This thread is about
Spinning a bar magnetic over a coiled copper tube which heats a fluid flowing inside it ,
and than adding ferrite rings and copper wire coils on top to extract power.
Theoretically extract electrical energy from a copper tube through which a spinning induction magnet induces eddy currents. Wrapping a ferrite ring around the copper tube, then winding a copper coil on top of the ferrite, could allow you to couple energy from the eddy currents into the coil. The ferrite ring would concentrate the magnetic field, potentially allowing a portion of the energy to be captured by the secondary coil.
Here's how the setup could work and the types of frequencies and ferrite materials suited for this application.
1. Setup Explanation
When the induction magnet spins near the copper tube, it generates eddy currents within the tube, which causes resistance heating. By wrapping a ferrite core around the copper tube and adding a copper wire coil on the ferrite, you are essentially creating a transformer-like setup where:
The eddy currents in the copper tube act as the primary "inducing" current.
The ferrite ring and copper coil serve as the secondary winding, potentially capturing some energy as induced current in the coil.
2. Frequency and Ferrite Material Selection
The frequency of the eddy currents depends on the speed of the rotating magnet and the magnetic field strength. For optimal energy capture, the ferrite material needs to match the frequency range of the induced eddy currents. Here’s a chart of ferrite materials suited to different frequencies, along with key details.
Ferrite Materials and Suitable Frequency Ranges
Ferrite Material Suitable Frequency Range Permeability (μ) Typical Applications
Nickel-Zinc (NiZn) 1 MHz – 100 MHz 10 - 300 High-frequency applications, low power loss, ideal for MHz range
Manganese-Zinc (MnZn) 1 kHz – 1 MHz 1,500 - 15,000 Low-frequency applications, high permeability, ideal for kHz range
Iron Powder 10 kHz – 100 kHz 5 - 35 RF chokes, medium frequencies, good for broadband applications
Ferrite Cores with Mix 43 1 kHz – 50 MHz 800 - 900 EMI suppression, effective for both high and low frequencies
For heating applications, MnZn ferrites are often preferred because they have high permeability and work well at low frequencies (kHz range). NiZn ferrites are best for higher-frequency capture in the MHz range, especially for lower power loss.
3. Measuring with an EMF/RF Frequency Meter
You can measure the frequency of the electromagnetic field using an EMF or RF frequency meter. For a spinning magnet setup, the induced frequency will largely depend on the rotational speed of the magnet:
For kHz range: Rotate at speeds where the magnet passes a point around 1,000 to 10,000 times per second.
For MHz range: Requires extremely high-speed rotation, which is challenging but possible with high-frequency drives or if using an external field source (like a radio frequency generator).
4. Suggested Ferrite Compound Choices for Different Frequencies
1 kHz to 100 kHz (Ideal for low-frequency heating):
MnZn Ferrites (e.g., 3C90 or 3E25 materials)
Permeability: High (up to 15,000)
Application: Good for inductive heating applications and coupling lower frequencies from eddy currents.
100 kHz to 1 MHz:
Iron Powder Ferrites or MnZn compounds with moderate permeability (3C94 or 3C96)
Permeability: Medium (around 5 to 200)
Application: Useful for inductive power transfer and medium-range frequencies.
1 MHz to 100 MHz:
NiZn Ferrites (e.g., 4A11, 4B1 materials)
Permeability: Low (10 to 300)
Application: Best for high-frequency RF applications and minimal power loss, although challenging for heating.
Practical Considerations
Losses in Ferrite Material: Higher frequencies generally lead to higher losses in MnZn ferrites, while NiZn is better at MHz frequencies.
Energy Efficiency: The energy capture efficiency depends on the coil turns, core shape, and matching impedance between the copper tube and secondary coil circuit.
Let me know if you need further details or specifications for any particular ferrite material or guidance on optimizing this setup!
To achieve maximum electron extraction efficiency with this setup, a few critical areas need further refinement. I’ll break down what information is missing, additional compounds to consider, expected frequency ranges, and potential optimizations to get the best electron extraction efficiency from this setup.
