Pierre's 170W in 1600W out Looped Very impressive Build continued & moderated

[konehead]

Hi Listener
Not so bad looks like about 40W output for 52Winput (?)
Can you try paralleling just two coils of the "long pole" string?
Such as the first and the last coils,  (#1 and #11) then the "trapped" coils in between (#s 2 3 4 5 6 7 8 9 10) all these un-pulsed coils in between  become induced pickup windings, which will make power everytime the two energized parallel coils get some juice.
Maybe then string the 6 pole pattern then in series, not parallel so resistance is not so low and tons of amps is drawn however Pierre was talking about 160W input so you could put 3 times more power into it via it drawing more current...
Anyways just an idea!
Thanks for continuing your experimenting and reporting to everyone  what you find...

[listener192]

No its only about 4.2W out for 52 W input. The scope shots are showing output voltage and input current.But there is no fall off in output voltage until you get above 150Hz, so 50/60Hz is achievable.

I am looking at how I can parallel drive 10 coils and then connect them in series at switch off.

Probably the reason that Pierre wanted to use a higher DC voltage was to get more current through the coils, as you can only do so much with parallel coil arrangements.
The BTS7960B half bridge devices become a real limitation, with regards to voltage. The BTN8962 half bridges can be operated up to 40V, performance only limited by their current limiter, whereas the BTS-7960B voltage limits at 27.5V.
Attached is the data sheet for the BTN8982 half bridge 50A continuous 40V  same pin out as BTS7960B. If the devices are replaced, this is the one to go for.

I noticed that 10 coils in series start to produce recovery current, on switch off. To get high levels of recovery current, either the cap potential need to be well below rail or the flyback voltage needs to be much higher than rail. The unloaded output voltage waveform starts to look more like that drawing with the spikes on the sine wave. The experiment pulsing the rail just didn't result in any meaningful voltage spikes.

I also noticed with this 10 coils scheme, that more flux is crossing the rotor, as at low frequency the rotor rotates unless firmly wedged.
The 6 pole scheme just lock the rotor in plus. PmgR's simulation shows that my rotor should be 3 stator poles wide instead of the 6 stator pole width I have an the rotor.
L192

[listener192]

Hi Listener
Not so bad looks like about 40W output for 52Winput (?)
Can you try paralleling just two coils of the "long pole" string?
Such as the first and the last coils,  (#1 and #11) then the "trapped" coils in between (#s 2 3 4 5 6 7 8 9 10) these two become induced pickup windings, which will make power everytime the two energized parallel coils get some juice.
Maybe then string the 6 pole pattern then in series, not parallel so resistance is not so low and tons of amps is drawn however Pierre was talking about 160W input so you could put 3 times more power into it via it drawing more current...
Anyways just an idea!
Thanks for continuing your experimenting and reporting to everyone  what you find...

Clarification 10 coils in series (between wire tap 1 and wire tap 11).

[Jeg]

You can use two additional discreet MOSFETs (one on high side input and one on low side ground connection) with the body diode in reverse direction. So on high side the drain of one of these FETs would be connected to all the drains (Vdd inputs) of the high side H-bridges. On the low side the source of the other FET would be connected to all the sources of the low side H-bridges (GND/sense connection). In that way you have two body diodes in reverse all the time which will prevent any recovery through the body diodes.

PmgR

Hi pmgr
Can you please say some more on this? Do you mean just using the body diodes without driving those two mosfets? And if yes, is there any particular reason for choosing this method instead of two simple diodes?

Thanks

[konehead]

Hi everyone
I made a mistake describing the idea I had, with only two coils (the end ones) of the string of 10 coils in a pole....I corrected it in my post a couple posts back.
Should read something like "all the un-pulsed coils in between become induced pickup winds" where before I described the coils in between as "these two" which made no sense
So I meant to say all those coils trapped and between the two energized pulsed coils become induced pickup coils....