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Author Topic: Pierre's 170W in 1600W out Looped Very impressive Build continued & moderated  (Read 429987 times)

listener191

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The first scope shot shows the coil current including the low side switch period.

So just 5 coils switching no overlap.

The second shot shows the board supply current.
Note the low side switch is on another board so you don't see that current.
No sign of any recovery current to the cap bank.
Perhaps the local cap on the board is taking this charge, so it does not appear on the supply rail?

I disconnected the loop and it made no difference, so I was wrong about that.

Regards

L192

TinselKoala

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Luc, we have mentioned before that the maximum rated continuous current output of the Mega is 200 mA total. You definitely should be using a current-limiting resistor in series with _each_ LED to limit the current to something like 5 mA per LED. With modern bright LEDs this will be plenty bright for visual display purposes. Even though you aren't turning on all your LEDs at once, you still need some current limiting for the LEDs. For a Green LED with a Vf of say 1.8 V, and the 5 V supply, you need to calculate the resistor value like this: R=V/I so R =(Vsupply - Vf)/5 mA = (5-1. 8) /0.005 = 640 ohms. So use a resistor value close to this for each LED. (I'm using 470 ohms on my test board.) This way even if all 30 LEDs are on the system will draw 150 mA, well below the total limit. (The speed control pot will draw a little current also but if you use a reasonable sized pot this will be negligible.)

It is possible that your uploading and intermittent problems have to do with the high current draw. (At fast speeds it "looks like" all LEDs are on at once, causing the thermal overload problem.) This is why I suggested earlier that you try the uploading with all external circuitry disconnected from the Mega. If this solves your uploading problem then you will know the cause, and can most probably cure it with adding current-limiting resistors to all your LEDs.

Driving a mosfet, as has been pointed out before, doesn't need much current usually. So you should be able to drive the LED+resistor, and the mosfet, for each of the 30 switches with no additional problem, once the LED current is limited.

There is no need to switch to the Propeller system. It will have similar output current restrictions, and it uses a different IDE interface and IIRC it uses a variant of the BASIC programming language. While any program can be written in just about any language.... I think you will have more help available if you stick to the Arduino system and the C++ language. If it turns out that you have a defective Mega we can arrange for you to get a new one. If it turns out that you need more current than the raw Arduino can supply you can always put in current-amplification transistors between the Arduino outputs and the mosfets (or H bridges or relays, whatever).

But FIRST THINGS FIRST, try uploading to the Mega with _all external circuitry disconnected_ to see if the current draw is really the problem.
If it works fine this way, then you can probably cure the present problem simply by adding the current-limiting resistors to each LED.

T-1000

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Looks like I have a problem.  I spaced my coils 6 slot wide and I'm having terrible results.  PmgR said it shouldn't matter but maybe it does?...  I need opinions as something is not right.

See results: https://youtu.be/aFQB-WOx-Oc
Hi Luc,

I am finding your coils aligment do not match Pierre's winding style.
Your setup have 2 coils in single slot while Pierre made just 1. Please see video screenshot attached.

The second very important thing to remember - the magnetic field strentgh weakens to the distance from coils squared. Which means in your setup you need to put out really strong magnetic field on stator to reach coil in the middle. Which also means the bare minimum power required will be high to induce current on the output. This is where bank of supercaps may play crucial role.

The third thing, when you attach 12V battery I suspect internal Arduino 5V stabilizer is messing up or is partially burned out. You may diagnose its issues or make external circuit to cope with power consumption on LEDs/etc. Personally I would introduce mosfet drivers to output transistors when driving coils.

Cheers!

listener191

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Hi Luc,

I am finding your coils aligment do not match Pierre's winding style.
Your setup have 2 coils in single slot while Pierre made just 1. Please see video screenshot attached.

The second very important thing to remember - the magnetic field strentgh weakens to the distance from coils squared. Which means in your setup you need to put out really strong magnetic field on stator to reach coil in the middle. Which also means the bare minimum power required will be high to induce current on the output. This is where bank of supercaps may play crucial role.

The third thing, when you attach 12V battery I suspect internal Arduino 5V stabilizer is messing up or is partially burned out. You may diagnose its issues or make external circuit to cope with power consumption on LEDs/etc. Personally I would introduce mosfet drivers to output transistors when driving coils.

Cheers!

Re post 410 in the other thread.
These were the numbers that Pierre provided.

 1-6,2-7,3-8,4-9,5-10,6-11,7-12,8-13,9-14,10-15,11-16, 12-17,13-18,14-19,15-20,16-21,17-22,18-23,19-24,20-25,21-26,22-27,23-28,24- 29,25-30,26-31,27-32,28-33,29-34,30-35,31-36,32-1,33-2,34-3,35-4,36-5

There are two coils in each slot.
Pierre's windings are very tight so you don't  see the second coil entries behind the first.

