Guru
Joined: 13/10/2014
Location: AustraliaPosts: 1860
| Posted: 04:49am 22 May 2025 |
There is a difference in the Toroids, these New units are marked as FM571060A, the old Toroids are MS226060-2. I cannot find any reference to FM571060A.
They both give exactly the same Inductance for the Number of turns and are the same size.
The newer units look to have a much softer curve. I have repeated the tests many times and every run is identical.
Yellow: Current 125A per volt.
Blue: Cap discharge voltage from 75V.
Original MS226060-2 Toroids:
The New Toroids:
If you compress the time scale, the second image is virtually the same as the first, it's almost as though there is a small resistance in play? I rechecked the cable, both use the same cable, everything looks identical and the display for each as shown above is always exactly the same no matter how many times I swap them into the JIG.
EDIT:
At 625A, the Cap voltage (blue) has dropped from 75V to 58V, there is still plenty of reactance left.
If the Choke is replaced with the same winding lenght cable, the Cap voltage trace is simply a narrow pulse from 50V to 0V ("almost" zero inductance).
A single power board bank of FETS handling 625A would not see anything like a short, especially as there are effectively two chokes in series with the Toroid.
So "32 FETS" and FOUR chokes in a Dual Inverter can easily handle 800A peak Induction motor start loads.
BTW: I proved that if built correctly, a single wiseguy Power board with two chokes and one Toriod, can easily handle repetitive 650A Peak start loads daily for months.
.
Edited 2025-05-23 12:03 by KeepIS