Good job.
See the heatsink on the 911-02?
Oropeza, used it because he had reason to. The 7706JA and 3825JA Leece-Neville alternators that the reg was designed to field, have similar resistance to your 50/120 That means an identical field draw (amperage).
With the Transpo F540SP he took my advice and used a 50-amp rated MOSFET and a decoupler circuit that protected the voltage divider, driver transistor and power transistor in case of reversed polarity. He asked me to rig up a pair of 240 volt probes. Direct to AC. I used a 100 watt isolation transformer. He was freakin' nuts!
"If you want a bullet-proof voltage regulator, it should endure this!"
He touched probes to all terminals plus the reg case!
I connected the reg to one of my hopped-up 25SI alternators on the test bench and God Almighty, the regulator worked perfectly! Frank hired newly out of work aerospace engineers and with them came part numbers and vendors for exotic integrated circuits and power devices. When NASA was finished with a component, the vendor was more than happy to dump the remaining inventory.
I was not impressed with the 540XHD variant with the big to-3 transistor externally mounted on it's own aluminum plate heatsink on the rear.
The SP could be ID'd by it's three 32 pin IC's on the inside.
The new owners of Transpo, Wetherill Associates International, could have had China do any number of changes on any of the Transpo regulators. Yuze a guinea pig.
