Noise quality detector for electric motors or other machines

Abstract

Abstract Such detector is adapted to detect a transducer signal indicative of the level of noise, or the actual measured noise, produced by an electric motor or the like, particularly for the purpose of quality control in connection with a production line, automated or manual, so that motors which produce excessive noise or are defective may be identified and rejected. The detector employs an accelerometer or some other transducer, i.e. a microphone, for receiving the vibration or noise from each motor and converting the noise into electrical signals. After amplification, the signals are sent through a bandpass filter or a plurality of filters which selectively transmit those signals which are within a particular band of frequencies, while attenuating signals which are outside such band. The filter preferably has controls for adjusting both the upper and lower cutoff frequencies of the filter. The output signals from the filter are compared with a predetermined level. One or more indicating devices are operated by the comparison device to indicate whether the detected noise level is above or below such level. The indicating devices may be in the form of lamps or a meter. It is preferred to detect both the peak signal level and the average signal level so that the motor will be rejected if either level is above the desired level. The disclosed device is adapted to detect and indicate the noise quality of a plurality of motors in sequence on an automatic basis.

Inventors

• 👤 John G Bollinger
• 👤 Robert J Sandberg

Bibliographic Details