DC Motor Positive and Negative Driver Module [6V-40V] [20A]

Description:
This is a DC motor positive and negative driver module or ESC(Electronic Speed Control), that controls and regulates the speed of the electric motor. It provides reverse rotation control of the motor by positive and negative drivers, switching any two of the three leads from the ESC to the motor. The input of the ESC module will be a switch with a voltage lower than 2V.
An electronic speed control follows a speed reference signal (derived from a throttle lever, joystick, Arduino platform or other manual input) and varies the switching rate of a network of field-effect transistors (FETs). By adjusting the duty cycle or switching frequency of the transistors, the speed of the motor is changed. The rapid switching of the transistors is what causes the motor itself to emit its characteristic high-pitched whine, especially noticeable at lower speeds.
Different types of speed controls are required for brushed DC motors and brushless DC motors. A brushed motor can have its speed controlled by varying the voltage on its armature and requires a different operating principle. Brushless DC motor controllers are much more complicated than brushed motor controllers.
The correct phase varies with the motor rotation, which is to be taken into account by the ESC: Usually, back EMF from the motor is used to detect this rotation, but variations exist that use magnetic (Hall effect) or optical detectors. Computer-programmable speed controls generally have user-specified options that allow setting low voltage cut-off limits, timing, acceleration, braking and direction of rotation. Many modern ESCs support nickel-metal hydride, lithium-ion polymer and lithium iron phosphate batteries with a range of input and cut-off voltages.
Most modern ESC contains a microcontroller interpreting the input signal and appropriately controlling the motor using a built-in program, or firmware. In some cases, it is possible to change the factory built-in firmware for an alternate, publicly available, open-source firmware.
Electronic speed controllers or ESC can be used in Electric cars, Electric bicycles, Helicopters, Quadcopters, etc.

Features:
Operating Voltage: 6V ~ 40V DC
Module Power Consumption: 0.6W (Without load)
Signal Input: Active low, the input is the negative of the optocoupler. If the voltage is lower than 2V, it is considered to have a signal.
Responding Speed: KI K2 is 20mS and SWI SW2 is 50mS
Motor Current: 20A
Size: 83mm x 46mm x 20mm

Function:
KI is the forward rotation start button 
K2 is the reverse rotation start button 
SWI is the forward rotation limit switch 
SW2 is the reverse limit switch
1. Press KI and the motor will start to rotate immediately until the SWI is closed.
2. Press K2 and the motor immediately starts to reverse until SW2 closes and stops.
3. When K2 is pressed during forwarding rotation, it will immediately switch to reverse; when reversed, pressing KI will immediately switch to forward rotation.

Package Include:
1 x DC Motor Positive Negative Controller