@ -88,42 +88,44 @@ Measuring the electric power makes most sense on the customer appliances. The fi
When it comes to measuring the electrical power, the first and the most important thing to discuss is safety. Only after all the safety precautions had been made clear, the theory can be clarified and subsequently, the practice can be applied.
\subsubsection{Voltage ranges and safety disclaimer}
The \gls{iec} international standard \textbf{IEC 60038:1983} defines a set of standard \glspl{voltage} for use in AC electricity supply systems.
%\subsubsection{Voltage ranges and safety disclaimer}
%The \gls{iec} international standard \textbf{IEC 60038:1983} defines a set of standard \glspl{voltage} for use in AC electricity supply systems.
%
%\begin{table}[ht!]
%\centering
%\caption{International standards grouping ranges of supply voltages to three categories}
%\label{t:volt_ranges}
%\tabcolsep=5pt
%\renewcommand{\arraystretch}{1.3}
%\begin{tabular}{|l|l|l|l|}
%\hline
%{\bf IEC voltage range}&{\bf AC}&{\bf DC}&{\bf defining risk}\\\hline
%High voltage &\textgreater 1000 V$_{RMS}$&\textgreater 1500 V & electrical arcing \\\hline
%Low voltage & 50–1000 V$_{RMS}$& 120–1500 V & electrical shock \\\hline
%Extra-low voltage &\textless 50 V$_{RMS}$&\textless 120 V & low risk \\\hline
%\end{tabular}
%\end{table}
%The appliances under test work on mains voltage. In Europe, the nominal voltage of mains line for appliances is 230 V / 50 Hz. This falls into the voltage range, with defining risk of \textbf{electrical shock} as described in the table \ref{t:volt_ranges}.
\begin{table}[ht!]
\centering
\caption{International standards grouping ranges of supply voltages to three categories}
\label{t:volt_ranges}
\tabcolsep=5pt
\renewcommand{\arraystretch}{1.3}
\begin{tabular}{|l|l|l|l|}
\hline
{\bf IEC voltage range}&{\bf AC}&{\bf DC}&{\bf defining risk}\\\hline
High voltage &\textgreater 1000 V$_{RMS}$&\textgreater 1500 V & electrical arcing \\\hline
Low voltage & 50–1000 V$_{RMS}$& 120–1500 V & electrical shock \\\hline
Extra-low voltage &\textless 50 V$_{RMS}$&\textless 120 V & low risk \\\hline
\end{tabular}
\end{table}
If not handled with care, operating or manipulating with voltage can cause permanent damage to appliance or health, or can cause fire or even death. Thus, respect, increased care and knowledge is necessary in all further practical steps involved.
The appliances under test work on mains voltage. In Europe, the nominal voltage of mains line for appliances is 230 V / 50 Hz. This falls into the voltage range, with defining risk of \textbf{electrical shock} as described in the table \ref{t:volt_ranges}.
%\subsubsection{Measurement procedure}
%With the formula for the electrical power being
%$P = I \cdot U$
%the conclusion can be made, that the procedure for measuring the electrical power produced or consumed by circuit consists of measuring the current flowing at the given voltage at the time instant and then multiplying them together. Repeating this sufficiently enough times, the power can be plotted with respect to time.
%
%However, as seen in a subsection \ref{ss:ac_power}, this procedure would measure the \textit{apparent} power, which includes the power stored in reactive elements and later returned to the circuit. To have a useful result of a measurement, the \textit{real} power is desired. Thu keeping track of the \textit{phase angle} is needed.
%
%
%\subsubsection{Measuring electric power with a microcontroller}
%some words about sampling too
If not handled with care, operating or manipulating with voltage can cause permanent damage to appliance or health, or can cause fire or even death. Thus, respect, increased care and knowledge is necessary in all further practical steps involved.
\subsubsection{Measurement procedure}
With the formula for the electrical power being
$P = I \cdot U$
the conclusion can be made, that the procedure for measuring the electrical power produced or consumed by circuit consists of measuring the current flowing at the given voltage at the time instant and then multiplying them together. Repeating this sufficiently enough times, the power can be plotted with respect to time.
However, as seen in a subsection \ref{ss:ac_power}, this procedure would measure the \textit{apparent} power, which includes the power stored in reactive elements and later returned to the circuit. To have a useful result of a measurement, the \textit{real} power is desired. Thu keeping track of the \textit{phase angle} is needed.
\subsubsection{Measuring electric power with a microcontroller}
some words about sampling too
\newpage
\section{ESP8266 wi-fi node}
since it is used, the whole section should be designated to provide some description about it
\newpage
@ -288,6 +290,10 @@ Whole printed circuit board of TL-WR703N was remade by the GL.inet team to expos
\end{figure}
\newpage
\section{ESP8266 wi-fi node}
since it is used, the whole section should be designated to provide some description about it
Peter Babič
9 years ago