The electric bike controller is a crucial component of an electric bicycle, responsible for managing and controlling the electrical system. It regulates the flow of power from the battery to the motor, allowing for smooth acceleration, speed control, and overall performance. In this article, we will explore the construction and principles behind the electric bike controller.

The electric bike controller consists of several key components that work together to control the electric system:

a. Microcontroller: The microcontroller is the brain of the electric bike controller. It receives input signals from various sensors and controls the output to the motor accordingly. It processes data, executes commands, and ensures the proper functioning of the controller.

b. Power Stage: The power stage includes power transistors or MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) responsible for controlling the current flow to the motor. These components handle high voltages and currents, converting the low-voltage signals from the microcontroller into higher voltage and current outputs.

c. Sensors: The controller incorporates various sensors to gather information about the system, including the speed, pedal cadence, pedal assist level, and battery voltage. These sensors provide real-time data to the microcontroller, enabling it to adjust the motor's power output and overall performance.

d. User Interface: The user interface allows the rider to interact with the electric bike controller. It typically consists of buttons, switches, or a display panel. The user interface allows the rider to adjust settings, select different power modes, monitor battery levels, and receive feedback on the system's status.

Principles of Operation:

The electric bike controller operates on the principle of pulse-width modulation (PWM). PWM is a technique that involves rapidly switching the power supply on and off at a fixed frequency. By controlling the duration of the power supply's on-and-off cycles, the controller can regulate the average power delivered to the motor.

When the rider inputs a command, such as twisting the throttle or pedaling, the sensors detect the input and send signals to the microcontroller. The microcontroller processes this data and determines the appropriate power level to be sent to the motor. It then adjusts the power transistors in the power stage to control the amount of current flowing to the motor.

The microcontroller generates PWM signals that control the switching of the power transistors. By varying the duty cycle of the PWM signal (the percentage of time the power is on versus off), the microcontroller regulates the average voltage and current sent to the motor. This control allows for precise speed control, acceleration, and power delivery.

Electric bike controllers often include safety features to protect the system and the rider. Some common safety features include:

a. Overcurrent Protection: The controller monitors the current flowing to the motor and can limit or cut off power if it exceeds a safe threshold. This protects the motor and other components from damage due to excessive current.

b. Overvoltage and Undervoltage Protection: The controller monitors the battery voltage and can prevent overcharging or excessive discharging, which can damage the battery. It also cuts off power if the battery voltage drops too low, preventing deep discharge.

c. Temperature Monitoring: The controller monitors its own temperature and that of other components. If the temperature exceeds safe limits, the controller can reduce power output or activate thermal protection measures to prevent overheating.

d. Regenerative Braking: Some electric bike controllers support regenerative braking, which converts kinetic energy during braking into electrical energy and stores it in the battery. This feature improves energy efficiency and extends the battery range.

The electric bike controller is a critical component that controls the power delivery and performance of an electric bicycle. Its construction involves a microcontroller, power stage, sensors, and a user interface. By utilizing the principles of PWM, the controller regulates the flow of power from the battery to the motor, enabling smooth acceleration, and speed control, and implementing various safety features. Understanding the structure and principles of the electric bike controller is essential for optimizing the performance and safety of electric bicycles.