Flexible and non-contact measurement of motor speed

摘要

Motor speed is usually measured by means of an internal sensor bearing or an optical encoder with fixed pulse counts, whereby a separate sensor or code disc (code wheel) is required for each pulse count. This has a negative impact on both flexibility in the application and storage of spare parts. When sensor bearings are used, the electronic unit is frequently not rugged enough and so is susceptible to external causes of malfunction. In addition, the time involved in servicing internal sensors and consequent loss of availability in the event of a sensor malfunction brings considerable expense.