Bedini Ferris Wheel Regauging Motor

[RS_]

Make certain that you have the face of the hall, facing the magnets, make certain what face the magnets have out, With all N 's out, and a small super pole S field squeezing out inbetween the N out magnets, will trigger the Hall just the same as all south pole magnets out, but acting inverse of the S out magnets

[RS_]

ED.

Add the 22ohm matched resistors, from the base of each MJL21193 to the 470ohm and 220ohm connection, and from each MJL21194 base to MJE2955 collector and 470ohm connection, as shown on John K. 's posted SCH

I don't know about using the single diode vs a bridge, as i have always used the bridge as shown in the patent, this is John K's development.....

RS

[BrentA929]

Confused

John K and RS,

Ok, now I'm really confused.

The MJE2955 (PNP) is what we have tried and it was still reversed. What else could cause that? Bad transistor maybe!

Thanks, Brent

[Ecancanvas]

can you make up a schematic

Hey RS
can you post a schematic of how your adding the R22 to the multi MJL. are you just adding them to the base? Why dont you want to use a bridge? to slow?
Thanks for the help
ED

[RS_]

Les,

Yes, a single strand per transistor SSG, up to 48 strands on my big machine.....

But the Idea of using a Base current divider network is the same, if it's a tranny per strand, or several trannys in parallel hooked directly to several parallel strands, as to keeping one of the tranny bases from hogging all the base current

The difference that JB indicates as i understand it, is that the 1 strand per tranny setup, will pull far more current, than having several trannys in parallel, hooked directly to several parallel strands setup, for an equal number of strands / trannys.

RS

[Les_K]

RS,
My Bad I am using a MJ2955 not a 8599 or MJE2955.

I am fascinated by the base current divider network I still don't see enough resistors in John B's video to account for that either....
your 8 and 16 strand coils were not paralleled though, Were they? didn't you have a single transistor for each strand?

The reason I am taking so much interest in this area is because I am just starting to get a grasp of something JB said about Ron Coles circuits that inductors in parallel didn't increase current through the circuit like you would think. and it drove the engineers nuts. So I am just trying to understand what is happening at that point when the impedance of the coil is matched. I am guessing but this must be a very low impedance coil with a very low inductive reactance and it must run at no more than about 28 RPM (16 *28 = 448/60 = 7.46 HZ) to hit resonance. and if you are not there then your CE current will be very low. And now that I have said all that I realize clearly why Scott has the only coil with the right impedance. And perhaps why my circuit is not manifesting the same heating problems....
However, I have noticed that as I have been running the machine for short periods of about 5 minutes each over the last few days I have seen the 94's get warm sometimes and then the 93's the next time. This went back and forth for a few days and today they all run cold to the touch. no heat anywhere in any of the circuit. None! but it runs the same. the input current draw has not changed. and the output is the same. the scope is the same....
Do these transistors beta self adjust? mmmmm

Teach me more

Les

Oh P.S. All my coils are in repulsion. I tested them one at a time on the battery before connecting them together and hooking up the circuit.

Les,

Using very small value resistors on the emitters is good for tuning the current to be equal through each of the parallel transistors, and if needed could be done on the Bedini/ Cole circuit. The Base resistors current divider network on parallel transistors, are so that no one tranny can hog all the base current for some reasion or another. Not quite the samething......

JB instructed me to do this Base current divider network, when I was building 8 and 16 strand SSG coil Driver circuits with the MJL's......

Is The window motor driver a muilty parallel transistor driver like this one, or single Bedini /Cole Driver...?

>>>"In the end the goal is to get the MJL's fully switched on without wasting excess current through the base. "

I agree, but go look at the Base current (Continuous) on the MJL Data sheet at 5 Amps DC, and then multiply by 4 parallel Tranny's

They need far more current to turn on fully, than the MPS8599 at 250ma can provide.......

