Bedini Ferris Wheel Regauging Motor

[david.brown]

Bedini Cole Switch Problems.

John K,

Thanks for that, I was starting to pull my hair out, I thought I tried everything save starting again.
Well saying that I am going to start again and start matching MJ's and testing different Base resistors.

Thanks Again.

Regards,

David Brown (Belfast)

Hi David,

If one transistor is getting hotter than the other then they are not matched. This means that one transistor is switching on before the other and yaking more of the load than its partner. See if you can get a pair with the same Beta. I use my meter on diode test mode and go for no more than 2% difference.

You could also try and replace the 470 ohm resistors with a higher value. The duty cycle will depend on the dwell for the hall so if you don't see 50% then adjust the dwell.

As John B suggested you can parallel the transistors. Also research how to connect Sziklai pairs.

I am still waiting for some ATS137 halls to arrive as I blew what I had and John B has suggested that the ATS137 works very well.

I hope this helps.


John K.

[ren]

Hi John K and David.

I got my device up and running last night. Its built using what I have laying around so its not up to 3gt spec. But it is the half circuit, triggered by a hall. Im running on 24v, 200-300ma, 8 pole rotor 500mm in diameter.

Coil is 6 filar, each strand 0.9mm @ 2.1ohms per strand. I presently have it running with 4 strands in parallel. I had some heat in my circuit, particularly the PNP and I got rid of most of it by adding a rheostat off the 220 ohms which was discussed before. Even with the rheostat at its lowest setting (effectively adding very little if any resistance) the heat generated is considerably less, barely warm to the touch now. Tweaking this resistance lowers the input current even more. Not that there is much current here when its up to speed anyway.

Charges a 2200uF cap up pretty fast, still have to build the discharge circuit.

Took a little time to get the hall in the right place. I couldnt figure out why it would work then get slower and slower and eventually stop. I eventually found that there was a spacer missing, so the timing disc on the shaft would slowly get further and further away from the hall, eventually switching off altogether. When I have made up the spacer for it I will post a vid.

Regards

[Rl2003]

Ok, I've finally made a video that I said I would. I just had a little trouble with
my video recorder, so I am using my phone for now. It's short because it takes
forever to upload a larger file.

I did flip the two led's and to the opposite direction and this worked. But only
one blinks, and only when the cap is not in the circut. I am letting it run for a
couple hours to see what heppens to the sec. battery. It was almost dead...

My transisitors are getting hot and I am in the process of matching some.
I have been looking on the internet on how to do this, as I have never matched
the Beta of transistors before. If any one can introduce me to a simple way to
do this I would be thankful, other wise I will make a test circuit to do this.

YouTube - VIDEO0008.3gp

Mark P.

[John_Bedini]

Bedini GT3

Mark P,
Most meters have a Beta tester on them. If not you can do it by hooking a transistor in a known circuit and a milliamp meter in the collector of the transistor match them to the same currents. Wish I had space to draw you a diagram as everybody should do this. But if using a PNP then you should know that to turn it on in the circuit it requires a negative bias. So the emitter goes to the positive of the battery through a 22 K resistor the collector goes to a milliamp meter and then to the negative of the battery. Select a resistor 20 K or so, from the negative of the battery to the base you should get a reading on the meter. Match them all to about the same reading for current 2 to 5% will be fine. On the NPN you would do it reverse. I did this when I did not have a curve tracer. Maybe someone could draw this and post it.
John B

[Rl2003]

GT3 Mini v2

Thanks for the help John,
I will match some in the morning.
I did play with the timing some more, and got the transistors to cool
off some. I can now hold them for a while before I need to let go.
Before they where much to hot to hold.
I am not sure I have the right cap yet although. It gets up to around 16-17v
and just hovers around that.
I am able to put a slight load on the wheel as it spins an keep up the momentum,
and I plan to test the amp draw soon, just to see where
we are at.
Mark P.

Mark P,
Most meters have a Beta tester on them. If not you can do it by hooking a transistor in a known circuit and a milliamp meter in the collector of the transistor match them to the same currents. Wish I had space to draw you a diagram as everybody should do this. But if using a PNP then you should know that to turn it on in the circuit it requires a negative bias. So the emitter goes to the positive of the battery through a 22 K resistor the collector goes to a milliamp meter and then to the negative of the battery. Select a resistor 20 K or so, from the negative of the battery to the base you should get a reading on the meter. Match them all to about the same reading for current 2 to 5% will be fine. On the NPN you would do it reverse. I did this when I did not have a curve tracer. Maybe someone could draw this and post it.
John B

[John_K]

Bedini 3GT

Hi Ren,

Looking good mate! I'll try the pot in series with the 220R when I'm up and running again. I imagine a 500R 1W pot would do there?

Happy Australia Day!


John K.

Hi John K and David.

I got my device up and running last night. Its built using what I have laying around so its not up to 3gt spec. But it is the half circuit, triggered by a hall. Im running on 24v, 200-300ma, 8 pole rotor 500mm in diameter.

