Why does your Microwave waste half its Power?
Vložit
- čas přidán 9. 05. 2024
- The circuit inside a microwave oven is a half-wave doubler, an incredibly inefficient design. How does it work? Why do we put them in microwaves?!
Huge thanks to Mehdi Sadaghdar (ElectroBOOM) for the consult:
/ @electroboom
________________________________
VIDEO ANNOTATIONS/CARDS
Alternating Current:
• What the HECK is a Pha...
Capacitors Explained:
• Capacitors Are Gaps! H...
________________________________
RELATED CZcams VIDEOS
EEVblog on Scope Safety:
• EEVblog #279 - How NOT...
Eugene on Rectifiers:
• AC to DC voltage recti...
Hawley Hobbies's 6000 Volt Power Supply:
• 6000Vdc power supply b...
________________________________
SUPPORT THE SCIENCE ASYLUM
Patreon:
/ scienceasylum
CZcams Membership:
/ @scienceasylum
Advanced Theoretical Physics (Paperback):
www.lulu.com/shop/nick-lucid/a...
Advanced Theoretical Physics (eBook):
gumroad.com/l/ubSc
Merchandise:
shop.spreadshirt.com/scienceas...
________________________________
HUGE THANK YOU TO THESE SUPPORTERS
Asylum Counselors:
Bosphorus
Asylum Orderlies:
Dhruv Singhal, Medec Hurtz
Einsteinium Crazies:
Benjamin Sharef, Eoin O'Sullivan, Ilya Yashin, Jonathan Lima, Joseph Salomone, Kevin Flanagan, OnlineBookClub, Sean K
Plutonium Crazies:
Al Davis, Compuart, Ellis Hall, Fabio Manzini, Kevin MacLean, Rick Myers, Vid Icarus
Platinum Crazies:
Bart Barry, Clayton Bruckert, David Johnston, Jon Adams, Jonas Wepeel, Jonathan Reel, Joshua Gallagher, Marino Hernandez, Mikayla Eckel Cifrese, Mr. Orn Jonasar, Olga Cooperman, Thomas V Lohmeier, William Hutchison
________________________________
OTHER SOURCES
www.circuitbread.com/tutorial...
hyperphysics.phy-astr.gsu.edu/...
hyperphysics.phy-astr.gsu.edu/....
electronics.stackexchange.com...
doi.org/10.1051/jphystap:0190...
www.physics-and-radio-electro...
________________________________
LINKS TO COMMENTS
• The Cosmic Illusion No...
• The Cosmic Illusion No...
• The Cosmic Illusion No...
________________________________
TIME CODES
00:00 Cold Open
00:45 Half-Wave Rectifiers
01:44 Giant Transformer
02:42 Giant Capacitor
04:12 ElectroBOOM Rant
05:35 Low-Voltage Analog
06:32 Diodes
07:36 The Capacitor's Purpose
09:17 Half-Wave Doublers
10:20 Summary
10:54 Outro
11:28 Featured Comment
________________________________
Corrections:
01:32 "Utilization" would have been a better word than "efficiency." Half-wave rectifiers have a 50% utilization, not a 50% efficiency. They only utilize 50% of the provided voltage.
01:57 Phone chargers from the 1990s and early 2000s were simple transformers. Modern phone chargers are a more complicated design called an "Switch Mode Power Supply" or SMPS.
![tattoo printer tutorial[제품단순선물]](http://i.ytimg.com/vi/g40_GwEJak0/mqdefault.jpg)
*Clarification:* By saying half the energy is wasted, I only meant that it was available but unused. In other words, the device doesn't take full advantage of what the wall is providing. It only uses 40-50% of the provided potential. I never meant to imply that the energy was dissipated as heat or dumped somewhere else. "Wasted" and "efficiency" felt like good words for that, but apparently I was wrong given the response in the comments. There's some ambiguity there that I did not anticipate. Oops! In hindsight, I can see how this could be misleading.
*Minor Correction:* Apparently, modern phone chargers are made with SMPS transformers rather than magnetic transformers. I learned about them in the early days of mobile phones when they were all magnetic transformers. I had no idea they changed the design. This doesn't really affect the video, but thanks for the correction anyway. It gives me another rabbit hole to go down.
I think phone chargers usually don't use piezoelectric transformers, but just high frequency ferrite transformers optimized for flyback converters.
Thanks for the warning, I was planning on fixing mine but decided to buy a new one
🧐 That's better, PhD Lucid 🤓🖖
@@maxxiang8746 Thanks. I've edited that word out of the comment until I do more research into phone chargers.
