Coil Ringing - Good/Bad?

[BobZilla]

I have been experimenting with various solid state setups and I have a question about coil ringing or humming. I have noticed that when I apply certain resistances on the trigger the coils will sing "EEEEeeeeee" A high pitch squeal type of sound. Different resistance values will produce different pitches. The tone will also vary depending on what is connected on the charge side.

I do not have a o-scope so a lot of what I am doing is just guess work as to what is happening. I am curious what the ringing could be indicating and the various tones. For example does it mean I have some resonance between the load and the coil, or am I over driving the circuit with too much current? Does it indicate anything at all? I do get good charging under this condition but I also know it is a fine line between taking advantage of the radiant spike and just brute force charging with the current.

Can anyone out there help me understand what this ringing is actually telling me? I would be happy to post more details about the setup if that would help. Thanks

[Tom C]

Bob,

in solid state mode the circuit "runs" at a much higher frequency than with a rotored version. you are hearing a physical manifestation in the wires of the frequency the coil is oscillating at. it is literally resonating the coil, those oscillations are creating a pressure gradient arount the coil, I.E. the on/off of the coil is creating sound waves you can hear. the nyquist frequency for most human ears is 20 Khz, as a sine wave. For Dogs its somewhere btween 60-100 Khz .other wave shapes can be heard by humans at higher frequencies. I can hear sawtooth shaped waves to 30 Khz. so the higher the pitch the higher the frequency the circuit is running at. if you were to record that, drop it into some decent recording software, it would tell you exactly what frequency you are running at. electrosensitivity is also a side effect of this for some people. they cant hear the circuit running but it gives them headaches and nausea....

Tom C

[BobZilla]

Tom that makes perfect sense to me. Thanks for such a thorough response. I forgot to mention that I mostly use air coils and as I understand it they will oscillate at much higher frequency. I still wonder though if I am over driving the circuit. Do you drive coils to singing too? On one of my setups I get a very distinct tone when I use 3k ohm on the trigger with 12 volt primary. The coil is two strands 21/22 and 75 feet. I will post some pictures on the next reply.

I would love to try recording some examples for you to check out. I have several setups all of which sing when given the right resistance. The larger setup pulls about 950ma when it starts to sing and has 18awg wire. That is charging 75AH deep cell but I have used it all the way down to little AA's with the resistance set real high.

It may take me a few days to get it done but I will try to record some samples. I happen to have a microphone kit for my drums and it has various kinds of mics for up close or full room etc. I will have to see if any of them can record it decent. I bet when I start that the sky opens up and strikes me into the void heh. The key to free energy is blast your coil sound through an amplifier ,,;-) heh ... I'll post back when I get some pics and the recordings.

[marshallrw]

Its been my experience that when that noise is going on, your resistance is too high. The air coils provide a higher oscillation, but not doesn't necessarily make the device run more efficiently. It seems as though the run battery dies quicker than the charge battery. There's a point when that ringing stops, you should try turning the resistance down till the noise stops then measure your input/charge batteries.

[Tom C]

Tom that makes perfect sense to me. Thanks for such a thorough response. I forgot to mention that I mostly use air coils and as I understand it they will oscillate at much higher frequency. I still wonder though if I am over driving the circuit. Do you drive coils to singing too? On one of my setups I get a very distinct tone when I use 3k ohm on the trigger with 12 volt primary. The coil is two strands 21/22 and 75 feet. I will post some pictures on the next reply.

I would love to try recording some examples for you to check out. I have several setups all of which sing when given the right resistance. The larger setup pulls about 950ma when it starts to sing and has 18awg wire. That is charging 75AH deep cell but I have used it all the way down to little AA's with the resistance set real high.

It may take me a few days to get it done but I will try to record some samples. I happen to have a microphone kit for my drums and it has various kinds of mics for up close or full room etc. I will have to see if any of them can record it decent. I bet when I start that the sky opens up and strikes me into the void heh. The key to free energy is blast your coil sound through an amplifier ,,;-) heh ... I'll post back when I get some pics and the recordings.

nah dont worry about the recordings, what you should do is wind a bigger coil, it will slow down a bit and give you better charging, the coil will store more potential that way. try thicker wire also. you wont be able to charge big batts with your current setup.

do you have the audix mic pack, the kick drum mic in that setup is awesome. I played for years, till carpel tunnel caught up with me. . 69 ludwig blue marine pearl. zildjian and Gibralter and yamaha hardware. now i just do live sound mostly.


