What is a square wave: The amplitude of a square wave at any instant can only be positive maximum, zero maximum and reverse maximum. In theory, the rate of rise and decrease of waveform is infinite.
What is a sinusoidal wave: The amplitude of a sinusoidal wave at any instant satisfies the sinusoidal relation of the phase angle corresponding to time (frequency). In theory, the maximum rise rate and decline rate of waveform are at zero, while in theory, the minimum rise rate and decline rate of waveform are at over-peak, and at this point, the rise rate and decline rate are zero.
Most customers choose sinusoidal wave because sinusoidal wave drive noise is better, but motor torque is smaller, motor efficiency is lower at low speed, and higher requirements for driving algorithm; however, square wave drive has obvious electromagnetic sound, but the torque is large, low speed efficiency is higher, driving algorithm is simple, suitable for simple software development; both have their own advantages, as for DC has no. Brush motor chooses sine wave or square wave drive, or mainly depends on customers'needs.
