Hot Coil Electromagnet

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Peterae

Re: Hot Coil Electromagnet « Reply #125 on: 2012-08-20, 20:04:16 »

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Hey ION
No waste of time, there's never a waste of time with anything we enjoy experimenting with, as you say we learn all the time, even if this turns out to be a dead end, who knows that we wont learn something that is crucial to understand and use as information when we build one of our next devices, i have learned so much lately, transistor sine wave oscillator, class A amps, and now heating elements i am having a great time and i thankyou for the encouragement for this.
I always try to post all my work for a couple of reasons, so that people know and can learn from my mistakes, yes most of what i do ends up not being unfinished or not working properly but i look at each item as a stepping stone to the future.

Very few share or really join in on builds and i feel it a privilege to be able to work as long side you and some of the others that do help.

I Just hope i have the wire identified correctly now you have bought some wire also

EMdevices

Re: Hot Coil Electromagnet « Reply #126 on: 2012-08-21, 00:12:37 »

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Quote from: ION on 2012-08-20, 14:04:59

Unfortunately I had the preconcieved notion that all infra red heaters were wound with a variation of Nichrome containing small amounts of iron, not enough to account for the "effect".

While I had heard of Kanthal A1, I had no good reason to believe it was being used in infra red heaters.

It was Peterae's discovery of the heater wire with high iron content that now dispels any chance that the effect is something special.

I formally apologize to anyone's time I may have wasted on this investigation.

On the flip side, I have learned a lot about many of the wire alloys and how they react under high currents, so it was not a waste of time for me.

I have also ordered a heater core made of Kanthal A1 to confirm my error.

This exercise also gave me the incentive to go through and inventory some of the many spools of wire I do have on my experimental shelf, Manganin, Karma, Alloy 11, Contantan, Chromel etc. Too bad I had no Kanthal A1 or this would have been put to bed many posts ago.

When I have some time, I would like to investigate some of these in a slightly different way, by winding the wires into a core, and overwinding with a fixed number of copper winds like a toroidal inductor in order to determine magnetic effects of the alloys.

I will continue to investigate the "effect", because like a child, I am in wonderment and who knows what can be learned or discovered.

For me it has been fruitful and educational.

Ion, you're doing a good job, basic science, and "basic" in this context is meant to mean VALUABLE.

but you are not done yet,

I would like to know if the main voltage spikes, at the zero crossing, are actually many fast Barkhausen spikes, which only appear to be one spike due to the time base setting of the oscilloscope. So, if you wanted to investigate this, trigger off of the spiky wavform, with a ONE SHOT setting, and set the trigger level so only those spikes trip it, and than set the time base to the nano second or micro second range and see if you can resolve the one spike into many shorter spikes. If you can resolve it into many spikes, it is clear we are seeing Barkhausen noise, like I predicted. And since I predicted it, it must be true! LOL

EM

Peterae	Re: Hot Coil Electromagnet « Reply #127 on: 2012-08-21, 08:54:26 »
Group: Administrator Hero Member Posts: 3975	We have a very interesting mix of metals here. Aluminium forms a thick oxide coating around the exterior of the Kanthal wire. I think MOS we also have 0.8% carbon this is enough carbon to make our iron into steel, causing grain boundary anomalies, at elevated temperatures the strength of a grain is stronger than the grain boundary, at lower temperatures the strength of a grain boundary is greater than the strength of a grain this is called "equi-cohesive temperature." then we have manganese which is paramagnetic A mixture of manganese and aluminium at low levels increases resistance against corrosion due to the formation of grains absorbing impurities which would lead to galvanic corrosion And then we have Chromium, The strengthening effect of forming stable metal carbides at the grain boundaries and the strong increase in corrosion resistance made chromium an important alloying material for steel. And again we now have the ability to form Silicon Carbide or as we know in the electronics business SIC I personally would say we have so much going on with this wire anything could be happening

exnihiloest

Re: Hot Coil Electromagnet « Reply #128 on: 2012-08-21, 09:50:32 »

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I observe that the pulses appear as soon as the current flows. So the heat is not their cause. I'm convinced we would still have the effect if the wire was cooled, for example in water.

The idea of new possible effects of a "hot" coil, which was interesting and led to the observation of the pulses, becomes now misleading.

The effect looks rather like magnetic saturations due to the current through undefined or not well identified components of the metal, with sharp transitions inducing strong dB/dt. We can use the temperature to change the conditions but it is not indispensable.

What do you think?

