Author Topic: The Ossie motor (Read 333019 times)

mscoffman · « **Reply #270 on:** February 17, 2010, 01:27:24 AM »

Quote from: woopy on February 16, 2010, 10:16:41 PM

Hi Captain

thanks for answer have you some shematic as how to transfer the cap energy back to the run battery or how to use and what for a Zener diode value ?

Is it a way to calculate the power going in the big cap along the time . As the time from about 12.5 to 50 volt was 30 minutes is it possible to deduce some power from those datas ?

Or what would be the datas to register to get the power of those Flyback spikes ?

regards

laurent

@laurent

Question A-
On the zener...it is not efficient for discharging the 10Kuf capacitor.
The zener to use, would be the voltage you want to see, lets say
12.5volts. You put a resistor in series with the zener so that at
12.5 volts you get your required .007 amps = 7ma. pass-current.
The resister has to be of the appropriate wattage. The problem is
that same resistor at 50.0 volts will be conducting 28ma so at the high
voltage the power wasted is very high. P=E*I. where E= (max V - base V)
where base V is 12.5 volts. A series pass DC regulator will have this same
wasted power. What you need is a switching regulator for efficient
energy conversion.

Question B -
I wondered the same thing. What happens if you turn all of
the charge energy of the 50V 10kuf capacitor into 12.5 volts
at .007amps to run the motor:

o) Well 1C=1amp for 1sec. which means C= .007amps * 1800 seconds
or about 12.5Coulombs charge required by motor to run for 1/2 hour.

o) Also equals 1C=1Farad at 1Volt which means the capacitor
is C = .01F * 50Volts or only .5Coulombs charge stored in the
10Kuf capacitor.

So the capacitor is fairly light duty for running the motor for so long.
This is not suprising given the narrow width of the back EMF pulse
in ratio to the motors total pulse cycle time. You'll need to look
at a supercap in this application to have a shot at success.

:S:MarkSCoffman

woopy · « **Reply #271 on:** February 17, 2010, 09:37:27 AM »

@Mscoffman

Thanks a lot for the very comprehensive explanation

Hebeh ! I am far from the goal.!

If i have right understood , if i need 0.007 amps to run the motor for 30 minutes (1800 sec), the stored energy in the cap should be at minimum 12.6 Coulombs.

And as the actual energy after 30 minutesa is only 0.5 coulombs, i am about 25 time under any attempt for a self runner by this way.

Even if i only consider the pure motor current needed that is 0.0014 amps (without the Hall circuitery) i am always 5 time under the goal.

OU is not to be searched in the Flyback this way. Unless there is a mean to get far more of them and or stronger ones. Any idea ?

Can i state that in this case with 0.007 amps motor current by geting back all the fly back spike power i could get back 4 % energy or improve the motor efficiency of 4 % ?

And if yes if we could reduce the Hall circuitery to zero (ideal case), In this case with 0.0014 amps the efficiency could be improved of 20 %?

Just for thinking

Regards

Laurent

Jimboot · « **Reply #272 on:** February 17, 2010, 11:09:07 AM »

Ok I put the gen motor aside for now. I'm attaching pickup coils. What sort of circuit would be best to capture current through the coils?
mmm just had a thought. What if I used the extra rotor & coils in series with the one below? The mags on the top rotor are opp polarisation to the one below. Could this cause some sort of phase cancellation?

captainpecan · « **Reply #273 on:** February 17, 2010, 11:14:05 AM »

After banging my head against the wall a bit more, I stepped away from the project for a bit. After thinking it all through again, I came up with an interesting variation that could be of use. I'm thinking of replacing the bridge rectifier with a voltage doubler circuit. In theory, it eliminates 2 diodes so there will be less voltage drop on the energy captured from the induction. Also, it would allow the turn of the rotor to generate less voltage than the run battery, and still charge the run battery anyway.

A quick rundown of how it works. AC current comes from the rotor induction and feeds into the voltage doubler. Each half wave charges it's own cap through only one diode. When the reed switch is tripped, both caps are hooked in series to double the voltage and dump into the run battery. Pretty simple, just wanted to share what I was cookin' up in my head. Haven't tried it at all, just kicking it around. But in theory it may be a way to suck a bit more energy from the turn of the rotor without adding more pickup coils yet.

Jimboot · « **Reply #274 on:** February 17, 2010, 11:22:12 AM »

Quote from: captainpecan on February 17, 2010, 11:14:05 AM

After banging my head against the wall a bit more, I stepped away from the project for a bit. After thinking it all through again, I came up with an interesting variation that could be of use. I'm thinking of replacing the bridge rectifier with a voltage doubler circuit. In theory, it eliminates 2 diodes so there will be less voltage drop on the energy captured from the induction. Also, it would allow the turn of the rotor to generate less voltage than the run battery, and still charge the run battery anyway.

