DLE-TEST20 : The VISCOUS REMANENT MAGNETIZATION (VRM) experiment with the DLE-TB v1
created on february 9, 2013 - JLN Labs - last update march 31, 2013
All informations and diagrams are published freely (freeware) and are intended for a private use and a non commercial use.
Toutes les informations et schémas sont publiés gratuitement ( freeware ) et sont destinés à un usage personnel et non commercial
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Mars 29, 2013 - DLE-TEST20 : So as to understand better the physical phenomenon of the Delayed Lenz Effect (DLE) which produces the acceleration of the magnetic rotor under certain conditions, I continue to explore in deep the effect by the experiments and the measurements. My tests platform dedicated to the study of the Delayed Lenz Effect (DLE-TB v1.0) is very useful and helpful for the exploration of this phenomenon.
In the previous test DLE-TEST18, I have observed that the maximal acceleration of the magnetic rotor with the loaded secundary coil occurs when the coil is placed at 30 mm from the magnetic rotor. If the secundary loaded coil is placed between 0 and 30 mm from the rotor, the rotor brakes. In all the cases, the acceleration effect is observed with a secundary coil with a ferromagnetic core and not with an air core coil. In this experiment, I have used a soft iron core (120 mm length, 8 mm diameter). In a video of the test DLE-TEST19, it has been shown that the Barkhausen effect is very important with this kind of ferromagnetic material.
Today, I have conducted the measurements with a Gaussmeter each 10 mm along the ferromagnetic core.
The purpose of this experiment is to measure the temporal phase shift between the magnetic field produced by the magnetic rotor (near to its surface) and the magnetic field of the core (at a distance x mm). This effect is known under the name of Viscous Remanent Magnetization : When the magnetic rotor is set in rotation, it produces a magnetic fluctuation, this fluctuation is captured by the end of the ferromagnetic core and it propagates like a magnetic wave in the soft iron rod due to the Bakhausen effect already tested in the test DLE-TEST19.
Below the setup of the test DLE-TEST20
To measure the intensity of the magnetic fluctuation along the soft iron rod, I have used a Gaussmeter with its Hall probe UGN3503U (here the full data sheet of the sensor). A measurement is done each 10 mm.
A digital oscilloscope is used to measure the phase shift between the magnetic field of the rotor (fully synchronised with the excitation coil pulses) and the magnetic field of this fluctuation at a distance of x mm from the magnetic rotor.
MEASUREMENTS RESULTS OF THE TEST DLE-TEST20
fully confirm that the magnetic field of the fluctuation at a
distance of x mm from the rotor is not in phase avec the
magnetic field of the rotor in motion.
This is VERY INTESTING HERE : Depending on the distance along the soft iron rod, the phase ofthe magnetic field of the fluctuation can be in leading or in lagging with respect to the magnetic field of the magnetic rotor. Below, the measured values :
Below, an animated picture which shows the phase shifting measured each 10 mm. The yellow curve is the pulse sent by the controller to the excitation coil and used as reference, the blue curve is the measured magnetic field of the fluctation. At the bottom left, (Dly_A) is the value of the phase shifting (in ms) measured between the magnetic field of the rotor and the magnetic field of the fluctuation.
Below is the graphical result of the phase shifting and the RPM change of the rotor when the secundary coil is loaded (data measured in the test DLE-TEST19)
We notice on the curve above, that the braking effect (common Lenz effect) and the accelerating effect (reverse Lenz effect) of the rotating magnetic rotor (blue curve) is DIRECTLY LINKED to the phase shifting curve of the magnetic fluctuation (red curve). The acceleration of the rotor is maximal when the phase angle switches from postive to negative (the green rectangle area at a distance of 30mm). The loaded secondary coil is set at the phase shifting point and acts as a wave reflector, it returns the magnetic wave in opposition phase to the magnetic rotor in rotation, producing its acceleration ...
Below the detailled analysis of the Delayed Lenz Effect phenomenon measured at a distance of 30 mm (optimal point for the max acceleration).
According to these three tests with the DLE-TB v1.0, we can now say that there is a relatively simple and effective method to optimize the DLE effect and produce the acceleration of the magnetic rotor.
Here are the key points to get the acceleration of the magnetic by the DLE effect:
for the magnetic core, it is necessary to use a ferromagnetic material which has a maximum Barkhausen effect (soft iron, steel, nanocrystalline),
to minimize unnecessary losses by eddy currents, it is preferable to use a laminated core,
a VRM measurement helps to locate the phase shifting point.
Below the video of the VRM measurements with DLE-TB v1.0
Below, an interesting video from the AT&T laboratories showing a mechanical analogy of transmission waves. This allows us to understand what happens in the ferromagnetic rod of the secondary coil when the magnetic wave propagates and reflects off the coil producing the inversion of the Lenz effect.
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