Peterae	Re: Hot Coil Electromagnet « Reply #129 on: 2012-08-21, 10:58:37 »
Group: Administrator Hero Member Posts: 3975	Quote I observe that the pulses appear as soon as the current flows. So the heat is not their cause Maybe i misunderstand what you are saying, but we know the effect stops when hot and that the effect is always there when cold and therefore surely we already know the heat is not what causes the effect and quiet the opposite. We know that once a certain temperature is reached the effect stops, and this temperature maybe quiet interesting to measure i personally would be expecting around 600 Degree's C, but if it's a lot lower then things will be really interesting because it maybe then something to do with a semiconducting layer. There's something very interesting about zero crossing as well, i noticed a big red sign when i worked on the Romero motor that said investigate me(unfortunately i have only just realized this DOH) Anyone remember that at zero crossing with the magnet on the rotor i was getting loads of spikes on my pick up coil, they were only just noticeable.I will try to dig the appropriate video out where did that noise come from i wonder.I will append the video here when i find it OK found it, i put this down to switching transients, but hang on, why would i be picking switching transients up on a rotor coil that is being driven by a magnet when the coil that drives is nothing to do with the coil i am scoping,maybe this is barkhausen noise [youtube]http://www.youtube.com/watch?v=XEhJkiOqOBw&feature=plcp[/youtube] « Last Edit: 2012-08-21, 11:26:19 by Peterae »

ion

Re: Hot Coil Electromagnet « Reply #130 on: 2012-08-21, 15:13:22 »

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It's turtles all the way down

Agreed Peterae, from the level of the spikes shown in your video they indeed look like Barkhousen noise, assuming of course there were no other switching transients taking place in your Romero motor.

You also have brought up many good points regarding the metallurgical properties of the wire we have been testing.

When you and I get the Kanthal A1 heaters in we will have some interesting tests to perform.

I might note that my Martel heater core was highly oxidized.

I noticed in my stock I have some copper clad steel wire. The copper has a thin oxide coating (dull brown).

This might be interesting to play with. Remember SM said he had good results with some "old" wire.

Also remember the patent of the guy (escapes me) who extolled the virtues of the oxide coating.

---------------------------

"Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy

Grumpy

Re: Hot Coil Electromagnet « Reply #131 on: 2012-08-21, 15:31:49 »

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tExB=qr

Was it Barbat?

ion	Re: Hot Coil Electromagnet « Reply #132 on: 2012-08-21, 15:49:25 »
Group: Elite Hero Member Posts: 3537 It's turtles all the way down	Quote from: Grumpy on 2012-08-21, 15:31:49 Was it Barbat? Yes it was G, thanks for that. --------------------------- "Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy

Peterae	Re: Hot Coil Electromagnet « Reply #133 on: 2012-08-21, 15:51:47 »
Group: Administrator Hero Member Posts: 3975	Right on ION, i have an infra red thermometer to point at it Quote Remember SM said he had good results with some "old" wire. wow forgot about that one, where did that quote come from, the reason i ask is that if we are even close to the first principle of the tpu's operation then there's a lot wrong with stuff we have been told, and in this case this statement was correct so it maybe worth looking up what else he said at the same time just in case there's more, as i suspect some stuff is BS but some is not. Quote I noticed in my stock I have some copper clad steel wire. The copper has a thin oxide coating (dull brown). Indeed, years ago in the UK the whole telephone system relied on twisted wire connections, hard to believe really LOL, the insulation is first stripped off and then literally both wires were twisted together and a cap was crimped over the top to seal it, well every now and then you would start getting radio stations playing down the phone LOL, offcourse this is because of the poor old wire coating had oxidezed and had formed a semiconducting layer DOH. Interestingly he did not state copper to be the old wire, and i remember some mention about iron wire, even the wire from an old heating element would count Quote When you and I get the Kanthal A1 heaters in we will have some interesting tests to perform. I not counting my chickens yet LOL but yes if this is indeed the correct wire we can start having some fun indeed

ion	Re: Hot Coil Electromagnet « Reply #134 on: 2012-08-21, 16:13:22 »
Group: Elite Hero Member Posts: 3537 It's turtles all the way down	From SM: Quote By the way, something strange is that, once I made a unit with some old corroded wire for the collector and it worked very well for it's size. Quote Now, electrons can travel only so fast along the surface of the wire because of magnetic flux. what if you disable the effects of the flux? Now the electrons float freely without anything holding them back. electrons at the sped of light are now a possibility Quote Speed of the electrons across the surface of the wire is part of the key in my conversion process. Some good clues when considered from the point of view of surface effects as in the Barbat patent. --------------------------- "Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy

