tests with a PULSED High Voltage.
By Jean-Louis Naudin
created on October 10th, 2001 - JLN Labs - Last update November 1st, 2001
All informations in this page are published free and are intended for private/educational purposes and not for commercial applications
You will find below a very interesting test with the Lifter v3.0. In the previous tests done on the Lifter v3.0 on Oct 11, 2001, I have measured that the power required for a stable flight above the ground is 69.5 Watts ( 27.5 KV DC @ 2.53 mA ) with a weight of 16 g and a payload of 4 g.
Previously, I used a DC High Voltage. Now, In this test, I have pulsed the DC power supply at a frequency up to 100 Hz.
If the Speakers volume of your computer is set to high, you may hear the humming noise at 70 Hz of the Lifter v3.0 while it is hovering...
TEST RESULTS :
The High Voltage power supply is controlled by a square wave frequency generator. So, it is now possible to pulse the High Voltage sent to the Lifter. Below, you will find a sample of the measured Pulsed High Voltage accross the Lifter at 70Hz.
These tests results are very encouraging, because, as you may notice in the datasheet below :
The power required for
hovering the Lifter is only
This is 4 time less at 70 Hz than in DC.
Test procedure :
1) The frequency is set the desired value,
2) The voltage has been adjusted so as to get a free hovering at 25cm above the base . In this case, the nylon wires doesn't hold the Lifter upward and are used only for security purpose.
3) The voltage/current values are measured.
Test with a pure HV DC :
Below, you will find the recorded DC voltage ( not pulsed ) sent to the Lifter cells during a manoeuvrability test. It is very interesting to notice that :
The Lifter slide on its sides very quickly and that very few voltage change ( about 2 KV ) are able to produce a high speed motion by sliding effect.
A minimum HV is required to get the Lift Off ( > 19 KV )
INTERESTING COMMENTS ( JLN 10-23-01 ):
At 70 Hz the power requirement for hovering the Lifter is about 886 W/Kg. I haven't yet tested a higher switching frequency ( due to frequency limitation of the HV Power supply used ), but, today, I think that the Lifter efficiency can be greatly increased and even overcome the efficiency of a conventional helicopter with better flight characteristics. Comparing to an Helicopter, the Lifter flies silently, it is highly manoeuvrable and seems to have a very high acceleration capability ( air dragless )....
The Lifter flies very well in open air as shown in the photos, below :
To see the videos, the free downloadable RealPlayer is required
Flight test video with a PULSED High Voltage
Click on the picture above to see the video ( 864 Kb )
See also :
Email : JNaudin509@aol.com
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