Glossary
BMS
BMS is an electronic circuit for battery monitoring. It increases a battery pack's
safety by making sure that all cells are operated within the permitted voltage
range only. When current is too high, the temperature is too high or one line of
batteries inside the battery is outside the permitted voltage range the charge
output will be switched off. This avoids the total discharge of the battery during
normal operation. An integrated balancer ensures that any differences in
voltage between single cells are equalised. In case of a problem with the
charging device, the BMS makes sure that the battery cannot be overcharged.
A capacity gauge may be included to display the remaining capacity.
Controller
The controller is the heart of any electric bicycle. It has the power electronics
to drive the motor and a microprocessor. The controller processes all input
signals coming from the different sensors and it talks to the display on the
handlebar. The microprocessor runs the firmware, which is the piece of
software telling the controller what to do. Firmware updates can be applied to
improve or add functions.
Display
The display is usually mounted to the handlebar and allows the rider to readout
vital information about the e-bike system and control the functions in the
controller. There are different kinds of controllers with LED or LCD interfaces.
Hall sensor
Hall sensors are used in motors, cadence sensors, brake switches, and power
throttles. Inside the motor, they determine the motor direction and submit it to
the controller so the motor will turn in the right direction right at the start.
Inside the PAS they detect if the magnet disc is rotating. Inside the power
throttle, they measure how far the throttle is rotated. Hall sensor can be of the
analogue or digital kind. Functional principle: When hall sensors are passing by
a magnetic field they emit an initial voltage, which is proportional to the
product of magnetic field strength and current (Hall Effect). They are named
after their inventor Edwin Hall.
17