Peterae	Re: Hot Coil Electromagnet « Reply #135 on: 2012-08-21, 16:56:54 »
Group: Administrator Hero Member Posts: 3975	Wow thanks ION It all seems to fit but i guess we could probably say that for a lot of instances. Quote disable the effects of the flux So we have AC current, and at our zero crossing point have we in effect disabled the effects of the flux? One minuet we have positive flux then we have zero flux then we have negative flux, notice we have the pulse each time, even when we go from positive to negative flux and also negative to positive flux, i would say we get the pulse each time the flux is zero

Peterae	Re: Hot Coil Electromagnet « Reply #136 on: 2012-08-21, 17:00:25 »
Group: Administrator Hero Member Posts: 3975	Now i am going into la la land Imagine that all iron wire was to do this but in varying amounts and it just so happens that you stumbled on a wire type that even SM did not know of, but SM worked out that by injecting a harmonic of a certain frequency or even maybe 2 different harmonics that this made the pulse appear in other types of wire how amazing would that be. I cannot wait to find out the effect of the speed at which we cross the zero point I cannot but help think there's a way to make that thermionic rectifier valve exhibit the same zero crossing kick you have, maybe time will tell me how to do this. « Last Edit: 2012-08-21, 21:23:04 by Peterae »

exnihiloest	Re: Hot Coil Electromagnet « Reply #137 on: 2012-08-22, 07:29:23 »
Group: Guest	Quote from: Peterae on 2012-08-21, 10:58:37 Maybe i misunderstand what you are saying, but we know the effect stops when hot and that the effect is always there when cold and therefore surely we already know the heat is not what causes the effect and quiet the opposite. ... You have well understood, it is what I said. Regarding the subject of the thread, I just wanted clarify what we handle: magnetic effects in resistive wires, not specially in hot coils.

exnihiloest	Re: Hot Coil Electromagnet « Reply #138 on: 2012-08-22, 08:06:16 »
Group: Guest	In my heater, the wire was brilliant. There was no apparent oxide before I run tests without the fan, and so the too hot temperature oxidized the wire which became gray. But I noticed the pulse effect before the wire was oxidized and no difference after. I don't believe in a surface effect.

Peterae	Re: Hot Coil Electromagnet « Reply #139 on: 2012-08-22, 08:07:21 »
Group: Administrator Hero Member Posts: 3975	Ah OK ex yes, i am sorry for the thread title we sort of veered offcourse when ION stumbled on the anomalous pulse using his heating wire. Maybe i should re title the thread, if we can verify the correct wire type then maybe call the thread Kanthal anomalous pulse during AC current flow. OR Even split the thread into 2

Peterae	Re: Hot Coil Electromagnet « Reply #140 on: 2012-08-22, 08:10:12 »
Group: Administrator Hero Member Posts: 3975	Quote But I noticed the pulse effect before the wire was oxidized and no difference after. That's good data and another thing ruled out thanks ex. can i ask does your wire exhibit a strong magnetic attraction.

exnihiloest	Re: Hot Coil Electromagnet « Reply #141 on: 2012-08-23, 09:30:37 »
Group: Guest	Quote from: Peterae on 2012-08-22, 08:10:12 ... can i ask does your wire exhibit a strong magnetic attraction. Yes it does. The wire is wound as star branches around an insulated disk. A branch is flexible, it bends strongly towards a neodymium magnet and sticks to it. I think the effect is less strong but not far from that of an iron wire.

Peterae	Re: Hot Coil Electromagnet « Reply #142 on: 2012-08-23, 10:58:07 »
Group: Administrator Hero Member Posts: 3975	Cheers ex Still waiting on the slow boat from Hong Kong

exnihiloest	Re: Hot Coil Electromagnet « Reply #143 on: 2012-08-24, 11:23:50 »
Group: Guest	I have put a diode in series with the heater (YG912S6 fast, low loss, 600v 10a). The goal was to see if the phenomenon still occurs when there is no current reverse. The result is strange. Here is the signal from my coil probe: I can't explain this shape. Perhaps an effect of sharp transition in the diode? It doesn't depend on the voltage that I could change with a variac. There is probably a high-pass filter effect because my coil impedance is not high enough. An idea? ------------------------ Hot Coil Electromagnet HeatingWireRect.jpg (23.7 kB, 547x318 - viewed 1043 times.) HeatingWireRect.mp3 (183.63 kB - downloaded 411 times.)

