What value is that?
I don't know, but R3 is 470Ω.
(no Catgirls anime, Mousegirls for real)
The making of Mouse computer advertising:
Without a Smith chart or a computer, can you do impedance matching and controlled attenuation in your head?
Yet another idiot (me!) who tried to get the password from the scripts.
A sharpie is 15 times thinner than a human hair.
Meh, about 140 millionths of an inch (3.5\$\mu\$m).
Hopefully she doesn't keep this for long. I don't think that would do her ear much good.
A solar water pump with no moving parts
Compared testing and choosing the proper light bulb:
Solder on Al with CuSO
4 + NaCl + FeCl
3 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.
Capiţa's Pendulum
https://en.wikipedia.org/wiki/Kapitza%27s_pendulumPyotr 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!
(Allan Penzias and Robert Woodrow Wilson "for their discovery of cosmic microwave background radiation.")
The cat is dead, long live the cat!
Triple Pendulum on a Cart
It's about time
- Complicated, but OK, got it!
- So, what time is it?
"Do one thing and do it well". Always loved that.
A clever design from
Leo's Bag of Tricks, a very promising YouTube channel!