RC-Monster Forums - View Single Post - 6 Pole operation on the MMM

himalaya · 12:28 AM

No, FET life has nothing to do with the number of poles.

The FETs keeps switching on/off in a certain frequency(eg. 8kHz or 16kHz) no matter how hard or soft you pull your throttle, no matter how fast the ESC commutates(changing motor current directions ). The only difference is the FET on-state time width---so callled Pulse Width Modulation. There are 3 phase coils, so each FET works(switch on/off) only during 1/3 active time, in the other 2/3 dead time it just keeps shut off, no matter how many poles the rotor has.

And, the FET switching in the ESC is just NOTHING. Your computer's CPU power supply converter is also based on FET components, they keep swithing about 100 times faster than your ESC, year after year.

	(#6)
himalaya RC-Monster Carbon Fiber Offline Posts: 392 Join Date: Nov 2008	01.16.2009, 12:22 AM No, FET life has nothing to do with the number of poles. The FETs keeps switching on/off in a certain frequency(eg. 8kHz or 16kHz) no matter how hard or soft you pull your throttle, no matter how fast the ESC commutates(changing motor current directions ). The only difference is the FET on-state time width---so callled Pulse Width Modulation. There are 3 phase coils, so each FET works(switch on/off) only during 1/3 active time, in the other 2/3 dead time it just keeps shut off, no matter how many poles the rotor has. And, the FET switching in the ESC is just NOTHING. Your computer's CPU power supply converter is also based on FET components, they keep swithing about 100 times faster than your ESC, year after year. ....What a Blue Sky.... Last edited by himalaya; 01.16.2009 at 12:28 AM.