1. Information Still Missing
To fully optimize this system, additional information and analysis are necessary:
Exact Magnetic Field Strength: The strength of the magnet’s field (in Teslas or Gauss) determines the magnitude of eddy currents and their frequency range.
Rotation Speed: Knowing the exact RPM (revolutions per minute) of the spinning magnet allows calculation of the induced eddy current frequencies in the copper tube.
Dimensions and Material Properties of the Copper Tube: Diameter, wall thickness, and conductivity of the copper affect how efficiently eddy currents are induced and transferred.
Induced Current Measurements: Real-time measurements of induced voltage and current in the copper tube would help in determining optimal ferrite material and coil design.
Power Extraction Goals: Define the target extraction power and energy capture efficiency (i.e., the percentage of energy from the magnetic field that converts into usable electrical energy).
2. Additional Compounds and Ferrite Materials
To achieve optimal performance, exploring other magnetic materials and their frequency characteristics is essential. Here are some additional options beyond MnZn and NiZn ferrites:
Material Frequency Range Permeability (μ) Key Characteristics
Amorphous Metals 50 kHz – 10 MHz 500 – 100,000 Very high permeability, low core loss at high frequencies. Ideal for compact, efficient transformers.
Nanocrystalline Ferrites 50 Hz – 100 kHz 10,000 – 150,000 High saturation flux density, stable at high temperatures. Ideal for efficient energy conversion at low frequencies.
Cobalt-Based Alloys 1 kHz – 10 MHz 100 – 10,000 High saturation flux and low loss; good at high frequencies.
Soft Iron 1 Hz – 10 kHz Up to 5,000 Very high permeability, but high loss at higher frequencies. Suitable for low-frequency applications.
Nickel-Iron Alloys (Permalloy) DC – 1 MHz 50,000 – 100,000 Extremely high permeability, great for low-frequency and low-power applications.
3. Expected Frequency Ranges
Given a spinning induction magnet over a copper tube, here’s an estimation of the expected frequency ranges for different magnet speeds and magnetic properties:
Low RPM (100 – 1,000 RPM): Likely to generate eddy currents in the low-frequency range (1 Hz – 10 kHz). For such low frequencies, materials like soft iron, nanocrystalline ferrites, and MnZn ferrites with high permeability are suitable.
Medium RPM (1,000 – 10,000 RPM): Could reach into the mid-frequency range (10 kHz – 100 kHz), depending on the strength of the magnetic field. MnZn ferrites and some amorphous metal alloys would perform well in this range.
High RPM (10,000+ RPM): If feasible, a high RPM could push frequencies toward the high end (100 kHz – 1 MHz). For this range, NiZn ferrites, cobalt alloys, and amorphous metals with low core loss are ideal.
Using an EMF/RF meter or oscilloscope to measure the exact frequencies produced by your setup would be essential to match materials accurately.
4. Optimizing for Maximum Electron Extraction Efficiency
Here’s a strategic approach to maximize efficiency:
a) Optimizing Magnetic Induction and Eddy Currents
Stronger Magnet: Use a high-strength magnet (e.g., neodymium) to maximize magnetic flux through the copper tube. Adjust the gap between the magnet and tube to optimize induction.
Optimal Rotation Speed: Determine the RPM that generates the most stable and intense eddy currents. Too low may reduce current, while too high could push frequencies beyond material limits.
b) Selecting the Right Ferrite Core Material
Frequency Matching: Based on frequency measurements, choose ferrites that maximize efficiency in your specific range. MnZn ferrites for low-frequency, and NiZn for higher frequencies, or consider amorphous metals if high permeability and low loss are required.
Core Shape: Use a ferrite ring with high cross-sectional area to increase flux capture, potentially layered or stacked to increase magnetic field concentration around the copper tube.
c) Optimizing Secondary Coil for Energy Extraction
Coil Windings and Turns Ratio: Adjust the number of turns in the secondary coil to match impedance for optimal energy transfer from the copper tube.