GibbsHelmholtz	Re: Hot Coil Electromagnet « Reply #144 on: 2012-08-24, 13:23:41 »
Group: Guest	Exn, Can you superimpose the current and pick up coil waveform like ION? I did it by hand but not sure if it resembled. ------------------------ Hot Coil Electromagnet Simpose.jpg (14.14 kB, 680x384 - viewed 611 times.)

ion	Re: Hot Coil Electromagnet « Reply #145 on: 2012-08-24, 14:26:43 »
Group: Elite Hero Member Posts: 3537 It's turtles all the way down	Ex Yes it looks like the diode switch-off causes the ringing oscillatory pulse, similar to a flyback effect. The ringing frequency will be a function of distributed capacitance of the wiring, diode capacitance, stored energy and impedance of the wire inductance. You can expand the scope timebase to examine the ringing frequency. This shows stored energy in the system from the content of iron in the wire which increases the value of inductance. Also the slower changing descending waveform does seem to coincide with the positive half of the pulsating DC. The current waveform would be helpful but will be very slightly lagged from the voltage input. Perhaps just use the input voltage as a phase reference. It is a bit difficult to explain the minor wiggles on the slow descending waveform and the flat spot around the middle. The flat spot could be the diode forward drop when current changes direction at the peak of the half cycle. --------------------------- "Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy

exnihiloest	Re: Hot Coil Electromagnet « Reply #146 on: 2012-08-24, 18:09:04 »
Group: Guest	Quote from: GibbsHelmholtz on 2012-08-24, 13:23:41 ... Can you superimpose the current and pick up coil waveform like ION? I did it by hand but not sure if it resembled. @gh @ion I can't monitor the current and the coil probe signal in the same time, because I need the two probes of the oscilloscope to monitor the current in differential mode. Nevertheless your surimposition is correct, replacing the trace of current by voltage that I have monitored. The voltage should be in phase with the current, because the heating wire is wound in order to minimize the inductance. Maybe there is only a slight delay between the zero crossing point of the sine, and the following transient of the signal. Not clear on my trace. Quote from: ION on 2012-08-24, 14:26:43 Ex Yes it looks like the diode switch-off causes the ringing oscillatory pulse, similar to a flyback effect. The ringing frequency will be a function of distributed capacitance of the wiring, diode capacitance, stored energy and impedance of the wire inductance. You can expand the scope timebase to examine the ringing frequency. This shows stored energy in the system from the content of iron in the wire which increases the value of inductance. Also the slower changing descending waveform does seem to coincide with the positive half of the pulsating DC. The current waveform would be helpful but will be very slightly lagged from the voltage input. Perhaps just use the input voltage as a phase reference. It is a bit difficult to explain the minor wiggles on the slow descending waveform and the flat spot around the middle. The flat spot could be the diode forward drop when current changes direction at the peak of the half cycle. I agree. And my measurement circuit can also add ringing: not only this from the inductance/capacitance of the coil probe, but also from a transformer that I use to insulate the measurement side from the mains. But why is there a so high rising transient just after the zero crossing, while the input is still not far from zero? It is not a possible flyback effect because at this instant, the diode becomes conducting.

ion	Re: Hot Coil Electromagnet « Reply #147 on: 2012-08-24, 23:05:03 »
Group: Elite Hero Member Posts: 3537 It's turtles all the way down	exn said: Quote But why is there a so high rising transient just after the zero crossing, while the input is still not far from zero? It is not a possible flyback effect because at this instant, the diode becomes conducting. I would think the diode is conducting in the forward direction during the positive half cycle and turns off or blocks shortly after the zero cross unless there is considerable inductance. In the latter case, current, not voltage must go to zero for the diode to turn off. If possible sketch your circuit , then we can see if your measuring transformer is also supplying some inductance. --------------------------- "Secrecy, secret societies and secret groups have always been repugnant to a free and open society"......John F Kennedy

GibbsHelmholtz	Re: Hot Coil Electromagnet « Reply #148 on: 2012-08-25, 13:43:34 »
Group: Guest	Quote from: exnihiloest on 2012-08-24, 18:09:04 ... But why is there a so high rising transient just after the zero crossing, while the input is still not far from zero? It is not a possible flyback effect because at this instant, the diode becomes conducting. I also like to see it as a domain avalanche effect. The domain is like a mass spring system. When it is in neutral position(no current), it moves fast. This creates high dB/dt. If there is no hysteresis losses, it would move back and forth and ringing forever like a fly wheel after input is removed.

Peterae	Re: Hot Coil Electromagnet « Reply #149 on: 2012-08-30, 18:40:21 »
Group: Administrator Hero Member Posts: 3975	My Kantanal Heating element arrived today and i can confirm it is indeed the correct alloy to show the pulse. I am using a relay coil with iron core as a pickup, towards the end i pull it away from the heating element because things are starting to heat up [youtube]http://www.youtube.com/watch?v=5envi-zRB1E&feature=youtu.be[/youtube]