h-bridge locked antiphase
i know only of the theory of locked-antiphase.
there are 2 common ways of controlling an H-Bridge.
1) Sign Magnitude.
2) Locked Antiphase
1) the PWM signal controls the voltage (magnitude) applied to the H-bridge, usually applied to only one quadrant, and the SIGN bit is applied to the opposite quadrant.
2) in locked antiphase the PWM is applied to both H-bridge legs simultaneously. if the PWM is the same duty cycle (percent ON) then of course the average is ZERO and your h-bridge does not produce any DC. i.e. if your h-bridge were connected to a motor, your motor would not turn. however, if the PWM duty cycle were to change, such that one h-bridge leg got 5% more ON time than the other, then the motor would rotate slowly in one direction. of that same leg received less PWM duty cycle, say -45% then the motor would spin VERY fast in the opposite direction. locked antiphase is called such because it "locks" the two PWM signals applied to the legs of a H-Bridge in complementary fashion (antiphase).
Mr.Cool