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

[gotoluc]

Thanks verpies for all the updates.

Luc

[itsu]

@Itsu

In the circuit you are using now, the "Discharge C" signal should be inverted (compared to Gotoluc's diagram), because the L2 requires a precharge period in order to build up energy in L2 which is used later to generate a gate pulse for Q3.  This gate pulse begins when the precharge period ends and your MOSFET driver interrupts the grounding current to L2 (when point F goes high).
Additionally in your circuit, the width of Q3's gate pulse is not determined by the width of the "Discharge C" signal but by the inductance of L2.

Note, that in the Pulse Sequencer circuit, that I had posted for Gotoluc, the width of the "Discharge C" signal is determined by U4, which is suitable for discharging the "flyback cap" by a relay. 
So don't be tempted to use Gotoluc's Pulse Sequencer with your motor circuit as is (without minor changes).  I will post these changes if you ever build Gotoluc's Pulse Sequencer (...or Gotoluc builds your motor circuit)

Ok,  i did not succeed in getting the signals right by using 2 555 timers, as the wrong side of the pulse was moveable.
Inverting the signal did not invert the moveable side, just the signal 

I went back to using one 555 timer for the Q1 drive (40Hz @ 20% duty cycle) and a Hall sensor amplified/inverted by some transistors as the input (feedback) for U2/Q3.

I think i now realized the signals as meant to be, see below screenshots (1st is overall, 2th is zoomed in).

Blue is the signal across the CSR (A) compared to point B
purple is the signal of the Q1 drain (C) compared to point B
yellow is the signal across the C2 (2.2uF) cap (D) compared tp point B
green is the signal at point F compared to point B

Due to the placements of the magnets, there is some jitter on the green/yellow signals).

Itsu

[verpies]

I think i now realized the signals as meant to be, see below screenshots (1st is overall, 2th is zoomed in).

Yes the signals are correct now.

Where is the zero volts for the yellow channel?
How narrow can you get the 0V period in the yellow channel?
What does a regular voltmeter connected across C2 show now ?

[itsu]

Ok,  the yellow zero is underneath the green zero marker

The screenshot below shows about the most possible narrow period.

A DDM across C2 shows the same as the P2P value of the scope  (± 80V), see the video (last part).

https://www.youtube.com/watch?v=qG7Xs8MnRWI&feature=youtu.be

Itsu

[verpies]

Which MOSFET drivers are inverting ?