E-Bike speed sensor targets high resolution signal
With the increasing popularity and growing trend of e-bikes, bicycle system suppliers have set goals to optimise power and performance of their drive systems.
To support the driver in the best possible way, sensors are needed to deliver the required data and therefore adapt the engine's power support. An essential component is the ZF e-bike sensor for measuring the current speed, which is based on Hall technology with significant advantages over conventional reed switches.
Especially for high-quality e-bikes, all components need to be functional, from the drive to the battery and cabling. This is also the case with the ZF e-bike sensor. Speed sensors of the GS series have been specially developed for use in Pedelecs and S-Pedelecs. The extremely compact design meets the necessary requirements for the use in e-bikes. The sensors are based on the principle of Hall-effect and therefore they are non-contact and durable. In combination with ferromagnetic target wheels, a high-resolution speed measurement with over 50 pulses per revolution can be implemented without any problems. In practice, this leads to a finer and quicker response from the e-bike drive - especially at lower speeds (e.g. when starting up a hill). The differential measurement of the magnetic flux also increases the robustness of the sensor against vibrations. In addition, there is no need for an external magnet, which is used with conventional reed switches. These are frail against even slight shifts on the spoke, which leads to functional failures and shut down of the drive unit.
The GS82-AA02 sensor is 21.75mm length, 9.35mm diameter. As an interface to the drive system, the Higo connector has a cross-section of 0.14mm² and due to its small size is prevalent in the e-bike industry. Depending on the customer's requirements the contact via connector, as well as the cable length, can be preselected individually. The sensor requires a constant voltage supply of 6.5 - 20VDC and measures frequencies between 1 and 2,500Hz. They are designed for a temperature range from -25°C to +85°C to fulfil the declaration of conformity in the e-bike industry.
This sensor was originally developed for ABS applications. In addition to e-bikes, other target markets include e-scooters and various sports equipment for this small and efficient sensor.