Fans; answering the question on lots of people's minds

Capacitors? I've got a real life car problem that I'm trying to fix without paying a mechanic lots of money: My fans (the ones on the dash for personal comfort) only have two speeds - Full and Off - because the other speeds now function like OFF as well. I've heard I need a new capacitor but I've yet to find it in the car to replace it. So... would you be thinking of making a fan capacitors for speed control video? Help me Techno-con vidobee... you're my only hope!

This was one of my favorite Technology Connections videos to date, but then again, I have yet to watch one I didn't like. TC is like watching Mr. Wizard when I was a kid. Except Mr Technology is not an impatient asshole to little kids. (If any of you watched Mr. Wizard in the early 90's, you know what I'm talking about.)

Chris Hutt

"your biggest fan" ... /snicker

clickallnight

I've just realized a video about stepper motors would be an interesting topic :)

István Nagy

more common in the US that 2 phase is split phase, where we have a center tap on a transformer on one phase. then we get 120v between each outside and the center tap, and 240v between the outsides for 240v appliances. i'm not sure how common 208v is in residential spaces.

adcurtin

This isn’t really _directly_ related, but since it’s a fun quirky thing about fans I figured I’d pass it along - the house we just moved into has a Casablanca Intelli-touch fan system that I think dates from the 80s or 90s, that apparently controls the ceiling fan over two wires using a series of electrical pulses, with a wall control that looks like this: https://www.fixmycasablancafan.com/shop/w-32/ It also beeps using different tones to tell you what the fan speed is and has all manner of super fancy features it can do: https://www.fixmycasablancafan.com/information/inteli-touch-operation/ Dunno if it’s video worthy ever, but I figured I’d bring it up :)

Rufo Sanchez

So, when my fan stalls on startup, it's because it has no flux to give? ... ... ... I'll see myself out. 😁

Travis Snoozy

and this is why I was able to temporally fix the heat in my house by pull starting my furnace. In most cases single phase motors don't fail their start capacitors do. So if you turn the fan on in your furnace and nothing happens you can wrap a string around the fan shaft bypass all the safety and start it up with a pull. PS if you like your fingers and don't know what your doing then DON'T TRY this. Have fun

I wonder if that clothes dryer note is the same sort of thing happening when you start a Leslie speaker.

Arthur Robillard

Hey, I think there is a part that can be misunderstood by a broader audience. At 12:35, you say that the full speed fan will give higher torque if you reach in and grab the blade. This is not true, it will hit you hard once as it comes to zero velocity, but it will not deliver a higher torque as the fan will instantly come to zero velocity. If you instead applied a friction brake, then your argument would be correct. Introducing a small velocity change (or preventing a velocity change) at zero speed, compared to introducing a velocity change at full speed would require much more friction at full speed, as per how induction motors works. Not trying to be picky nitty here, just think it might be worth mentioning. Great explanations as always, love the format

Lars Kuur

Your correction has been been added to the post-bloopers captions :)

Technology Connections

I was under the impression (can't tell you why at this point) that Delta configs have essentially been phased out (pun absolutely intended) and at this point are quite rare. I recall something about there being greater potential for mishaps and so the Y configuration is far more common.

Technology Connections

'tis very stiff

Technology Connections

Dude, you crack me up. Thanks!

B3

Interesting, but to be honest you went through the theory in the first 2/3 of the video too fast for me to really understand it correctly. But an excellent video as always!

Big Car

Ow, and all fans I have encountered in my lifetime here (Netherlands) didn't have this design. Most have the buttons like you showed, and the ones with a rotary knob simply went 0,1, 2, 3. Or like the current one in the corner of the livingroom... 0,1,2,4 , because, you know, it has four buttons so the highest should be 4. ¯\_(ツ)_/¯

Buzzin

I would love to hear about the US electrical system, as it has me stumped. Three phase electricity is relatively normal here (Netherlands), even in households. Most household will only have 1 phase connected to their breakerbox, but almost all house have all three phases coming into the utilitybox below it (owned by the electricity company and sealed, but still inside your house). It is/was common for household that used induction cooking to have a 3 phase cooker and for a very small fee you can get the other two phases connected as well. Well, small fee if you are handy enough to do the entire breaker box yourself...like I did. So, this whole 2 phase standard sounds weird to me....But I guess it's just not what I am used to. But I want to learn :)

Buzzin

I love your ridiculous level of background info and also your ridiculousness

Adam Wishneusky

Interesting, I've never seen a fan switch like that, only the button type... (and still: my last fan didn't last for so long as you antique one...)

