5 filar specs

[Rob_Esq]

Hi Rob_Esq

My 2c of newbie help, (you need to re-post your circuit diagram so that we can see what is going on and not speculate, cause this will just frustrate you even more)

Maybe your new styrofoam wheel does not have enough momentum ?
Theuns

Hi Theuns. Can you not see the photo of the circuit in my previous post, or do you mean that the photo is not clear enough? (I can add some clearer photos of the circuit if it helps.) Both of my previous wheel builds were bicycle wheels, and had the same phenomena: high resistance = high rpm / low resistance = low rpm.

What effect do you think that low momentum would have on performance? The wheel is actually quite heavy because it has a lot of magnet in it, but it has a very low free spin time. This is compensated for by lack of drag - the wheel is fast and efficient.

Rob

[Prinsloo]

Rob_Esq

Yes I can now see the the photo's,

Do you mean higher resistance (on the pot) = less amp draw on the meter from the primary, or is it the other way round ?

When you start your wheel, how many times do you get the peak amps go-up and drop back on the meter as the wheel picks up speed? I think you need just that little more amps to push it over to the next (gear) with a bit more amp draw to get to the higher volts on the secondary.

Do you know of any one else that built a styrofoam wheel that is working fine?, Maybe on this one Gurus can chime in on this one.

Theuns

[Prinsloo]

Hi Theuns,

I just meant did you ohm all your solder joints with an ohmmeter. As I'm soldering my board I'll check each connection with an ohmmeter to make sure it's a good joint. Then after it's done I'll go through the board again just to double check, as the board is out and it's easy to do.

A poor joint would have high resistance and an ohmmeter would show this. Right now you're using 22 ohm resistors and it sounds like the resistance is still too high, so you might have a bad joint, or something that's adding resistance to the trigger circuit in addition to the resistors. That's what sounds most likely to me at any rate.

Especially check that you got all the insulation off the magnet wire where you soldered it. I scrape it with a utility knife and then sand it after that. You'll see the color change and you can see the fresh copper of the wire so you know you got it all off. Then put your ohmmeter on both ends of the magnet wire and ohm your coil to make sure the insulation is all off and you have good connections at both ends.

You can't go much lower than 22 ohms on the resistors, and if it doesn't even move at 100 ohms it sounds like it's not even close to being tuned, so I don't think a lower resistor is going to do it. I'd really be looking for extra resistance somewhere that shouldn't be there.

Good luck!

Robert

Hi Robert

Thanks for the advice I did the resistance test and found 1 coil wire not connected and 1 of the base resistor wires was a dry connection. We test it further this weekend.

Theuns

[alfinip2000]

Prinsloo,if i were you..ill try to make as close as possible to JB spec..ive been adventrous and make ssg from wheel to wood.duff transistor etc...what igeve found is the closer to jb spec..the better the result(also save more money ) as long as you can learn nothing to loose then..cheers
Alfin

[Rob_Esq]

Rob_Esq

Yes I can now see the the photo's,

Do you mean higher resistance (on the pot) = less amp draw on the meter from the primary, or is it the other way round ?

When you start your wheel, how many times do you get the peak amps go-up and drop back on the meter as the wheel picks up speed? I think you need just that little more amps to push it over to the next (gear) with a bit more amp draw to get to the higher volts on the secondary.

Do you know of any one else that built a styrofoam wheel that is working fine?, Maybe on this one Gurus can chime in on this one.

Theuns

Hi Theuns.

Here is a graph of my pot vs. primary draw, with RPM, and number of gear shifts up to full speed. (This is with a gap of about 2.5 - 3.00mm on the coil - no doubt it wld be a lot different with a different gap.) Quick answer to your question: Yes, I mean higher resistance on Pot equals less draw on primary battery, plus higher RPM.



As you can see the ratio of RPM to primary draw is over 3x greater at maximum resistance, than it is at minimum. Can you see why I'm having problems tuning it .. going from these figures, how else would you adjust it, other than at full resistance?