I have a class 2 12vdc power supply. It's about 10-30x heavier than my switched mode 12vdc power supply and only able to source half the current (1a vs 2-5a).
Hey awesome, the scope survived!! oh and good, you survived too! 😁 great video!
Someone: Avengers endgame is the greatest crossover of all time
Mehdi: Hold my full bride rectifier
Nick: Hold my 2,999,792,458 clones
Mehdi - why not microwave uses efficient smps Stepup ?
I guess I'm shipping you another probe lol
Definitely need you to weigh in on the title, oh great master of the full bridge rectifier. We really don't think it's accurate to say it "wastes half it's power". Please respond Senpai. 😉
@@omsingharjit Because that is a lot more expensive, so you only find this on the high end microwaves made by Sharp and Matsushita, who make them that way. The transformer, capacitor and diode are cost wise a third the cost of the microwave, and the magnetron is half, the rest being the steel case and everything else. You only have inverter microwaves at the top end of the market, never at the $40 Walmart special end. For inverter you start at $230 from what I see online, and go up in price then.
Unless I misunderstood something, the half-wave rectifier doesn't actually waste half of the energy (in the sense : dissipating it to heat) ; it just doesn't let power go through 50% of the time, but during the "blocked" half-period, no energy is taken from the source.
That's what I was thinking.
I agree with you. It’s not wasted (turned into heat or something), it’s just not used.
Thank u, so i don´t have to tipe so much! ✌
That was my assumption, as well. There will be losses from the transformer from eddy currents, and maybe it even saturates a bit, but it's nowhere near "Half its power".
so whole why your microwave waste half its power thing is incorrect? :D
Judging from the amount of damage in the small scale version of the experiment, not trying to mess around with the real thing was extremely wise decision 😂
Agreed.
One can't be too cautious when dealing with powers surpassing human body durability.
sure bruddah, dont touch that shit, the inside of a microwawe kills more hobby electricians than ANYTHING related to electronics on this planet, it will fry ur nervous system and brain so bad that youll be dead dead before you hit the ground, its srsly not funny...
The collab we didn't know we wanted, but the one we deserved.
Are you kidding? it as has been my wet dream for ages
My first thought when Nick started talking about rectifiers was that Mehdi should be consulted. Little did I know!
@@northgrave Apparently, I thought the same thing when I was researching this 😉
It makes so much sense in retrospect.
@@NoActuallyGo-KCUF-Yourself Absolutely
Imagine being me, waking up to find @ElectroBOOM putting my probes in a microwave
😂
Gotta say, I think your products are great! We use them at the company i work at and they're very professionally made!
@@HAWXLEADER thanks!
Just a small arm and a leg for hobbyists at home 😅🥲
Having a working relationship with Mehdi, you should know it is only a matter of time before he puts anything in a microwave...
Half wave rectifiers don't "waste" half the energy, they just don't use it, so it stays in the system. Makes a big difference as dissipating half the energy would be a nightmare depending on how much power you are drawing with the half wave rectifiers.
Exactly.
This was almost word for word, what I was gonna post. ^^^ that exactly "waste" is very very much the wrong word.
I've pinned a comment clarifying.
It introduces harmonic distortion and low power factor to the power grid.
@@ScienceAsylum do we have any ballpark numbers on how much energy is wasted *as heat* in this setup?
Love the way Mehdi called it a megatron . . 😀
You are mixing duty cycle (conduction angle) with efficiency. With a half wave rectifier you still can get almost 100% efficiency, you just waste half of your conduction angle, so half of the time your rectifier is not pulling electricity from the wall.
yeah that's my thought too. At most you could say it wastes half of the power in the sense : the time-averaged power is half what it would be without the rectifier (so the device must be sized to allow 2000 W, where you have 1000 W "effective" only).
But saying that it wastes half of the energy is misleading, bc no energy from the source is lost.
I clarify in the pinned comment.
Enjoyed seeing a "trained professional" who knows "how to work with electricity without..." so easily fry a diode and bake a capacitor.
Another fun and educational lesson in your library. Loved it.
😆 Sure, but I didn't get hurt!
I often play with breadboards and home made designs, and I cannot count the times I've blown up Electrolytic caps by putting them in wrong way round. Always that little pop, and then "Uhhhh!" (me)
@@paulmichaelfreedman8334 tantalum caps do the same, but much more violently, btw
@@paulmichaelfreedman8334 Why not just use unpolarized capacitors so you don't have to worry about it?
@@paulmichaelfreedman8334 I actually haven't had it happen one single time. That's not because I'm awesome. Rather I'm kind of crap, but I've been lucky as a leprechaun for many years now.