A quick rundown of how it works. AC current comes from the rotor induction and feeds into the voltage doubler. Each half wave charges it's own cap through only one diode. When the reed switch is tripped, both caps are hooked in series to double the voltage and dump into the run battery. Pretty simple, just wanted to share what I was cookin' up in my head. Haven't tried it at all, just kicking it around. But in theory it may be a way to suck a bit more energy from the turn of the rotor without adding more pickup coils yet.

I like it CP, except the bit about tuning 3 reed switches. The simpler te better tho I think.

gyulasun · « **Reply #275 on:** February 17, 2010, 11:57:08 AM »

Quote from: woopy on February 16, 2010, 05:12:33 PM

....
Effectively the amps went dow almost by the half with 4.7 kohm resistor at the collector . Can i try higher resistor value or will it destroy the transistor ?

Hi Laurent,

Yes you can use a higher value resistor but do not go higher than 10-15 kOhm because switch-on time of the FET may suffer. (You cannot destroy the MOSFET by changing that resistor value to anything.)

Quote

My tle 4905 is rated at typical current 3 to 7 max miliamps , do you know better one ?

Will study this, at the moment I am not sure there are much types with lower current consumption.

Quote

What is this circuit that Tropes mentionned in the above post, do you know it ?

He asked me last year to give him a schematic on his opto interrupter device for his piston motor and he used different battery voltages for his motor tests (12-24V) and this involved using different resistors in series with the input diode of his interrupter. So that he should not bother on changing that resistor whenever he changed battery voltages he used a small 2V battery just for the input diode and this made his opto interrupter input side independent from the 12-24V side. Here is that circuit by the way:
http://www.overunity.com/index.php?topic=3318.msg83314#msg83314 (it may need a 15V Zener diode between its V_cc and GND pins and series 3-4 kOhm resistor from its V_cc to the 24V battery input if there is a need for 24V operation, to protect the interrupter from excess supply voltage.

Quote

the charge consume a lot of miliamps very shortly (some seconds) until the cap was at 12.5 volts than until the 56 volts charging process DO NOT TAKE ANY MILIAMPS at the motor as if the cap nor bridge was there. I tried to diconnect the cap than the bridge and reconnect it and the amps stay at 10 miliamps steady The charging process uses only the flyback spike.

'The lot of mA' consumption in the first moments of the cap charging is normal, I mentioned a discharged capacitor is a short circuit at the very first moment the charging starts, then this peak current exponentially reduces as the voltage increases across the cap. After the voltage across the cap is about the same as the pulse amplitude that was rectified to charge the cap, there will be no any loading effect of the cap on the pulse. However the moment you take charge away from the cap i.e. you start using the stored voltage of the cap, the loading effect appears on the pulse again, proportionally to the charge consumed from the cap.

rgds, Gyula

neptune · « **Reply #276 on:** February 17, 2010, 12:06:19 PM »

@Jimboot . Re the cicuit using the torch motor to charge a battery thru a diode . use a switch to short out the diode once things get up to speed . this will save energy waste in the diode and improve charge rate .

captainpecan · « **Reply #277 on:** February 17, 2010, 07:11:25 PM »

Quote from: Jimboot on February 17, 2010, 11:22:12 AM

I like it CP, except the bit about tuning 3 reed switches. The simpler te better tho I think.

I know exactly what you mean, I've already ruined my 3rd reed switch on my project. Which is the reason I was banging my head against the wall to start. The reed in the picture though would be set to only trip once per revolution or so to dump the caps. Either way, i'm not sure how well it work anyway, just something I was kicking around, as a way to get some extra charge from that rotor motion. May be able to use a zener diode to keep the caps dumping at a specific voltage.

woopy · « **Reply #278 on:** February 17, 2010, 10:12:57 PM »

Hi all

a lot of learning today and so interesting

Thanks Gyula and Cp and Ms and Jb and all contributors

Now i have separated the trigger sensor circuit from the power motor circuit see pix 1 schematic. And so i can look at the real current consumption of the motor. And i can confirm a small 2 miliamps for the motor itself under 12.2 volts battery, and a 3 miliamps for the Hall circuitery undewr 4.1 volts.

And this evening i concentrated the efforts to get the form of the pure motor impulses current. This is made with the scope probe across 1 ohm resistor at the + of battery and the circuit

And the scope shot shows different variation dependly of the Hall sensor position on the magnets . See the 2, 3, 4 pix .

