% Author: Prof. Dr. Matthias Jung, DL9MJ
% Year: 2026
\begin{tikzpicture}
    \begin{scope}
        \begin{axis}[
            axis lines=center,
            axis line style={-Triangle},
            scale only axis,
            axis on top,
            height=2.2cm,
            width=\linewidth*\getDarcImageFactor,
            xmin=0,
            xmax=24*pi,
            ymin=-1.15,
            ymax=1.45,
            ticks=none,
            xlabel={$t$},
            xlabel style={anchor=north},
            ylabel={$U$},
            ylabel style={anchor=east},
            clip=false,
        ]

        % Input signal: f = 1 kHz, one period corresponds to 1 ms
        \addplot[
            smooth,
            mark=none,
            DARCblue,
            thick,
            domain=0:24*pi,
            samples=1800
        ]
        {0.8*sin(deg(x))};

        % Gate boundaries
        \draw[dashed, thick]
            (axis cs:8.7*pi,-1.0)
            -- (axis cs:8.7*pi,1.15);

        \draw[dashed, thick]
            (axis cs:13.3*pi,-1.0)
            -- (axis cs:13.3*pi,1.15);

        % Gate-time arrow
        \draw[Triangle-Triangle, thick]
            (axis cs:8.7*pi,1.18)
            -- node[above] {kurze Torzeit $T_\mathrm{G}=\qty{2,3}{\milli\second}$}
            (axis cs:13.3*pi,1.18);

        % Counted positive zero crossings
        \foreach \x in {10,12}{
            \addplot[
                only marks,
                mark=*,
                mark size=1.8pt,
                DARCblue
            ]
            coordinates {({\x*pi},0)};
        }

        \node[anchor=north]
            at (axis cs:11*pi,-1.0)
            {$N=2 \quad\Rightarrow\quad f_\mathrm{M}=\dfrac{N}{T_\mathrm{G}}\approx\qty{870}{\hertz}$};

        \end{axis}
    \end{scope}

    \begin{scope}[
        shift={(0,-3.4/\getDarcImageFactor)}
    ]
        \begin{axis}[
            axis lines=center,
            axis line style={-Triangle},
            scale only axis,
            axis on top,
            height=2.2cm,
            width=\linewidth*\getDarcImageFactor,
            xmin=0,
            xmax=24*pi,
            ymin=-1.15,
            ymax=1.45,
            ticks=none,
            xlabel={$t$},
            xlabel style={anchor=north},
            ylabel={$U$},
            ylabel style={anchor=east},
            clip=false,
        ]

        % Input signal: f = 1 kHz, one period corresponds to 1 ms
        \addplot[
            smooth,
            mark=none,
            DARCblue,
            thick,
            domain=0:24*pi,
            samples=1800
        ]
        {0.8*sin(deg(x))};

        % Gate boundaries
        \draw[dashed, thick]
            (axis cs:0.7*pi,-1.0)
            -- (axis cs:0.7*pi,1.15);

        \draw[dashed, thick]
            (axis cs:21.3*pi,-1.0)
            -- (axis cs:21.3*pi,1.15);

        % Gate-time arrow
        \draw[Triangle-Triangle, thick]
            (axis cs:0.7*pi,1.18)
            -- node[above] {lange Torzeit $T_\mathrm{G}=\qty{10,3}{\milli\second}$}
            (axis cs:21.3*pi,1.18);

        % Counted positive zero crossings
        \foreach \x in {2,4,6,8,10,12,14,16,18,20}{
            \addplot[
                only marks,
                mark=*,
                mark size=1.8pt,
                DARCblue
            ]
            coordinates {({\x*pi},0)};
        }

        \node[anchor=north]
            at (axis cs:11*pi,-1.0)
            {$N=10 \quad\Rightarrow\quad f_\mathrm{M}=\dfrac{N}{T_\mathrm{G}}\approx\qty{971}{\hertz}$};
        \end{axis}
    \end{scope}
\end{tikzpicture}