The half-wave rectifier is not wasting power or energy.
It is just not utilizing the other half-wave. No current is drawn during the other half-wave thus no momentary power is taken from the wall outlet, thus also the integral over all negative half-waves and thus the energy consumed is zero.
The only losses are in the finite forward voltage drop over the diode when it is conducting, the tiny leakage current in reverse direction and the fact that the load does not behave like an ohmic load and thus generates harmonics in the electricity grid.
A typical microwave oven taps some AC power for the lamp, fan, and turntable before it goes through the HV transformer. Not to mention any AC power which is tapped off for other power transformers (to power magnetron and triode filaments, the timer and control panel, etc).
So in practice much more than half of the available AC power is utilized.
@@pwnmeisterage in most cases those are insignificant in comparison. And in my statement I was only referring to the half-way rectifier not the total consumption of the microwave oven.
As a kid 9 year old started playing with electricity by blowing up capacitors for 9 transistor radios with my RC car power supply. Uncle got me the radio on my birthday, only lasted a month before I took it apart.
58 years later I'm a retired electronics engineer, life long electronic hobbyist still fascinated by electronics still blow up stuff.
Sounds like electronics really had an impact on you 🙂
In the early 1980's, whilst working on a faulty device designed to detect trigger signals for remote control bombs in an Ops Room in Northern Ireland, I mistakenly assumed the circuit was rated for 12V when in fact it was 6V so on connecting a 12V battery the electrolytic capacitor exploded filling the Ops Room with little bits of foil. It did not make me popular.
My age and story is very similar to yours. I seemed to have had some genetic electrical knowledge at a young age. My dad was an electrician (as was his father) and I would use things he had around to wire up batteries, lights and switches that actually worked without ever being shown how to do it. Later when I was about 12 I was given a volt ohm meter and the book Radio Amateur's Handbook, what a book, read it cover to cover many times. Using the books information about power supplies, circuit schematics, dipole antennas, TV frequency charts, coil winding data and using parts from old scraped equipment and vacuum tube TV sets, built a 750vdc power supply and basic oscillator transmitter that could screw up every TV for miles around. Anyway have to go, there are a couple of things on the bench that I want to take a look at..
Great username!!
Took electronics in high school. The lab needed some new bench power supplies but couldn't afford the full price so the school bought kits which had to be assembled by the students.
Everyone gathered around the power up of the first completed kit. The cover had not been put on yet. When the switch was flipped there was an explosion and the air in the room became filled with something that looked like feathers. You guessed it! The large primary filter capacitor (electrolytic) had been installed backwards (polarity reversed). That was a lesson I never forgot.
I've always found the cavity magnetron to be the most elegant piece of engineering ever made. So many concepts and scientific fields involved in its inception, but ultimately a hunk of shaped metal that is easy to mass produce. It really is genius, the poetry of science.
hey it works it has always worked that's all that matter's
A SUPER clever concept using an electron beam and stamped metal to form the right geometry for the desired RF frequency.
The lost art of tubes.
Two of my favorite youtubers in a great collab! What a great week! Thanks God! Although Medhi isn't a little crazy. He's COMPLETELY INSANE! Lol. Love you guys.
Firmly second this!
Me too.
I was thinking the very same thing lol!
Think you misspelled "Mehdi"
@@davemarm yes you're right. I'll correct it. Thanks.
Great to see you again, Nick ☺
Mehdi's guest spot was hysterical AND informative- as always.
Three Cheers for Science Asylum and ElectroBOOM!
imagine how powerful a microwave would be if it's transformer was 90%instead of 45% efficient🤔
I like this a lot, nice to take a break from things like gravity and entropy (which can hurt my brain) once in a while!
Agreed. I always need a break and I had fun with this one.
I'm still trying to wrap my head around entropy and information and the Landauer Limit!
At least gravity keeps you grounded.
Goes to show the rich diversity between us all. I can grasp gravity and entropy just fine, to me it's completely intuitive. Involve electronics or algebra and I check out.
Having learned a good chunk about sound-waveforms, I find other varieties of waves fascinating-props to your little-craziness for this demonstration!
Nice to see you and Mehdi working together 💪
This actually explained some key concepts from electroBOOM videos for me, like the rectifier ⚡💡 Thanks guys!!💙
Happy to help! 🤓
Congratulations on 600k! Your uploads are BRILLIANT! Cheers from England.
Thanks! I'm still shocked 600k people want to follow my work.
