Hall Effect - Sixty Symbols

[@AnushaathP]

sir,u just made this concept 100 times clearer...

[@ffmaer]

0:24 the Lorentz force: A magnetic field bends the current. 1:40 the question posted by Edwin Hall 4:00 It's not the voltage down the wire. It's the voltage across the wire. 4:34 the use of Hall Effect

[@physicswallahbmsharmafreev6262]

👍

[@taith2]

"I touch pieces of apparatus and they break down" I can relate, so hard.

[@TheMordi1]

Best explanation on youtube

[@ahmedhegazy699]

If you really mean it then i will not look for another video

[@CapitanBizarrely]

Lots of people know lots of stuff about lots of things, but only a few have the gift of passing on that knowledge in a concise way that can be easily understood. Thanks much for the great explanation professor.

[@ylette]

This finally explains the Monty Hall problem for me, thanks!

[@ledheddred]

+YourLaughzZ You know--Door #1, Door #2, or Door#3. Quite a vexing problem, actually, especially when Carol Merril is pointing at the doors!

[@josephcote6120]

One door has a magnet, two doors have sensors.

[@sahilbhagwat3254]

If only my professors had the ability to explain stuff as beautiful as this gentleman here.

[@akilghosh]

I wish I had a teacher like him.

[@RobertoTifi]

Sirs, you're ab-so-lu-te-ly BRILLIANT!! I can't stop watching this "sixtysymbols" series! Addictive! Thanks for the excellent job!

[@obiwanjacobi]

I knew about the hall sensor - that is was for detecting magnetism, but now I know how it works. Thanx!

[@AgentLogik]

You guys are great in that you make this sort of vital information simple for anyone's understanding. And just as importantly it seems you are doing something you enjoy thoroughly and comes naturally. Bravo and thank you.

[@chrisbotics]

I like the way Professor Bowley explained the problem. He must be an incredible lecturer. Thank you

[@yudanielk]

Sir, that was absolutely brilliant. You have explained to me what my textbook has failed to do for the past two days in just over six minutes.

[@LewisCampbellTech]

That little demonstration was really useful. Puts the theory into context.

[@shaikmuhammadikram5031]

finallly someone who explained hall effect very clearly ,thanks buddy

[@olaniyishow]

Thank you professor, you simplify the explanation of Hall effect by making it quite interesting and understandable

[@TerrenceJoneskrews_]

Thank you so much. It could not have been explained any clearer.

[@ThrowingItAway]

This is what I wish they showed me in physics 12 =) thank you Sixty Symbols I love you guys for this.

[@zamanraja9531]

my man bowley is a physics king. thanks professor, that really helped to understand and visualise the effect

[@EddyScbr]

"I touch pieces of apparatus and they break down". Glad to know I'm not alone in this...

[@sarowie]

Professor Bowley would be a greate teacher for basic (or advanced) electronics courses; it's really great how he can explain correct, significant and still in a way that is easy do understand.

[@anantikamehra1694]

This is a very clear and interesting explanation! Thanks so much for this.

[@ErikOosterwal]

We use this for measuring RPM . Several small magnets are attached to shaft so that they pass by a Hall Effect sensor when the shaft is turning and we count the pulses generated by the sensor. There are other ways of measuring RPM, of course, but this method is cheap, reliable, and essentially frictionless.

[@JiveDadson]

When I was in the robotics game, we used brushless DC motors with Hall-effect sensors, known simply as "halls".

[@edgeeffect]

I've been playing with brushless motors recently... so it's nice to find out what that Hall effect sensor is actually doing. :)

[@adarshsrinivas9]

finally a video that clearly explains the hall effect to me, I really loved this!

[@KevinVanOrd]

Professor Bowley, I wish you'd be my best friend. Watching you teach makes me happy.

[@JohnnyAdroit]

Another great thing about the Hall effect is that it was used to discover which particle actually moves in an electric current. In a wire, a flow of positive charges moving in one direction is indistinguishable from a flow of negative charges in the other. With the Hall effect, the charge buildup on the sides of the wire will be opposite depending on which charge is moving. This effect is the reason we know that electicity is due to electrons moving instead of protons.

[@pauljager5798]

Great explanation. Thank God for the Internet. This professor has a passion for teaching - the not so good academics who seem to derive pleasure from making things seem 'harder' than they are... :-)

[@strengthbuild]

I've been spelling it "Hail effect" all this time. I guess I should throw away all my notes now.

