Bedini SG

[ZeropointEnergy]

Solid-state

"the more resistance I use with my pot the faster my rotor goes until the resistance gets high enough to cause the coil to self oscillate which makes the rotor slow back down in a hurry".

Hey N8,

I was just wondering if you have obtained self-oscillations in the SSG causing a solid state function?.

I have saturated my coil (not sure how, have 2mm welding rods, unless is the magnetic air gap distance, last variable to tick off.) during last test and the SSG started to generate a high pitch squeel then rotor slowed down.
Then began to charge solid-state drawing 200mA (no meter on output)
and seemed efficient. However, makes more noise than the fast pulsing 2400-2500RPM on SSG.(removed all noise, except the trigger pulses)
The sound was so loud I hit my STDP switch just to ensure wasnt about to explode a component and if I was to create a solid-state model I would have to add sound proof case to tollerate being in the same room as it.

Are you still adding to your "first SSG" post or just here now bro?

Regards
Zero

[Neight]

That sounds about right to me.
one thing you can do, once you find the sweet spot (and salmon is right it will change depending on the batteries) as long as you are using the same batteries though, once you find the sweet spot, stop the wheel measure the pot find the resistor/s that match/es (as I'm sure you already did). have this resistance "on hand" so once you get the rotor up to speed, you can flip a switch or move a wire to go from the pot to the resistor/s. "viola" you don't have to waste your time tunning every single startup.
I'm sure you thought of this or are already doing it prior to my typing, so this is just for anyone else who comes along as well

Patrick

Hey Patrick
thanks for the confirmation and the tip!
I was fairly certain that was what I had going on, since I didn't seem to have the same issue with the ceramic magnets on my larger rotor. I have considered using a fixed resistor with a jumper to switch back and fourth, but it honestly doesn't bother me enough to do anything to change it. it still only takes a few seconds to get the rotor up to top speed, and I like playing with it anyway
I have been ridiculously busy lately, and haven't had much time to do any builds, though I have several that i would like to attempt. I have still been reading things here every day and learning quite a bit, especially on the romero/muller post, which is where I learned that cogging was a likely issue with the magnets I was using.
I have put a biasing magnet on the empty end of my coil core. using the same magnets for the biasing mag as I am the rotor magnets. it doesn't do much to help the efficiency, (not a noticeable power usage effect anyway) though it does reduce the noise quite a bit, and the cogging seems to be less of an issue, though it doesn't help with tuning at all. it might get a slight RPM bump, but not much if any. just something to play with and test while i don't have time to sit and build anything new.
thanks again!
N8

[minoly]

Hey Salman, thanks for the reply and input!
I don't think that is what is going on in this case though. the "sweet spot" (highest RPM @ lowest amp draw) remains the same. I can turn my motor off, change nothing at all and turn it right back on and I still have to re-tune with the pot to get it back up to speed and lower the amp input. when it is running best, my 1k pot is turned all the way up to highest resistance. when i turn my motor on, I have to turn the pot all the way down (probably not all the way down, but it speeds up faster if I start at the lowest resistance and slowly turn it up, otherwise I have to wait a longer time for the rotor to get to speed before I turn the resistance back up), then once the rotor is no longer speeding up, I can turn the pot up slowly and the rotor will speed up with the resistance until the 1k pot is all the way up. If i go too fast with the pot knob, I get "in front" of the rotor speed and it will slow back down again.
it's kind of odd, and I am assuming it is because of the magnets I am using (double stacked 1/2" x 1/8" neo cylinders totaling one cylinder that is 1/2" (dia x 1/4" depth) I am thinking the magnetic field is a bit too strong and I am getting cogging at lower speed, reducing the initial RPM cap. once it gets enough RPM in the rotor, it then has the momentum to overcome the drag and speed up to it's max RPM which is a bit over 3k by my calculation.
it takes very low resistance to let the rotor get to speed and once it has maxed out RPM at lower resistance i can then up the ohms and speed the rotor all the way up.
just my opinion of what's going on here. I have a large wheel rotor with 16 ceramic mags on it, and I don't have to tune it every time, it will get up to speed, though it does so slowly.
thanks for the input, I appreciate it!