@@ScienceAsylum Oh come on, you've got some brilliant episodes, you put so much effort into them and explain things much better than most CZcams scientists do. In fact, you should have much more subscribers, given how good your videos are.
“You don’t need it to be perfect. You just need it to work.”
Engineering in a nutshell.
and programming.
@@lajya01 Coincidentally, I learned both from the same teacher.
But I want it to be perfect, and work
The magnetron is in itself also a diode, and a load. The regular diode conducts on the positive half cycle, charging up the capacitor, then, on the negative half cycle, the magnetron diode starts to conduct, with the forward voltage being the 5kV, as power is being generated in the spiralling electron flow inside the magnetron, charging the capacitor to zero, then to -2.5kV at the peak, with the magnetron then seeing briefly the full 5kV. Thus the 2 magnets in the magnetron, there to make the electrons spiral between the hot cathode, and the grounded cold anode. The spiralling electrons create resonance inside the magnetron in the cavities, and this is at 2.4GHz, fed out via a tap in the one cavity via a feedline to the end cap, where it is introduced into the waveguide cavity at the top, and from there through a RF transparent window into the large oven cavity. the magnetron will start oscillating at some voltage between 3-4kV, absorbing the energy out of the capacitor and transformer, so while it only is being turned on for a half cycle, the energy is basically doubled, as the other half cycle is storing energy to be used then.
No Beryllium oxide in the commercial microwave magnetron, it is way too expensive to use in that cheap product, so instead it is either white, pink or purple fused aluminia, aluminium oxide crystal, otherwise called when the crystal is large and not a powder, ruby. Here just a high temperature ceramic insulator. But the magnetron is still dangerous, the 2 strong magnets can shatter if slammed together, and they will attract small metal dust to them.
Also never run a microwave with nothing in the cavity, the energy not absorbed in the load is reflected back into the magnetron, heating it up a lot more thna normal, and eventually the magnetron will become too hot, and the thermal cutout for the magnetron will turn off the microwave, or the transformer, till it is cool enough, and another turns off the microwave if the cavity itself gets too hot.
How did you make this video, colab with Mehdi, talk about rectifiers and not once did we ever hear, "FULL BRIDGE RECTIFIER!" ? :-) Great video.
I'm sure it has been cut out. I find it too unlikely it never happened! :D
Same Question A fool bridge Rectifire
Love your channel! No plans to ever take one apart but I appreciate everything you put into this vid!
Now you don't have to 😉 because I did it for you.
I had my OTR microwave suddenly stop working a few months back, and it took a bit to find the fault. First I thought it was the door switches, but replacing those did nothing. Then I decided to check the capacitor, which rightfully scared me as I already knew how dangerous it could have been. So after unplugging, I did a very similar method to what you employed with the pliers and piece of wood, hehe. Turned out the capacitor was completely bad and shorted. Found an OEM replacement for like $15 (just had to search for matching parameters), and the microwave came right back up and running.
I'm glad you survived 👍. The microwave at an old job failed once. Turned out to be a couple burned out thermal sensors. Easy fix.
@@gags730 Thanks for the tips! I actually have a few good multimeters already from having to work on other electronics stuff, including an LCR meter for the trickier things. You're right, I should have checked the diode, hopefully it's still good and will continue to be good until I move to a different place and get a new microwave regardless :)
This is the second time I had an issue with this microwave too, but at least between the first and the second there was a span of 7ish years of no issues. The first issue was it breaking literally a year and two months after purchasing (aka just out of warranty). That one took a while to figure out, but thankfully the manufacturer included a full schematic. Before finding the schematic, I checked every thermal fuse and saw no problems. Looking at the schematic, I realized that there was one more thermal fuse buried way off on the other side of the microwave. Disassembled the microwave further to get to the fuse, and saw that it just melted and broke the wire due to a bad crimp. Had to get a new temperature and voltage rated wire, new connector, new thermal fuse just in case, crimper, etc... still way cheaper than getting a new microwave or hiring someone else to fix it :D
@@gags730 Yep to both questions, including convection cooking. For that year before the connection failed I had been sensing a slightly burnt plastic smell... that was apparently the connector slowly melting under high load until it finally failed. Why, have you seen this type of failure before as well?
Huge fun, and with Mehdi as technical expert, what's not to like? Leakage inductance in those transformers is the key design element that helps control the peak current without resistive loss. That's the really clever bit of the ultra-simple design. How magnetrons work is like blowing air across the top of a bottle to make a musical note, but using electrons in a magnetic field and "blowing" them across the edges of lots of metal "bottles". Total magickery.
