Sharing ideas on how to make a more efficent motor using Flyback (MODERATED)

[gyulasun]

Hi Luc,

I think your question on the Lenz issue could be answered by giving a certain mechanical load to the spinning wheel when it already established a constant speed from the input pulses and then monitor the input current. In order to do this, you would need to insure a more stable current measurement method to filter out fluctuation.
It is sure your bucking coils draw several Ampers of peak current what the power supply cannot readily insure, this is seen from the decreasing top part of the voltage across the coil (voltage is lower at the switch-off moments with respect to the instanteneous ON moment value).
You could make the power supply more happy by using a choke coil of some ten mH (or higher) and with low DC resistance in series with the positive output of the power supply, preceeding the RC filter you have with the input DC voltage and current meters. A choke like an original MOT primary coil with an open core like you use for the bucking coils or similar would serve. The series inductance would smooth out the huge current demand the ON moments represent and current meter fluctuations would be much less. More filter capacitors would also help but a series choke is better.

Brad addresses problems you need to check of course.  MileHigh, I think Luc uses the power supply for the bucking coils and the battery is used for the pulse generating circuit on his PCB board.

Gyula

[MileHigh]

MileHigh, I think Luc uses the power supply for the bucking coils and the battery is used for the pulse generating circuit on his PCB board.

Gyula

Thanks, I missed that in the clip.  So the power supply is croaking from the load put on it.

[tinman]

  So that would translate into an average current of about 7 amps during the pulse which would make it seem reasonable.  The voltage pulse starts at 11 volts, which is the battery voltage.



The battery voltage is about 11 volts, and I am going to guess that it is a lead-acid battery that would normally be at 12.6 volts.  So I believe that gives two options, the battery is relatively new but quite discharged, or the battery is quite old.

For the sake of argument let's assume that it is a relatively new battery that is quite discharged.  That means that it's internal impedance is rather high, and that's why you see the huge voltage droop from the battery as it starts to supply current to the two coils.  The battery starts to croak from the current demands being made by the coils.  The moral of the story is to try to do your experiments with fresh batteries, especially if the load will be drawing heavier currents.  Also, when currents are in the range of 5 amps and above I personally would switch from alligator clips to terminal block type connections.

I am not a fan of this "bucking coils" business, for the most part I view it as doing something "alternative" just for the sake of "being alternative."  In this case when the slab of metal is between the bucking coils, the magnetic fields are mostly cancelling each other out.  Even when the coils have air between them, they are cancelling each other out.

If I can make a suggestion to you Luc it's this:  Just wire a switch to turn the coils on and off manually.  Move the slab of metal through the gap between the two coils step-by-step and feel the pull on the slab when you switch the coils on.  Very low tech, just feel what is going on with your hands.  Then reverse the wiring in one of the coils so they are no longer bucking and repeat the same procedure.

I am willing to bet you that you will get a much stronger pull force when the coils are "normally" wired and not in a "bucking" configuration.

Finally, what do you mean by "counter-EMF trying to negate Lenz" for your design?

You should say, "around 560 watts during the pulse" so as to not confuse power with energy.  You quote energy per pulse.

Where did i quote that MH ?.
I quoted-->So using the screen capture below,i see around 560 watts per pulse,and that CVR looks like a 1 watt CVR

I think saw <black,brown,black> on the resistor so that would make it a one-ohm CVR.

I only used what Luc quoted the value as,as i cant make heads or tails of what the colors are on the resistor-->see screen capture below.

[itsu]

It looks like a 5-band resistor with colours black (0) - brown (1) - black (0) - silver (x0.01) - brown (1%)
making it a 0.1 Ohm resistor like Luc said, see http://nearbus.net/wiki/index.php?title=File:Resistor_color_codes.jpg

I think there is more a probe x1 or x10 mixup in play here.

Itsu

[MileHigh]

Brad:

"i see around 560 watts per pulse" - that is the wrong terminology and doesn't make sense, please see my posting again.  You should quote energy per pulse to use the terminology of electronics properly.

Itsu:

Thanks, it's been so long for me that I got it wrong and I thought it was <digit, digit, multiplier, tolerance>.  I realize now how I missed a digit.  There were some neurons in my head that haven't been fired up in a long time.