Jones, even at 40 kHz it is going to be extremely difficult to get enough current to flow inside a coil of wire. Remember, they normally drive the expansive sheet of resistive metal that has an effective resistance that is much less than an ohm. The coils that we are using is in the vicinity of 10 ohms.
So, you have a magnetic field that enters a much larger area of resistive metal when a pan is placed upon the unit than with the small coil. Then, the length of wire used in the coil has a large series resistance whereas the pan is more of a parallel resistance and much less in total value. Both of these effects are working against you. In the RF world we would say that you are mismatching the drive source by trying to use a load that is not proper. The load in the case that you are suggesting would not permit the driver to deliver any significant power into it. You can model a system of this type as a transformer. I am pretty confident that you will not deliver significant power into the coils under this condition. Dave -----Original Message----- From: Jones Beene <[email protected]> To: vortex-l <[email protected]> Sent: Fri, Mar 20, 2015 11:05 am Subject: RE: [Vo]:Am I the only one.. From: David Roberson Ø That would ensure that the induced current within the coils was very close. If the induction heater operates at 60 hertz then you are going to have a very hard time getting enough current to flow inside the coils. This is because the resistance of the wires is far, far greater than what is observed within a metal pan. I don't think your plan will work unless RF is used for the source power. Of course you will have to consider the direct heating of the fuel due to the changing magnetic field. Recall that one of the Russian companies that the MFMP guy visited is using induction heating that is only applied to the fuel plus without any other coils. Why not use the normal easy to measure systems? Dave The” normal easy way” is difficult for comparison of an active tube when side-by-side with a control. This suggestion is meant to be used in addition to water bath calorimetry – but a setup which is more sophisticated than what Parkhomov was using. BTW those hobs we are talking about use power ICs to convert the 60 hertz to something like 40 kHz. Do you see that as a problem? There is a certain logic to using side-by-side comparisons - which is completely absent from even the best calorimetry
