Scicos Diagram
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Continuous Voltage Controlled Oscillator

\epsfig{file=scicos_vco_diagr.eps,height=9cm}

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Description

This diagram realizes an open loop model of a continuous Voltage Controlled Oscillator.
Regular output of the VCO is described with the following formula :

\begin{eqnarray} y_{\rm {s}}\left(t\right)=\cos \left[\left(\omega_{0}t\right)+\int^{t}_{0} k_{\rm {v}} u_{3}\left(\tau\right)d\tau\right], \end{eqnarray}


with $ \omega_{0}$ the free pulsation of the VCO, $ k_{\rm {v}}$ the linear sensitivity (expressed in rad/s) and $ u_{3}$ the control voltage.
Integration of input voltage and detection of crossing are made with the integral block and zeros crossing block of scicos which use the integrated solvers lsoda or daskr.

Context 


Fo     = 10e6
To     = 1/Fo
wo     = 2*%pi*Fo
alpha  = 60e6
kv     = 60e6
j_vco  = 100e6
N      = 3
Nsampl = 80
Tsampl = To/Nsampl
Fsampl = 1/Tsampl
Tfin   = 15*To

Scope Results

\begin{figure}\begin{center} \epsfig{file=scicos_vco_scope_1.eps,width=330.00pt} \end{center}\end{figure}
Figure : Input and output voltage of VCO

\begin{figure}\begin{center} \epsfig{file=scicos_vco_scope_2.eps,width=330.00pt} \end{center}\end{figure}
Figure : Events generated by the - to + block

\begin{figure}\begin{center} \epsfig{file=scicos_vco_scope_3.eps,width=330.00pt} \end{center}\end{figure}
Figure : Events generated by the frequency divider block

See Also

Authors

A. Layec