[Robert Darrah]

Hi Rob,

I think the final arbiter as far as tuning goes is what kind of cop you get from a particular tuning. It's a laborious method, but you could try different tunings and see which gives you the best cop.

If you get a scope this will help you a lot. You need a good "h" wave with no extra triggering going on and the scope will show you that. With my ssg I started getting double triggering just around and above 600 ohms so I had to keep my resistance below that. Anything higher and I would get one or more spikes between my "h"s and that's not good, so the scope showed me the max resistance that was useable.

Looking at your chart, around the 700 ohm range the amp draws look about right, so I don't think you're that far off. Both charging and primary amps do increase as base resistance increases, so I think your amp draws look ok. It's the rpms that don't make any sense to me. I could adjust from 200 ohms up to 800 ohms and my rpms were 152 at 200 ohms and 147 at 800 ohms and they stayed in that range all the way through. I didn't get the wild increase that you're getting.

The way I see it you have 2 different issues. One is that you need to tune it and two is the strange rpm increase. I think you could separate the two issues, meaning forget about the rpms for now and just work on the tuning. Going by what my ssg would do, I think if you can charge a battery in 40 hours (what size battery do you have?) and it's somewhere around 700 ohms then the tuning isn't too far off.

If you're on the mp3 group I'd also suggest looking in the files section at other people's builds. That's what I'd do if I had questions. I'd try to find people that had a build similar to mine and see what results they got and where their sweet spots were. There was a wide variation in results between different builds and you can learn a lot from that.

If you were using a bike wheel and everything was per specs then it would seem your results should be similar. But if you're getting this huge increase in rpms and nobody else is, then something about your build is different. So if something is different you should be able to look at the original instructions and see what about your build is different, and hopefully that will point you to why your rpms increase like that.

Robert

[Michael Luton]

Hi Theuns. Can you not see the photo of the circuit in my previous post, or do you mean that the photo is not clear enough? (I can add some clearer photos of the circuit if it helps.) Both of my previous wheel builds were bicycle wheels, and had the same phenomena: high resistance = high rpm / low resistance = low rpm.

What effect do you think that low momentum would have on performance? The wheel is actually quite heavy because it has a lot of magnet in it, but it has a very low free spin time. This is compensated for by lack of drag - the wheel is fast and efficient.

Rob

The circuit schematic that you are using is not available, and the pictures of your circuit are not clear enough. It appears as if your trigger is connected to the collector and the only thing connected to the base is the diode.

[Rob_Esq]

Hi Rob,

I think the final arbiter as far as tuning goes is what kind of cop you get from a particular tuning. It's a laborious method, but you could try different tunings and see which gives you the best cop.

If you get a scope this will help you a lot. You need a good "h" wave with no extra triggering going on and the scope will show you that. With my ssg I started getting double triggering just around and above 600 ohms so I had to keep my resistance below that. Anything higher and I would get one or more spikes between my "h"s and that's not good, so the scope showed me the max resistance that was useable.

Looking at your chart, around the 700 ohm range the amp draws look about right, so I don't think you're that far off. Both charging and primary amps do increase as base resistance increases, so I think your amp draws look ok. It's the rpms that don't make any sense to me. I could adjust from 200 ohms up to 800 ohms and my rpms were 152 at 200 ohms and 147 at 800 ohms and they stayed in that range all the way through. I didn't get the wild increase that you're getting.

The way I see it you have 2 different issues. One is that you need to tune it and two is the strange rpm increase. I think you could separate the two issues, meaning forget about the rpms for now and just work on the tuning. Going by what my ssg would do, I think if you can charge a battery in 40 hours (what size battery do you have?) and it's somewhere around 700 ohms then the tuning isn't too far off.

