Find alternators magnetic field?

In summary, the conversation discusses the design of an alternator for a car's battery. The mechanical engineers have specified a 10-cm-diameter rotating coil, and 250 turns can be fit into it. The desired peak output is 16 V when the alternator is rotating at 1300 rpm to charge a 12-V battery. The question asks for the specification of the alternator's magnetic field, with a hint to consider the rotation rate of the coil in revs per minute. The attempt at a solution suggests using Gauss's Law for B fields but is unsure of the exact equation to use.
  • #1
jlmccart03
175
9

Homework Statement


You're an electrical engineer designing an alternator (the generator that charges a car's battery). Mechanical engineers specify a 10-cm-diameter rotating coil, and you determine that you can fit 250 turns in this coil. To charge a 12-Vbattery, you need a peak output of 16 V when the alternator is rotating at 1300 rpm.

What do you specify for the alternator's magnetic field? HINT: Notice that the rotation rate of the coil is given in revs per minutes, not revs per second.

Homework Equations


I think Guass Law for B fields?

The Attempt at a Solution


I really do not know where to start. I am in general confused on what form of equation I should be using. I want to say using gauss's Law for B fields, but I can't come up with a definitive solution. Any guidance would be appreciated.
 

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  • #2
Have you googled.. voltage produced by a rotating coil?
 

1. How do alternators produce a magnetic field?

Alternators produce a magnetic field by using a combination of a stator (stationary) and a rotor (rotating) component. The stator contains a set of windings that are connected to an AC power source, creating an electromagnetic field. The rotor, which is connected to the engine through a pulley, contains a set of permanent magnets that rotate within the stator's electromagnetic field, producing a magnetic field.

2. What is the purpose of the magnetic field in an alternator?

The magnetic field in an alternator is essential for the conversion of mechanical energy into electrical energy. As the rotor rotates within the stator's magnetic field, it induces an alternating current (AC) in the stator windings, which is then converted into direct current (DC) through a rectifier.

3. Can the strength of an alternator's magnetic field be adjusted?

Yes, the strength of an alternator's magnetic field can be adjusted by changing the amount of current flowing through the stator windings. This is typically done through a voltage regulator, which controls the amount of current supplied to the stator.

4. What factors affect the strength of an alternator's magnetic field?

The strength of an alternator's magnetic field is affected by several factors, including the number of turns in the stator windings, the amount of current flowing through the windings, and the rotational speed of the rotor. Additionally, the type and strength of the permanent magnets used in the rotor also play a role.

5. How can I test the strength of an alternator's magnetic field?

There are several ways to test the strength of an alternator's magnetic field, including using a gaussmeter to measure the magnetic flux density, performing a load test to see how well the alternator can sustain a load, or using a multimeter to measure the output voltage. It is recommended to consult a professional mechanic or electrician for accurate testing and diagnosis of an alternator's magnetic field.

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