MrHammond

I wonder if it's different with 230V fans such as here in Ireland. Our cooker extractor fan starts on low and the same with my 18" high velocity fan. If left unused (e.g. over winter), I usually need to turn it to '2' to start, after which it will start on '1' until it's stored away again over the next winter. Although not related to fans or electricity, I have noticed that most gas cookers start on high.

Seán Byrne

Timely, I just ran across these 2 fascinating videos on electro-magnetics last night. https://www.youtube.com/watch?v=OI_HFnNTfyU , https://www.youtube.com/watch?v=oWiYsRi2Dss

Paul Malloy

I counted four additional topics being foreshadowed for later videos, one of which I see is “in the works” per a comment above, and I’m looking forward to all of them! Thanks for another fun, informative, video :-) Ewen

Ewen McNeill

Decepticons :D Does noticing that make me your biggest fan? (I'll show myself out now :P)

Jason Wellband

I await the video on star-delta startup on three phase motors.

Chris Crowther

Interesting video thanks, even though I knew the answer already. Here in the UK there was a standard for extractor fan switches - a four position rotary switch with off at the top, low at the bottom, and standard and high in the other two positions. So whichever way you turned it, to get to low you had to go through one of the higher speeds to give the motor a kick. (I say "was" as this was back in the 80s when i was a kid, these switches were all over the place. I still work in a building with these 80s controls but there are probably more modern versions available like your automatic switch you demoed at the end.

Were you tempted at all to reference the Korean fan death superstition?

Michael Dunn

This is the stuff I'm here for. Stuff that seems insignificant but has reasons, and we get to find out through you!

Sam Cyanide

Fascinating video! I also had a ceiling fan that sometimes wouldn't start spinning when turned on. I totally recall hearing it hum but nothing happen. It was probably just a really cheap fan though, because I also remember the glass cover for the light bulb falling out and landing on my bed - but that's a story for another time.

Ian Spence

I would not speak out of turn on YouTube, but privately here in the Patreon comments is it ok to mention that — in the Venn diagram of robots in disguise — both Autobots *and* Decepticons are Transformers. Still and all... Holy hell, Alec, you are perfect and your videos are also perfect and you bring joy to our worlds without fail. Thank you for all of the wisdom, the jokes, and the happiness you bring to everyone!

Deviant Ollam

I do want to point out that tapping across two legs of three-phase power can give either 208V or 240V, but it’s entirely dependent upon whether the entire system is a Delta or Wye configuration. In a Wye (Y), or star, configuration, the voltage potential across two legs of the circuit is 204V, and from one leg to the neutral return is 120V. In a Delta (Δ) configuration the voltage potential across two legs of the circuit is 240V, and from one leg to neutral is 120V.

Sean Hearrell

This video was great, as usual, and I just wanted to share that the knob on that Kmart box fan brought me straight back to the one we had in my childhood.

Kevin Kostka

Probably going with eletromagnetically

Technology Connections

I realized I hadn't had captions on the whole time until the credits song came on, and I wanted to know what sort of Jazz was playing. Perfection isn't attainable, but I do appreciate the above average attention you give to captions.

Japanese rail fans have a hobby of building variable frequency drives to simulate the sound / noise patterns of their favorite rail equipment. It's impressively nerdy!

Darren Pierce

I had always wondered about that. Now I know.

No I meant 240. In a typical household panel you get 240 across the two legs and 120 from each leg to neutral. When you're on a three-phase wye configuration it's still 120 from phase to neutral, but from phase to phase it's 208

Technology Connections

5:05 "giving you 208 volts rather than the standard 240". I'm guessing you meant 120 not 240.

nothings

Not in something like an apartment building, though. There it's two legs of a three phase supply. You have 120 on each phase to neutral but 208 across the two phases because of the difference in phase angle

Technology Connections

You actually only have one phase in your US residential service panel. It's split (or however you want to conceptualize it) with a center-tapped neutral so it naively appears to the user as 2 "phases", but you're really only seeing two halves of a single phase.

Darren Pierce

I'm certified. Not a physicist, tho. I did sleep at a Holiday Inn last night ...

Darren Pierce