[@7thrx]

Resistance is voltage over current not voltage times current. It's a mistake that I make sometimes too. I always enjoy the sixty symbols videos. Keep them coming.

[@johnclavis]

Marvelous and easy to understand. Now I know what the Hall Effect is! Thanks for yet another wonderful video!

[@Chronix74]

Finally, someone who can explain it clearly. thanks!

[@exxzxxe]

A really excellent explanation and demonstration by a first-rate teacher.

[@HomeDistiller]

alarm door switches are normally just that, a switch (called a reed switch) hall effect sensors are used more in cars to detect the crank angle, or another fast moving magnet (as reed switches wont work fast or accurate enough, and reluctance type sensors are large and prone to noise)

[@madhurigupta1052]

Clear message, clear structure, easy to understand, thank you

[@Tom-sp3gy]

The best explanation of Hall effect ever !!!

[@ShoumanBaruaShuvo]

Thank you sir. What my sir couldn't make us understood in 2 years, you did that in 6 minutes.

[@SitiakosPoilitis]

thanks, i just remembered the Hall effect!

[@josephcote6120]

Excellent explanation. I've used them for years, never quite had a handle on how they worked.

[@KazantzidisRomanos]

Sir you have charisma you can teach students like no one else

[@3800S1]

these are used in sensors in many applications including most cars and machinery. They are called hall effect sensors. eg. crank angle sensor, proximity sensor, speed sensors, linear and rotary decoders

[@xenocore01]

I remember a quote from Einstein saying, "If you cant explain it easily, you don't understand it well enough." This gentlemen is a giant. Enjoy your retirement sir, you have earned it.

[@yusukeshinyama]

"Plan(c)k length" and then "Hall effect"... this professor is onto something!

[@deltaforce229]

I wish I had these videos when I was in high school. If I was a science teacher I would definitely show them to my classes.

[@BikerBry]

Matter of fact, the Hall Effect is used in several modern automotive technologies such as the camshaft sensor, crankshaft sensor, and the Anti-Lock brake system.

[@giannidebruycker335]

Finally, the video I was looking for! Thank you so much for explaining this so well!!!

[@CalvinDilbert]

This is a great video. Very nice explanation. Thank you so much. This really helps me to understand this topic.

[@imrsk]

I wish I had a teacher like you...Thanks a million

[@HailG3]

This saved my life! Best explanation ever!

[@yellowmetalcyborg]

@chrisofnottingham It's also used in brushless motors as a feedback mechanism so that the controller can switch on the right coil at the right place at the right time when a rotor magnet passes over it.

[@gabrielaguiar1935]

Here where I live the burglar sensors dont use this concept. They use a switch which is activated by a magnetic field. The magnetic field bend one of two metal wires that are very close together and make them touch.

[@kd1s]

Don't forget one of the bigger uses of the Hall Effect. It's used as a sensor in cars to detect the rotation of the spark rotor.

[@MakisHMMY]

Dude you just explained to me how the Inductor works. MANY thanks!

[@chrisofnottingham]

It is also often used to measure rotational velocity or rotational position in various things. If there is something like the teeth on a cog or a shaft with a non uniform cross-section then a Hall effect sensor will give a varying reading as the thing rotates. This can be filtered and counted to give a speed or position. Advantages of this are that it is non contact method and also it continues to work in dirty environments when optical methods might be unsuitable.

[@omsrswt]

Thank you for these videos... They often help to illustrate and make more memorable some dull classes in A Level Physics. :)

[@chrisdaley2852]

Sorry to disturb you and I don't know if someone has already said this but the drift velocity is the general velocity of the current. The actual velocities of the electrons are much higher although not all the the same direction at . Some are even going backwards. They also change. Drift velocity is the average of these velocities. Usually quite low. While there are photon transfers between electrons, the cause of a detected current is the actual movement of electrons.

[@DamoclesAurelius]

You are correct todiwan. Conductive materials like metal have an interesting material property where electrons sort of just "float" around in the material and can thus be pushed around within the material (which is why they are conductive) The positive charge is the "absence" of all the electrons (it's positive relative to the more negative side).

[@oooooooooorly]

That bit about theoreticians causing apparatus to fall to bits is absolutely true - I can recall quite a few funny stories to that effect...

[@OOZ662]

A good every-day example for Hall effect sensors is in joysticks. The oldest joysticks were digital, meaning they basically pushed down a button when you moved the stick, kind of like on a modern controller's D-Pad. Then they started using analog potentiometers, which let current through based on how much of two metal surfaces are touching each other. Problem there is the metal wears out, gets dirty, or oxidizes. Now they're starting to use Hall sensors and permanent magnets; no degrading!

