eldo_user

Eldo Control Language
Library of Functions for Tasks
* Parallel RLC circuit.
vin 1 0 ac 10
r2 1 2 50
r3 2 3 50k
r5 3 0 50
l1 2 3 100u
c4 2 3 10n
.ac dec 10 1 1g
.option eps = 1.0e-6
.plot w2=v(2) w1=v(1)
.define_task plot_bandwidth
set w1 = 0
set w2 = 0
set w_db_gain = 0
set w_bandwidth = 0
set fcut[] = 0
/* Run the simulation and calculate gain. */
simulation(w1 = @w1, w2 = @w2)
/* Compute the gain and save the waveform. */
w_db_gain = db(w2 / w1)
wsave(wstdout, w_db_gain, "results")
/* Compute the -3dB bandwidth. */
fcut = xval(w_db_gain, -3)
if (fcut.size != 2)
fprint(stdout, "Failed to compute the -3dB bandwidth.\n")
return -1
else
fprint(stdout, "\n\t-3dB bandwidth = (%.2eHz, %.2eHz)\n",
fcut[fcut.imin], fcut[fcut.imin + 1])
endif
/* Create enum data type: 0: cut, 1: pass. */
wcreate_data_type("cut_pass", "-Enum")
wadd_data_enum_value("cut_pass", "cut", 0)
wadd_data_enum_value("cut_pass", "pass", 1)
/* Create the waveform showing graphically the -3dB bandwidth. */
w_bandwidth = wcreate_wave(wstdout, "bandwidth", "results",
"double_frequency", "cut_pass", "-LOG_X")
/* It is usually more efficient to create 2 vectors for x and y values
and call wset_values only once. But here since there are few values, it is
not a real problem to do this: */
wset_values(w_bandwidth, 1, 0)
wset_values(w_bandwidth, fcut[fcut.imin], 1)
wset_values(w_bandwidth, fcut[fcut.imin + 1], 0)
wset_values(w_bandwidth, 1G, 0)
fprint(stdout, "\n\tPlot of bandwidth succeeded.\n")
.end_define_task
976
Eldo® User's Manual, 15.3