commit 6529ae14e52aeb91aac811974462ac03f5b1f3ac parent 6a5341b95d9de70377b260f9a35a296a068e8796 Author: jatinchowdhury18 <[email protected]> Date: Mon, 11 Feb 2019 15:02:59 -0800 add biasing section to paper Diffstat:
| M | Paper/420_paper.pdf | | | 0 | |
| M | Paper/420_paper.tex | | | 19 | ++++++++++++------- |
2 files changed, 12 insertions(+), 7 deletions(-)
diff --git a/Paper/420_paper.pdf b/Paper/420_paper.pdf Binary files differ. diff --git a/Paper/420_paper.tex b/Paper/420_paper.tex @@ -387,16 +387,21 @@ $27$ kA/m \cite{jilesBook}. \end{itemize} \subsection{Tape Bias} -A typical analog tape recorder modulates the input signal by a -"bias" signal to avoid the "deadzone" effect whenever the input -signal crosses zero \cite{Camras:1987:MRH:27189}. Thus, the -input signal to the record head can be described by: +A typical analog recorder adds a high-frequency "bias" +current to the signal to avoid the "deadzone" effect when the input signal +crosses zero, as well as to linearize the output. The input +signal to the record head can be given by +\cite{Camras:1987:MRH:27189}: \begin{equation} - \hat{V}_{head}(n) = \hat{V}_{in}(n) \cos(2 \pi f_{bias} n T) + \hat{V}_{head}(n) = \hat{V}_{in}(n) + B \cos(2 \pi f_{bias} n T) \end{equation} % -An output signal in the audio frequency range can be recovered -by a simple low-pass filter \cite{Camras:1987:MRH:27189}. +Where the amplitude of the bias current $B$ is at least one order +of magnitude larger than the input. The output signal can be +recovered after the recording and playback processes +by subtracting out the bias current. + +\subsection{Tape Speed} %\newpage