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

[pmgr]

Luc, one more question I have about the last picture you posted is how Pierre controls the direction of the current. The Arduino appears to only control the transistors that control the relays, but what determines if the top relay turns on or the bottom relay? I would assume one transistor controls both at the same time.

E.g. in your picture, let's say the left two relays with the forward flowing arrows are turned on with transistor 1 (so coil 1 on), then if for that particular coil he wants to switch current direction, what transistor(s) would he need to turn on? If he turns on the second transistor, it would give the same forward flowing current in the second coil, not reverse current. He would need to turn on the GND connection of coil 36 (controlled by transistor 36).

If he turns on the first transistor (so he gets the GND connection for second coil for negative flow), he would also need to turn on the third coil. Then he will get reverse current in second coil, but the third coil will also be on in forward direction. And he would have transistor 1 and 3 on at the same time. His Arduino code doesn't show any evidence of that kind of transistor switching.

PmgR

[e2matrix]

I'm not sure if these were mentioned before but in cruising eBay I notice these 8 channel 8 relay module boards for Arduino for only $4.96 (from Hong Kong) or same one from a U.S. seller for $7.95 which appear to be identical to the 8 relay boards in Pierre's video as seen at 6:16 into his second video which showed it completely self running.   You can easily find them on eBay by these item numbers:  eBay item number:172396554144 for the $4.96 one from H.K. and eBay item number:231682185473 for the $7.95 one from the U.S.   I'm quite sure they are identical to the one's in Pierre's video for anyone wanting to do a relay type replication.  Nine of the boards would be needed for your 72 relays which only comes to about $45 total with shipping - not bad for all that many relays with screw connections and rated 10 amp at 250 VAC and Arduino ready.

[r2fpl]

Building H-Bridge,  I suggests used 2 sets:

AOD609: N/P-MOSFET;  http://aosmd.com/pdfs/datasheet/AOD609.pdf
or
FDD8424H: N/P-MOSFET; http://www.mouser.com/ds/2/149/FDD8424H-92711.pdf

[e2matrix]

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]

It seems Arduino's have gotten so cheap ( $10 to around $18 for a Mega 2560 R3) that they are as cheap or even less than many PIC controllers and can do a lot more with them if you decide to use it for something else.   But if you are more familiar with PIC controllers and can get the same results thats all good too.   

[listener191]

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

Hi Gotoluc,

I believe that  diagram Pierre made was just to demonstrate the switching principle, the larger diagram in the video showing all the coils, was made to show that 6 coils were energize in series.

Regards

L192