L192

T-1000

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Pierre's windings are very tight so you don't  see the second coil entries behind the first.

L192
Which is critical point in regards to magnetic field polarity. The closest to the center you see are just 1 way wiring making 1 magnet pole. The other coils looking to the outside of the stator make second pole.
So it is like magnet N/S looking towards center. When 2 coils are activated at once that makes N+N/S+S magnetic aligment towards center. A bit of tease for this case - the aligment of magnets in E. Leedskalnin generator in Coral castle - http://www.leedskalnin.com/LeedskalninImageArchive.html .

P.S> 1 slot I ment are 1 slot looking towards center and 1 slot looking towards outside of the stator.

Cheers!

gotoluc

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Luc, how did you connect the LEDs? Did you use a serial resistor with them? If not, each of them is probably at least drawing 20-30mA if not more. Multiply that with 30 and you are drawing 750mA. The Arduino can't supply that and the computer USB can't supply that either (probably only 500mA), yet the battery can supply the current, but the Arduino is turning on and off (Arduino fuse on board is probably heating up and disconnecting; I believe that board has a thermal 500mA fuse).

Yes, I kind of figured the LED's are a little too much current demand for the Arduino. Are there LED's that use less current?

You should remove your LEDs as the Arduino can't supply that much current directly. Even with a series resistor in place, it might not be able to handle it. This is also why the USB no longer shows up at your computer. The Arduino board simply can't handle the current load and so everything gets messed up.
PmgR

Sorry, that's not why the USB no longer shows up at your computer. I remove the ground between Arduino and the L298N which shuts off the load on the Arduino and no difference.
I've had nothing but communications errors and problems with this Chinese Arduino version right from day one (new out of the box). Only ever got 2 successful uploads out of 60 tries.
It needs to be replaced, period.

Regards
Luc

gotoluc

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Luc, we have mentioned before that the maximum rated continuous current output of the Mega is 200 mA total. You definitely should be using a current-limiting resistor in series with _each_ LED to limit the current to something like 5 mA per LED. With modern bright LEDs this will be plenty bright for visual display purposes. Even though you aren't turning on all your LEDs at once, you still need some current limiting for the LEDs. For a Green LED with a Vf of say 1.8 V, and the 5 V supply, you need to calculate the resistor value like this: R=V/I so R =(Vsupply - Vf)/5 mA = (5-1. 8) /0.005 = 640 ohms. So use a resistor value close to this for each LED. (I'm using 470 ohms on my test board.) This way even if all 30 LEDs are on the system will draw 150 mA, well below the total limit. (The speed control pot will draw a little current also but if you use a reasonable sized pot this will be negligible.)

It is possible that your uploading and intermittent problems have to do with the high current draw. (At fast speeds it "looks like" all LEDs are on at once, causing the thermal overload problem.) This is why I suggested earlier that you try the uploading with all external circuitry disconnected from the Mega. If this solves your uploading problem then you will know the cause, and can most probably cure it with adding current-limiting resistors to all your LEDs.

Driving a mosfet, as has been pointed out before, doesn't need much current usually. So you should be able to drive the LED+resistor, and the mosfet, for each of the 30 switches with no additional problem, once the LED current is limited.

There is no need to switch to the Propeller system. It will have similar output current restrictions, and it uses a different IDE interface and IIRC it uses a variant of the BASIC programming language. While any program can be written in just about any language.... I think you will have more help available if you stick to the Arduino system and the C++ language. If it turns out that you have a defective Mega we can arrange for you to get a new one. If it turns out that you need more current than the raw Arduino can supply you can always put in current-amplification transistors between the Arduino outputs and the mosfets (or H bridges or relays, whatever).

But FIRST THINGS FIRST, try uploading to the Mega with _all external circuitry disconnected_ to see if the current draw is really the problem.
If it works fine this way, then you can probably cure the present problem simply by adding the current-limiting resistors to each LED.

Thanks TK

The Arduino (communication side) is definitely defective and that was from day one right out of the box. The first time I tried it was on my Ubuntu laptop and I never got it to work.
Got it to work once with a new install on windows 7 but now every time I unplug it and plug it back in (without powering the LED's or L298N "ground removed") windows no longer recognizes it.
If I uninstall the Arduino software and reinstall then the first time I connect it it windows recognizes it but always get an upload error.

I've done everything possible. This is crazy.

Regards
Luc

gotoluc

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Interesting no one here has picked up why my device has such a low current output!!!
Often in morning when I wake up I get a clear answer on something I've been contemplating on. I showed you all in my last video that my coils are 6 slot apart but it hasn't hit anyone.
It was clear to me this morning that in my configuration all my coils are Bucking... and no wonder I hardly get any output.
Pierre picked up on it and sent me a PM late last night which I only got this morning and he concluded the same thing.