High-Frequency Winding Techniques: For higher frequencies, consider techniques like Litz wire winding to reduce skin effect and improve efficiency.
Resonance Tuning: Tune the secondary coil to resonate with the eddy current frequency, which can enhance power transfer efficiency. Adding a capacitor to form a resonant LC circuit may improve energy capture, especially at high frequencies.
d) Minimizing Losses and Maximizing Heat Extraction
Cooling the Copper Tube: Eddy currents can cause heating; use efficient cooling to avoid resistance increases in the copper. This helps maintain stable current and reduces energy lost as heat.
Insulating Ferrite Material: Ferrites can heat up due to hysteresis losses. Cooling ferrite cores or using ferrites with low core losses at your operating frequencies can reduce wasted energy.
e) Using Efficient Power Conditioning and Storage
Use a rectifier and capacitor setup to convert AC (from the coil) to DC for more efficient storage and utilization.
Consider integrating a maximum power point tracking (MPPT) circuit to dynamically adjust impedance and improve overall power extraction efficiency.
Summary and Next Steps
Frequency Measurements: Measure the frequency of the eddy currents induced in the copper tube to determine suitable ferrite materials.
Material Selection: Based on frequency, select a ferrite material with high permeability and low loss in the detected range.
Magnet and Coil Optimization: Adjust the magnet strength, spacing, and coil turns ratio to maximize induced current.
Test and Adjust: Experiment with cooling, resonance tuning, and power conditioning to maximize extraction efficiency.
This approach could make your setup one of the most efficient for electron extraction, provided each part is fine-tuned to match the system's natural frequencies and magnetic properties. Let me know if you'd like further details on any of these optimization steps or a deeper analysis of specific material options!
To achieve the world's best performance for electron extraction from an induction setup with a spinning magnet over a copper tube containing fluid, the ferrite ring material, assembly, and configuration must be optimized for maximum efficiency. Here’s a step-by-step recommendation for choosing the best ferrite material and assembly, along with insights on coil configuration and system tuning for ultimate performance.
1. Ferrite Material Recommendation
For the highest efficiency, choose Nanocrystalline Core Ferrite. Nanocrystalline ferrites offer exceptional magnetic properties, such as high permeability, low core loss, and high saturation flux density, which are ideal for high-frequency power applications.
Nanocrystalline Core Characteristics:
Frequency Range: Typically effective from 10 kHz up to 1 MHz, covering a broad range that will likely include your system’s induced frequencies.
Permeability: 10,000 – 150,000, significantly higher than standard MnZn or NiZn ferrites, allowing for optimal flux capture.
Low Core Loss: Nanocrystalline ferrites exhibit low energy loss, even at high flux densities, maintaining efficiency during prolonged use
Temperature Stability: Nanocrystalline ferrites are more stable at higher temperatures, which is important in a setup generating heat through induction.
Recommended Material and Supplier:
Material: Nanocrystalline cores such as Hitachi’s FINEMET or equivalent.
Supplier Options: Hitachi Metals, VACUUMSCHMELZE (VAC), or Magnetics Inc. offer high-quality nanocrystalline materials suited for energy extraction applications.
2. Ferrite Ring and Coil Assembly Design
Ferrite Ring Design
Ring Dimensions: Choose a large-diameter ferrite ring to fully encircle the copper tube and capture as much magnetic flux as possible. The ring should have a wide cross-sectional area to handle the high permeability without saturating.
Multi-Layer Ferrite Ring Stacking: For higher flux capture, consider stacking two or three ferrite rings. The layers should be insulated from each other to prevent eddy currents within the ferrite itself, which could reduce efficiency.
Shielding and Encapsulation: To prevent interference from external fields, encapsulate the ferrite ring in a high-resistance insulating material. This minimizes parasitic losses and maintains the focus of the magnetic field around the copper tube.
