Method and apparatus for determining fan bearing friction

Abstract

A fan test system and method for determining fan bearing friction and available life, including a power controller for changing the fan's power level for at least a predetermined time period and a measuring device for measuring the change in rotation of the fan. A memory is preferably coupled to the power controller for storing a plurality of rotation values for providing a history of fan bearing performance. A current sensor or current limiter is preferably coupled in series with the fan, where the measuring device detects voltage pulses or poles of the fan. The power controller preferably includes a timer for determining the time period and a counter for counting rotation events. The power controller also preferably includes a control circuit for controlling a switch coupled between a power source and the fan. In a first embodiment, the power controller removes power from the fan for a relatively short period of time during normal operation while the fan is operating at a desired operating speed or energy level. In a second embodiment, the power controller activates the fan from a rest position and the measuring device measures the spin-up rotation of the fan. In a third embodiment, the power controller controls a variable power source for incrementally increasing the voltage applied to the fan during startup for determining a startup voltage.

Dependencies are inferred from the claim text.