Problem 11.2 - Input Impedance from Frequency-Domain Analysis
*
* The circuit for this problem is from textbook Example 11.6.
*
* Determine the input impedance of the right hand loop from the ratio
* of phasor voltage at node 1 to the phasor current through the
* resistance R2. Use PROBE to obtain a graph of the magnitude of the
* complex impedance Z2=V(1)/I(R2) and a separate graph of the angle.
* Also use PROBE to obtain graphs of the magnitudes and angles of the
* impedances Z1 and Z12, as identified in the problem statement.
*
* ===> To obtain a graph of the magnitude of the impedance, you can either
* take the ratio of magnitudes of the variables in the form
* VM(1)/IM(R2) or you can use the PSpice Version 4.04 complex number
* magnitude function M(x). The magnitude function finds the magnitude
* of any complex number x. In this case the form is M(V(1)/I(R2)).
*
* Also, the angle of the complex impedance can be found by taking the
* difference of the angles of the voltage and current in the form
* VP(1)-IP(R2) or by using the complex phase function in Version 4.04
* to find P(V(1)/I(R2)).
*
* At what frequency (approximately) are the impedances of the right-
* hand loop and the inductance equal in magnitude? What is the angle
* of each at that frequency? Note that it may help to plot another
* PROBE graph with a display of the two functions of interest.
*
* ===> CHALLENGE PROBLEM! In this circuit the node voltages V(1) and V(2)
* are approximately equal at all frequencies! The maximum amplitude of
* each of them approaches 1000 volts and yet the maximum amplitude of
* voltage V(1,2) is only 1 volt.
* Use PROBE to obtain graphs of VM(1) and VM(2) on one page a graph
* of VM(1,2) on another page. Using these graphs and the impedance
* magnitude and angle graphs from above, try to answer the questions
* asked in the problem statement.
*
.OPT NOPAGE NOBIAS ; This statement is for Versions 4.03 and later.
; For earlier versions, delete the NOBIAS term.
IS 0 1 ; Complete the source specification.
L1 1 0 1M
R1 1 2 1K
R2 2 0 1K
C1 1 2 1U
.AC ; Complete the .AC sweep command statement.
.PROBE
.END