Coil is 6 filar, each strand 0.9mm @ 2.1ohms per strand. I presently have it running with 4 strands in parallel. I had some heat in my circuit, particularly the PNP and I got rid of most of it by adding a rheostat off the 220 ohms which was discussed before. Even with the rheostat at its lowest setting (effectively adding very little if any resistance) the heat generated is considerably less, barely warm to the touch now. Tweaking this resistance lowers the input current even more. Not that there is much current here when its up to speed anyway.

Charges a 2200uF cap up pretty fast, still have to build the discharge circuit.

Took a little time to get the hall in the right place. I couldnt figure out why it would work then get slower and slower and eventually stop. I eventually found that there was a spacer missing, so the timing disc on the shaft would slowly get further and further away from the hall, eventually switching off altogether. When I have made up the spacer for it I will post a vid.

Regards

[John_Bedini]

Bedini GT3

Ren,
Good looking happy to see it working, Great job. Hope you guys are nowhere the floods as I have been watching that on a special report.
Great Job.
John B

[John_K]

Bedini 3GT

Hi Mark P.,

Nice video, thanks for sharing.

I was able to get the RPM down by increasing the gap between the coils and the rotor magnets.

If the cap is not dumping and you are using the SCR/Zener/LED method it could mean that gate voltage is not high enough to trigger the SCR. But if that is the case it doesn't explain why the battery is charging.

Great looking setup!


John K.

Ok, I've finally made a video that I said I would. I just had a little trouble with
my video recorder, so I am using my phone for now. It's short because it takes
forever to upload a larger file.

I did flip the two led's and to the opposite direction and this worked. But only
one blinks, and only when the cap is not in the circut. I am letting it run for a
couple hours to see what heppens to the sec. battery. It was almost dead...

My transisitors are getting hot and I am in the process of matching some.
I have been looking on the internet on how to do this, as I have never matched
the Beta of transistors before. If any one can introduce me to a simple way to
do this I would be thankful, other wise I will make a test circuit to do this.

YouTube - VIDEO0008.3gp

Mark P.

[John_Bedini]

Bedini GT3

John K
Motor running on Iron Pyrite Battery New setup.
YouTube - Iron-Less Monopole Motor Runs On updated Iron Pyrite Battery 2
John B

[wrench76]

beta test circuit

John B, nice Flintstone battery
very cool!
Is this right?

[nvisser]

My transisitors are getting hot and I am in the process of matching some.
Mark P.

I did not test on 24V yet, but could I suggest that you insert an ammeter on the input supply and monitor that while adjusting the hall timing. If the dwell gets too long, meaning the hall is positioned in the middle of the round ceramic, the circuit can easily draw over 1A from 12V and that will heat up the transistors if you leave it like that.
Vissie

[ren]

Hi Ren,

Looking good mate! I'll try the pot in series with the 220R when I'm up and running again. I imagine a 500R 1W pot would do there?

Happy Australia Day!


John K.

I used 1k 20w because its what I had. 500R should do nicely.
Happy Australia Day right back at ya, Im being very un-Australian and working so have some for me.

Regards

[ren]

Ren,
Good looking happy to see it working, Great job. Hope you guys are nowhere the floods as I have been watching that on a special report.
Great Job.
John B

Thanks John.

Ill post a video soon.

Funny (well, more like lucky) story about the floods up in Queensland, my daughter was up at a +2000 kids pathfinder camp (like scouts) in Toowoomba, QLD for 5 days. The day after she came back the inland "tsunami" wiped out their campsite

needless to say, we were a little shaken when we saw the McDonalds she had eaten at the day before 6 feet underwater on the tv...

Regards

[John_K]

Hi John B,

Great work, that's awesome!

Is the magnesium under the paper towel a disc or magnesium tape? Maybe you could shoot a quick video of ti if you get some time? Also, where do you get the calcium chloride crystals from? Wikipedia says it is used for lots of things, so it looks pretty easy to get.

Calcium chloride - Wikipedia, the free encyclopedia

I'm heading off to the crystal shop over the weekend to pick up some Iron Pyrite to give this a go and see if I can replicate this.

I did get a something similar working last night, running off a couple of AA NiMh cells. I used that wind trigger rotor we made up a couple of years ago at your shop, the Monopole one with 8 poles. I had it running really nice once I had the reed in the right position. At first I used just the reed, but the reed would stick from the spikes pretty quick. So I used a transistor just like you did and also collected the spikes into a second battery - worked great! I was using an old relay solenoid from a 70's pinball machine, 800 turns of #26 on a 1" x 1" bobbin and an air core.

I'm also going to try the Zero Force Motor setup using this type of switching to see what I get.

Thanks for sharing!


John K.

P.S. No floods where I am, although the river that is 200 yards behind us did get to a 30 year high, rising halfway up the bank by about 20 feet. Sad for the farmers, we just came out of a 10 year drought and now their crops are ruined by the floods - which insurance won't pay for. No surprises there!

John K
Motor running on Iron Pyrite Battery New setup.
YouTube - Iron-Less Monopole Motor Runs On updated Iron Pyrite Battery 2
John B

[Rl2003]

GT3 Mini v2

Thanks Wrench76,
I going to match some now.

Mark P.