Hall Effect.

Now why didn't they just say so...? Thank you!

I just Knew someone would have to do it.

BAB

Have you checked out Hyperphysics ?

What is confusing you?

You have a current carrying object. On this a magnetic field is applied, perpendicular to the direction of the current.

As per flemings left hand (or may be right hand not sure) rule a force will be applied on the current carrying condector in a direction perpendicular to both.

If the conductor is stiff enough, then, assuming individual electrons (and holes) as conductor, the forces are applied in this direction.

This will results in electrons getting accummulated in a direction perpendicular to both B and I, and holes too, but the opposite edge.

Of course if you want the mathematics, there is a beutiful one here

http://hyperphysics.phy-astr.gsu.edu/HBASE/magnetic/hall.html

and also check the derivation in the <show> on bottom right where the equation is given.

But in english it is as above.

Regards.

A GA for most suitable worded reply.

I like to add:

Hand-piece used by Dentists where water + Air is also making the cutting-bit & Tooth keep cool is one of the examples of Hall-Effect devices [Brush-less motors].

Have a fine day !!!!!

One fact has been missed in all of the previous answers. It is unlikely that anyone would notice the hall effect voltage in a metalic conductor simply because it is too conductive. The hall effect is observable in a semiconductor with a limited concentration of charge carriers, an intrinsic semiconductor not heavily doped. As the holes and electrons move in opposite directions along the long dimension of a semiconductor bar with a magnetic field at a right angle, they will deflect orthoganally causing a detectable voltage difference along opposite sides of the semiconductor bar proportional to the product of the magnetic field and the test current. This is similar to the way electrons moving through a vacuum inside a CRT are deflected by the magnetic fields. Instruments made possible by analog Hall effect sensors are DC clamp-on ampmeters and static magnetic field strength meters. There are many more digital uses for Hall effect sensors as well, but a very important one is controling the phase of the rotating magnetic field in PM motors and timing the commutation of voltage to the windings in response to the motion of the armature. An inexpensive angle encoder is sold for a few dollars today using quadrature detection and Hall effect sensors sensing a rotating permanent magnet where expensive glass encoders were required previously.

Luther,

Thanks for agreeing with my post (right before yours) and including a more in-depth description.

Jon

so how does a hall effect sensor work?

Regards.

Google:

https://search.yahoo.com/search?p=how+a+hall+effect+sensor+works

Quobalt,

They say it was named after HALL but considering what historians do with facts in the politically correct environment maybe it was changed from the original of the effect of seniors running freshmen in to the walls of the HALL.

Jon

A Gaussmeter measures the strength of magnetism in a given object. It works on the principle of Hall Effect. It has a probe (small electric coil) which is brought near the object at right angles (this position will identify itself by giving the maximum readout) and the value of the magnetic field in the object found out.

In simple words it can be explained thus: A current carrying conductor has an induced magnetic field surrounding it as shown. This is a zero or stable or balanced position on the meter when on its own. If this conductor is placed in an external magnetic field (from the object in our case), the 2 fields interact and cause an imbalance in the circuitry which is noted by the meter in terms of the value of the external magnetic field strength. + or - sign to the figure indicates direction of the field.

Where did you get this idea?

Nachi,

Looks like some kind of gauss measuring thing without a Hall effect sensor.

You said: "It works on the principle of Hall Effect. It has a probe (small electric coil) which is brought near the object at right angles "

A Hall effect probe is not an electric coil.

There seems to be something very wrong with your information source.

Jon

Well, that is what I have in my notes. If not a coil, what do you think it is? Looking fwd to an improvement to my input, appreciate it.

Nachi,

I was never a good note taker because it took away from my listening and storing ability.

Your note seems to be of an inductive sensor used for measuring ac current.

There is no Hall effect device (except that hall effect is mentioned) in your description or in your sketch. And there are no "coils" in your sketch.

Check the earlier discussion that talk about Hall effect devices and see what I'm talking about.

Also:

For a given current flow, a proportional magnetic field is produced around the current carrying conductor. Current sensors measure this field using "Hall Effect" for DC currents while for AC currents use "Inductive" technology. Your note speaks of the latter.

The Hall Effect sensor has a core, Hall Effect device and signal conditioning circuitry. The current conductor passes through a magnetically permeable core that concentrates the conductor's magnetic field. The Hall Effect device is mounted in the core at a right angle to the concentrated magnetic field. A constant current in one plane excites the Hall device. When the energized Hall device is exposed to a magnetic field from the core, it produces a potential difference (voltage) that can be measured and amplified into process level signals.

The Inductive sensor has a wire-wound core and a signal conditioner. The current conductor passes through the core that magnifies the conductor's magnetic field. AC current constantly changes potential from positive to negative and back again, generally at the rate of 50 or 60 Hz. The expanding and collapsing magnetic field induces current in the windings. This secondary current is converted to a voltage and conditioned to output process level signals.

Does that help?

Jon