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IMPROVED SENSORLESS CONTROL WITH THE ST62 MCU FOR UNIVERSAL MOTOR

Figure 10. calculated current versus time at constant speed for various triac

firing delays (resistive and inductive model). Current at t0 is

constant, except at the largest firing delay td of 9 mS.

Figure 11. calculated current at mains zero crossing versus firing delay for

various speeds. For speeds larger than 600 rpm and firing delays

smaller than 7 mS, this current depends only upon speed.