Do you not see it?... 2 coils (in the same slot)  are powered together but each with the current in the opposite direction.
I need to take all the stator coils out and reposition them to 5 slots apart.
I'll be busy for some days.

Regards
Luc

gotoluc

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Hi Luc,

I am finding your coils aligment do not match Pierre's winding style.
Your setup have 2 coils in single slot while Pierre made just 1. Please see video screenshot attached.

The second very important thing to remember - the magnetic field strentgh weakens to the distance from coils squared. Which means in your setup you need to put out really strong magnetic field on stator to reach coil in the middle. Which also means the bare minimum power required will be high to induce current on the output. This is where bank of supercaps may play crucial role.

The third thing, when you attach 12V battery I suspect internal Arduino 5V stabilizer is messing up or is partially burned out. You may diagnose its issues or make external circuit to cope with power consumption on LEDs/etc. Personally I would introduce mosfet drivers to output transistors when driving coils.

Cheers!

Look at the pictures below, around 4 o-clock. You can clearly see the last winding goes into the slot over the previous winding.

Regards
Luc

e2matrix

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Thanks TK

The Arduino (communication side) is definitely defective and that was from day one right out of the box. The first time I tried it was on my Ubuntu laptop and I never got it to work.
Got it to work once with a new install on windows 7 but now every time I unplug it and plug it back in (without powering the LED's or L298N "ground removed") windows no longer recognizes it.
If I uninstall the Arduino software and reinstall then the first time I connect it it windows recognizes it but always get an upload error.

I've done everything possible. This is crazy.

Regards
Luc


Luc,  Does your Arduino have the CH340G serial chip?   If it does that may be the problem.   I recall something about that serial chip being blocked by a Windows update and it seems that this cheaper Chinese serial chip has caused a lot of headaches with drivers and connection to computers.   Some Arduino's use that chip but better ones use a different serial chip (Atmega 16u2 ? ).   

e2matrix

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If you do have that CH340G serial chip I just found a possible fix for it.  I'll try to attach it here.  I've run it through Virustotal.com also and it is all clear but you can check it too at www.virustotal.com

r2fpl

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I also have a problem with loading a file, but only when a magnetic field is generated. After turning off the power and waiting for 10 seconds, arduino is programmed again. This is not a driver problem or power supply.

listener191

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Interesting no one here has picked up why my device has such a low current output!!!
Often in morning when I wake up I get a clear answer on something I've been contemplating on. I showed you all in my last video that my coils are 6 slot apart but it hasn't hit anyone.
It was clear to me this morning that in my configuration all my coils are Bucking... and no wonder I hardly get any output.
Pierre picked up on it and sent me a PM late last night which I only got this morning and he concluded the same thing.

Do you not see it?... 2 coils (in the same slot)  are powered together but each with the current in the opposite direction.
I need to take all the stator coils out and reposition them to 5 slots apart.
I'll be busy for some days.

Regards
Luc

Hi Gotoluc,

I am finding that a single coil set outputs a reasonable voltage on the rotor however, when you add additional coil sets, output reduces and input current rises.

I have 4 poles between the coil 5 slot pitch, so  there is a 1 pole gap between poles.

So far, I have not  found an answer to this. 

Regards
L192

gotoluc

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Luc,  Does your Arduino have the CH340G serial chip?   If it does that may be the problem.   I recall something about that serial chip being blocked by a Windows update and it seems that this cheaper Chinese serial chip has caused a lot of headaches with drivers and connection to computers.   Some Arduino's use that chip but better ones use a different serial chip (Atmega 16u2 ? ).

Hi e2matrix. Listener191 sent me the same information (see his below message)  Turns out the Arduino I have is the 16U2
However, just got it working again but using my Ubuntu laptop. Don't know why it's working now since this was the first laptop I used and only had errors ???
I'm uploading a video now of the LED firring sequence.

Regards
Luc

 PM from L192
 If you have the original board then I would look at the components around the reset button and make sure you don't have a missing cap. Some of these boards have deliberately left a coupling cap to the reset line out so you have to manual reset the board each time.
 
 http://forums.reprap.org/read.php?146,705810
 
 Check which board you have, if its the CH340 chip then you need to load a driver for it.
 
 If you see the board listed under ports in device manager, does it have an exclamation mark against it? if so click on it to open the window and select  search for driver.
 
 Regards
 L192

gotoluc

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A visual of the Arduino firring sequence program to the L298N's

Video demo: https://youtu.be/fO2vIJj5xtI

The below Images are made by PmgR
« Last Edit: April 15, 2018, 01:38:16 AM by gotoluc »