calculate_voltage_scaler_resistors.py

import math


def calculate_voltage_range(min_in, max_in, rf=47_000, radj=180_000):
    rin = 100_000
    adj_v = -10

    min_out = abs((rf / rin * min_in) + (rf / radj * adj_v))
    max_out = abs((rf / rin * max_in) + (rf / radj * adj_v))

    return min_out, max_out


R_SERIES = set([
    1.00, 1.05, 1.10, 1.15, 1.21, 1.27, 1.33, 1.40, 1.47, 1.54, 1.62, 1.69, 1.78, 1.87, 1.96,
    2.05, 2.15, 2.26, 2.37, 2.49, 2.61, 2.74, 2.87, 3.01, 3.16, 3.32, 3.48, 3.65, 3.83, 4.02,
    4.22, 4.42, 4.64, 4.87, 5.11, 5.36, 5.62, 5.90, 6.19, 6.49, 6.81, 7.15, 7.50, 7.87, 8.25,
    8.66, 9.09, 9.53
])
R_SERIES.update([1.0, 1.1, 1.2, 1.3, 1.5, 1.6, 1.8, 2.0, 2.2, 2.4, 2.7, 3.0, 3.3, 3.6, 3.9, 4.3, 4.7, 5.1, 5.6, 6.2, 6.8, 7.5, 8.2, 9.1])


def calculate_component_values(min_in, max_in):
    # inverting op amp
    max_out = 0
    min_out = 3.3

    rin = 100_000
    adj_base = 100_000
    rf_base = 10_000
    adj_v = -10

    for rfmul in R_SERIES:
        for adjmul in R_SERIES:
            rfval = rfmul * rf_base
            adjval = adjmul * adj_base

            min_out_candidate = abs((rfval / rin * min_in) + (rfval / adjval * adj_v))
            max_out_candidate = abs((rfval / rin * max_in) + (rfval / adjval * adj_v))
            zero_v_value = abs((rfval / rin * 0) + (rfval / adjval * adj_v))

            if abs(min_out_candidate - min_out) > 0.1:
                continue
    
            if abs(max_out_candidate - max_out) > 0.1:
                continue

            print(f"Vmin: {min_out_candidate:.2f} Vmax: {max_out_candidate:.2f} Spread {abs(max_out_candidate-min_out_candidate):.2f} V0: {zero_v_value:.2f} Rf: {rfval:.0f} Radj: {adjval:.0f}")



calculate_component_values(-2, +2)