@@gags730 The history of development of the cavity magnetron is fascinating, the basic principle was understood from the early 1900s but the compact multicavity magnetron was developed with the aim of making an aircraft- based radar. The Tizard Mission followed the surge of development by the UK General Electric Company and the 10 kW version was one of the technologies shown to the US committees in the search for a manufacturing facility and finance. I should do a video about the history and tech detail, but I'm a bit tied up with my work on the Great Seal Bug project for BBC television and projects on Gyrotrons and a quadrupole mass spectrometer.
I'd love to see a video produced, similar to how Jeremy Fielding does on his channel. If you haven't seen his channel, he has put together some good explanations geared toward the non-technical
@@gary.richardson Jeremy is a brilliant presenter and engineer, I've watched his channel since he started and he's definitely a role model.
I got really scared for Experiment Clone for a bit there. 😲 I'm glad it all worked out. This was so cool Nick!
ElectroBOOM, saving lives.
Nice to see you covering the Doubler. I don’t think I’ve seen someone explain the difference in the voltage you can get simply by changing where you put the load in that simple circuit since my EE classes in college… 30+ years ago. Nice!
Always good to hear from Nick. Great stuff brother 👏
50% of the energy is not really wasted, though. It's just not used, but it doesn't get turned to heat or anything. In other words it doesn't end up in your energy bill :)
I clarify in the pinned comment.
@@Kevin-mp5of they are unlikely to do that. Also, even in terms of apparent power it's not 50% wasted :)
Thanks for another super fun, Awesome video, Nick!
There is a micro wave (called „Dialog oven“) ait works so precisely it is able to cook fish within an ice block.
A great video and a forceful reminder to me to never, ever take a microwave oven apart. Loved the collab.
This was a perfect time for that collaboration. It’s how I originally found your channel.
Now I’m back after taking apart an older microwave, and finding out it was old enough to contain beryllium. Thankfully my local (public) electricity provider takes dangerous goods at no cost.
Not a bad description. It turns out the positive half cycle is used to boost the negative half cycle so the energy isn't lost. The magnetron uses a negative 5,700 volts not positive. That particular tube (yes, it's a vacuum tube) doesn't like continuous operation. It likes to be hit with pulses of energy. 60 times a second, bam a new 5,700v pulse.
4:45 the great realisation 😂😂
Yep, now I'm even more terrified of microwaves.
There's a reason they usually have a warning label telling people not to open the casing.
Your videos are always great. I bought your book! I live in wyandotte so ik about downriver so awesome you are from here! Keep up the good work and I will hopefully be Patreon supporter really soon when i finish school!
Thanks for buying the book! I hope you like it 🙂
@6:41 I had to laugh. This reminded me of my high school electronics class when I bread boarded a circuit with a zener diode with the polarity backwards.
A Collab with Electroboom? Christmas has come early this year.
Great video, learn some new stuff, really enjoyed the circuit tour and seeing the scope in use.
Just really like electronics 😎👍🏻👌🏻
Thanks
Thomas Mogensen
Amazing how a microwave can be so simple, yet so complicated at the same time. Thanks for the good video man!
Right?! I love it.
Re: not talking about angular diameter turnaround. I think it's less that we perceive it as an obstacle, and more that they think people will find it to be an uninteresting detail that they can't prove with pretty pictures. Basically, it contributes to cosmological surface brightness dimming, and statistical statements about the size of galaxies compared to what we expect. Without context about surface brightness being constant in a non-expanding universe, or comparative measurements of galaxy sizes, it just isn't as easy to grasp in a single picture as "further things look redder".
That makes sense. Scientists don't always have a good perspective on what the general public will find interesting.
I didn't know all that was going on inside my microwave. Thanks for rectifying the situation! 🙂
Good pun 👍. Glad I could enlighten you.
Never realized it was a half wave doubler! You learn something new every day.
Love the cameo and really cool visuals! Thank you thank you!
Another fantastic video. Love the way you explain topics, thank you!
I am now thankful that me and my friend never realized the microwave weapon we planned to build from a microwave oven back in the days.
Great video love it that your doing experimental stuff, yes please show us in more detail how the magenatron emits microwaves using this electrical wave! 🤩
Great video as always, and very entertaining rant from ElectroBOOM! Glad you and the scope are ok!
It has been many a year since I used an oscilloscope, and almost as long since I understood an electronics discussion. Thank you for an excellent video.
My two favorite youtubers finally together spreading knowledge. Dope!
A half wave rectifier DOES NOT waste 1/2 the energy, even when configured as voltage doubler. If it did the 1000W oven will put 1000W into the food and 1000W into the kitchen cabinet starting a fire.
