> In fact I said the 3-phase input to the box was particularly unnecessary > *because* only single-phase was used for the box.
There are legitimate reasons to prefer 3-phase input. If the output of the control box is a pulse width-modulated DC signal, then you need a high-power DC source. There might be requirements on the control waveform. Using three phases you can get DC with decent ripple using only a handful of diodes. The power never goes to zero, whereas it would go to zero 100 times a second if you were using a full-wave rectifier with single-phase input. If the peak power required by the e-CAT is around 1 kW, then you would need caps supplying up to 1 kW. We're talking ~100 µF caps rated at 350V supplying 3.5A. Such large caps are difficult to find and it makes more sense to go with multiple caps in parallel to supply that current. These caps would dissipate a couple watts each. Temperature very quickly shortens the lifetime of aluminum electrolytic caps. Hence, if you use them you reduce the reliability of your device, which could be a problem for the e-Cat. And the above assumes the peak power is 1 kW. So I don't think you can say that 3-phase input is particularly unnecessary, unless you know things about the e-Cat we don't know. On Wed, May 29, 2013 at 7:57 AM, Claudio C Fiorini <claudio.c.fior...@gmail.com> wrote: > Joshua Cude wrote: > > > ...I'm almost certain they were using 3-phase power on the input to the box. > > They write: "a control circuit having three-phase power input and > single-phase output". And it's on the input that the power measurement is > made, and so that's where it's relevant. That also forces a particular line > to be used, and makes much higher power available, which may have been > necessary for the glowing red experiment... > > > What if they used 3 phase power to the control box, and a single phase to > the resistors, but not as you write "forces a particular line to be used", > but two. I mean two phase lines. The result is a single phase signal but > with a significant higher voltage then using one single phase line and the > neutral pole. Tension would be greater by factor 1.73. The current would > also increase according to the Ohm law and would increase by factor 1.73. > The power dissipated would increase by 1.73 x 1.73 = 2.66.
