AC/DC and the E-Cat [Updated]

There have been a few comments on the Journal of Nuclear Physics on a technical detail that Andrea Rossi brought up over the weekend: that the E-Cat cannot run on DC (direct current) electricity; only AC (alternating current).

I posted the following question on the JONP to try and to get some more information from Rossi about this:

You say that the E-Cat needs AC current to operate. My understanding is that the electricity is needed to run an electric resistance heater — could not DC current power a resistor and achieve the same effect?

So what is additional purpose behind the need for AC?

Rossi responded, but didn’t really address my question, simply saying again that the E-Cat needed AC, and could not run on DC.

Rossi has said that they are working on using heat from natural gas to drive the E-Cat, but it appears that there is still work to be done to perfect this process. Rossi said recently “We have an R&D section working on gas activated E-Cats, and I think we will be able to resolve the problems we have.”

Heat is heat, regardless of the source, but maybe heat from natural gas is not so easy to control as heat from electrical resistors.

The issue raises the point that it seems that there is more involved than heat in making the E-Cat work. We know there is a control panel involved which needs (according to the first third party report) around 100 Watts of power to operate, and maybe it is simply this control system requires AC to operate. Regarding the electricity supply, Rossi also said, “it must be e very elastic source, due to the control system technology.”

Today Rossi mentioned that AC at frequencies of either 50 Hz or 60 Hz will allow the E-Cat to work properly.

UPDATE: On the Journal of Nuclear Physics, Hank Mills made a comment/question regarding this issue:

The requirement for AC makes me think an magnetic field, altering in polarity, may be needed to stimulate the reactions until they reach a certain level at which they become self sustaining. Another possibility is that the resistor coil acts like a helical antenna emitting an RF signal into the reactor. This second possibility seems less likely, due to the possibility that red hot resistors might have such a great resistance they may not transmit well. Can you elaborate at all on this? As always, I understand if you cannot.

Rossi responded: “In your question there is the answer. Obviously I cannot comment. Our Team is making all the necessary work to make the E Cat operate.”

So it does seem from this response that there is more to the AC power issue than just providing heat and powering the control module. To me, it looks like he is dropping a hint that Hank is onto something here; the AC could be providing either an alternating magnetic field or important radio frequencies to help stimulate the reaction.

This could help explain why IH is having problems with the Gas Cat, if more than a simple heat source is required.

  • Omega Z

    This is 1 of those questions of which Rossi would state: I can not discuss what happens inside the reactor.

  • Bob

    I think you are right.
    DC power is very easy to measure accurately with very much less scope for fiddling the measurments. Modern DC to AC inverters are now very cheap, even high power ones. There is no reason why DC could not be used and simply converted to the required AC or any voltage for use in the e-cat control circuits. The control circuits would not see any difference in how the AC was derived.
    I believe the work in trying to get a gas powered e-cat to work is more to do with finding some aspect of the input to output energy equation which can be fiddled to give the appeaarance of a COP greater than 1. So far it appears a convincing smokey mirror has not been found.
    If it had, then there would be no reason why a DC powered heater could not do the same job.
    There is minimal possibilty of the AC being required for the generation of a magnetic field in the heater elements because from the earlier publications of the heater configurations, they lie longitudinal to the core and would not direct any magnetic field into the core area even if a field was generated.

    • Ged

      Actually, the longitudinal orientation of the lines is exactly what you need to drive a magnetic field into the core. Remember, a magnetic field wraps around the wire in the direction of the flow, perpendicular to it. Coiling the wire (like a solenoid) helps to strengthen the overall intensity density of a field.

      Other thing to remember is any possible AC power measurement errors would be not in favor of the E-cat in the case of the equipment used in the first test. This was touched on in the report itself, as they would measure a larger power draw than in reality.

      In the end, if it makes significantly more heat than electricity is drawn, then AC or DC is irrelevant. We’ll see.

  • Fortyniner

    deleted by author

  • Paul

    Very probably, he can use DC, provided an high quality inverter is inserted between DC source and the E-Cat. So an E-Cat could be powered by PV panels. DC + inverter should be indistinguishable from AC.

