10 coil machine

[Howard Wetsman]

A little more on my refurbished 10 coiler:
Still having trouble adding pictures.
Have replaced all the wiring with 10AWG wire and added a bank of switches and a larger pot.
I started retesting each coil after installing the #10 wires and noticed that in spite of all the coils firing at the same time they don't all fire the same.
For instance I have different peak voltages on my spikes measured on my scope with 10x leads:
coil 1: 50v
coil 2: 55v
coil 3: 55v
4: 60v
5: 60v
6: 60 v
7: 66v
8: 64v
9: 60v
10: 60v

And I tested at a fixed resistance for which coils when added actually increased RPMs and found that 4 of the coils actually slow the machine down (2,3,5, 9) so I'll have to pull those and do some more testing. On a good note, I had to change to a 215AH charging bank for the testing because I was filling my 25AH bank up too fast.

[John_Koorn]

Hi Howard,

I'm not sure that is a method where you can confidently say that your coils are different. In my experience the spike voltage jumps all over the place and unless you have a really fast scope you won't get an accurate measurement. Analog scopes will generally show it better as I think digital scopes will average the measurement over a number of samples.

The spike voltage will also vary depending on the state of both primary and charge batteries.

I think the best way to match the coils is with a milli-ohm meter and make sure your magnet to coil gap is exactly the same for all coils.

If you have switches on each of the boards you can run just the master coil and one of the slave coils at a time to determine if the coil and supporting board are all working correctly. You could even go down to one transistor at a time by disconnecting the other coils from their transistors.

John K.

[knagtegl]

John K.

It is nice to have switches on every circuit but every time you switch on an extra transistor you also change the situation at the triggercoil
because it has to deliver more energy for switching this extra transistor. How do you solve that problem?

Karel

[Howard Wetsman]

Hi Howard,


If you have switches on each of the boards you can run just the master coil and one of the slave coils at a time to determine if the coil and supporting board are all working correctly. You could even go down to one transistor at a time by disconnecting the other coils from their transistors.

John K.

Thanks John,
That's what I did and noted which slave added the most in RPM to the master coil. I then added that one as the second and did the whole thing again to see which 2nd slave added the most RPM as the third coil. I repeated that until I got six coils going and the other 4 all lowered RPM. Last night I adjusted the coil magnet gap on those 4 and noted that 2 of them now worked to increase RPM. So I went from 6 coils at 475 RPM pulling 3570mA to 8 coils at 502 RPM pulling 2940mA. Still have the last two to work on. Charging nicely I think. I will be rechecking the transistors on those two boards and all the connections.
thanks
h

[John_Koorn]

John K.

It is nice to have switches on every circuit but every time you switch on an extra transistor you also change the situation at the triggercoil
because it has to deliver more energy for switching this extra transistor. How do you solve that problem?

Karel

Hi Karel,

You are absolutely correct. My point was only for diagnosing faults. Once Howard has all 10 coils running correctly I would recommend to him that the switches are removed - the problem he is seeing could even be caused by a faulty 10 cent switch. JB never had switches on his multi-coil machines, no doubt for a good reason. I think you need to run the machine with all 10 coils or not at all, the switches were a silly idea on that kit in the first place. When I was experimenting with a friends 10 coiler kit I removed them all to remove any possibly that a cheap switch could be affecting the results.

Actually I found exactly what you are talking about. If I tried to run it with some coils switched off it ran like a pig until I switched them all on. Much better to have just one "holy crap" switch on the primary negative.

The whole machine must be tuned as one. This is why multi-coil machines are so hard to do. It would be much easier to have a single 80 strand coil than ten 8 strand coils. Also a lot easier to diagnose a faulty transistor.

John K.

[John_Koorn]

Thanks John,
That's what I did and noted which slave added the most in RPM to the master coil. I then added that one as the second and did the whole thing again to see which 2nd slave added the most RPM as the third coil. I repeated that until I got six coils going and the other 4 all lowered RPM. Last night I adjusted the coil magnet gap on those 4 and noted that 2 of them now worked to increase RPM. So I went from 6 coils at 475 RPM pulling 3570mA to 8 coils at 502 RPM pulling 2940mA. Still have the last two to work on. Charging nicely I think. I will be rechecking the transistors on those two boards and all the connections.
thanks
h

Hi Howard, it sounds like you are making progress. What I would do is just run the master coil with one of the slave coils at a time and note the RPM and draw current. You will need to adjust the master base resistor to get the most RPM. Once you have it tuned you now have a baseline to work from.
Then disconnect the slave (remove the coil wires from the board) and connect up the next slave coil. Keep doing this until you have tested all of the slave coils individually. The idea is to get all the slave coils running the same. Once you're happy that they all run the same connect all 9 slave coils together and re-tune the master base resistor. I'd remove all the individual switches and just have a main switch in case you have to kill the power in a hurry.

