Flexible measurement of motor speed

Using conventional methods (e.g. internal sensor bearings, optical encoders), precise measurement of the speed of motors is a very difficult, error-prone undertaking. Difficulties arise through insufficiently rugged electronics, excessive installation tolerances between the code disc and optical module, excessive temperature-related material expansion or dust vulnerability. To counter these problems, Contelec has launched an innovative sensor concept. In this solution, based on Vert-X MH-X2 technology, a flat, external sensor records the speed of the main shaft – without any physical contact. All that is needed is to tap a thread in the main shaft to secure the magnetic actuator.

The sensor unit in turn is attached to the back of the motor or the fan housing and aligned. The shape of the sensor unit has been optimised to create a negligible influence on the air flow. To simplify installation, Contelec can supply preconfigured incremental encoders. These can be programmed with various customer-specific pulse counts (pulses per revolution and channel). The encoder concept is convincing with its impressive features, including up to 12-bit resolution (quadrature) and the various available interfaces (TTL, Differentiel RS422, Push-pull/HTL, Open collector). Another significant advantage is that the rugged, fully moulded incremental encoders (IP68) are suitable not just for use in new motors. They can also be easily retrofitted to existing motors. Installation is further simplified by the large permissible axial and radial offset.

Automotive / Motor Sports

Railway technology


Heating / ventilation / air conditioning



Mechanical engineering


Measurement instruments

Mobile vehicles

©  2021 Contelec AG