N8

That sounds about right to me.
one thing you can do, once you find the sweet spot (and salmon is right it will change depending on the batteries) as long as you are using the same batteries though, once you find the sweet spot, stop the wheel measure the pot find the resistor/s that match/es (as I'm sure you already did). have this resistance "on hand" so once you get the rotor up to speed, you can flip a switch or move a wire to go from the pot to the resistor/s. "viola" you don't have to waste your time tunning every single startup.
I'm sure you thought of this or are already doing it prior to my typing, so this is just for anyone else who comes along as well

Patrick

[Neight]

This is because of the impedance of the load connected. I think, at sweet spot the output impedance of the system is closely matched with the load (in this case batteries) impedance. But, since the impedance of batteries changes as they charge up and so does the sweet spot.
If you change the battery at the output sweet spot will change because that new battery will have a different impedance.
For best results you must match the two impedances.


Regards,
Salman

Hey Salman, thanks for the reply and input!
I don't think that is what is going on in this case though. the "sweet spot" (highest RPM @ lowest amp draw) remains the same. I can turn my motor off, change nothing at all and turn it right back on and I still have to re-tune with the pot to get it back up to speed and lower the amp input. when it is running best, my 1k pot is turned all the way up to highest resistance. when i turn my motor on, I have to turn the pot all the way down (probably not all the way down, but it speeds up faster if I start at the lowest resistance and slowly turn it up, otherwise I have to wait a longer time for the rotor to get to speed before I turn the resistance back up), then once the rotor is no longer speeding up, I can turn the pot up slowly and the rotor will speed up with the resistance until the 1k pot is all the way up. If i go too fast with the pot knob, I get "in front" of the rotor speed and it will slow back down again.
it's kind of odd, and I am assuming it is because of the magnets I am using (double stacked 1/2" x 1/8" neo cylinders totaling one cylinder that is 1/2" (dia x 1/4" depth) I am thinking the magnetic field is a bit too strong and I am getting cogging at lower speed, reducing the initial RPM cap. once it gets enough RPM in the rotor, it then has the momentum to overcome the drag and speed up to it's max RPM which is a bit over 3k by my calculation.
it takes very low resistance to let the rotor get to speed and once it has maxed out RPM at lower resistance i can then up the ohms and speed the rotor all the way up.
just my opinion of what's going on here. I have a large wheel rotor with 16 ceramic mags on it, and I don't have to tune it every time, it will get up to speed, though it does so slowly.
thanks for the input, I appreciate it!

N8

[salman144]

On my SSG i can't use a dedicated resistor for tuning. every time I turn it on, I have to adjust the pot to get it to top speed/lowest amp draw. I am not really sure why that is...

N8

This is because of the impedance of the load connected. I think, at sweet spot the output impedance of the system is closely matched with the load (in this case batteries) impedance. But, since the impedance of batteries changes as they charge up and so does the sweet spot.
If you change the battery at the output sweet spot will change because that new battery will have a different impedance.
For best results you must match the two impedances.


Regards,
Salman

[Neight]

here is my experience with more and less magnets and my opinion on why...
with my SSG setup I started with 4 mags and then doubled that to eight. I have also used 6 magnets on one setup and my largest rotor has 16 magnets on it. watching the difference in amp draw and top RPM between 4 and 8 magnets on the same rotor i noticed that the amp draw at startup is the same. it wasn't until I got the RPM's to settle where the circuit wanted to run that the amp draw dropped to any significant degree.
I was fortunate enough to be given an oscilloscope and when I hook up the scope and the ammeter I noticed a few things with any number of magnets. as the rotor speeds up faster and faster the amp draw increases until it gets fast enough to drop to 2 pulses per magnet. it will stay at about the same amp draw from there until the rotor is going fast enough to drop to one pulse/magnet. that is when the amp draw drops to it's lowest. the more resistance I use with my pot the faster my rotor goes until the resistance gets high enough to cause the coil to self oscillate which makes the rotor slow back down in a hurry.
on my 4 mag setup the amp draw would again start to go up as the rotor sped up after dropping to one pulse per magnet. at top speed I was drawing about 110mA. when i doubled that to 8 mags I can run the rotor all the way up to top speed and the amp draw keeps decreasing until it hits it's peak RPM just before the coil would start to self oscillate. with 8 magnets I get a much lower amp draw (about 65-70mA) and much higher top RPM and better torque.
the conclusion i drew from this is pretty simple. with 4 magnets the spacing between the magnets sort of caps out the RPM for tuning purposes. at it's lowest amp draw you are not at top speed. to get a 4 mag rotor up to top speed, it takes more power because you are working with half the pulses. with 8 mags there is half the space between the magnets and much less time between pulses. that keeps the momentum up by default and since you are not losing as much momentum between pulses it doesn't take as much power to drive the rotor. sort of like quicker on/off time, but not exactly, just less power needed to maintained speed. I think there would be an ideal magnet spacing for best efficiency. if they are too far apart you are limited to how much RPM you can get at XX amp draw. too close and you don't get a sharp on/off and that will really limit your output power and increase your input amp draw or worse, it wont run at all .
On my SSG i can't use a dedicated resistor for tuning. every time I turn it on, I have to adjust the pot to get it to top speed/lowest amp draw. I am not really sure why that is...
my machine runs best with the pot turned all the way to highest resistance, but from a dead stop it wont get up to high RPM or low amp draw unless I back the resistance down and let the rotor speed up, then turn the resistance back up. once it is at top speed, it runs easily below 70mA input current and is reasonably efficient. play around with magnet spacing and magnet types. it sounds like you are using a bigger rotor, which will take more power to run anyway, though once it gets up to speed, should have a better fly-wheel effect and run pretty smooth. watch your meter as the rotor speeds up, you can see when the coil is only pulsing once per magnet because the input draw will drop off suddenly. once you see that needle drop, that is going to be your "sweet spot" (lowest amp draw at highest RPM) even if you can go higher on RPM, for charging purposes you really want lower amp draw. If torque and speed are your aim, then turn it up!!
hope this makes sense, it is about 90% observation and opinion, so if anyone sees anywhere i need correcting, please do so, I am very much still learning here