  • fritz194

    Hot Cat)
    The known photos do not show the HotCat in a (technical) useful setup.
    The mock-ups I have seen are just some proof-of-concept that this heatsource has the potential to supply heat at more than 500 deg celsius – and that is what they want to show: we can produce high temperature heat at a COP of maybe 6.
    The energy produced by the hot cat is just as high to maintain the radiation and convection in room air. This is maybe 3kW ? – should be in the report from 2013.

    1)A system using pulsed DC current at high peak levels will cost a multiple of a simple direct mains driven AC full wave packet regulation.
    2)I think Rossi mentions AC – because its unsafe to operate the e-cat in a non-pulsed way.
    3) For me, a pulsed DC or AC excitation seems logical because of the nature of the problem –

  • Job001

    No, it is not an easy error and was addressed long ago.

  • Gerard McEk

    If AC would be needed to make the E-cat work, than it would presumably be the magnetic effects of it as they are prominent at low frequencies. Therefore the heating element must be a serial one wound around the core. That will cause a AC magnetic field over the axis of the E-cat. The original triac control will have caused some higher harmonics in the field which may have contributed to the CF or Rossi effect.

    • Omega Z

      The hot-cat had resistance coils(appearance similar to door spring) in rows around the E-cat from end to end. I do not recall if they were wired in parallel or series.

      The new configuration of mouse/cat is confusing. Rossi has indicated that the Cat portion of the reactor has no resistance coils or any powered connections what so ever. Basically a slug. Also that the mouse is not in the cat nor vice verse which leaves only being butted against each other.

      This indicates either a more complex assembled device, OR, at least 1 misunderstanding in communications. A correction in such a misunderstanding in itself would just create new questions.

      Maybe I should try to pose some questions in a manner he would answer & provide some clarity. He seems to have become quite adept lately at answering without answering. Me thinks he has been in close proximity to Political circles. He’s become infected by the political speak virus. OMG…

  • JDM

    Perhaps the reaction can be initiated with DC but tends to run away. In that case maybe AC applied reigns in the reaction as a control parameter? Didn’t AR once state something along those lines?

    • JDM

      Andrea Rossi
      December 29th, 2013 at 6:10 PM
      Hank Mills:
      1- no
      2- confidential
      3- no
      4- the temperature of the Cat raises when the Mouse is turned off, lowers when the Mouse is turned on
      Warm Regards,

  • fritz194

    Controlling an E-Cat

    We want to control a nonlinear, spontaneous active heat generation….
    The ideal approach would be to attach a control system with fast, instantaneous perfect heat/cooling capability – to keep this nonlinear effect under control.
    In practice, there is a permanent cooling done by the thermal load of the circulating media. This cooling has a thermal capacity probably a multiple of the e-cat itself.
    There is a sliding set-point – determined by the secondary thermal transducers – and the possibility to control the heat flow using a modulated pump. Such a system is way too slow to control /compensate such a system/effect.
    To overcome that – the e-cat is operated below the thermal threshold of this spontaneous effect (non-self-sustaining)- and triggered by high energy thermal pulses which exceed this threshold. The important thing is that the thermal capacity in the system generating the heat-pulses has to be lower than the emitted heat capacity by the NAE environments.
    This would mean that you have to scale up the excitation system if you want to increase the output.
    Here comes the cat&mouse into play. You control the mouse with modulated heat(with fast thermal response) – this gives you a modulated, amplified heat flow from the mouse(with medium thermal response) – and this triggers the cat(with slow thermal response).
    Using this scheme, you can increase the output power, the cop, and scale up the device without the need of thermal pulse generation in the MW range.
    Operating such a system using slow regulated (==DC) heat source which slow response is probably quite difficult from point of safety concerns.
    If Rossi talks about “elastic” supply – he probably means that the dynamic response of the supply as well as the amount of spontaneous energy drawn has be fast/high.
    In this special setup – this demand can be easily achieved using full wave packet modulation – from 50/60Hz mains.
    If you would design that for DC – you would need huge inverters / battery backed up to supply the necessary peak power.
    Having all these thermal capacities designed properly is the only way to achieve safety – even in situations when there is a failure in the media/cooling system.