I've pinned a comment clarifying.
Awesome video! Loved the cameo and how your lower voltage circuit matched the microwave one.
Safety first 👍
I've been with this channel since it's first debut and I love how he approaches topics. Makes learning feel less formal and fun
Thanks for the positive feedback 🙂
Love this! Hey can you do a similar video on common Air Fryers? I've been fascinated to learn how it works at this level and see the inside of one!
its way simpler than microwave, it just a heating element to heat the air and a fan to direct heated air to food
It's just a hair drier for your food.
@@Barnaclebeard beat me to it lol
WE NEED MORE OF YOU AND MEHDI
Thank you so much for this video! Besides explaining the awesome electronics of microwaves, this actually made me understand half-wave rectifiers better. As I had a rough time with electronics in my previous lab course 😅.
Glad I could help 🙂
Hah, nice collab!
Did not expect you two to team up, but that's pretty fun.
Although i haven't actually watched the video yet, but i just got excited and wanted to comment.
Maybe 2023 will finally be the year you'll have 1.000.000 crazies!
Science Asylum and Electroboom? This can't get any better!
When the capacitor is shorted out at 3:10, something DID happen. The audible click was very likely the sound of electric discharge via an arc to one end of the pliers just before contact was made.
That was an excellent video and cleared up a few things I did not fully understand. Would love to see more electronics like this.
2 of my favorite channels coming together for this. Awesome guys😎👍
1st video i stumbled upon from your channel. Sympathic host, funny and yet educating. Yeah that's an insta sub. Much love.
A 900 Watt microwave oven don't waste other 900 Watt as heat.
The half wave rectifier simply doesn't present a load to the secondary winding of the HV transformer, when the diode is reverse biased. This load unbalance cause the magnetic field in the transformer core to be skewed toward one polarity. In theory it could saturate the iron core, but the core is designed to operate that way. The current peaks charging the paper-in-oil capacitor are present only at half wave, 60 times per second in the US. In contrast, a full wave rectifier would work on both half waves, showing a 120 Hz ripple. But the oven is built to be as cheap as possible, by saving either three diodes, or a tap in the secondary winding.
The transformer has another low voltage winding to light up the filament of the magnetron, which is also the cathode from where the electron are emitted and spun into the multiple LC circuit (in a vacuum). These tuned circuits are made of wavy copper. Of the multiple LC resonant cells inside a magnetron, the antenna output can be connected to any of them; the geometry operating the electrons beam rotation under the influence of a static magnet (at a fixed frequency, equal to the resonance of the water molecules) is a kind of black magic. Keep in mind that a magnetron is one of the very few application where a vacuum tube (the magnetron itself) hasn't been replaced with a semiconductor equivalent.
Thank you for the great video!
I clarify in the pinned comment.
Thanks for the beautiful video ! Learnt something new today !
My pleasure 🤓
just both of you together in one video is extremely fantastic ....we love you guys.
this video earned you a rung bell keep up the explanations about electrical waves and circuits that manipulate them its such and under discussed topic for obvious reason most people cant even understand it let alone break into easily digestible bit like this
Thanks! Glad you appreciate it.
ElectroBOOM in the thumbnail + "half-wave rectifier" name card = me bracing myself for the next parts of the video.
What a great Collab!!!! Lovely 😍
Dog gone it! Nick, I needed this video last week! I would have used it as a part of my magnetism and induction unit for my AP Physics 2 class. Great video, next year's students will be the lucky ones.
Like I said at the beginning of the video, I wouldn't recommend that most people play around with microwave parts. So dangerous.
Good you made a model. People were making devices to burn arcing patterns into wood using salvaged microwave transformers and the injuries were pretty bad. Best not to mess with them.
Just to add a little detail to the circuit :) It looks like the diode is usually connected between the capacitor and chassis. This allows for an ac current applied to the fillament of the magneton to be DC biased to high voltage (think hot filament electron emission). The electrons dump into the shell of the magnetron, back to ground. A video detailing the magnetron would be awesome! They're ingenious little vacuum tubes :)
All the big components are grounded to the chassis. I didn't realize there was a sneaky reason for that.
@@ScienceAsylum I was always nervous about letting metal objects touch a microwave casing while it was on (careful not to put a fork or spoon on top of the microwave while waiting for my lunch to cook, for instance).
Now I guess have a really good reason for that.
@@AlexandarHullRichter The casing of a microwave oven is simply an earthed metal box. There's no difference between it and any other grounded metal surface - if the microwave is next to a refrigerator, there would be no difference between placing a fork on the refrigerator or the operating microwave.
