Name: faraday disk dynamo and dc output
Uploaded: 2023-09-18T17:11:16.000Z
Duration: 1 min 23 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Physical Science

motion-and-stability-forces-and-interactions

Motion and Stability- Forces and Interactions

PS.PSc.6.5

Faraday Disk Dynamo

דינמו דיסק פאראדיי הוא מחולל זרם ישר שעובד על עקרון האינדוקציה.
הוא מורכב מדיסקה מוליכה המסתובבת במהירות זוויתית קבועה באמצעות פיר מוליך, המוצב בשדה מגנטי אחיד בניצב למישור הדיסקה. סיבוב הדיסק גורם ל- EMF תנועתי בתוכו.
שקול קטע קטן של הדיסק עם וקטור מהירות משיק אליו. הכוח המגנטי על קטע זה הוא רדיאלי כלפי חוץ. זה צובר מטענים חיוביים חופשיים לכיוון השפה ומטענים שליליים חופשיים לכיוון המרכז, וכתוצאה מכך EMF.
שילוב המשוואה של EMF בגבולות אורך הקטע והחלפת גודל וקטור המהירות נותן את גודל ה- EMF התנועתי.
ניתן לחבר דיסק זה למעגל באמצעות שתי מברשות נייחות, המוליכות את הזרם על פני הלולאה הסגורה.
על פי חוק לנץ, הזרם המושרה מתנגד למהירות הזוויתית הקבועה של הדיסקה. לכן, יש לעשות עבודה כדי לשמור על הדיסק מסתובב במהירות זוויתית קבועה.

<ol>
	<li>יאנג, ה.ד. ופרידמן, ר. (2012). פיזיקה אוניברסיטאית עם פיזיקה מודרנית. סן פרנסיסקו, קליפורניה: פירסון. סעיף 29.4, עמודים 971.</li>
</ol>

דינמו דיסק של פאראדיי

<div style="direction:rtl">דינמו דיסק של פאראדיי הוא מחולל DC, המייצר EMF קבוע בזמן. הוא מורכב מדיסק מוליך שמסתובב במהירות זוויתית קבועה בשדה המגנטי, בניצב למישור הדיסק. סיבוב הדיסק גורם לשינוי בשטף המגנטי, הגורם ל-emf, הגורם להתפתחות מטענים מנוגדים על השפה ובמרכז הדיסק. ניתן לקבוע את הקוטביות של ה-emf המושרה לפי כיוון השדה המגנטי וכיוון הסיבוב של הדיסק. אם הדיסק המסתובב מחובר למעגל חיצוני באמצעות מברשות, אז זרם מושרה זורם. על פי חוק לנץ, ה-emf המושרה תמיד מתנגד לגורם שמייצר אותו. עבור דינמו הדיסקה של פאראדיי, ה-emf המושרה מתנגד לסיבוב הדיסק. לכן, יש לספק כוח חיצוני נטו כדי לשמור על סיבוב הדיסק במהירות זוויתית קבועה. ה-emf המושרה בדינמו כזה יכול לנוע בין כמה מילי-וולט לכמה וולט. ניתן להגביר עוד יותר את גודל ה-emf המושרה על ידי חיבור מספר גנרטורים בסדרה או על ידי הגדלת עוצמת השדה המגנטי, רדיוס הדיסק ומהירות הזווית של הדיסק.</div>

דינמו דיסק פאראדיי הוא מחולל DC, המייצר EMF קבוע בזמן. הוא מורכב דיסק מוליך שמסתובב עם זוויתי קבוע ...

Education

JoVE Core

Physics

פיזיקה

Unit 1

יחידה 1

Electromagnetic Induction

השראה אלקטרומגנטית

KEY TERMS AND CONCEPTS

מונחים ומושגים מרכזיים

faraday disk dynamo and dc output

A Faraday disk dynamo is a DC generator that produces an emf constant in time. It uses a conducting disk that spins at constant angular velocity in a magnetic field. The magnetic field is perpendicular to the plane of the disk.

As the disk rotates, the magnetic flux changes and an emf is induced. This causes opposite charges to build up at the rim and at the center of the disk. The direction of the induced emf depends on the direction of the magnetic field and the direction of rotation.

If brushes connect the rotating disk to an external circuit, an induced current flows. Lenz’s law explains that the induced emf opposes the cause that creates it. In this case, the emf opposes the rotation of the disk, so outside power is needed to keep the disk moving at a constant angular velocity.

The induced emf in a Faraday disk dynamo can range from a few millivolts to a few volts. Its size can be increased by connecting multiple generators in series. It can also be raised by using a stronger magnetic field, a larger disk radius, or a faster disk rotation.

Faraday Disk Dynamo and DC Output

induction

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faraday disk dynamo

A Faraday disk dynamo is a DC generator that produces an emf constant in time. It uses a conducting disk that spins at constant angular velocity in a magnetic field. The magnetic field is perpendicular to the plane of the disk. As the disk rotates, the magnetic flux changes and an emf is induced. This causes opposite charges to build up at the rim and at the center of the disk. The direction of the induced emf depends on the direction of the magnetic field and the direction of rotation. If...

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key terms and concepts

Learn how a Faraday disk dynamo makes steady DC output, builds charge on the disk, and uses Lenz’s law to resist rotation.

Faraday Disk Dynamo and DC Output | JoVE K12

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Faraday Disk Dynamo and DC Output

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