    • Fortyniner

      This research is on surface plasmons in copper nanoparticles, but I think the principles uncovered probably apply also to nickel, and there may be clues here about Rossi’s ‘control system’:!divAbstract

      Specifically, the author looks at how tuning surface plasmon modes to infrared frequencies (i.e., specific temperatures) enhances plasmon generation, and how electron-phonon interactions act to ‘dephase’ or dampen localised surface plasmons. Rather than tuning (by size selection) the particles to an IR wavelength, the dominant IR band could be varied by controlling temp, to resonate with a fixed particle size.

      In other words, specific IR wavelengths (as determined by temperature) may ‘pump’ plasmon generation, while free electrons (deriving from eddy currents in the Ni particles, created by external EM fields?) may act to suppress surface plasmons. Assuming surface plasmon generation to be a driving factor in LENR (an assumption at this point) these two factors might be modulated to provide the up and down regulation inputs required for system stability.

      • Andreas Moraitis

        There are some nice animations in the WP-article:

        I wonder how changes in the (micro-)geometry of the surface would influence the process. One could guess that not only the size, but also the shape of the grains could be important.

        • Fortyniner

          Thanks, yes the animations are very helpful for assisting visualisation of the phenomenon. Unfortunately there is no tool that might help me with the maths! (that’s why I chose microbiology as a first career).

          If my suggestion that IR is the up-regulator, and EM fields are the down-regulator has any merit at all, there may be a further implication in considering the 2-part ‘cat/mouse’ configuration. This is that if the ‘mouse’ has a self generated magnetic field under certain conditions (as observed by Rossi and others in similar devices) then this may act in some way to disrupt SPP formation within the ‘cat’ at a certain point in the regulation cycle.

          This would mean that as well as generating the heat necessary to create IR ‘illumination’ internally in the ‘cat’, the mouse might also be the source of intense EM fields, creating the damping effect. This could be a passive function depending on various parameters used in its construction, or an active one in response to control inputs. Despite OZ’s insistance that the two parts are separate, a concentric arrangement would provide much better coupling for both thermal and magnetic inputs to the ‘cat’, so perhaps the design may have subsequently evolved in this direction.

  • Fortyniner

    That’s an entirely feasible – but rather boring – interpretation!

  • malkom700

    Interestingly, the issue of self sustained mode only makes sense in terms of a single device. In terms of the interaction of thousands of devices, this issue has no meaning because the demand for electricity can be produced by other devices. In general, this is not a problem because the electricity in the future will be totally cheap.

    • fritz194

      I think we should not extrapolate the actual e-cat performance and requirements.
      The actual published achievable COP as well as the possibility/or impossibility of a sustained mode is tightly coupled to the actual design.
      I do not think that centralized electricity can be totally cheap. On my bill, the actual energy costs are only 40%, the rest is for maintaining the net and whatever.
      Totally cheap electricity is only possible off-grid.
      And then a form of independent operation is quite important.
      If Rossi talks of “sustained mode” he definitely means something different.

      • malkom700

        Yes, totally cheap electricity is only possible off-grid. Now. But you have to distinguish between the current situation and the more distant future. Grants may be used in the interim period.

      • Omega Z

        Off grid would not be cheap. The cost of the hardware & it’s short life-cycle just doesn’t add up to cheap. Many also ignore peek capacity. As individuals, total peek capacity per-capita would far exceed what is produced today.

        You may need 10Kw electric capacity for peek periods, tho averaged may be 10% of that on a monthly bases. You pay the cost of this whether you use it or not.

        Power plants shift this around allowing a much lower peek production capacity. Not all AC’s or refrigerators Etc, are used all at the same time. This provides cost sharing & cheaper energy costs per person. Our Present Grid system is actually cheaper.

