This post was submitted by ECW reader ‘Anon’
Looking at the Vessy photo the three test hot cats seem to be wired in a Wye 3 phase configuration and being fed from a 3 phase supply (big cable in the centre with cores coloured red/white/black). You can actually follow the cables reasonably well on the pictures available on the web even with the reduced resolution compared to the original which I’ve not seen posted anywhere. Additionally the coloured tapes on various wires are consistent with three phase markings although Rossi seems to use both Euro and US colour standards. He is standing in front of the wall with the power sockets so cannot confirm the supply is three phase.
So from the picture Rossi had one e-cat on each phase which is reflected in the latest design where three coils are used. IH would most certainly want a 3 phase product for industrial use as commercial 2P is rare outside of office buildings, especially in the US where the line voltage is low.
The post-it note on the table shows an interesting waveform but only for a single phase so giving no clue to the triac triggering apart from the fact the wye would have to be balanced as there is no neutral visible (3P3W).