At 11:33 AM 2/15/2010, Harry Veeder wrote:
Feb. 14 update Naudin finds the current through the toroïdal stator coils does not change when a load is applied: http://jnaudin.free.fr/steorn/indexen.htm (towards the bottom of the page) Harry
Very nice page. Naudin provides a lot of great detail. However, what might be the most important detail is missing.
Let's suppose he's correct, that the current doesn't change under load. (If it changes, it doesn't change much; the problem is that only a little power "escaping" into the rotor might be enough.)
He is showing about 0.4 amp through the coil, but that's a meter, showing average current, I'd think. AC. Could be tricky. Average power, roughly 5 watts. (It's 12 volts, apparently).
Now, the load is a pickup coil with high-current LEDs connected to it. What do they do? They blink! At much lower frequency than the rotation speed, apparently. What's happening?
My guess is that the rotational speed is oscillating so that the LED forward voltage is alternately blocking current and passing it. Passing current, there is a load, the rotor slows down, and blocking it, the rotor speeds up. How much power is being drawn off? The LEDs will only show light when the voltage is above the forward drop, so those LEDs, even when they appear to be on, are actually only showing flashing (4 times per rotation? For how long?) Or is the circuit there more complex, did I miss something?
Here is the problem. Steorn claims that input power and output power are not actually related. That increasing input power will not increase output power. That may well be true. The input power switches the magnetic attractiveness of the ferrite cores for the permanent magnets on the rotor. It takes a certain amount of power to do that. This switching allows work to be done on the rotor by the permanent magnets, but how much work?
Nothing that Naudin has shown so far indicates that there is an energy gain, at all. It would only take a very small fraction of the coil power to be diverted from generating heat to applying some torque to the rotor and thus doing work on it to accumulate energy.
It looks to me like only a very small amount of power is being drawn off by the pickup coil and dumped through the LEDs, compared to the power being dissipated in the toriod circuit. The current in the LEDs may be perhaps 40 mA, peak, I can't tell. Suppose that's peak current. There is only that much current for a fraction of the duty cycle. And the voltage across the LEDs may be about 0.5 volt. 5 watts in, what, maybe 10 milliwatts average out? More? Less?
That the input current does not seem to vary with the load tells us practically nothing except that this is not an ordinary motor. It could be one that, from the configuration, transfers a small and fixed amount of power to the rotor energy. So under load the rotor slows down, when the load is removed, it speeds back up, but the input current does not vary. So?
It takes X power to switch the coil on and off. That does not vary with rotational velocity, it is, so to speak, a fixed cost. Spending that fixed cost allows the core to be used to power a permanent magnet motor, but it would appear that there is only so much power that could be developed from this attraction. Build the thing differently, with bigger cores and bigger toroids, you could develop more power. But still, it would appear, not much power. Steorn is claiming twice as much power in the load as in the toroid circuit. That seems preposterous from the Naudin work. It seems preposterous from everything Steorn has shown (i.e., why are very-low-friction magnetic bearings needed?)
So far, no measurement of actual heat dissipation in the toroid circuit, such hand-waving about no back EMF. If there were really accurate calorimetry of the toroid circuit, and then accurate measurement of load power as well, we'd see if there was any extra energy. Steorn is promising calorimetry data by the end of February, as I recall. From Naudin, much better data than from Steorn, but the critical data (power in the toroid circuit and power in the load circuit) is missing still. All he has shown is that there is some power in the load circuit, but not how much, and that toroid circuit current does not appear to vary with load. But how much is that load? Looks like it's tiny to me! -- compared to toroid power.