[@zaneal-amood5474]

There’s been some developments on muon catalyze fusion using the hall effect And you can use to Hall effect control plasma to control the electron holes the positive and negative ions in the way the electrons line up with the positive negative ions and holes

[@MrOldprof]

@mcjhn The origin of the force on the current-carrying wire is the Lorenz force. Each moving electron that makes up the current experiences a Lorenz force, (the force that bends the path of the charge in the video) and the forces on each electron add up to give a net force on the wire which is proportional to the current times the strength of the magnetic field. The force is maximum when the wire lies perpendicular to the magnetic field. The Lorentz force is the common feature.

[@mathon2462]

thanks professor bowley

[@sirsideways]

I'm an electronic engineering student (1st year UG). I've used a PIC microcontroller with a Hall Effect sensor to measure the RPM of a rotating shaft (about a year ago). I think back then I would have benefitted from such an easy to understand explanation - it would have saved me from a lot of headaches! A very interesting video as per usual - the enthusiasm and friendliness of the professors’ is what makes this channel so great! Many thanks to Brady also. Thanks.

[@rewrose2838]

Thank you for that illustrious explanation

[@gexwing]

@rahkshifan99 he's not bending light, he's bending a stream of electrons, which make a photofluorescent tube glow when they hit it, the light is no there when it's bend. (This is used in Old CRT Monitors, you got a stream of electrons and when they hit the screen making it glow in different colors, producing the image on the screen.)

[@thenaimis]

Burglar alarms use reed switches. Already been pointed out, I know. I like to be redundant. Atari made joysticks for their arcade games using Hall effect sensors (not all of them of course). "I, Robot", "Road Runner" and "Escape from the Planet of the Robot Monsters" all used Atari's Hall effect joystick.

[@1400740]

Beautifully explained

[@jerommeke69]

The positive charges are "electron holes". Look it up on wikipedia, it's very clearly explained.

[@blahblah0715]

@DakaSha Agreed. Thse people are the real heroes of this day and age.

[@piasc2142]

Physics homework done! Thank you so much this is really helpful and much easier to understand than the text in my school book:)

[@The88Nomad]

"But it's nothing to do with the Ohm's Law, this is the Hall Effect" reminds me of the commercial "This is not just food, this is M&S food" lol

[@175griffin]

I thought it had something to do with the spin of the electron. spin up goes on one side while spin down goes to the other? I read an article about the recent discovery of the hall effect on light and they explained it by spin up/down electrons

[@tubby1]

***** That's the spin Hall effect. It's an analogous but different effect.

[@manasikashyap]

More of Professor Bowley please 😊

[@jackwhite3820]

In practical applications the Hall sensor is made out of a semiconductor where you can have electrons or holes or both. The reason is because you can manufacture it so that there are only few free charges available for the current transport, which means the few charges will have to move very fast in order to get the same current. And the faster the charges the stronger the Lorentz force and therefore the stronger the Hall effect. But I digress, let's go back to the plain metal conductor ...

[@atomicdmt8763]

this helped me understand my crankshaft position sensor for my vehicle......recent problem! thanks! i recently put in a NEW (but bad) CKP sensor and its apparently shorted internally- screwing up my fuel level gauge, ignition coil/ignitor(?) and setting off a host of other selonoids- et al! I cleaned all grounds, rebuilt my fuse box, new ECU, cleaned everything........no changes UNTIL i just now decided to swap back in the old CKP sensor. All the electrical clicking, etc went away immediately and Im not going thru the KEY RELEARN process for the new ECU

[@JuanPabloCarbajal]

Hall effect is also used in the electronic compass that some watches and some robots have.

[@davefoc]

The Hall effect device only functions as a sensor. When the electronics detect that the Hall effect device no longer is sensing a magnetic field they turn on current to the alarm.

[@DevilMaster]

The Hall effect was used in the analog joysticks of the arcade game "I, Robot". Unfortunately, they were very unreliable. Dave Theurer, the creator of the game, said he wishes he could just take those joysticks and dump them to the bottom of the ocean.

[@motormiracles]

+DevilMaster Its also used on just about every newish car as an accurate and mostly reliable way of measuring crankshaft/camshaft speed.... GM wish they could dump the batch they bought for the 3.8l v6's at the bottom of the ocean

[@GRAHAMAUS]

@flux1969 No. That's a ferrite block which adds some parasitic inductance to the lead to prevent high frequency signals either from escaping from the monitor or getting into it from the outside and causing interference.