RS

[RS_]

Brent, Scott,

Your Hall Sw part number, is a south pole activated , active Low output, that turns on the PNP , that turns on the MJL's , and is a correct operational circuit.... So, make sure you have the south pole out, on your timing wheel magnets.......

other wise, put the BD677A NPN darlington you mentioned elsewhere, in place of the MPS8599, and use the MPS8599 as a inverter base driver for the BD677A from the Hall Sw to get the Hall over the magnets and coil on condition.....

RS

[John_K]

John K,

Thanks for the clarity...

That is what RS is suggesting too and seems to make more since. You may have already made the adjustment on your schematic, but your last revision shows a PNP (MJE2955) instead of a NPN for the hall section. The post near the beginning of the thread and your schematic is where we have started to create the circuitry.

Also, is the bottom of the coil suppose to connect to the MJL21194 and the top of the coil to the MJL21193 transistors? That's how we have it now.

Also, thanks for clearing up the polarity on the halls. Ours is a ATS137-PL-A-A. I think that was one JB had mentioned.


Thanks as always, Brent

Hi Brent,

No , the PNP (MJE2955) is correct. If you are using an NPN there that is possibly why your coils are on when they should be off and vice versa.

Yes, the top of the coil goes to the 93's and the bottom goes to the 94's. This will give you a North pole on the top of the coil when it is on, which pushes away the North facing magnet on the rotor.

The ATS137 is also what I have ordered. They should be here any day now. Some wire arrived yesterday, so I expect the rest of the parts won't be far away. As soon as they turn up I can come and play in the sandpit with you guys.

I've attached an updated schematic, in the previous the zener on the cap dump was backwards.


John K.

[BrentA929]

Hall sensor

John K,

Thanks for the clarity...

That is what RS is suggesting too and seems to make more since. You may have already made the adjustment on your schematic, but your last revision shows a PNP (MJE2955) instead of a NPN for the hall section. The post near the beginning of the thread and your schematic is where we have started to create the circuitry.

Also, is the bottom of the coil suppose to connect to the MJL21194 and the top of the coil to the MJL21193 transistors? That's how we have it now.

Also, thanks for clearing up the polarity on the halls. Ours is a ATS137-PL-A-A. I think that was one JB had mentioned.


Thanks as always, Brent

Hi Scott,

The coils are supposed to energize when the hall is over the magnet, not the other way around. Most halls use a South pole to trigger it, you may want to check the datasheet for the one you are using to be sure. Make sure you are using a unipolar hall and not a bipolar.

Feel free to PM me or email john_koorn at yahoo dot com dot au about the side project.


John K.

[John_K]

Are the coils supposed to be energized when the hall is over the magnet or the reverse? The way we have it right now, when the hall is over (using this term loosely) the magnet the coil switches off. Also, are we correct to use the south pole of the magnet for the hall switching? Do you recommend using the north?

EDIT: @John K. You may be interested in one of our little side projects involving a Renaissance Charge Rejuvenator. I can PM you the details if you're interested.

Hi Scott,

The coils are supposed to energize when the hall is over the magnet, not the other way around. Most halls use a South pole to trigger it, you may want to check the datasheet for the one you are using to be sure. Make sure you are using a unipolar hall and not a bipolar.

Feel free to PM me or email john_koorn at yahoo dot com dot au about the side project.


John K.

[RS_]

Les,

Using very small value resistors on the emitters is good for tuning the current to be equal through each of the parallel transistors, and if needed could be done on the Bedini/ Cole circuit. The Base resistors current divider network on parallel transistors, are so that no one tranny can hog all the base current for some reasion or another. Not quite the samething......

JB instructed me to do this Base current divider network, when I was building 8 and 16 strand SSG coil Driver circuits with the MJL's......

Is The window motor driver a muilty parallel transistor driver like this one, or single Bedini /Cole Driver...?