Tom C

[BobZilla]

Thanks for the input guys. That coil I mentioned is my tiny one. I use that little setup for small loads like 10AH, 5AH, and 9 volts for my meters etc.

For larger loads 75AH and up I have a setup with 2 strands 200ft 18awg and 200ft 21awg for the trigger. That device has a pot on it so I can get a large sweep through various freq. It will sing too when I have just the right resistance set.

I am kind of thinking that pushing it up that high is not helpful but it's all guess work. I have the larger machine in a branch diode configuration and usually charge two 75 AH from one 75AH but I would say I am not getting a good full charge in the end. After a rest of at least an hour the charge side will rest to 12.4 or so, sometimes a little better and sometimes a little less. They are starting their charge from about 11.75 resting. I run them down under load with about 1.5 amp until they read 10.5 under load then they bounce back to 11.75 or so with load removed. That is when they get re-charged. I feel like I am almost there but not quite. I can easily get a one to one out of it but that is not really accomplishing much.

As I said I have a pot on there so I do try at different draws from the primary. Typically I will pull at about 900ma, sometimes up to 1a. I let it run until the primary is reading 11 volts under load and then stop.

For coils I have generally been trying to use size and length that comes out to be around 1.2ohm. My next phase of experimenting is going to lead me into using longer lengths. I am thinking about increasing my ohm's to maybe 3 or so and compare the performance. That is why I like working with the smaller design, less footage to achieve the target coil resistance. It all gets pretty confusing when you read what others report and especially those with o-scopes. I was under the impression that to long of a coil will lead to to many spikes or some kind of phase issue. I don't know, I just keep trying things out for myself and try to improve as I go.



Off topic but since you asked here is my setup for my drums. I know what you mean Tom. I don't play as much but I still mess around here at home once and awhile. I almost got Ludwig when I purchased this set, always loved Bonham's sound.

7 piece PDP X7 maple series. Silver/black fade sparkle
X7 Series - PDP Pacific Drums & Percussion


Zildjian ZBT series cymbals 16&18 crash, 20 ride, 14HH
ZBT Drumset Cymbals

Ludwig stands, Pearl HH pedal stand.

CAD 7 touring Mic set
CAD Audio - The Brand Used by Professionals!

Tascam US-2000
Product: US-2000 | TASCAM

[longhorn]

Bob,

in solid state mode the circuit "runs" at a much higher frequency than with a rotored version. you are hearing a physical manifestation in the wires of the frequency the coil is oscillating at. it is literally resonating the coil, those oscillations are creating a pressure gradient arount the coil, I.E. the on/off of the coil is creating sound waves you can hear. the nyquist frequency for most human ears is 20 Khz, as a sine wave. For Dogs its somewhere btween 60-100 Khz .other wave shapes can be heard by humans at higher frequencies. I can hear sawtooth shaped waves to 30 Khz. so the higher the pitch the higher the frequency the circuit is running at. if you were to record that, drop it into some decent recording software, it would tell you exactly what frequency you are running at. electrosensitivity is also a side effect of this for some people. they cant hear the circuit running but it gives them headaches and nausea....

Tom C

Tom C.

So am I to understand that an oscillating coil that is audibly resonating is a good thing? If it is my coil is a ringing humdinger.

Not to mention that it is creating microwaves providing me with a nice red shift for a maximum Doppler effect.

longhorn

[Tom C]

Tom C.

So am I to understand that an oscillating coil that is audibly resonating is a good thing? If it is my coil is a ringing humdinger.

Not to mention that it is creating microwaves providing me with a nice red shift for a maximum Doppler effect.

longhorn

I do not know if its good or bad, you feeling sick? if I could hear it it would drive me crazy.....

Tom C

[PetersonElectric]

I have just built my first motor, and while experimenting i stumbled upon the self oscillation. What i have noticed is that when the frequency is increased (higher pitch) the amplitude of the radiant spikes decrease along with the input amperage and oppositely the lower the frequency the higher the amplitude of the spikes and higher input amperage. making the most efficient spot for charging batteries at the very point were the motor self oscillates. but i was curious, would a high frequency low amplitude would be useful for any tasks? and if anyone has also noticed this and found any use of different frequencies?
Thanks

[BobZilla]

Hi Peterson,
I have a bit more experience with this now so I can comment a little more on it. I would agree with what you said about the draw changing at higher and lower freq. I now tune my machines to intentionally produce the ringing, I have found that it is indeed a good thing. The trick though is that your charge side battery must be able to handle the load. If it cannot than you will quickly get heat buildup either on the coil or the transistor.