The "coming soon" explanation of the 2.4 GHz solid state magnetron should also cover why they moved away from the ~900 MHz vacuum tube style. (Running the oven empty creates an impedance mismatch that could start a fire and/or break the glass) Would also be great to see how @The Science Asylum explains the quarter wave choke energy seal that works even if you hang a kitchen towel on the door before you close it.
@@woll3Y I've tried to follow the line of your post, but I'm not sure I get what you're saying. Either 900MHz or 2.4GHz are used depending on what will be most effective and practical for the application, more than because of any particular type of technology available. The physical constraints of the wavelength, with the resulting mechanical sizes, and the inevitable difference in load energy absorption and depth of penetration govern the suitable usage. Because of this, 900MHz is usually used in large equipment in commercial and industrial arenas and at high powers, where improper usage could certainly produce spectacular results.
Small nit: that cellphone converter you held up is NOT transformer based. Rather it has a switching power supply. That's why it is so small and light.
I'll admit, I based that statement on my knowledge of those bulky phone chargers from the 90s. I wasn't aware the design changed.
There is a transformer inside, to separate the main from the output. It just doesn't operate at 60 Hz, but at 100 KHz, so it can be very small and convert energy very efficiently...
@@ScienceAsylum I just assumed they became switching power supplies from their light weight for their power rating. Pick one up, hey Where did all the Iron and copper go?
It still has a transformer, albeit quite a bit smaller
@@keysersmoze The other clues are the high pitched whistling sounds they make, the weird vibration you feel if you run your finger along a metal surface on the device being charged, and the electric shock you get if a single hair on your finger is touching a metal surface on the device being charged!
These crazy videos are always amazing and fun! Keep 'em comin'! 😃💯💫💢💖💥
I'm amazed you did that whole video without once having Mahdi shout "FULL BRIDGE RECTIFIER!!!"
It would have been interesting to try a capacitive probe near the transformer. This would have protected you and the DSO, but the amplitude may not have been perfectly accurate.
Much of this is used on automobiles for charging batteries or even ignition (spark).
Very well done, sir.
I haven't heard of anyone checking batteries with those, since a basic multimeter is usually sufficient, but that type of probe is used to detect ignition timing in cars that have distributors.
IF you thought Nick was crazy...wow...that ELECTROBOOM guy is off the hook.
Grear video. For once, this is a video topic I understood completely. If there's one thing one of my circuit classes' professor drilled into us, it was that diodes are not loads.
Congratulations 600K 🎉 onwards & upwards 💪🏻
Thanks!
Seeing Mehdi always bring joy... ⚡⚡⚡ The biggest electrician...
Hey 👋 nick! Thanks for these wonderful videos.
That capacitor still had a significant charge! That loud tick when you shorted it with the pliers was a good arc.
Hey there, I'm new here from Mehdi's channel. Great video! You've got a new subscriber 🥳I've had to install a few similar looking transformers in home-heating boilers. They are spookily noisy while running, giving off a high frequency buzz. I told my wife, that's like the rattlesnake's tail, giving you a warning to steer clear!! Fortunately, nobody was injured 😆
I remember when I studied at the Applied Mathematics faculty, we had a course of physics - electromagnetism. And I remember how teacher was describing how electromagnetic field behaves when we cook a chicken in the microwave oven. It was funny 😄
Yeah, the whole cooking process is a video all by itself... which I'm hoping to make soon.
@@ScienceAsylum sometimes I regret that I didn’t become a physicist. It is so interesting. Ended up being iOS developer 🥲
Well, I know the basic principles of the Microwave, but I didn't even knew the circuitry have such drama, thanks for letting me know that.
The collaboration with Mehdi @ElectroBOOM is always fun 😅 But funny, we call his name Mahdi, not Mehdi... but don't tell him that 🤣
10:23 Can't wait for this video.
I SUBSCRIBED TO YOU IN THE FIRST 9 SECONDS because of the energy you bring i know for sure this will be interesting video channel.
Thank you there are several scientific experiments I've been wanting to do and the way you described a microwave means now I can do them as it has all the parts already wired up
But, remember to heed my danger warning!
@@ScienceAsylum oh I absolutely take all the precautions as a side note you ever think of using a electrical equivalent of an overflow valve to prevent overload like a spark gap I got the idea from the Marx generator and a bathtub not at the same time mind you I'm not trying to electrocute myself
The reason a transformer rated at 12 Volts is usually around 15V is because it allows for a full bridge rectifier and a voltage regulator, which contain diodes and thus always have some voltage drop.
