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

[tinman]

Hi Brad,

yes i am sure, but i think 27% is more in line with what to expect.

I will shoot a video when running and show the measurements and then stop the rotor with the same measurements taken.

Itsu

Thanks Itsu.

[verpies]

Ok,  found the error, the C2 capacitor is 1uF,  not 10uF as i mentioned before, i mixed up with some 10uF caps i also had on order but not yet received     Sorry about that.

Shit happens !
So all efficiency numbers have to be divided by 10.

[itsu]

New measurements taken both in running and stopped state.

First 2 screenshots are when running (overall and zoomed in on ontime), second 2 screenshots are when stopped (overall and zoomed in on ontime).

As mentioned earlier, the power consumption when stopped goes up

Video here:  Https://www.youtube.com/watch?v=Can3bdMC7HY&feature=youtu.be


Itsu

[verpies]

OK, so crunching numbers for the zoomed scopeshot with the rotor stopped, now gives:

E₁ = 5.382W * 4.32ms = 5.382 * 0.00432 = 0.02325024J = 23.25024mJ
E₂ = ½ * 37.8mH * (824mA)² = ½ * 0.0378 * 0.824² =  ½ * 0.0378 * 0.678976 = 0.0128326464J = 12.8326464mJ
E₃ = ½ * 1μF * (99.6V)² = ½ * 0.000001 * 9920.16 = 0.00496008J = 4.96008mJ

E₃ / E₂ =  4.96008mJ / 12.8326464mJ = 0.38652 = 39%  (stored to recovered energy)
E₃ / E₁ =  4.96008mJ / 23.25024mJ = 0.21333 = 21%      (expended to recovered energy)

[gotoluc]

Verpies and Gotoluc,

OK.  The low resolution is probably due to the "Fast Trigger" acquisition mode being current selected. To change, under the front panel "Acquire", press the "Menu" button. This will bring up a bottom screen menu that has the current acquisition mode indicated in the 2nd from left position. The choices are in the right hand vertical screen menu so select the "Normal" (10k point) which will give you the highest horizontal resolution.

To get the Math functions working with vertical cursors, you can refer to the instructions I gave Itsu but in general, you must have "Cursor Gating" selected in the Measure menu and "VBar" selected in the Quickmenu to activate the vertical cursors. From there you should be able make any selective measurement on screen between the cursors.

partzman

Thanks for the reply partzman

The below pic is the scope and what comes up when I press acquire. No "Menu"

Luc