John K.

[knagtegl]

John,

Thanks for your comment, I had put the multicoil machine away for a while because it made me mad. The head is biting the tail so to speak. Everything has a influence on everything. If the speed is going up the triggercoil generates more power en thereby changing the the parameters again.
After doing a lot of experimenting I do see some new possibilities for the machine but you are right one big coil is way easier and better than a multicoil machine
but even than you can have problems with more transistors but it is a wonderfull learning experiance.

Karel

[Howard Wetsman]

Thanks John, I didn't remove the coil wires when I did that before. I'll do it again.
thanks for the advice.
h

[Howard Wetsman]

10 Coil

John,
In preparation to follow your suggestion I decided to measure the resistance from the trigger lead to the pot to the attachment at the board. The ohmmeter didn't settle down even waiting 3 minutes but continued to oscillate. The following are the ranges of resistance that I found at each board:
Board 1 - 16.5-16.9
2 - 16.7-17.0
3 - 16.5-16.9
4 - 16.5-16.9
5 - 16.5-16.9
6 - 16.5-17.1
7 - 16.5-16.8
8 - 16.7-17.0
9 - 16.5-17.0
10 - 16.6-17.0

Any suggestions on how to proceed? Could this be the source of the unevenness?
h

[Howard Wetsman]

John,
another question. I've got the switched attached to an inductive loop from the pot so as to decrease variability of resistance between the different leads. How do you have the ten wires coming from the pot to the boards so that they all have the same distance from the pot. I thought about a buss bar but they'd be variable distances from the attachment to the pot and that would change the resistance.
How does one solve that?
h

[Howard Wetsman]

10 Coil Machine

John,
another question. I've got the switched attached to an inductive loop from the pot so as to decrease variability of resistance between the different leads. How do you have the ten wires coming from the pot to the boards so that they all have the same distance from the pot. I thought about a buss bar but they'd be variable distances from the attachment to the pot and that would change the resistance.
How does one solve that?
h

I've heard recent concerns about 1:1 charging and I've had my machine sort of mothballed for the winter. I want to report a recent run I did after turning it back on for the "season." My charge bank and run bank are both made up of two identical 6v 215AH golf cart batteries connected together to give me 12v banks. The mechanical system is described in the posts above. I had done one previous "warm up" run prior to this and before that everything had been dormant for a few months.

At the start my primary was at 13.55 having just come off the charger and the charging bank was at 12.72 having had 1 AH taken out of it and been left sitting for a week. I ran the system for 1.48 hours at an average primary draw of 4.4A for a total of 6.52 AH. After 2 hours of resting the primary was at 12.63 and the charge bank was at 12.90. I then took 1AH out of the charge bank by running a 4A load for 15 minutes. After that the primary was still at its resting 12.63 and the charge bank was down to 12.28. I then started another run calculating AH every minute given average primary draw over .0167 hours (one minute). I stopped the run at .9968 AH in.
One hour later the primary stood at 12.61 and the charge bank stood at 12.92.

It seems to me that I started with a charge bank at 12.9, took out 1AH, pub back in 1AH and had a charge bank of 12.92. I think I have at least 1:1 charging without resorting to any of the kinetic energy expended. If others feel differently, I will certainly listen to procedural critique.
h

[Brodie Gwilliam]

howard have you ever tried advancing the trigger coil on a machine that big?

[Howard Wetsman]

howard have you ever tried advancing the trigger coil on a machine that big?

Not sure what you mean Brodie. Closer to the magnets?
h

[Brodie Gwilliam]

no moving it sideways so the magnet passes over the coil at a different time than your other coils, if repulsion mode you would want to move it after and attraction mode before..... you can just move it over say 1 inch(either way it shouldnt matter) and then your wheel will only want to spin one way... but it should increase rpm.... base tuning may need to be done after

[Howard Wetsman]

I did have that on my smaller machine but really didn't see any benefit to doing it. Maybe I didn't do it right. Advancing the coil on this machine, if I remember correctly, (I'm not in front of it at the moment) would be difficult as I have everything screwed into place in the plexyglass. But I'm open to it. I really just wanted to say that 1:1 was possible. Someone had asked on another thread if anyone had done it. Certainly others have, and more, but I just wanted to add my voice.
h