Also the open-circuit voltage will be higher than at load.
Not quite. The real reason is that it's rated voltage is at the rated current/power, because especially with small transformers like this, their voltage drops significantly with load, because of copper losses in the very long thin wires.
@@Basement-Science right diodes do not change the voltage drop much. Are there any things that can cause the multimeter to read a lower voltage instead of higher?
@@NealIRC Diodes so cause a not insignificant voltage drop because of the PN junction.
Such transformers..(low cost ones)..are energy inefficient...for the simple reason of cost...these are said to have poor
" LOAD REGULATION " ..
A transformer with good load reg.would probably have...
1) higher ampere (copper..but not CCA) wire gauge in both pri & sec....
2) thinner and better grade ( low eddy loss)
laminated magnetic core material....
this may involve using the next larger core size......hence the cost is kept down by smaller manufacturers.......
Load regulation.. in % , .. for (the sec. winding under test)...is usually measured
as ... { o/p volts @ rated load ÷ o/p volts @ no load}×100..and keeping/ensuring same value of input volts.(pri.)...in both load & no load measurements.
The value closer to 100 the better the regulation...
Hahaha, love the exploding diode & capacitor. So glad that you did this with a toy version rather than the beefy real thing 🤪
Yeah, that could have been really bad.
Great work man, loveit.
0:08 Yes I have done so to replace the safety switches when they were faulty causing the microwave to not turn on at all. And yes I know the capacitor can easily kill you so I made sure that I deenergized that first. In the unit I worked on there are three 15A momentary switches that are activated when the door is opened for added redundant protection against failing in the energized position. There is also a relay that is activated when all 3 switches are in the proper position. 2 of the switches have wires on both the NC and NO positions of the switch.
👍A real hazard is the beryllium oxide that is contained in the ceramic insulators in the magnetron.
They are no hazard as long as it's not disturbed and does not become airborne. Often people are taking them apart for scrap or to get the magnets and may not know that any breaking grinding or cutting may free the beryllium and cause an incurable respiratory health problem called chronic beryllium disease.
I actually think they stopped using beryllium insulators in the magnetrons decades ago
He said a half wave rectifier waist half the wave and was less than 50% efficient. It's not shunting half the wave, it;s blocking half the wave. It's not waisted (dissipating energy as heat), it's just not using half the wave. As for efficiency, the only loss is in the transformer and resistance loss in the wire. There is a energy loss through the diode, but it's tiny. you're looking at a ~90% efficiency, not 40%.
You are correct, except that the magnetron actually wastes a lot of energy , leading to a total efficiency of around 65% or so.
Thanks for the correction. I clarify in the pinned comment.
I've run into some microwave transformers that do limit current. With a suitable core design you can get it to limit current when for example in short circuit. I thought all were like that.
I think energy is not wasted. Energy conservation shall not be violated! Half wave rectification only uses half the cycle and leaves the other half cycle unused. I wonder if the magnetron has something against too continuous power of if that is just a way to save some diodes. A full bridge rectifier takes 4 diodes after all and 4kV (or whatever) rated diodes tend to cost way more than pennies the usual mains diodes cost.
Dawg the constant finger twitching everytime you say *_"Please share in the comments"_* gets me *EVERY SINGLE TIME* 🤣🤣🤣👍👍
Very good content , wish u could release videos more frequently
Is there ever going to be a video on how lasers work?
I wish I could release more often too.
@@richardhare1734 Eventually, probably.
@@ScienceAsylum what are the limitating factors?
@@hachibolomaboyd7910 I'm almost sure it's time. Producing a well-edited video takes time, a lot of time: coming up with a topic, script writing, additional research, experimenting, filming, creating animations, editing, rendering the video, creating a good title+thumbnail+description, etc.
As soon as I heard that pop of the capacitor I knew exactly what happened AND what you smelled. My first job was testing circuit boards to make sure they worked as intended. And whenever something got installed backwards, especially capacitors, it was trouble. After a while I recognized the smell and was able to shut the power off before anything caught on fire or exploded. Cause that happened a few times.
Also this was a collab I never knew I needed.
Smell memory is wild, isn't it?
@@ScienceAsylum it really is, as the capacitor popped i got the smell of it and stopped the video for a few sec to sniff around me lol
My two favorite Mad CZcams Scientists in one video! What a time to be alive! Congrats for the awesome and informative video!
more collabs with famous youtubers! well on the way to 1mil now Nick. Remember the days when it was just a handful of us and we said you must keep pushing! 😊