        Our present system has certain constraints & located geographically accordingly.
        Fuel: Gas powered requires being located near a major gas terminal. Coal requires a major rail line. This necessitates the building of very large power plants to minimize cost of the fuel delivery structure which is very expensive. From 100’s of Megawatts to several Gigawatts producing very large amounts of heat to be dealt with. Now you need to build near very large water sources. Lakes, Rivers, & Oceans for cooling. This all results in a very hefty & expensive UHV power grid to transport that electricity to where it’s needed 100’s of miles away. E-cats/LENR would technically reduce costs, Except this Grid is aging fast & cost of maintaining or replacing will be expensive. The best hope would be that E-cats/LENR would offset most of this.

        Presenting the E-cat/LENR. This Changes all the Dynamics.
        Fuel delivery is no longer a constraint. Have UPS drop it off annually.

        Power plants can now be built local & much smaller. Gigawatt plants no longer necessary. In fact several small facilities near a city can supply power to each other by way of the local grid. Separate but looped. At most, you could get by with a 1Mw genset for backup should issues arise.

        Large bodies of Water are no longer necessary. Their small enough it becomes very economical to be self contained using cooling towers. Excess heat could be sold cheaply in an economical fashion to commercial users, Greenhouses etc who build near the Power plant. Shared costs. They get cheap heat without the major investment.

        You now have savings of eliminating the national grid, you retain the savings of shared peek demand costs & additional savings through better utilization of selling what would be waste heat.

        Just recently, GE/Siemens were in a bidding war for a French company that specializes in smaller turbines. In the 10’s of megawatts. Note this seemed to be their primary interest.

        You could ask why when they already build huge turbines. The French specialize in small. They have a technological edge in small. They have more expertise in this design for high efficiency in smaller scale. Many times, It is cheaper to buy this technology & expertise in both time & R&D costs.
        These would be very important in rebuilding a Large Central grid to a more decentralized local micro-grid. Note: this would greatly increase the speed of transitioning.

  • Jim Anderson

    There is an easy way to convert DC to AC. The device is called an inverter. It is a mature technology. DC goes in AC comes out. It is used to let a car battery provide energy fir an AC appliance.

    • Andreas Moraitis

      Modern inverters reach an efficiency of 98%. Thus, the effectiveness cannot be the problem. Maybe it’s instead the “elasticity” which has been demanded by Rossi. The reactor might need high amperage for short periods, so that the inverter and its source will have to be oversized, and would therefore be too costly.

      • Fortyniner

        And potentially unreliable, if the inverters (presumably several would be needed for a multi-core reactor) would need to run intermittently for thousands of hours. Rossi generally seems to like to keep things as simple as possible, perhaps for maximum reliability and/or minimum cost of production.

        • Omega Z

          And ultimately, Your still using AC.
          So why go thru the hassle of an inverter etc when you just start out with AC. Seems like a silly argument so that one can say yes, you can use DC. 🙂

      • fritz194

        A 4kw inverter may have 85% efficiency with 3kw load and 30% efficiency at 10 watts.

  • Ophelia Rump

    I am disappointed.
    I thought the band was endorsing the technology.

    • Frechette

      Maybe Air Supply will take the place of AC/DC.

      • bachcole

        God!! I hope so.

  • ecatworld

    Dear Andrea Rossi,
    Could the gas-powered reactors use a DC source (for example, a battery) as electrical input?
    Best regards,
    Andreas Moraitis

    Andreas Moraitis:
    Gas powered E-Cats are still in a very primitive R&D status, therefore I am not able to answer to your question. Sorry.
    Warm Regards,

  • Mark
  • Sandy

    Perhaps the alternating current causes the nickel tubercules to sway back and forth in resonance with each other and with the electric current, thereby causing cracks in the tubercules to rapidly open and close, and thereby trapping and compressing hydrogen ions and causing nuclear transmutations and heat emission.

    James Patterson found that his “Power Cell” worked much better when the electric current that was routed through the cell was pulsed. Dr. Patterson received a U.S. patent on his “cold fusion” device.

