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

[listener191]

L192

If you use just few coils instead of 12 in series for single phase it will take lots of amps and will be energy waste.
Also if you watch Pierre's video and see how coils are made they are overlapping just like in car alternator and can be used with 3x12 sets.

EDIT: In Pierre's video I noticed 5 overlapping coils when started from 1st then counted to 5th position going back to stator.

Hi T-1000,

My stator is wound for 30 slots with a 5 coil pole, so 30 coils in a series loop, lapped at a 5 pole pitch.
Basically the 30 slot version of Pierres 36 slot.

36 Turns per coil.

The problem is the harmonics created with this scheme.

If you pulse just a single set of 5 coils with overlap turned off, you can  achieve 80 volts on the rotor with dim illumination of a 25V 230V lamp. Note, this rotor has the  (original 230V generator windings). This is achieved with a 2amp drive.

As soon as you start introducing other coils group, the harmonics start to cause destructive cancellation. I  would be not be surprised if this is what caused the L298N failure(s).

Attached is the test I conducted with 6 coils (no overlap)

Regards

L192

 

[pmgr]

My connection scheme is a little different, I only switch one half bridge at a time on the same board. This reduces the heat dissipation on each L298N.
Also I use the enable lines to switch the transistors, so the high and low side transistors float when enable is low

I achieved a reasonable rotor output waveform until I pushed the setup too hard at about 4A per half bridge. This was after about 20 mins of running. This took out at least 5-6 boards, after one L298N exploded. No heatsink was over about 40 deg C.

I had done this before without problem however , this time we have the shorted coils due to the overlap. In each coil line you could see the overlap current step.

I rechecked all connections and drive signals, everything appears to be in order. There were no apparent voltage spikes on the power +rail. Each board had its +/- power lines taken from a distribution strip with heavy duty cable linking to the super caps.

I have  three spare boards but  I am thinking that I will use relays next.

Disappointed but not surprised.

L192

Luc has similar setup: H bridges are switched by the EN pins (both tied together going to Arduino). Inputs 1-2 are tied to Vcc, inputs 3 and 4 to GND, so bridges are floating as well when Arduino signal is low.
PmgR

[T-1000]

Hi T-1000,

My stator is wound for 30 slots with a 5 coil pole, so 30 coils in a series loop, lapped at a 5 pole pitch.
Basically the 30 slot version of Pierres 36 slot.

36 Turns per coil.

The problem is the harmonics created with this scheme.

If you pulse just a single set of 5 coils with overlap turned off, you can  achieve 80 volts on the rotor with dim illumination of a 25V 230V lamp. Note, this rotor has the  (original 230V generator windings). This is achieved with a 2amp drive.

As soon as you start introducing other coils group, the harmonics start to cause destructive cancellation. I  would be not be surprised if this is what caused the L298N failure(s).

I am assuming you still have 3 coils overlapping each other and if lets say:
1) the coil A begin is on 1st pin the coil end is on 4th?
2) the coil B begin is on 2nd pin the coil end is on 5th?
3) the coil C begin is on 3th pin the coil end is on 6th?

Please remind me your coils arrangement on stator.

The reason why am asking is how we make three phase on alternator stator. Please see diagram attached.
You also may try to think what resulting polarity should be on the output coil core which is covering positions from 1th to 3th and from 15th to 18th.
Ideally we should do from 3 phase to 1 phase conversion.

[listener191]

I am assuming you still have 3 coils overlapping each other and if lets say:
1) the coil A begin is on 1st pin the coil end is on 4th?
2) the coil B begin is on 2nd pin the coil end is on 5th?
3) the coil C begin is on 3th pin the coil end is on 6th?

Please remind me your coils arrangement on stator.

The reason why am asking is how we make three phase on alternator stator. Please see diagram attached.
You also may try to think what resulting polarity should be on the output coil core which is covering positions from 1th to 3th and from 15th to 18th.
Ideally we should do from 3 phase to 1 phase conversion.

Hi T-1000,

My coils bridge 4 poles, whereas Gotolucs stator bridge 5 poles.

5 coils per N/S pole overlapped 1 slot.


Regards

L192

[T-1000]

Hi T-1000,

My coils bridge 4 poles, whereas Gotolucs stator bridge 5 poles.

5 coils per N/S pole overlapped 1 slot.


Regards

L192

Hi L192,

I just tried to see in Excel spreadsheet what output would be like when merging 3 phase arrangement over different amounts of coils.
No joy for 2/4 coils for results. The best was 3 rolling coils around ring.

Please see spreadsheet attached. Maybe you will have some ideas how to properly simulate moving magnetic fields around the ring without too much losses.

Cheers!