Example milli-volt amplifier given a diagram

presentations/fmea/fmea_pres.tex

@@ -45,20 +45,42 @@
 
 
 \begin{frame}
-
+ \frametitle{ FMEA Example: Milli-volt reader}
 Example: Let us consider a system, in this case a milli-volt reader, consisting
 of instrumentation amplifiers connected to a micro-processor
 that reports its readings via RS-232.
+\begin{figure}
+ \centering
+ \includegraphics[width=175pt]{./mvamp.png}
+ % mvamp.png: 561x403 pixel, 72dpi, 19.79x14.22 cm, bb=0 0 561 403
+\end{figure}
+
+
+\end{frame}
+
+
+\begin{frame}
+ \frametitle{FMEA Example: Milli-volt reader}
 Let us perform an FMEA and consider how one of its resistors failing could affect
 it.
-For the sake of example let us choose a resistor in an OP-AMP
-reading the milli-volt source and that if it were to go open, we would have a gain 
-of 1 from the amplifier.
+For the sake of example let us choose resistor R1 in the  OP-AMP gain circuitry.
+\begin{figure}
+ \centering
+ \includegraphics[width=175pt]{./mvamp.png}
+ % mvamp.png: 561x403 pixel, 72dpi, 19.79x14.22 cm, bb=0 0 561 403
+\end{figure}
 
+\end{frame}
+
+
+
+
+\begin{frame}
+ \frametitle{FMEA Example: Milli-volt reader}
 \begin{itemize}
   \pause \item \textbf{F - Failures of given component} The resistor could fail by going OPEN or SHORT (EN298 definition).
    \pause \item \textbf{M - Failure Mode} Consider the component failure mode OPEN
-   \pause \item \textbf{E - Effects} This will disconnect the feedback loop in the amplifier causing a LOW READING
+   \pause \item \textbf{E - Effects} This will disconnect the feedback loop in the amplifier, driving the minus input HIGH causing a LOW READING
   \pause \item \textbf{A - Analysis} The reading will be out of normal range, and we will have an erroneous milli-volt reading
 \end{itemize}
 \end{frame}
@@ -83,26 +105,28 @@ approach in looking for system failures.
 Consider the analysis
 where we look at all the failure modes in a system, and then 
 see how they can affect all other components within it.
-
- 
-We need to look at a large number of failure scenarios
-to do this completely (all failure modes against all components).
-This is represented in equation~\ref{eqn:fmea_state_exp},
-where $N$ is the total number of components in the system, and 
-$cfm$ is the number of failure modes per component.
 \end{frame}
 
 
-\begin{frame}
+ \begin{frame}
 \frametitle{Rigorous Single Failure FMEA}
-
+We need to look at a large number of failure scenarios
+to do this completely (all failure modes against all components).
+This is represented in the equation below. %~\ref{eqn:fmea_state_exp},
+where $N$ is the total number of components in the system, and 
+$cfm$ is the number of failure modes per component.
+  
 
 \begin{equation}
   \label{eqn:fmea_single}
   N.(N-1).cfm % \\
   %(N^2 - N).cfm 
 \end{equation}
+\end{frame}
 
+
+\begin{frame}
+\frametitle{Rigorous Single Failure FMEA}
 This would mean an order of $N^2$ number of checks to perform
 to perform `rigorous~FMEA'. Even small systems have typically
 100 components, and they typically have 3 or more failure modes each.
@@ -330,7 +354,7 @@ safety Integrity.
 For Hardware 
 
 FMEDA does force the user to consider all components in a system
-by requiring that a MTTF value is assigned.
+by requiring that a MTTF value is assigned for each failure~mode.
 This MTTF may be statistically mitigated (improved)
 if it can be shown that selfchecking will detect failure modes.
 \end{frame}
@@ -421,8 +445,8 @@ FMEDA is a modern extension of FMEA, in that it will allow for
 self checking features, and provides detailed recommendations for computer/software architecture.
 It also has a simple final result, a Safety Integrity Level (SIL) from 1 to 4 (where 4 is safest).
 
-FMEA can be used as a term simple to mean Failure Mode Effects Analysis, and is
-part of product approval for many regulated products in the EU and the USA...
+%FMEA can be used as a term simple to mean Failure Mode Effects Analysis, and is
+%part of product approval for many regulated products in the EU and the USA...
 
 \end{frame}
 
@@ -672,7 +696,9 @@ not all the components in the system.
 \textbf{traceability}
 Because each reasoning stage contains associations ($FailureMode \mapsto Sypmtom$)
 we can trace the `reasoning' from base level component failure mode to top level/system
-failure.
+failure, by traversing the tree.
+
+
 \end{frame}
 
 \begin{frame}