The Steorn magnetic motor V2 replication by JL Naudin
created on december 26, 2009 - JLN Labs - Last update January 5, 2010
Toutes les informations et schémas sont publiés gratuitement ( freeware ) et sont destinés à un usage personnel et non commercial
All informations and diagrams are published freely (freeware) and are intended for a private use and a non commercial use.
Cliquez ici pour la version FRANCAISE
5 - The new Steorn motor v2 design
According to my comment about the V1, I have decided to rebuild the toroidal coils with more turns so as to reduce dramatically the input current.
The inductance of these new toroidal coils is about 30 time more than the previous used in the V1. The electronic drivers used is the same.
To wind the coil, I have used a very usefull method from Ossie Callanan (thanks Ossie...). You will find a very well done tutorial to wind a toroid coil here
The new coils have replaced the old one and the Hall probe have been placed in a new position.
The position of the hall probe has been optimised with the scope so as to get the minimum current for the max turn rate.
See a video of the Steorn motor v2 in action below :
Due to the high inductance (12 mH) of these new coils, there is a short spike of Back EMF in the measured voltage produced by the coil itself but NOT induced by the motion of the rotor. The Back EMF current spike produced by the inductive coils can't be seen in the current curve because there is a protection diode in the N-Mosfet transistor (BUZ 11) itself which protects it and acts as a free wheel diode. This voltage spike has also been measured when the magnet rotor doesn't move ( see the test : Measuring the current lag ), this confirms that this Back EMF spike is only generated by the inductive coil itself and not by the motion of the rotor.
The current (0.4 A) and the voltage ( 12V ) on the main power supply
6 - No stator coils induction during a free run at full speed
With these new high inductance (12 mH) stator coils, I have checked again if there is a measurable voltage across the toroidal coils when the power supply is switched off at full speed. In this test the coils have also been disconnected from the controller during the voltage measurement with the oscilloscope.
No voltage across the coil has been measured during this test, see the video below :
7 - Measuring the current lag in the stator coils and fine tuning
Now, a very interesting experiment which shows current lag effect during the approach of the rotor magnet on the toroidal stator coil. Click on the picture below to know more.
Measuring the current lag
Measurement of the coil inductance Vs the angle of the rotor magnet
The Steorn motor is still worth to be explored, so the testing phase continue... Stay tuned
Interesting documents :
Technical datasheets :
Email : JNaudin509@aol.com
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