[@gexwing]

@kristijan0kroflin Charge is a State, which is not dependend on other quantities, SI-Base System defines 7 units (see wikipedia for International System of Units, the one used in "Science" most of the time), one of which is Ampere (Electric Current, (which can be derived from moving Charges through a Surface (so C(Coulomb)/m^2(Square meters)). The thing is things depend on each other, so you can express it in different forms and they still mean the exact same thing, just in different quantities.

[@LaugeshariBA]

Omg this really helped me where I have some doubts Very well explained 👏👏

[@bigboam]

Fantastic explanation, sir. Cheers!

[@GilesHutchison]

Great explanation - thank you.

[@noxure]

@guitarfish83 A lot of great inventions use this effect. Measuring the rotation speed of a wheel, used for anti lock brake systems or frictionless speedometers on bicycles. The joysticks used in cranes or the analog controllers for video-games. Also it allows you to build instruments that measure the magnetic flux leakage which is handy for technicians to check the structural integrity of pipelines without having to dig them up or breaking walls. It's pretty useful. ;-)

[@GreedPainLove]

I've had to do even calculations with the hall effect and still had absolutely no idea what the hecc I was doing until I watched this video, nice

[@joshhyyym]

It isn't the same as a reed switch. Reed switch have a segment of broken wire that it reconnected when a magnetic force pulls both of them together, however I believed that reed switches were used in the door frame sensors. I suppose it depends on if you need a binary input or an analogue measurement.

[@FalcoGer]

you can also set up a very easy burgler alarm you can actualy build yourself with a piece of iron. you put a magnet on the door and put an electrical contact with the piece of iron at the door that is held open by the magnetic field. if the magnet is moved away (due to the door opening) the metal snaps back and forms the electrical contact that you then can use to sound an alarm or something. no need for high tech expensive equipment if you can build it for 5€

[@DenUil]

Most used for the ABS system of your car. Because you can sense with it if your tire is still rotating or its blocked. Together with an accelerometer you can see if the car is slipping over the road.

[@rwz]

I really like the simple explanations. :)

[@mrnarason]

Really cool, just got my idea for my advance lab technique term project.

[@junk4dimeji]

I just fell in love. Thank you Doc.

[@LUVCHUNK]

iv been involved with alarms for 20 years nobody uses hall effect sensors yet. its all still argon filled reed switches. i think its because a reed switch only uses two cable cores so they are more cost effective and reliable

[@MrOldprof]

@2112murphy "This is not really to scale"---An electron has no size that can be measured; it is also obeys the laws of quantum mechanics rather than classical mechanics. You might doubt that the model presented in this video is correct. And you would then be right, for at very low temperatures (say 0.02 K) and in a very strong magnetic field (15 tesla) the Hall effect breaks down, as discovered by von Klitzing. "I apologize for the crudity of this model." Well said, Doc Brown.

[@jackwhite3820]

If I remember correctly you can use hydrogen, which will give you a bluish colour, but I would imagine every noble gas would do the trick as well. However it will only work at a very low pressure! At atmospheric pressure the electrons won't even fly as far as a millimetre. Little note, the professor said the electrons were ionizing the gas, which isn't true for this particular tube. This tube is evacuated and the electrons are hitting the white scale where phosphorous produces the green light.

[@keyboard_toucher]

The Hall effect presents completely differently when in an accelerating reference frame. In such a case, it's known as the haul effect.

[@looncraz]

Hall-effect sensors are used in several places in automobiles. RPM sensor, CAM position sensor, ABS sensors, and plenty more I'm sure...

[@jackwhite3820]

... in a metal you have free electrons and fixed atomic cores and in total the charges cancel each other out, so everything is neutral. If the Lorentz force now moves the electrons on one side the positively charged atomic cores remain on the other, because they can't move in the grid, hence the positive charge.

[@patrickleahey4574]

I enjoy your explanations, Professor. The Hall Effect was unknown to me. At about 4:40, you mentioned that apparatuses often go hay wire when you use them. In uncertain circles,we call this the (Wolfgang)Pauli Effect. How about doing a presentation on it?

[@4pharaoh]

Very well done. The door sensor is not the best example, but you are a theorist, (all is forgiven;-) Hall effect switches are used when you want high reliability, and/or high speed. Hall effect sensors are used to measure the strength or direction of a magnetic field.