Title text:
‘This HAZMAT container contains radioactive material with activity of one becquerel.’ ‘So, like, a single banana slice?’
Transcript:
[Cueball holds a stick while talking with Megan and White Hat.]
Cueball: This stick is one meter long.
Megan: Cool.
White Hat: That’s a nice stick.[Cueball holds a smallish rock.]
Cueball: This rock weighs one pound.
Megan: I’d believe it.
White Hat: Looks like a normal rock.[Cueball holds a small battery.]
Cueball: This battery is one volt.
Megan: Seems fine.
White Hat: Might need a recharge.[Cueball holds a capacitor while Megan and White Hat panic.]
Cueball: This capacitor is one farad.
Megan: Aaaaa! Be careful!!
White Hat: Put it down!!
Source: https://xkcd.com/3106/
Haha that’s a good one
Capacitors are usually in the realm of pico to micro farads
A one farad capacitor charged to a respectable voltage would feel like a doomsday device in your hand
You see low voltage ones for things like memory backup on hi-fi gear. I have some 3F/5v capacitors in an old Technics tiner.
Wait so this is like one mistake away from turning that stickman into a fried stickman?
Depends on the voltage it’s charged with, but household current would give it more energy than a shotgun has.
Realistically one would not do that unless you were dealing with something industrial. You would use them otherwise for things like dampening lower voltage systems that need a lot of current.
Closer to the danger level of someone holding two exposed wires plugged into the wall.
Household current pumped through a full bridge rectifier, that is.
Capacitors don’t seem to do very much with AC Other than attenuate it a bit
Read in electroboom’s voice: FULL BRIDGE RECTIFIER!!!
Technically correct. The best kind of correct. :)
I basically solved for shotgun, confirmed in was in the ~100V range and disregarded every other consideration for actually doing it.
I’m pretty sure most hand sized capacitors would just pop if you actually tried to put that much in them.
Actually, they act like a short circuit to high-frequency AC, so it is more like “blow up” (in general case).
AC units have beefy capacitors, right? Do you know in what range, for comparison?
If by AC you mean air conditioner, I just replaced mine with a 50+5uF dual cap @ 370/440 VAC
Still tens to maybe low hundreds of microfarads.
Oh. I thought it would be more impressive, but that’s still orders of magnitude away. Thanks!
And when they are used for air-conditioning units, they are typically boost capacitors, which means they store up a nice amount of juice for when the compressor powers on and needs a sudden rush of energy, but that’s only a very small amount, like you couldn’t crank a car with the amount of energy in these capacitors.
No. They provide phase shift to give the single-phase induction motors a rotating rather than oscillating magnetic field. They charge and discharge 100/120 times per second depending on grid frequency.
They do not cover inrush current, and would need to be orders of magnitude bigger and a different topology to do so.
As long as the voltage is high enough, it does not need a whole Farad to wreck havoc. One of the first pranks they played on me in the lab was the “hey, catch” thing with a large, charged capacitor. Yes, I caught it. And I regretted it soon afterwards.
Worked with an industrial robot one that had 700V 0.5F electrolytic capacitors on its power supply. Those things were massive.
I was in the building when when a 3F 1200V capacitor, part of a multi-rack mounted capacitor bank (powered a magnetohydrodynamic modeling experiment), failed. It ripped the rack’s 30cm mounting bolts out of the floor, launched the three-tonne rack hard enough to crack the ceiling and shattered every window in the facility. I want to say that afterwards I never broke the rule about not being allowed to enter the experiment room until the banks were discharged, but I’d be lying. Undergrads are idiots, and holy cow don’t fuck around with those caps…
Damn!
That is why I like supercapacitors.