Vibrating Ferrites Provide DC output

[Grumpy]

EM sent my this and I thought it was pretty cool:

https://www.youtube.com/watch?v=dkcggzRIFnY

Part 2:

https://www.youtube.com/watch?v=71vtcl-G4dw

[Smudge]

The ferrite rings don't vibrate.  The stack of rings simply form an elongated toroidal transformer core.  The system is just a transformer with a single turn input (the internal metal cylinder) and a single turn output (the thing he places inside the cylinder) and of course the external circuitry provides the closed paths.  He drives it from an alternating high impedance current source.  When the cylinder is slid out from the core it no longer has much inductance (because there is no ferrite around it) so the only voltage across it is tiny resistive voltage drop.  When inside the core it acts like a single turn and you get induced voltage across it if the external circuit through load or voltmeter completes that turn.  Sorry if this sounds like a teacher to pupil lecture .

Smudge

[BEP]

Look into it a little deeper and you'll see that it has little to do with transformer action.

It is said that there is no such thing as a voltage drop across an inductor. This is true when applied voltage and resulting current are at a steady state (barring resistance of the conductor).

However, there is a voltage drop across and inductor when the applied voltage and resulting current are changing. The ferrite cores around the conductive tube makes for a higher inductance (higher possible voltage drop). Enough to light the LEDS.

The LEDS don't light when reversed because they are also diodes and the signal applied to the conductive tube would be pulsed DC.

The LEDS also work off of the inserted rod/nail/etc. because that inserted conductor becomes the secondary of a one-one turn transformer with both conductors having a higher inductance because of the ferrites.

Ohm's law dictates that the current going through that core will be extremely high - but only for very short periods.

I agree that vibration is not an important part of the device.

There is a variation on this which replaces the ferrites with coils. The results are a bit different. One even lights a 20W 12VDC auto bulb quite brightly.

>>Edit

Just so folks can search for the operating principle.... This is basically a simple 'delay line oscillator'. The frequency and output voltage can be controlled by adding a a bias winding through the ferrites wound in a conventional manner. Applying a bias current to this added winding will control the effect the cores have upon the conductor core.

[Allcanadian]

Nice video's, I like these kinds of experiments because they are somewhat disturbing for both the novice and expert alike. Oh I understand there is an easy common sense explanation however that does not change the fact that when we look at the device everyone without exception thinks....I did not expect that.

When we think about it this explains most of the history of science doesn't it?. We make certain assumption concerning the way we think things should work and then when we have creative thoughts or do something out of the ordinary something may happen which we didn't expect.  In fact we could go far as to say everything we ever wanted to know may be obvious and common sense, it may be staring us in the face however we have simply failed to connect the right dots in the correct order.

Who knew simply moving an airflow over a wing would enable us to fly, who knew simply connecting transistors in the correct sequence forming logic gates would enable the modern computer, who knew a thin filament of glass, fiber optics, would enable global communications in real time which few could imagine?.  Why we could even go far as to say the "unexpected" is our future, oh it was right in front of us the whole time and it was perfectly reasonable however we made false assumptions and simply failed to connect the right dots in the right order.

I think this circuit may simply be a low voltage variation on Tesla hairpin circuit effects, the impedance created by the ferrite cores causes energy to accumulate in that region increasing induction not unlike Tesla's high voltage nodes. Simple enough however that does not change the fact that everyone who saw this thought... I didn't expect that , I didn't think it was possible, I never thought of that. Why we could say all of the incredibly impossible things we will see in the future may be defined by a single statement.... I never thought of that?.

AC

[BEP]

AC,

I'll agree with most of your post above but this circuit isn't anything special. I really don't see how it compares to a hair-pin device. The term 'resonance' can barely be applied to this circuit. It may be a little out of the ordinary for some but is well known by folks familiar with passive delay lines and other similar devices.

I think what may confuse matters is the conductor is the core and any voltage drop across it would be assumed to be almost nothing because of the low resistance.

It is the old problem where folks always seem to think in terms of D.C. Hams see it all the time because their antenna circuits appear to be shorted circuits but really aren't.

One thing that is unique about it is the lack of reciprocal coupling when you use windings instead of ferrite toroids.