If you're on the mp3 group I'd also suggest looking in the files section at other people's builds. That's what I'd do if I had questions. I'd try to find people that had a build similar to mine and see what results they got and where their sweet spots were. There was a wide variation in results between different builds and you can learn a lot from that.

If you were using a bike wheel and everything was per specs then it would seem your results should be similar. But if you're getting this huge increase in rpms and nobody else is, then something about your build is different. So if something is different you should be able to look at the original instructions and see what about your build is different, and hopefully that will point you to why your rpms increase like that.

Robert

Hi Robert. Yes, I'm on the verge of buying my first scope, so hopefully I'll have a better idea what's going on in the near future. Separating out the tuning and rpm issue is a good strategy, assuming they're unconnected issues, which I'm not sure they are, especially given the (relative) simplicity of the system. Lacking any other strategy however, I'll take your advice. I'm currently charging a 6Ah SLA (motorcycle) battery. The annoying thing is that in a previous build, before the 'improvements', I was able to charge up to 14.5V in 40hrs.

I must admit that somewhere along the line, with all this tinkering, I've lost track of how many winds are on the coil. It looks less than the specified 850 - I think I'll rewind the coil again as my next move, and check this is to spec. First I'll give it a whirl at 700 ohms though and see how this goes.

Thanks for the advice .. Rob

[Robert Darrah]

Hi Rob,

Sometimes when the theory doesn't work and the troubleshooting skills just aren't cutting it, then you're down to your last resort, which is to be a parts changer. I've done it on my car at times when I just couldn't diagnose the problem, so I'd just try new parts until I found the problem. The ssg circuit is pretty simple and inexpensive, so maybe just solder up a new board and pop it in and see what happens. Or a different coil.

My electrical teacher used to look with scorn on parts changer. "If you're not a troubleshooter then you're just a damn parts changer!" Works for me!

Robert

[Rob_Esq]

Hi Rob,

If you get a scope this will help you a lot. You need a good "h" wave with no extra triggering going on and the scope will show you that. With my ssg I started getting double triggering just around and above 600 ohms so I had to keep my resistance below that. Anything higher and I would get one or more spikes between my "h"s and that's not good, so the scope showed me the max resistance that was useable.

Robert

Hi again. I finally bought myself a scope, and have got it up and running.


Here are some screenshots at 1,000 ohm and zero ohms on the pot. As you can see, its not an 'h' wave - its more of an 'n' wave. For some reason its not spiking. The scope shows a rise of between 25-30V. I tried this at various different resistances, and also with a different gap size between the wheel and electromagnet, and on each attempt the result was the same: 25-30V. This explains why I'm unable to charge above about 13.5V, this question is though, why isn't my SSG spiking?

I was curious to know why the neon is lighting when the battery is disconnected, if its only achieving about 30V. This third scope screenshot shows a test I did with the battery disconnected. This was at a very low rpm, straight after starting it,since I did not want to damage my components. What I think this is showing is 5 spikes per magnet. The scope's display is at a different resolution here, and the spikes are actually at 60V, compared with the 30V max with the battery connected.

I'd really appreciate it if anybody could give me some insight into why its not spiking when the battery is connected.

Rob

[Rob_Esq]

The circuit schematic that you are using is not available, and the pictures of your circuit are not clear enough. It appears as if your trigger is connected to the collector and the only thing connected to the base is the diode.

Hi Michael, sorry for the delay in responding - a 7 month old baby makes it difficult to get anything done. The schematic is the standard monopole SSG circuit as shown:



Here are a couple of photos of my setup:



These shots are taken with the circuit disconnected from the coils and the battery:
- The middle pin (collector) is fed from the bottom of the power coil, and feeds the positive of the charging battery via the diode;
- The left hand pin (base) feeds from the top of the trigger coil, and links to the emitter via the small diode;
- The emitter returns to the negative of the power battery, and also the bottom end of the trigger coil.

