nerds
« Reply #108 on: April 20, 2020, 04:15:04 pm »
A sharpie is 15 times thinner than a human hair.   :o



Meh, about 140 millionths of an inch (3.5\$\mu\$m).   ;D

Offline SiliconWizard

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Re: Fun for nerds
« Reply #109 on: April 20, 2020, 04:23:09 pm »
Hopefully she doesn't keep this for long. I don't think that would do her ear much good.
 

Offline RoGeorge

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Re: Fun for nerds
« Reply #110 on: April 22, 2020, 01:28:22 pm »


 ^-^

Offline RoGeorge

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Re: Fun for nerds
« Reply #111 on: May 16, 2020, 09:16:21 pm »
A solar water pump with no moving parts   :-+


Offline RoGeorge

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Re: Fun for nerds
« Reply #112 on: May 19, 2020, 08:34:32 am »


 8)

Offline RoGeorge

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Re: Fun for nerds
« Reply #113 on: May 30, 2020, 09:29:38 pm »
Compared testing and choosing the proper light bulb:   :-DMM


Offline RoGeorge

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Re: Fun for nerds
« Reply #114 on: June 05, 2020, 05:47:08 am »

Offline RoGeorge

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Re: Fun for nerds
« Reply #115 on: June 07, 2020, 09:08:34 am »
Solder on Al with CuSO4 + NaCl + FeCl3   8)

https://www.instructables.com/id/Solder-Electronic-Components-on-Aluminum/



Or just skip the whole procedure and solder normally, straight on aluminium, like you would do when soldering on a normal copper PCB, except for aluminium soldering you need to keep the soldering point covered in oil, so the oxigen won't reach the aluminium to form aluminium oxide.  Aluminium oxide is the one that prevents the solder to stick, and it forms almost instantly in air.

Put a drop of oil on the future soldering spot, scratch a little the aluminium surface under the oil drop in order to remove the invisible oxide, then solder under the oil blob.  Solder has no problem sticking on unoxidized aluminium, and the drop of oil stays in the way of atmospheric oxigen to come in contact with the aluminium at the soldering spot.

I've tried soldering under a drop of motor oil and under a drop of cooking oil, both oil worked.  Soldered this way on kitchen aluminium foil and on solid aluminium radiators.  It works almost as easy as it were copper.  Just don't use your best soldering tool, the oil will be hard to remove from the soldering tip.  Use a sacrificial tip, or cover it in Al foil for protection.
« Last Edit: June 07, 2020, 09:10:53 am by RoGeorge »
 

Offline RoGeorge

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Re: Fun for nerds
« Reply #116 on: June 09, 2020, 09:00:15 am »
Capiţa's Pendulum





 :o

https://en.wikipedia.org/wiki/Kapitza%27s_pendulum

Pyotr Leonidovich Kapitsa or Peter Kapitza (Russian: Пётр Леонидович Капица, Romanian: Petre Capiţa), Soviet physicist, Nobel Prize in Physics (1978) https://www.nobelprize.org/prizes/physics/1978/summary/

You probably never heard of his 1/2 of the Nobel Prize in Physics ("for his basic inventions and discoveries in the area of low-temperature physics"), because he was eclipsed by the two dudes that got the other 1/2 prize that year for scratching the pigeon's poop from their antenna in order to remove radio noises, and thus discovering the Big Bang!  ;D
(Allan Penzias and Robert Woodrow Wilson "for their discovery of cosmic microwave background radiation.")

Offline RoGeorge

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Re: Fun for nerds
« Reply #117 on: June 21, 2020, 10:52:54 am »
The cat is dead, long live the cat!   8)


Offline RoGeorge

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Re: Fun for nerds
« Reply #118 on: June 24, 2020, 10:15:59 pm »


 :o

Offline RoGeorge

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Re: Fun for nerds
« Reply #119 on: June 25, 2020, 07:14:30 pm »


 >:(

Offline Doctorandus_P

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Re: Fun for nerds
« Reply #120 on: June 25, 2020, 10:19:01 pm »
Triple Pendulum on a Cart

 

Offline RoGeorge

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Re: Fun for nerds
« Reply #121 on: June 26, 2020, 03:05:52 pm »


Inside tales and unique items from the history of science/technology.
 :popcorn:

He also has a very good 101 for metalworking and prototype building on his channel:
https://www.youtube.com/user/dgelbart/videos

Offline RoGeorge

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Re: Fun for nerds
« Reply #122 on: June 27, 2020, 05:47:44 pm »
It's about time  ;D



- Complicated, but OK, got it!   :)
- So, what time is it?



 :palm:

Offline RoGeorge

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Re: Fun for nerds
« Reply #123 on: June 29, 2020, 08:16:25 am »
Hangover



 :phew: 

Offline RoGeorge

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Re: Fun for nerds
« Reply #124 on: July 02, 2020, 05:50:14 pm »
"Do one thing and do it well".  Always loved that.



A clever design from Leo's Bag of Tricks, a very promising YouTube channel!  :-+


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