[Centraflow]

Magnetic loop more than a delay line

regards

G6GVA 

[e2matrix]

I built one like this a couple years ago - at least I think it was the same setup but used a copper pipe with a split all the way along a side.  Very cool to see the LED's light up across nails, screwdrivers etc.   I just used a signal generator for the input.   People over at OU were saying it's nothing but basic transformer.   I like WaveWather's explanation here.   The one I built was based on a youtube from a Russian guy - same basic thing as seen in these videos.   The guy doesn't really show a close up of the tube or the other side to show a split all the way down one edge but I think it may be necessary.

[BEP]

I built one like this a couple years ago - at least I think it was the same setup but used a copper pipe with a split all the way along a side.  Very cool to see the LED's light up across nails, screwdrivers etc.   I just used a signal generator for the input.   People over at OU were saying it's nothing but basic transformer.   I like WaveWather's explanation here.   The one I built was based on a youtube from a Russian guy - same basic thing as seen in these videos.   The guy doesn't really show a close up of the tube or the other side to show a split all the way down one edge but I think it may be necessary.

The 'split' you mentioned could mean yours was acting as a transformer. It depends on the construction details. The split isn't required for this one. Neither, is a tube. The core conductor could be a solid rod or a single small wire as long as it is encased in something ferrous or a coil carrying current.

Think about how adding a ferrite bead around a conductor helps filter noise traveling down that conductor. If you used such a configuration to work as a filter (common practice) you could measure that noise as a voltage drop between the entrance and exit of that ferrite bead. He uses LEDs to indicate the voltage drop of the oscillator's 'noise' between the inlet and outlet of the filtering ferrite toroids.

This is portrayed as something unusual but it isn't. Only the application is unusual.

Notice how applying a magnet to the ferrites disables the effect. When you saturate the ferrites they can't improve the reactance of the conductive core and therefore, cannot cause a higher voltage drop across the conductor.

The folks thinking this example is just a basic transformer need to ask themselves a question .... What is a transformer with only one winding -or- multiple windings all shorted together? Answer: it is not a transformer. It is a simple choke or basic inductor.

[Allcanadian]

@Wavewatcher

I'll agree with most of your post above but this circuit isn't anything special. I really don't see how it compares to a hair-pin device. The term 'resonance' can barely be applied to this circuit. It may be a little out of the ordinary for some but is well known by folks familiar with passive delay lines and other similar devices.

I think it is more important to the understand fundamental principals rather than textbook examples or known effects because when we understand the how and why of things then the extraordinary may seem quite ordinary.

The circuit in question uses the ferrite toroids to increase the impedence across the short length of conductor which increases the potential difference across it which is why the LED lights. We could simply replace the short conductor and ferrite toroids with a simple resistor to replace the impedance and achieve basically the same effect. It is not a question of AC or DC or resonance or noise, it is a question of the rate of change per unit length of conductor.

Tesla's hairpin circuit used a high voltage with a very high rate of change, not the frequency persay but how fast the voltage would rise or fall ie. the switching speed. The higher the rate of change the higher the resistance/impedance per unit length and the higher the potential difference between any two points on the conductor ie.. a bird on a wire. So we can see that we may have a lower rate of change and higher impedance (the circuit here) or we may have a very high rate of change and a lower impedance (Tesla's hairpin circuit) and achieve the same potential difference per unit length.

Think about how adding a ferrite bead around a conductor helps filter noise traveling down that conductor. If you used such a configuration to work as a filter (common practice) you could measure that noise as a voltage drop between the entrance and exit of that ferrite bead. He uses LEDs to indicate the voltage drop of the oscillator's 'noise' between the inlet and outlet of the filtering ferrite toroids.

I would agree and believe you have basically described the whole of the effect however I would disagree with the usage of the term "noise". Noise is as much Energy as any other form of Energy and I do not discriminate between the many forms Energy may take, it is what it is and fundamentally it always relates to change.

AC

[BEP]

I would agree and believe you have basically described the whole of the effect however I would disagree with the usage of the term "noise". Noise is as much Energy as any other form of Energy and I do not discriminate between the many forms Energy may take, it is what it is and fundamentally it always relates to change.

AC

Yes, any signal is made up of energy. I used the term 'noise' to help in understanding the filtering aspect of this circuit. After all, the energy is transformed and goes somewhere. In this case, it is converted to heat in the ferrites and/or light & heat in the LEDs.