The magnetic effect of a current and the motor · 一个电流的磁效应与电动机
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| solenoid/ˈsəʊlənɔɪd/ | 螺线管 | luó xiàn guǎn |
| d.c. motor/ˌdiː ˈsiː ˈməʊtə/ | 直流电动机 | zhí liú diàn dòng jī |
| motor effect/ˈməʊtə ɪˈfekt/ | 电动机效应 | diàn dòng jī xiào yìng |
| left-hand rule/left hænd ruːl/ | 左手定则 | zuǒ shǒu dìng zé |
| commutator/ˈkɒmjuːteɪtə/ | 换向器 | huàn xiàng qì |
Electricity makes magnetism
- A wire carrying a current creates a magnetic field around itself.
- Put that wire in another magnet's field and it feels a force — the idea behind every electric motor.
- This is where electricity and magnetism meet.
电产生磁
- 一根携带电流的导线在它自己周围产生一个磁场。
- 把那根导线放在另一块磁铁的场中,它感受到一个力——每个电动机背后的想法。
- 这是电和磁相遇的地方。
The magnetic effect of a current
- A current in a straight wire makes circular field lines around it; reverse the current and the field reverses.
- A solenoid 螺线管 (a long coil) makes a field just like a bar magnet, with a N and a S pole.
- Make it stronger by: more current, more turns, or a soft-iron core.
- Used in relays and loudspeakers.
A d.c. motor 直流电动机
一个电流的磁效应
- 一根直导线中的电流在它周围产生圆形的场线;反转电流,场就反转。
- 一个螺线管(solenoid,一个长线圈)产生一个就像一块条形磁铁的场,有一个 N 和一个 S 极。
- 通过以下使它更强:更多电流、更多匝数,或一个软铁芯。
- 用在继电器和扬声器中。
一个直流电动机
The force that spins a motor · 让电动机旋转的力
A current in a magnetic field is pushed at right angles to both — reverse the current or flip the magnet and it pushes the other way. That is what turns a motor. · 磁场中的电流被推向与电流和磁场都成直角的方向——反转电流或翻转磁铁,它就朝相反方向推。这就是电动机转动的原理。
The magnetic field of a solenoid (a long coil carrying current) looks like the field of: · 一个螺线管(一个携带电流的长线圈)的磁场看起来像以下的场:
A solenoid produces a bar-magnet-like field, with a north pole at one end and a south at the other. · 一个螺线管产生一个条形磁铁式的场,一端有一个北极,另一端有一个南极。
Which change makes an electromagnet stronger? · 哪个改变使一个电磁铁更强?
More current, more turns, and a soft-iron core all make the field stronger. · 更多电流、更多匝数和一个软铁芯都使场更强。
The motor effect 电动机效应
- A current-carrying wire in a magnetic field feels a force — the motor effect.
- Reverse the current, or reverse the field, and the force reverses.
- A bigger current or stronger field gives a bigger force; the force is greatest when the wire is at right angles to the field.
- Find the direction with the left-hand rule 左手定则: thumb = force, first finger = field (N→S), second finger = current.
电动机效应
- 一根在磁场中的载流导线感受到一个力——电动机效应(motor effect)。
- 反转电流,或反转场,力就反转。
- 一个更大的电流或更强的场给出一个更大的力;当导线与场成直角时力最大。
- 用左手定则找方向:拇指 = 力,食指 = 场(N→S),中指 = 电流。
In the motor effect, reversing the current direction: · 在电动机效应中,反转电流方向:
Reversing either the current or the field reverses the force. Reversing both leaves it unchanged. · 反转电流或场任一都反转力。反转两者使它不变。
In Fleming's left-hand rule, the thumb points in the direction of the: · 在弗莱明左手定则中,拇指指向以下的方向:
Thumb = force, first finger = field, second finger = current — all at right angles. · 拇指 = 力,食指 = 场,中指 = 电流——都成直角。
The force on a current-carrying wire is greatest when the wire is at right angles to the magnetic field. · 当导线与磁场成直角时,一根载流导线上的力最大。
The force is largest when the wire is perpendicular to the field, and zero when the wire lies along the field. · 当导线垂直于场时力最大,当导线沿场放置时为零。
Match each idea to what it describes. · 把每个想法与它描述的内容配对。
Each item links the term to its correct meaning. · 每一项把术语与它正确的含义联系。
The d.c. motor
- A current-carrying coil in a field feels a turning effect: the forces on its two sides act in opposite directions.
- A split-ring commutator 换向器 swaps the current direction every half-turn, so the coil keeps spinning the same way.
- The turning effect is bigger with more turns, a bigger current, or a stronger field.
The motor effect on a current-carrying wire
直流电动机
- 一个在场中的载流线圈感受到一个转动效应:它两侧上的力以相反的方向作用。
- 一个分裂环换向器(split-ring commutator)每半圈交换电流方向,所以线圈保持以同样的方式旋转。
- 转动效应随更多匝数、一个更大的电流,或一个更强的场而更大。
一根载流导线上的电动机效应
What is the job of the split-ring commutator in a d.c. motor? · 分裂环换向器在一个直流电动机中的工作是什么?
Without the commutator the coil would stop after half a turn. Swapping the current each half-turn keeps it rotating the same way. · 没有换向器线圈会在半圈后停止。每半圈交换电流使它保持以同样的方式旋转。
You've got it
- a current makes a magnetic field: circles round a wire, bar-magnet field for a solenoid
- stronger electromagnet: more current, more turns, soft-iron core
- motor effect: a wire carrying current in a field feels a force (left-hand rule)
- a d.c. motor spins; the split-ring commutator reverses the current each half-turn
你掌握了
- 一个电流产生一个磁场:绕一根导线的圆,一个螺线管的条形磁铁场
- 更强的电磁铁:更多电流、更多匝数、软铁芯
- 电动机效应:一根在场中携带电流的导线感受到一个力(左手定则)
- 一个直流电动机旋转;分裂环换向器每半圈反转电流