For example if I were to tune a run with a 75AH battery on the charge and had the coil singing at a certain freq and everything was looking good, meaning good charging, no heat etc. this would be fine. If I were to change that battery to say a 10AH and keep the machine basically at the same setting with the same ring I would quickly have a problem with over heating.

The idea is going to be to design your setup with the load in mind, specifically the coil size. You can charge smaller batteries with a larger coil but only if you do not push the coil so hard that it is ringing (if it rings on large batteries with no issue). So if you need to charge different size batteries with the same machine, design it to ring on the large ones and you can always turn it down with a pot for smaller ones or use a 3way switch with different (higher) resistance on one throw for smaller stuff.

If you have a pot on your trigger you can find sweet spots in the ringing range. I have a setup that when I dial it in to ringing it will pull around 1.5A, then if I decrease the resistance slowly It will climb, 1.6, 1.7 like that BUT you will see a spot where it will drop backwards,, go back to 1.6, 1.5 even though you are still decreasing resistance. That is what many call a sweet spot. You can observe this on a mechanical system quite easily but for solid state it is a bit harder to find.

So more in line with your question, I do not concentrate to much on a high pitch or a low pitch. I look for a sweet spot, usually the second one, yes there are a few to be found. Then at that point I do pay attention to the tone and I use that as a reference for myself to keep in the sweet spot. See as the primary voltage goes down you need to adjust the resistance (decrease) to hold the same freq or draw however you look at it. So once I am in the sweet spot I can hear it drop out of the sweet spot by listening to the tone. Usually I am running in a lower tone and it will jump high when it falls out of the spot but not always. Different machines behave differently and the load battery will affect it too but these are some general observations than may help---Bob

[PetersonElectric]

hello Bob,
I have found, while watching the oscilloscope, that the point of the circuit first starting to oscillate is the spot that charges the battery fastest, I presume because the frequency is much higher than with the rotor, but also the amplitude potential of the spikes are still very high. And at this point it is still drawing about half of what it would with the rotor. I'm not sure if this is the same sweet spot as yours, and the one you have been describing, but this is what i have noticed. I haven't experienced any overheating issues yet either, but that is probably because i have been using the same batteries.

Also i have notice that when charging and object, what ever it is, the tone increases as the object charges, so I predict that the rate of charging decreases as the battery (or whatever) gets charged more, like a logarithmic graph, probably until the circuit stops oscillating when the object is fully charged. and this maybe could be counteracted by changing the resistance periodically.
I was curious if my predictions are correct and if you have noticed anything similar to this.

[BobZilla]

Hi Peterson,
I would agree with your statement about the spikes at the first oscillation. I am at a disadvantage because I do not have an O-scope. I would say this; it is only guessing so don't take it as fact. The reason is that at that point you are getting a good crisp pulse across the coil, not over saturation. The way these systems work is too get the voltage across the coil but we don't want the current to move(well as little as possible), and then rapidly switch it off. The collapsing field pulls in the radiant so if we go too hard or too fast we do not get a good collapse before the next cycle and that makes the spike weaker and in extreme cases heat buildup. I have been playing with a large setup and I think I may be having this very issue, not the heat but I may be trying to drive it too hard with current and hurting the spike..

On the second point I have observed the tone increasing. I have experimented with putting a cap across the pot and a diode on the way to the base which is Patricks (Min2oly) mod by the way not mine. If done with the right values you get a very nice trigger pulse. While experimenting with that I used big caps & small caps. If you take an AM radio and dial it in to a dead spot you can listen to your circuit this way. At one point I put two 160uf 330v flash-caps in parallel across the trigger and with the radio I could really hear them wind up. The tone started very low and climbed higher, higher, higher, then the cap dumped and it started over again. I don't know if this is the same as you are referring too but it immediately came to mind when you mentioned it.

There are many others here on the forum with MUCH more experience than myself. Perhaps some of them will chime in. Keep tinkering and share your results with us in the meanwhile. It's nice to see someone like yourself coming to discuss these things. ---Bob

[PetersonElectric]

Thank you Bob, yes my next plan is to make a larger device, specifically designed for self oscillation and do more extensive testing with that, and post my findings with that