    • Warthog

      Brillouin says exactly the same thing. In fact, they say that it takes a very specific waveform of pulse to get the best results

    • Jim Anderson

      Sandy the AC reminds me of a video put out by Brillioun which also does LENR work. If the resistive heater does more than just heat if it also has an electro magnetic effect then this could tie what’s going on to Brillioun. Brilliouns idea is that there is a zone where the LENR effect takes place caused by the hydrogen moving in to and out of this zone. AC would cause that effect. Both Rossi and Dekalion report EMF effects so it is possible that the AC is not needed because the device produces it’s own AC effect. But really this is way over my head.

  • Chris I

    Possibly due to using a variac (and other electronics) to maintain stability.

  • builditnow

    Sounds like alternating magnetic fields help the E-Cat. This can be achieved by using fine wire and small amounts of power and current as is found in common transformers. The electrical heater can be thick heating wire that is separate.
    DC can easily be converted to AC with an inverter, with the advantage that the inverter frequency can also be changed to what ever frequency is most effective.

  • Gerrit

    “whole lotta Rossi” is all I can think of regarding AC/DC and the e-cat

  • Andreas Moraitis

    The electronics of the control system should anyway run on DC. Therefore it seems likely that Rossi rather refers to the device that has been called the “internal heater” (whereas it might be more than a heater in reality). One could guess that a persistent change of polarity is required, since a non-alternating EM field would possibly disturb the reaction – especially if superconductivity is involved, as occasionally has been suspected.
    But maybe I’m indeed reading too much into it, as Asterix has pointed out below.

    • Fortyniner

      The inclusion of both ‘main’ and ‘auxiliary’ heaters in the early LT models probably only makes sense if it is assumed that one of them was in fact a coil used to generate an oscillating EM field.

      One of Rossi’s ‘serendipitous’ discoveries perhaps, if he found early on that the EM field generated by a heating coil driven by AC mains potentiated the reaction, while DC heating didn’t. If this is an essential component of Rossi’s CF reactor, he was incredibly fortunate that standard mains frequencies of 50/60Hz happened to be exactly what was required.

      • Andreas Moraitis

        That’s certainly another option. In this context it would be instructive to know if the gas-powered Cats still require an AC source. If so, you were probably right.

        • GreenWin

          A 50-60Hz polarity reversing EM field is a likely catalyst for surface plasmon polaritons providing free electrons for H1 transitions. It would be interesting to test with pulsed reversing polarity DC to the heater – to observe any change in heat production.

          • Andreas Moraitis

            As well, I’d like to know what happens when an electron is captured by a proton, with a resulting neutron, so that its charge suddenly ‘disappears’. Wouldn’t that lead to some kind of domino-effect in the lattice? A large number of such events should be able to generate a strong electric current, which would heat up the charge. An alternating EM field might be suitable to maximize that effect.

            • Andreas Moraitis

              Of course, the charge of the proton would also disappear, but since the electrons in the lattice are much more mobile, I would nevertheless expect an imbalance which could lead to the suspected effect.

            • Omega Z

              Have you considered the possibility of annihilation.
              My understanding is this is “Not” something that would normally happen in nature, However an environment could be created that would allow such a possibility.

              If I recall, “?” Rossi & Focardi discussed an annihilation as well as possible ZPE, Tho I could be wrong as to it concerning electron/proton.

              Zero Point Energy is another fringe science that may be coming in from the cold. I suspect this is because Military research considers this an area of research interest. Follow the money..

              • Andreas Moraitis

                I did not mean annihilation, which would require antimatter (for example, a positron, that is emitted from a nucleus via beta-plus-decay), but inverse beta-decay (according to Widom-Larsen). The known problem is that inverse beta-decay would need a very ‘heavy’ electron. That is, you would have to add a lot of energy to initiate the reaction. So, presumably my post was not well-thought. Anyway, I sympathize with the idea of a ‘domino-effect’ in the lattice (or, perhaps more likely, at the surface), of whatever kind.

                • Omega Z

                  Yes, I believe antimatter also was mentioned.
                  I’ll see if I can find that, but it was long ago (Hard to find) & likely all their opinions changed since then.

