load_line1.py

import matplotlib.pyplot as plt
import numpy as np

# Given values
VCC = 30  # Volts
RC = 2_000  # Ohms
RE = 1_000  # Ohms
RB = 300_000  # Ohms
beta = 100
VBE = 0.7  # Volts

# Calculated values
R_total = RC + RE
IC_sat = VCC / R_total  # Saturation current (V_CE ~ 0)

# Base current
IB = (VCC - VBE) / RB
IC = beta * IB  # Active region collector current

# Create points for load line
IC_points = np.linspace(0, IC_sat, 100)
VCE_points = VCC - IC_points * R_total

# Plotting
plt.figure(figsize=(8,6))
plt.plot(VCE_points, IC_points, label='Load Line', color='blue')

# Mark Q-point
VCE_Q = VCC - IC * R_total
plt.plot(VCE_Q, IC, 'ro', label='Q-Point (Operating Point)')

# Labels and Title
plt.title('BJT DC Load Line')
plt.xlabel('VCE (V)')
plt.ylabel('IC (A)')
plt.grid(True)
plt.legend()
plt.xlim(0, VCC)
plt.ylim(0, IC_sat * 1.2)

plt.show()