Robin Clark
c0e57b4513
After meeting (Dave?} at methodist church talking about resistor failure modes with him.
73 lines
1.9 KiB
TeX
73 lines
1.9 KiB
TeX
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% Make the revision and doc number macro's then they are defined in one place
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\ifthenelse {\boolean{paper}}
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{
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\begin{abstract}
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\end{abstract}
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}
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{
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\section{Overview}
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Component failure modes are documented for most generic
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components~\cite{mil1992}~\cite{rac}. There are some differences in
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the failure modes that we are required to consider for various
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safety standards.
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For an example of this we can look in detail at one particular
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type
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of component, and examine potential causes of failure modes and
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and how various standards demands in terms of possible failure modes.
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For this study the common resistor ahs been chosen.
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}
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\section{Resistor Failure Modes}
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Most common failure OPEN
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ENXXX ays only consider OPEN
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EN298 considers OPEN and SHORT
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\subsection{Physical causes for a resristor short}
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* over heating causing a solder bridge
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* over heating causing the component to melt and short (wirewound)
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\subsection{Physical causes for a resristor open}
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* Over current causing the component to burn out (acting like a fuse).
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* vacuum conditions can cause solder joints to sublime (space ref jbis)
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\subsection{Physical causes for a resristor parameter change}
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*the resistor can react to over heating by becoming
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damaged so that the resistance track is internally shorted, making the
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part read a lower resistance
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*the resistor can over heat and the resistance track and be made thinner leading to a higher resistance
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*chemical attack could alter the properties of the resistance track.
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*RAC give parameter change as well
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this means that the resistor may change its resistance value
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as a failure mode.
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\section{Properties of a resistor network}
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RAC gives a resistor network
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as having only failure modes of
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OPEN and SHORT.
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Let us consider a simple resistoir network.
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Examine all causes.
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Assume resistors not from same batch.
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Show how parameter change is cancelled out, use sum of squares statistics
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to show by how much.
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