N8

[blackchisel97]

BTW this isn't a full SSG, i don't have the diode connecting to a charging battery, this may account for differences between mine and yours.

I think the duration of the pulse is altered by the number of magnets.

When i double the number of magnets, i am getting moee 'push' and therefore higher RPM.

Higher RPM means each magnet spends less time passing the drive coil, which in turn means a shorter pulse.

Shorter pulses = less current draw.

When you doubled the magnets you're getting more mpm (magnets per minute) and also double the amount of pulses (assuming you have tuned to single pulse per magnet). SSG has its own "sweet spot" which needs to be tuned to. Best charging doesn't occur at highest speed.

V

[qvision]

BTW this isn't a full SSG, i don't have the diode connecting to a charging battery, this may account for differences between mine and yours.

I think the duration of the pulse is altered by the number of magnets.

When i double the number of magnets, i am getting moee 'push' and therefore higher RPM.

Higher RPM means each magnet spends less time passing the drive coil, which in turn means a shorter pulse.

Shorter pulses = less current draw.

[mbrownn]

The duration of the pulse is not altered by the number of magnets however; the speed the magnet passes the coil can have an effect. If slow enough you may get two or three pulses per magnet pass.

This results in slower speed higher current draw to some extent.

It could be that your magnet spacing was a little too wide in the first instance.

[mbrownn]

On my SSG more magnets gave a lower RPM, torque seemed to be the same although I have not measured it. It is as if the circuit only wants to run at a particular number of pulses per second.

[qvision]

Why do more magnets on a rotor draw less current ?

I was experimenting this evening, i had a rotor disc with magnets attached and a bifilar drive coil using the Bedini circuit to repel the magnets.

With 8 magnets the rotor was drawing around 300 mA.

I doubled the magnets to 16 and the rotor was drawing around 200 mA.

I would have thought that more magnets meant more 'on' time thus drawing more current ?

Is it because more magnets results in faster RPM so each pulse is then shorter ?

If that's the case then what's the critical threshold of the tradeoff between additional magnets (and the resulting additional rotor mass) and decreasing current draw ?

Unfortunately i don't have enough of these magnets to experiment further.


Any advice greatly appreciated,

Gary.

[salman144]

Why is it that inverting the trigger coil connections does not works. Circuit did not draw any current from the input.

[minoly]

Update:

My 90Ahr battery just charged up from 10.5V to 12.7V in two days.
During the charging input current was 600mA and output was 300mA as
measured by the meter.

Now i am gonna convert this system to self runner just like the School boy
version.
Any ideas or suggestions are welcome.......!!




Regards,
Salman.

I recomend cycling that battery 30 + times, document how long it holds it's load each time.
Keep us posted

Patrick

[salman144]

Update

Update:

My 90Ahr battery just charged up from 10.5V to 12.7V in two days.
During the charging input current was 600mA and output was 300mA as
measured by the meter.

Now i am gonna convert this system to self runner just like the School boy
version.
Any ideas or suggestions are welcome.......!!




Regards,
Salman.

[salman144]

I would if it was mine. Links work for me from a diff computer even. last try - this is a link to his folder:

http://tech.groups.yahoo.com/group/Bedini_Monopole3/files/Experimenters%20File%20Section/Dave%20Sw/

otherwise go to the files section then experimenters files then Dave Sw.

Patrick

All right Got it...Thanx