How to DC-sweep resistive voltage divider using PySpice

The following code simulates a resistive 10kΩ / 1kΩ voltage divider using PySpice using a DC sweep and can serve as a suitable starting point for simulating simple circuits. We sweep from 0V to 5V in steps of 10mV.

Also see our previous post How to simulate resistive voltage divider using PySpice for an alternate version using transient analysis:

import PySpice.Logging.Logging as Logging
logger = Logging.setup_logging()

from PySpice.Probe.Plot import plot
from PySpice.Spice.Netlist import Circuit
from PySpice.Unit import *

circuit = Circuit("MyCircuit")
# Create voltage source: 5V DC
source = circuit.VoltageSource('in', 'in', circuit.gnd, [email protected]_V)
# Create resistor divider
r1 = circuit.R('R1', 'in', 'n1', [email protected]_kΩ)
r2 = circuit.R('R2', 'n1', circuit.gnd, [email protected]_kΩ)
# Simulate for 1 second with steps of 1 millisecond
simulator = circuit.simulator(temperature=25, nominal_temperature=25)
analysis = simulator.dc(Vin=slice(0, 5.0, 0.01))

You can access the array of output voltages of the divider (i.e. node n1) using analysis['n1']Keep in mind that if the first argument of circuit.VoltageSource is 'in', the argument to simulator.dc will be valled Vin,  not just  in! A Vwill automatically be  prepended!

 

This is the code we used to plot this:

import matplotlib.ticker as mtick
import matplotlib.pyplot as plt
from UliEngineering.EngineerIO import format_value

def format_volts(value, pos=None):
    return format_value(value, 'V')

plt.style.use("ggplot")
plt.xlabel("Input voltage")
plt.xlabel("Divider output voltage")
plt.gca().yaxis.set_major_formatter(mtick.FuncFormatter(format_volts))
plt.gca().xaxis.set_major_formatter(mtick.FuncFormatter(format_volts))
plt.gcf().set_size_inches(8,5)
plt.plot(analysis["in"], analysis["n1"], label="Input voltage")
plt.savefig("/ram/PySpice-Voltage-Divider-Sweep.svg")