联系我们
联系我们 库存

磁铁 & 磁场

为什么要做磁映射?

In reed sensor applications it is important to understand the exact pull-in and drop-out fields.  This information then allows one to properly position the magnet and sensor well within appropriate guard bands and avoid any tolerance issues.  Most users have no idea what the actual magnetic field looks like. Presenting the fields in a three dimensional view gives the user a better chance to have an optimized design.  This will help define adequate operate and deactivate points. Additionally, this will insure operation takes place well within the magnetic envelopes to avoid tolerance issues.  We can insure acceptable hysteresis between the operate and deactivate points.  We can optmize the sensor and magnet costs.

什么是磁映射?

Magnetic mapping is the method of incrementally measuring the pull-in and drop-out points by either holding the sensor stationary while moving the magnet or vice versa.  The movement must be carried out in all three dimensions.  Software is then used to bridge all the points allowing the magnetic field to be visualized in three dimensions.

电磁是指什么?

An electromagnet is a magnetic field generated when a coil of wire is formed in a cylindrical shape.  The magnetic field will be uniform through the entire length of its inner opening.

铁磁体是指什么?

Ferromagnetic is the property of a material that allows it to become magnetized permanently or temporarily when in the influence of a magnetic field generated by a permanent magnet or an electromagnet.

如果将磁铁放置于硬表面上,磁铁磁性会改变吗?

不会。传闻磁性强度会受影响,但是事实上磁性不会改变。

为什么使用不同类型磁铁?

我们可以根据磁铁特征选择一款最适合应用领域的:

  • 铁素体成本最低
  • 铝镍合金,在广泛的温度范围内最稳定
  • 稀土提供最强磁场
如何生成均匀磁场,为什么?

A uniform magnetic field can be made by making a relatively long cylindrical coil. Once current is flowing through the coil a uniform magnetic field will exist all along the inside of the coil. This is not true at the very ends of the coil.  Helmholtz coils can be bought for the very reason of supplying a uniform magnetic field.  In either case, the uniform magnetic fields allow for calibration.

有没有理想尺寸磁铁?

Yes there is and it clearly depends on the type of magnet.  The length to diameter is the key ratio.

  • Alnico 5 is 5:1
  • Alnico 8 is 3:1
  • Ferrites are 1:1
  • Rare earth is 1:1
为什么使用亥姆霍兹线圈?

Using a Helmholtz coil makes it very easy to calibrate magnetic fields in either ampere turns (AT) or milliTesla (mT).

什么是亥姆霍兹线圈?

A Helmholtz coil is actually two concentric coils mounted parallel to each other and when energized by passing a current through them they will produce a uniform magnetic field between the two coils.

什么是居里效应?

居里效应是指当一个磁铁到达一定温度时,它的磁属性将会消除。一旦温度下降至居里温度,磁性将会恢复。

磁场如何生成?

Generally winding fine copper wire in a cylindrical configuration will create a magnetic field internal to the cylinder, when a current is passed through the copper wire.

人造磁铁如何形成?

Artificial magnets can be created by doping iron, nickel, and/or cobalt with other elements.  Doping with rare earth materials has been particularly successful, producing very strong magnets.

磁场能量从何而来?

The magnetic force is generated at the subatomic level and the energy comes from heat.  Any temperature above absolute 0 (-273°C)

什么是偶极?

A dipole is the basic building block of a magnetic field.  A dipole is the magnetic effect from a single atom.  When taken many million times over, one has a magnetic field being generated from a magnet.

磁铁有哪些类型?

主要有三种不同类型的永久磁铁:
1.铝镍合金 – 稳定和最佳温度效应
2.稀土-最强磁铁
3.铁素体-成本最低

什么是磁铁?

磁铁由铁磁材质组成,这就意味着它必须包含以下至少一种材质:镍,铁或钛,且必须能够维持磁性。

什么是磁性?它从何而来?

Magnetic is a force produced at the subatomic level.  It is caused by electrons spinning and also rotating around the nucleus of the atom.

什么是热处理?

When metal is subjected to a very high temperature bath, that process is called annealing.  The temperature is slowly increased to a max temperature where it is stabilized for a period of time, and then the temperature is slowly reduced back to room temperature.  This process will leave the metal in its softest state.  For a reed switch this is very important because this point is also where the nickel/iron leads have near zero magnetic retentivity.  This means when the reed switch contacts are subjected to a magnetic field and then the magnetic field is removed, there will be no residual magnetism on the leads.

如果一个干簧管受到一个极强磁场约束会有净效应吗?

没有。对干簧管没有净效应,一旦磁场使干簧管触点饱和,它就不再有任何影响。

磁铁与干簧管能转换为温度传感器吗?

A magnet and reed switch can be turned into a temperature sensor by using a magnet that has a certain curie temperature for the temperature you want to sense.  When that curie temperature is reached the magnet loses its magnetic properties whereby the reed switch contacts open.  When the temperature drops below the curie temperature, the reed contacts will close.

订阅我们的电子邮件

We Will Use The Email Address You Provide To Send You Marketing And Promotional Materials.

展览活动

electronica india 2022
Booth No.: EH15
更多信息 点击这儿

关注我们

领导层聚焦

Video
表格下载
Products compare