ApisQueen U20 Underwater Thruster 50V 20Kg Thrust 1200W For Kayak, unmanned boat, etc.

Highly qualified full metal construction, precision machining,Made by material aerometal and digital machinery.

Full waterproof technology，Fully encapsulated waterproof, dust-free, grit prevented, anti-corrosive, long last working underwater

High precision baring prolongs the motor life

Best matched power system，Highly strengthened metal propeller, best matched motor, provides most efficiency

Easy assemble，Modularized base, meeting with different field requirement.

ABOUT PWM 

PWM full name is (Pulse-width modulation). It is also called duty cycle signal, which indicates the proportion of the high level duration to the whole signal period. 2ms for the whole period of PWM, 1.5ms stop, 1.5-2ms forward, 1.5-1ms reverse.

From the diagram, we can clearly see that when PWM is 75% (1.5ms), the motor stops rotating, when PWM is 50% (1ms), the motor rotates in reverse, and when PWM is 100% (2ms) the motor rotates in forward.Of course ESC will not only make the motor turn forward and reverse, but can adjust the speed of motor rotation by the duty cycle size of PWM. When the PWM is gradually changed from 75% to 50%, the motor will keep reversing and accelerating from stop until the reverse rotation reaches the maximum. And when PWM is gradually changed from 75% to 100%, the motor is continuously accelerated from stop to forward until the forward rotation reaches the maximum value. That is, PWM is a signal that can be continuously varied, and the effective range is from 50% to 100%.

The frequency of PWM signal is 50hz, 100hz, 200hz or 500hz, etc. The higher the control frequency, the shorter the period, the shorter the control interval, and the faster the ESC and motor response speed The faster the ESC and motor response. Conversely, the lower the control frequency, the longer the period, the longer the control interval, and the slower the ESC and motor response.