                • Andreas Moraitis

                  I remember that discussion. Electron-positron-annihilation would result in two gammas, each of 511 keV (which equals the mass of the particles). At that time, many people were keen to know if such a signal had been detected, but, of course, Rossi did not disclose his data. If the material and thickness of the actual shielding were known, one could at least check if it would be sufficient for gammas of that energy. But as far as I remember, Rossi has some time ago indicated ‘between the lines’, that the gammas inside the E-Cat originate rather from Bremsstrahlung than from annihilation.

          • Fortyniner

            There is also the possibility that magnetostrictive effects at this frequency range may play a part, perhaps by continually changing the width of fissures.

            If even one essential effect occurs at the standard mains frequency of 50-60Hz, I would need to re-think my views on ‘coincidence’.

            • GreenWin

              Yes. In this respect changing the EM frequency, amplitude and or phase angle, would cause oscillations which may vary the fissure and Casimir gap distances – each of which should have damping effect on the reaction.

        • Fortyniner

          Unfortunately there is no indication of electrical connections in the (one and only) picture of a prototype ‘gas cat’. However it may be far from complete as pictured. Gas and electrical power supplies would need to be connected to the burner assembly AR is holding, but no supply cables or hoses are shown, and in any case, any terminal blocks on the reactor casing could be on the opposite side.

        • Omega Z

          Even Gas E-cats will need electricity. Heat is only part of the equation. It needs to reach a certain temp to start the process.
          Other means(Waves/RF/??) are used to actually control the effect.
          The control box itself needs about 110 watts of electricity. A portion of that(10 watts) is used for the RF or whatever.

      • Steve H

        I suspect they are driving the process with a square wave rather than a sinusoidal one.
        This is apparently the secret sauce to split water into it’s constituent parts efficiently, as opposed to brute-force electrolysis.

        • Fortyniner

          There may be a connection – perhaps the SPP that GW suggests below may also allow molecular bonds in water to weaken and temporarily re-form in atypical (gas phase) configurations. However it seems likely that at least in early e-cat prototypes, the waveform applied would have been sinusoidal – i.e., unmodified mains AC – unless of course Rossi’s control box contained some fairly complex electronic devices (far from impossible).

  • Jimr

    It sounds to me that the A/C is used for other than just heating.

  • Asterix

    The notion that AC is somehow better than DC for a resistance heater is silly–a simple PWM controller running from DC could probably do a better job at control than Rossi’s triac controller.

    I think that people are reading too much into what Rossi is saying. Rossi uses a triac (AC) controller that needs an AC supply to operate. Were he to change controllers, he could use DC.

    • Fortyniner

      While it would be possible to use an inverter to produce 50/60Hz from a DC supply, this would be adding complication if the mains frequency is all that is needed. Rossi’s later ‘explanation’:- “I meant that the E-Cats can work properly “from the electrical point of view” if the frequency is either 50 or 60 Hz, I was not referring to the other data.” sounds like back-pedaling to me. He may have accidentally given away something quite important – the reaction driver frequency.

      • Omega Z

        Read ecatworld Franks post below.
        All Rossi was saying is it work with @50Hz/Europe @60Hz U.S.
        He’s not back peddling, but just heading people off at the pass who may construe this as confirmation of the E-cat before the TIP.

        Rossi has become quite adept at changing posts completely or annihilating them all together if he slips. One must be on his toe’s these days to catch a slip up. It may appear for only moments. Rossi has made many here at ECW appear foolish on occasion. Even Frank. I sometimes copy/paste info from JONP to a file I’ve setup just for this purpose.
        Sadly, My judgement on what & what not to copy/paste needs work.

  • ecatworld

    From the JONP:

    Dear Andrea, you say “50 Hz or 60 Hz are frequencies at which the E-Cat can work properly”. So The E-Cat works properly… Very good news!!! Negative or positive? “Hot” regards. Piergiorgio Mongioj

    Piergiorgio Mongioj:
    I meant that the E-Cats can work properly “from the electrical point of view” if the frequency is either 50 or 60 Hz, I was not referring to the other data.
    Warm Regards,