Its not the prettiest circuit ever, but I'm pretty sure it follows the schematic. Rob

[Rob_Esq]

The circuit schematic that you are using is not available, and the pictures of your circuit are not clear enough. It appears as if your trigger is connected to the collector and the only thing connected to the base is the diode.

Hi Michael, sorry for the delay in responding - a 7 month old baby makes it difficult to get anything done. The schematic is the standard monopole SSG circuit as shown:



Here are a couple of photos of my setup:



These shots are taken with the circuit disconnected from the coils and the battery:
- The middle pin (collector) is fed from the bottom of the power coil, and feeds the positive of the charging battery via the diode;
- The left hand pin (base) feeds from the top of the trigger coil, and links to the emitter via the small diode;
- The emitter returns to the negative of the power battery, and also the bottom end of the trigger coil.

Its not the prettiest circuit ever, but I'm pretty sure it follows the schematic. Rob

[Michael Luton]

Rob. Understand the 7 mo old. Yes it appears to be correctly connected. Where were the scope shots taken at? For now the main points you need to look at are the transistor collector and base. With everything else tried you may want to consider the polarity of your coil. If possible swap the bottom leads from the coil with the top leads and see if it will run at all and if so, is there an improvement.

[Robert Darrah]

Hi Rob,

The way I understand it is the spike you're not seeing in the wave is when the coil collapses and the radiant spike comes in, which explains why the battery isn't charging very high. I'm wondering if there isn't some kind of high resistance short in the coil that only shorts out when there is high voltage and it's shorting out the coil and bleeding off the radiant spike.

Did you check the coil for turn to turn shorts or shorts between windings? You might need a megger if it's a high resistance short. If you use a megger make sure you completely disconnect all leads on the coil!!!! You don't want to fry the electronics.

On your scope shot when you were turning it by hand, right, you've got about 5 pulses per magnet pass. That's normal to get extra pulses at slow speeds. You'll get fewer pulses as the rotor speeds up, until you just have an h wave when it's up to speed.

That's normal, so it's the missing spike of the radiant that's the problem. It seems like either the coil isn't being fully energized for some reason, or the spike is being shorted somewhere.

You've got the R60 1/16" rods in the core, right? Have you tried different batteries, just to be sure that's not it? Did you get all the insulation off the magnet wire? I scrape it with a utility knife and sand it until it's shiny copper. A high resistance connection might keep the coil from fully energizing, so you don't get as much radiant coming in when the field collapses.

You know, those crimp connectors might be the problem. I've had them come off enough times when I thought they were on solid. There might be a high resistance connection in one of those. You might try soldering everything instead. Good luck.

Robert

[Rob_Esq]

Hi all. Thanks for you advice over the last couple of weeks about improving my charging, and voltage spikes. As it happens I've now moved on from this bifilar coil and single transistor circuit. I had an 8 filer coil which I wound a few weeks ago, sitting about doing nothing, and the temptation was too much. So I've now got this set up (on a temporary bread board for now) and firing on 7 transistors.

I'm getting spikes around about 57V with this. They're still not as high as I hoped, plus the gradient looks pretty poor as well. The voltage in the battery is rising very fast, then levelling out at about 14.45V (give or take depending how I have it tuned in). I still don't think I have this totally cracked, but its certainly an improvement on before. I'm going to start some proper COP tests today and I'm excited to see how it compares with the previous builds. I'll be posting questions on other threads over the next few days, as I still have lots of questions about voltage spiking, and how this effects the battery charging.

I never did get to the bottom of why I was only getting 30V 'spikes' on my 850 bifiliar coil. My best guess at the moment is because the wheel magnets are too close together, meaning that the coil did not have time to energise properly. This doesn't explain why the spikes increased to 60V when I disconnected the charging battery though. I also never got to the bottom of why I was seeing such large RPM increases, or why my wheel was accelerating as I increased the resistance on the pot (contrary to what seems to happen to every one else).

Anyway, onwards and upwards ... Rob