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

[listener191]

J'espère que ce ne sera pas trop confus. Il s'agit d'une tentative de visualisation des champs magnétiques, laquelle semble mettre en évidence que les bobines, dans 30 rainures / 36, ont leurs lignes de champ en opposition.

On est toujours avec le stator de Pierre avec ses 36 rainures (fentes), et 36 bobines au pas de 6 rainures. Chaque bobine est composée de 6 bobines en série (une couleur pour chacune).

J'ai indiqué une légende sur la gauche de l'image :

- Dans 30 rainures du stator, les 2 bobines qui s'y trouvent ont leurs champs en opposition (répulsion) Nord/Nord ou Sud/Sud ;
- Dans 6 rainures du stator, les 2 bobines on leur lignes de champ en attraction.




On peut estimer que les mêmes répulsions se produisent dans le chignon (où les fils se croisent aux deux bouts du stator).

Au lieu de couvrir 6 rainures, si chaque bobine en couvrait 7, dans l'ensemble du stator les lignes de champ seraient en opposition.

Hi MichelM,


Yes exactly.

Regards

L192

[pmgr]

Are Input 1,2 and 3,4 connected to Vcc and GHD of the Arduino or Vcc and GND of the input power rails?

Sorry but the way I understood Pierre's circuit is, even though all the coils are connected in series they are individually driven, so I don't understand why you wrote "We are driving 5 coils in series"
It would be important we be on the same page before moving forward.

Yes, I agree and understood it this way
Thanks for your help and kind regards

Luc

Input 1,2 should be connected to Vss (not Vs) of the H-bridge. This is the logic supply voltage, so 5V, not your input voltage (unless it is 5V as well). Please see attached image. Input 3,4 to GND. GND in general should all be connected together, so GND of H-bridge and GND of Arduino should be connected as well. And then input 3,4 to GND (you can do it on the H-bridge as well).

I note that this bridge has actually transistors and not FETs. The voltage drop across the collector-emitter is around 1-2V when driving 2Amps of current through each of them (4A total per 2 outputs). So your rails voltage can be higher than 5V, e.g. it could be 7-9 volts. I suggest you start at 5V then go to 9V max. Then measure the voltages at a coil compared to GND. Current through the coil will be voltage drop over the coil divided by the 0.5ohm resistance.

Regarding the coils, they are driving six at a a time. Just driving a single one will not generate a large magnetic field. You drive six (in your case 5) in series and the field strengths add up.


PmgR

[gotoluc]

Hi Gotoluc,

In the case of the 36 slot stator there are 6 coils driven in series. Pierre shows this on his diagram.  From the switch high side feed the current goes through 6 coils in series clockwise and 6 coils anticlockwise. At the end of the 6th coil the low side switch is turned on completing the current flow. This generates an adjacent North and South pole. This is repeated at two more times to createtwo more sets of poles. The three high side switches and 3 low side switches are then all rotated to the next switch positions before the previous set of switches are turned off.

Regards

L192   

That video of his complete circuit was him sharing a possible solution to eliminate the WWW wave he was seeing on his scope.

Pierre's instructions and diagram prior to making that video.

Eng. About the sequence of the arduino, you will have to turn on one coil and then the other and then turn off the first coil otherwise you will break the magnetic field. The goal is not to turn off the magnetic flux but only to keep it moving ex: 1 on, 2 on, 1 off, 3 on, 2 off etc.

Fr. pour de ce qui est de la séquence de l'arduino quand vous ferez la séquence vous devrez allumer une bobine et puis l'autre  et par la suite éteindre la première  sinon vous allez coupé le champ magnétique le but étant de ne pas éteindre le flux seulement le déplacer    ex:1 on, 2 on, 1 off ,3 on, 2 off etc.

I don't know but I read that and see the diagram he provided with those instructions as coils are individually powered and not 5 or 6 powered in series in a row.
However, there are 6 poles, so at all times there are 6 coils powered plus another 6 for the overlap time.

Regards
Luc

[pmgr]

So I am looking back over the sequence of progression on how the coils are supposed to be configured. I originally thought only one coil was powered at a time which appears what Luc's previous picture shows as well.


Then Pierre posted his video where he makes one coil out of six coils (by putting them in series) so then I thought this is how he has his current machine wired.


But maybe this is not the case. Maybe his last video was just a way to improve his current machine.


Maybe someone who can read over his French replies once more can shed some more light on this.


PmgR

[keykhin]

Hi everyone! This is my first post here. I'm following this thread for a while and I want to give you some advice. That L298 is suitable for RC's and small stepper motors used in 3D printers or small CNC machines. In this DZ particular case you have to deal with coils that have low resistance and high inductance. Use specially designed mosfets with logic level drive and very low on-resistance like IRLR2905 or IGBT's like IXDH35N60B from IXYS Corporation or equivalent. But I advice everyone for the first build to use relays. As a personal project I have in my mind to design a simple and low cost sequencer based on a PIC microcontroller. Using one Arduino for this simple job is like killing a mosquito with a sledgehammer. I will return when I finish the code. Cheers, K.[/size]