>>>"In the end the goal is to get the MJL's fully switched on without wasting excess current through the base. "

I agree, but go look at the Base current (Continuous) on the MJL Data sheet at 5 Amps DC, and then multiply by 4 parallel Tranny's

They need far more current to turn on fully, than the MPS8599 at 250ma can provide.......

RS

[genessc]

[I would also ditch the FWBR and replace it with a single STPS8H100D, which is a 8A 100V Shottky rectifier diode. Make sure the positive of the cap goes to the cathode of the diode. It only has a 0.7V forward voltage drop and switches real fast. ]

You know, putting up to 4 in parallel will lower that drop to about .4V... same concept as paralleling anything else... drops the overall resistance. Or at least thats what it looks like on the diode measurement from the DVM. Should be pretty straight forward to personally verify.

Just fyi.
Gene

[Les_K]

Scott, Brent,

It's Looking good......

Looking at your SCH, i have several recommendations, based on my work with Muilty Strand SSG's, etc.... and i think JB will agree with these.

The MPS8599 at 250ma Collector current, is too small to effectively drive the Bases on muilty MJL transistors. and a NPN is needed here so that you have the Coils ON when the Hall is over the magnet. if you have a BD243C transistor, it should work in place of the MPS8599, If it needs it, use a MPS size tranny to drive the base of the BD243C so that the Hall can handle the current.

Use a 22ohm resistor on each of the bases of the MJL transistors, as a current divider network, so that none of the trannys can hog all the current. Use your ohm meter to select a matched value set of 22ohm base resistors.

Hope this helps, and if ya'll need Help, Let me know, and I will come up to see you......

RS

RS,
I am using an MJ8599 that goes to a 680ohm resistor in place of the 220.
Still have two 470 ohm resistors at each base of the MJL's I get about 3 amps through the coils if I hold the wheel so the hall is steady on I should test the coils directly to the battereis and so how close this is. My coils are not the same so this may make the difference in the circuit but it looks like the MJL's are fully on and the 8599 never even get's warm just stays cold. I am not using any zener's on the front end like John K. As I am only running at 24 volts right now. And I only have three sets of matching MJL's right now.
Anyway As I was thinking about your change to the base resistors, and looking at the video John B. posted showing the high RPM window motor you can freeze the frame and see there are only a couple resistors inside the box. Unless there are some underneath the circuit board, but he is not one to build that way. I was always taught that you needed to add resistors to the emitter side to get feedback to the base to balance paralleled transistors but it looks like nobody is doing that.
In the end the goal is to get the MJL's fully switched on without wasting excess current through the base. So I am very, Very... interested in hearing more about what you folks do with the circuit so please post here as you go if possible.

Thanks
Les

[txaggie00]

Hope this helps, and if ya'll need Help, Let me know, and I will come up to see you......

RS

RS,

Good to hear from you! It's funny, b/c last night, Brent and I were talking about shooting you an email to ask if you could come give us a hand and see the setup! We certainly appreciate the offer! Thanks for your suggestions as well. Brent's out picking up some parts now, and we are working on setting up another timing wheel. I'll shoot you an email and maybe we can figure out a good time and whatever is most convenient for you.

Thanks,
Scott

[RS_]

Scott, Brent,

It's Looking good......

Looking at your SCH, i have several recommendations, based on my work with Muilty Strand SSG's, etc.... and i think JB will agree with these.

The MPS8599 at 250ma Collector current, is too small to effectively drive the Bases on muilty MJL transistors. and a NPN is needed here so that you have the Coils ON when the Hall is over the magnet. if you have a BD243C transistor, it should work in place of the MPS8599, If it needs it, use a MPS size tranny to drive the base of the BD243C so that the Hall can handle the current.

Use a 22ohm resistor on each of the bases of the MJL transistors, as a current divider network, so that none of the trannys can hog all the current. Use your ohm meter to select a matched value set of 22ohm base resistors.

Hope this helps, and if ya'll need Help, Let me know, and I will come up to see you......

RS