S-plane modelling of DC motor

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  • s refers to the Laplace transform complex variable, s = σ + j ω ,    j = √(-1) ,    σ and ω Real
  • the one-sided Laplace transform is assumed: F(s) = 0-∫ ∞ e-st f(t) dt



    • The test jig to measure motor characteristics is built from 16- and 45mm MDF board. The brushed motor is from a Shugart 5¼ inch floppy disk drive. The small nylon pulley - from a cassette recorder - is for torque measurements: a thin nylon line is run around the periphery of the SP10 rotor, over the pulley, and a small suspended container of sand provides adjustable tension.


    Test jig: click for bigger.

    Page 3 describes the feedback system. Page 4 has preliminary circuits.