What is BIZARE is that on a single pulse the current goes Sharply up than down and may be negative in a U shape (pix 3 ) and goes up again to a strong positive spike and down is there any interpretation of those scope shots ?

regards

Laurent

Schpankme · « **Reply #279 on:** February 17, 2010, 10:20:32 PM »

Quote from: Light on February 04, 2010, 04:15:40 AM

Have tried Ossie but with two coils only. Seems ok, running for long time; maybe with 4 coils it gets betterâ€¦
http://www.youtube.com/watch?v=6EZKxu5qTJI

Light (Mopozco),

Your video shows a circuit very similar to the one attached.

- Schpankme

futuristic · « **Reply #280 on:** February 17, 2010, 10:32:46 PM »

Hi after looking at your scope shots for some minutes they don't look so bizare any more.

What we see here is induced voltage which seems to be visible only when FET is conducting.
Depending on the hall position you were catching certain part of the sinus wave of induced voltage.

Pulse from the battery is so small that is not even visible. You said it's 2mA and induced sine wave shows approx 70mA of induced AC current.

If you get your motor to max rpm and then quickly replace FET with just wire, you should see on the scope complete sinus wave and not only a part of it like now.

Anyway I think you have something really amazing there.

To get full wave on the resistor I would suggest to try putting schottky diode in reverse direction to FET, because its internal diode doesn't seem to work?

Any way great work!

Frenky

futuristic · « **Reply #281 on:** February 17, 2010, 10:40:16 PM »

For this type of results we should have smiley like this one:

http://i133.photobucket.com/albums/q79/ComicsReader/bow.gif

futuristic · « **Reply #282 on:** February 17, 2010, 10:48:43 PM »

BTW if I didn't say it specifically.

I think that it should be fairly easy to make you motor to selfrun from a capacitor.
Because with 70mA:2mA current ratio it just can't get any better.

Frenky

woopy · « **Reply #283 on:** February 17, 2010, 11:03:10 PM »

HeHe

thanks Frenky

but now goind to bed and night will connect all the good ideas hopefully

good luck at all

Laurent

captainpecan · « **Reply #284 on:** February 18, 2010, 02:08:00 AM »

Quote from: futuristic on February 17, 2010, 10:32:46 PM

Hi after looking at your scope shots for some minutes they don't look so bizare any more.

What we see here is induced voltage which seems to be visible only when FET is conducting.
Depending on the hall position you were catching certain part of the sinus wave of induced voltage.

Pulse from the battery is so small that is not even visible. You said it's 2mA and induced sine wave shows approx 70mA of induced AC current.

If you get your motor to max rpm and then quickly replace FET with just wire, you should see on the scope complete sinus wave and not only a part of it like now.

Anyway I think you have something really amazing there.

To get full wave on the resistor I would suggest to try putting schottky diode in reverse direction to FET, because its internal diode doesn't seem to work?

Any way great work!

Frenky

I'm usually fairly good at reading the scope traces, but this one is a bit over my head I think. It's just not really making sense to me yet. I'm still waiting for my scope to show up so I can get some more hands on to learn it better. But how are you reading the 70ma current coming out from that scope shot? I'm not saying your wrong, I'm just saying I don't understand it. 2ma going in and 70ma coming back out is making think something may be a bit weird with the calculations. I hope I'm wrong, but that's a 35 times increase, or course only if the voltage was exactly the same, but you know what I mean. Even if the voltage coming out was only 1 volt, it's way over power than what is going in. Maybe we should take a couple more close looks here, and make sure it is being read right.

@woopy, is there any chance you have a DPDT switch you can hook up at that fet. If you hook one set of poles to a shorting wire, and other to the fet, you could easily just flip the switch to see the difference in scope traces.

Either way, great work! It's nice to see a group of builders, moving along from hands on experience than just kicking all theories around.

News:

User Menu

Author Topic: The Ossie motor (Read 333019 times)

mscoffman

Re: The Ossie motor

woopy

Re: The Ossie motor

Jimboot

Re: The Ossie motor

captainpecan

Re: The Ossie motor

Jimboot

Re: The Ossie motor

gyulasun

Re: The Ossie motor

neptune

Re: The Ossie motor

captainpecan

Re: The Ossie motor

woopy

Re: The Ossie motor

Schpankme

Re: The Ossie motor

futuristic

Re: The Ossie motor

futuristic

Re: The Ossie motor

futuristic

Re: The Ossie motor

woopy

Re: The Ossie motor

captainpecan

Re: The Ossie motor