Acoustic Diagnostics of Electrical Origin Fault Modes with Readily Available Consumer-Grade Sensors

Acoustic diagnostics, traditionally associated with mechanical fault modes, can potentially solve a wider range of monitoring applications. Typically, fault modes are induced purposefully by the researcher through physical component damage whilst the system is shutdown. This paper presents low-cost real-time fault diagnostics of a previously unreported acute electrical origin fault that manifests sporadically during system operation with no triggering intervention. A suitability study into acoustic measurements from readily available consumer-grade sensors for low-cost real-time diagnostics of audible faults, and a brief overview of the theory and configuration of the wavelet packet transform (including optimal wavelet selection methods) and empirical mode decomposition processing algorithms is also included. The example electrical origin fault studied here is an unpredictable current instability arising with the PWM-controller of a BrushLess DC motor. Experimental trials positively detect 99.9 % of the 1160 resultant high-bandwidth torque transients using acoustic measurements from a USB microphone and a smartphone. While the use of acoustic techniques for detecting emerging electrical origin faults remains largely unexplored, the techniques demonstrated here can be readily adopted for the prevention of catastrophic failure of drive and power electronic components

NIOBIUM METALLABORANES - A NOVEL METALLABORANE ANALOG OF PENTABORANE(11)

Treatment of [Nb(η-C5H5)2H3] with pentaborane(9) gives the novel arachno-metallaboranes [Nb(η-C5H5)2B4H9 ] (1) and [Nb(η-C5H5)2B3H8 ] (2). Compound 1 is the first reported base subrogated analogue of the neutral arachno-pentaborane(11) and has an apex to niobium hydrogen bridge. Compound 2, for which the X-ray crystal structure has been determined, is an analogue of the neutral arachno-tetraborane(10). © 1990

NIOBIUM METALLABORANES - A NOVEL METALLABORANE ANALOG OF PENTABORANE(11)

Treatment of [Nb(η-C5H5)2H3] with pentaborane(9) gives the novel arachno-metallaboranes [Nb(η-C5H5)2B4H9 ] (1) and [Nb(η-C5H5)2B3H8 ] (2). Compound 1 is the first reported base subrogated analogue of the neutral arachno-pentaborane(11) and has an apex to niobium hydrogen bridge. Compound 2, for which the X-ray crystal structure has been determined, is an analogue of the neutral arachno-tetraborane(10). © 1990

TERMINAL SUBSTITUTION AND CAGE INCORPORATION OF AN ETA-CYCLOPENTADIENYL RING INTO BORANE CAGE STRUCTURES - CRYSTAL-STRUCTURES OF [MO(ETA-C5H5)(ETA-5 ETA-1-C5H4)B4H7] AND [MO(ETA-C5H5)(ETA-3 ETA-2-C3H3)C2B9H9]

The synthesis and crystal structure of the molybdaborane [Mo(η-C 5H5)(η5:η1-C 5H4)B4H7] (1) and of the molybdacarbaborane [Mo(η-C5H5)(η3: η2-C3H3)C2B9H 9] (2) formed via cyclopentadienyl ring activation are reported

TERMINAL SUBSTITUTION AND CAGE INCORPORATION OF AN ETA-CYCLOPENTADIENYL RING INTO BORANE CAGE STRUCTURES - CRYSTAL-STRUCTURES OF [MO(ETA-C5H5)(ETA-5 ETA-1-C5H4)B4H7] AND [MO(ETA-C5H5)(ETA-3 ETA-2-C3H3)C2B9H9]

The synthesis and crystal structure of the molybdaborane [Mo(η-C 5H5)(η5:η1-C 5H4)B4H7] (1) and of the molybdacarbaborane [Mo(η-C5H5)(η3: η2-C3H3)C2B9H 9] (2) formed via cyclopentadienyl ring activation are reported

SYNTHESIS OF SMALL NIDO-FERRAPENTABORANES - A NOVEL BORANE-CAPPED NIDO-DIFERRAPENTABORANE

Pentaborane(9) reacts with [Fe(PMe3)3(η 2-CH2PMe2)H] to give [2,3-{Fe(PMe 3)2}2(μ-H)B4H9] (1) and [2-{Fe(PMe3)3}B4H8] (2) in yields of up to 1 and 22% respectively; the X-ray crystal structure of (1) shows a nido-pentaborane(9) structure in which a BH3 fragment caps the Fe2B face