LTSpice_Simulator module

A Module responsible getting LTSpice simulation data as for verification. Ensure that ‘LTSpice_exe_Path’ in this file points to your LTspice installation. Requires the the LC interface spice file template ‘LC_Spice_Input.txt’ which must be in the root directory.

LTSpice_Simulator.get_Spice_Arrays(**new_Spice_values)

Runs a LTSpice simulation on a Circuit theory LC interface as well as a distributed LC interface. Returns associated arrays. Useful for comparing distributed effects to lumped element effects, and the distributed soltuion made in using Wavefront_Generation.Full_Cycle().

Parameters:

new_Spice_values – A set of key-value pairs used to configure the simulaiton. This dictonary is calculatedd on the creation of a Wavefront_Storage.Data_Input_Storage,

storete under the parameter of SPICE_input_values. Default simulation values are as follows and will be overwritten with provided key-values.

new_Spice_values:

  • L_impedance (str) - The inductor impedance. Default is ‘100’.

  • L_time (str) - The inductor time constant. Default is ‘1’.

  • C_impedance (str) - The capacitor impedance. Default is ‘1’.

  • C_time (str) - The capacitor time constant. Default is ‘1’.

  • number_periods (str) - The number of periods to simulate. Default is ‘1’.

  • L_tot (str) - The total inductance. Default is ‘L_impedance*L_time/2 ‘.

  • C_tot (str) - The total capacitance. Default is ‘C_time/(2*C_impedance)’.

  • Simulation_stop_time (str) - The simulation stop time. Default is ‘2*number_periods*pi*sqrt(L_tot*C_tot)’.

  • Step_size (str) - The step size for the simulation. Default is ‘0.01’.

  • V_source (str) - The voltage of the source. Default is ‘1’.

Returns dictionary of output arrays [np.ndarrays]:

dict{

  • “Time”,

  • “Inductor_Voltage_Circuit”,

  • “Inductor_Current_Circuit”,

  • “Capacitor_Voltage_Circuit”,

  • “Capacitor_Current_Circuit”,

  • “Inductor_Voltage_Tx”,

  • “Inductor_Current_Tx”,

  • “Capacitor_Voltage_Tx”,

  • “Capacitor_Current_Tx”

}

manual SPICE simulaiton
from LTSpice_Simulator import get_Spice_Arrays
import matplotlib.pyplot as plt

# Do manual simulation

# Change Impedances and simulaiton timestep
LTSpice_Arrays = get_Spice_Arrays(L_impedance = '500',C_impedance = '20', Step_size='0.1')

# Plot Inductor votlage using Lumped circuit elements
plt.plot(LTSpice_Arrays['Time'],LTSpice_Arrays['Inductor_Voltage_Circuit'])
plt.title('Lumped Element analysis of Inductor Voltage')
plt.xlabel('time (s)')
plt.ylabel('Voltage (V)')
plt.show()
Using SPICE to verify output
from LTSpice_Simulator import get_Spice_Arrays
from Wavefront_Generation import Full_Cycle
from Wavefront_Plotting import plot_time_interconnect
import matplotlib.pyplot as plt

interface = Full_Cycle(L_impedance = '500',C_impedance = '20')

# get spice kwarg array
spice_kwargs = interface.data_input.SPICE_input_values

# set step-size to be GCD/8 to be safe
step_size = interface.data_input.GCD/8

# get arrays
LTSpice_outputs = get_Spice_Arrays(**spice_kwargs,Step_size=str(step_size))

fig,ax = plt.subplots()

# plot lumped current
ax.plot(LTSpice_outputs['Time'],LTSpice_outputs['Capacitor_Current_Tx'])

# plot distributed from LTSpice
ax.plot(LTSpice_outputs['Time'],LTSpice_outputs['Capacitor_Current_Circuit'])

# plot distributed from simulator
plot_time_interconnect(interface.data_output_ordered,ax,'Current Capacitor',True)

ax.legend(['LT-lumped','LT-dist','Wavefronts'])

plt.show()

Warning

does not account for the lengths of the capacitor and inductor. Also only wokrs for LC osscialtor configuration with no load.