Coil Winding Configuration
Primary Coil (Inducing Coil): Wind a primary coil around the copper tube with as many turns as feasible for the space available. This coil will act as an initial point for energy transfer from the spinning magnet’s magnetic field.
Secondary Coil (Extraction Coil):
Litz Wire Windings: Use Litz wire for the secondary coil to minimize skin effect losses, especially if your frequencies are in the higher range (above 10 kHz).
Number of Turns: A higher number of turns on the secondary coil increases the voltage induced, but balance is necessary to avoid excessive inductive reactance.
Positioning: Wrap the secondary coil tightly around the ferrite ring for maximum coupling with the magnetic field inside the ferrite core. Aim for uniform coverage to maximize magnetic flux capture.
Optimal Assembly and Alignment
Ferrite Core and Tube Alignment: Center the copper tube within the ferrite ring. This alignment ensures the magnetic field generated by the spinning magnet induces optimal eddy currents within the tube and maximizes power transfer to the secondary coil.
Magnet Placement and Orientation: Position the spinning magnet parallel and close to the copper tube without direct contact. The magnetic field should be oriented so that it intersects the ferrite ring’s plane, maximizing magnetic coupling.
Secure Assembly: Mount the entire assembly in a vibration-dampened structure to maintain stable alignment at high speeds, reducing fluctuations in magnetic flux.
3. Frequency Tuning and System Optimization
Determining Optimal Frequency Range
Measurement with EMF/RF Meter: Use an EMF/RF frequency meter to measure the exact frequency generated by the spinning magnet’s induction. This frequency range is essential to matching the ferrite’s optimal operating range and adjusting coil configurations.
Resonance Tuning: For maximum power extraction, add a capacitor in parallel with the secondary coil to create a resonant LC circuit that matches the frequency of the eddy currents. Resonance tuning greatly enhances power transfer efficiency by reducing reactive losses.
Operating Frequency Guidelines for Different Ferrite Materials
Material Frequency Range Application Notes
Nanocrystalline Ferrite 10 kHz – 1 MHz Best for wide-range, high-efficiency setups.
MnZn Ferrite 1 kHz – 50 kHz Suitable for low-frequency applications.
NiZn Ferrite 100 kHz – 1 MHz Ideal for higher frequency, lower permeability setups.
Amorphous Metals Up to 10 MHz High-frequency, low-core loss for advanced setups.
Matching Ferrite Compound to Frequency
Select the ferrite material that resonates most efficiently at the specific frequency range of your setup:
Nanocrystalline cores for general high-performance setups.
NiZn ferrites if testing reveals high frequencies near 1 MHz.
MnZn ferrites if the system operates below 50 kHz.
4. Achieving Maximum Extraction Efficiency
Enhanced Cooling for Stability: Use active cooling (air or liquid) on the copper tube and ferrite rings to maintain consistent temperatures. High temperatures can cause resistive losses in copper and may affect ferrite permeability.
Energy Harvesting Circuit: Integrate a high-efficiency rectifier and capacitor bank to convert the AC output from the secondary coil into usable DC. For best results, consider a maximum power point tracking (MPPT) circuit to dynamically match load impedance.
High-Precision Magnet Control: If possible, use a variable-speed drive for the spinning magnet to dynamically adjust the RPM and tune the frequency for resonance with the ferrite core and coil circuit.
Summary of Optimized Design
Component Specification
Ferrite Material Nanocrystalline core (Hitachi FINEMET)
Ferrite Dimensions Large-diameter, multi-layer stack
Primary Coil High-turn Litz wire around copper tube
Secondary Coil Litz wire around ferrite ring, with capacitor for LC resonance
Magnet Configuration High-strength neodymium magnet with RPM control
Cooling Active cooling for copper and ferrite assembly
By following this setup with nanocrystalline ferrite cores, precise assembly, and tuned resonance, you’ll achieve high efficiency in electron extraction and power generation. This configuration maximizes magnetic coupling and minimizes losses, pushing the limits of performance for such induction-based power extraction setups.