- #1
Noe
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Electromagnets heat up quickly...shouldn't heat destroy its magnetic properties?
Can heat damage the magnetic properties of an electromagnet?
- Thread starter Noe
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- Electromagnet Heating
In summary, the curie temperature of iron is about 1000°K and the insulation of the magnet windings may fail before reaching this point. The resistance of copper wire used for winding magnets increases with temperature, which can lead to increased power dissipation and heating. To prevent this, it is important to keep the magnet cool. The equation V = L * di/dt is crucial for turning magnets on and off, and a parallel flyback diode should be used when turning the magnet off to reduce current and negative voltage.
- #2
DaveC426913
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Heat affects permanent magnets, not electromagnets.
It's the core of the electromagnet (rotor) through which the current runs that gets particularly hot.
If the motor uses permanent magnets at all, they are part of the stator, which does not get very hot.
It's the core of the electromagnet (rotor) through which the current runs that gets particularly hot.
If the motor uses permanent magnets at all, they are part of the stator, which does not get very hot.
- #3
Baluncore
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Hi Noe, welcome to PF.
The curie temperature of iron is about 1000°K. The insulation of the magnet windings may fail before the curie point is reached.
Magnets are usually wound with copper wire. The resistance of copper rises in proportion to absolute temperature. If the windings are allowed to get hot, they will then need more voltage to maintain the required field current. That will increase the power dissipated, which will heat the magnet faster. At 1000°K the magnet will be over three times more resistive than at room temperature. Keep the magnet cool.
The important equation when it comes to turning magnets on and off is V = L * di/dt.
To quickly get the current flowing in the coil of an electromagnet, a high DC voltage is needed. Once the required magnet current has been reached, the voltage should be dropped to maintain that set current. That will reduce the heating while it is on.
A parallel flyback diode should be used when the magnet is turned off. A resistor having a resistance similar to the magnet coil, in series with the flyback diode, will speed the reduction in current by increasing the negative voltage across the inductance.
The curie temperature of iron is about 1000°K. The insulation of the magnet windings may fail before the curie point is reached.
Magnets are usually wound with copper wire. The resistance of copper rises in proportion to absolute temperature. If the windings are allowed to get hot, they will then need more voltage to maintain the required field current. That will increase the power dissipated, which will heat the magnet faster. At 1000°K the magnet will be over three times more resistive than at room temperature. Keep the magnet cool.
The important equation when it comes to turning magnets on and off is V = L * di/dt.
To quickly get the current flowing in the coil of an electromagnet, a high DC voltage is needed. Once the required magnet current has been reached, the voltage should be dropped to maintain that set current. That will reduce the heating while it is on.
A parallel flyback diode should be used when the magnet is turned off. A resistor having a resistance similar to the magnet coil, in series with the flyback diode, will speed the reduction in current by increasing the negative voltage across the inductance.
Related to Can heat damage the magnetic properties of an electromagnet?
1. What is the purpose of heating an electromagnet?
Heating an electromagnet increases its resistance, allowing for more current to flow through it and strengthening its magnetic field.
2. How does heating affect the strength of an electromagnet?
Heating an electromagnet increases the movement of its atoms, which creates more collisions and resistance. This resistance increases the current flowing through the magnet, making it stronger.
3. Can overheating an electromagnet damage it?
Yes, overheating an electromagnet can cause its wire to melt or its insulation to break down, resulting in damage to the magnet. It is important to monitor the temperature and not exceed its maximum operating temperature.
4. How can I safely heat an electromagnet?
To safely heat an electromagnet, use a low voltage power supply and slowly increase the current until the desired temperature is reached. It is also important to monitor the temperature and not exceed its maximum operating temperature.
5. What are some applications of heating an electromagnet?
Heating an electromagnet is often used in industrial settings where a strong and controlled magnetic field is needed, such as in metal processing or particle accelerators. It is also used in medical devices, such as MRI machines, to create powerful and precise magnetic fields.
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