Measuring the current lag and fine tuning by JL Naudin
created on december 27, 2009 - JLN Labs - updated on January 1st, 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

Now a very interesting experiment which shows current lag effect during the approach of the rotor magnet on the toroidal stator coil.

I have used the Steorn motor v2 for conducting this test. Firstly, I have measured the max turn rate frequency of the rotor with the scope which is about 73 Hz, see below :

Then, a pulse generator has been connected instead of the Hall probe of the controller. The pulse generator has been set so as to produce the same pulse (frequency, duty cycle) than the previous Hall probe signal for the max turn rate.

A foam disk has been set in front of the rotor to help the measuring of the rotor magnet angle Vs the axis of the toroidal stator coil.

Then the voltage and current flow in the coil have been recorded with the scope while the rotor angle goes from +30° to -30°

You will find the full video of the test below :

To summarize

This very interesting experiment shows that, while the rotor approachs to the toroidal stator coil, the current lag increases dramatically due to polarisation of the ferromagnetic core and to the increase of the magnetic viscosity. This experiment shows also a good method to find the optimal angle where the stator coils must be energized. If the toroidal coils are energized at this point, the current will be minimum and thus the energy spent in the motor optimized...

Interesting documents :

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