The original TO-220 75100 was designed by a college kid. Flipsky bought one from him anonymously and reverse engineered it. The original designer posted a bunch of detail on endless-sphere. Performance wise it got hot very quickly.
The Aluminum PCB version is totally different. It’s not a simple “aluminum PCB” version of the original. Flipsky’s nomenclature is pretty terrible. I don’t know if it’s an in house design, or if MakerBase designed it, or if they commissioned it or what. It’s an impressive ESCs though. This 75300 should be a beast.
The current problem is that they put 75_300_R2 firmware (from a Trampa 75/300) on them, which is specified to use phase shunts (these units have low side shunts), is reading from 3 temp sensors even though only 1 exists which gives bad “average” temp data, and at least on the models I had, the input voltage reading was off by a volt or two. The hardware config I came up with, first on the original, then adapted for the aluminum PCB designs, addresses all those things. Now that firmware in the VESC project… but it has to be manually loaded to get it off the 75_300_R2 firmware.
Long story short, @sp3swj, if you are currently on firmware 75_300_R2, then try loading the FSESC_75_200_ALU no limit firmware from here
That should help the 75300 to perform better. It’s only been tested on the 75100 and 75200, but since all of those are shipped with 75_300_R2, and the hardware layout is the same except for the number of mosfets, then I see no reason why it wouldn’t work… and you’d be a great tester for a true Flipsky 75_300 firmware.
Does the VESC tool, with 75_300_R2 loaded, show three temperature sensors but only gives a correct reading for one of them?