ELC-40

Norton current

Norton source from Thévenin.

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CircuitsNorton current

Governing equation

I_N=V_{th}/R_{th}

$R_{th} \in \left[0.1, 40\right]$

where

V_{th}: Vth (V)
R_{th}: Rth (Ω)
I_N: Norton (A)

The figure, part by part

Each numbered marker wears the color of its card. Hover a card to light the marker. Tap a marker to jump to that card. The slider walks a red point along the curve; Animate drawing traces it like a pen.

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①

Governing law — red

I_N=V_{th}/R_{th}

$R_{th} \in \left[0.1, 40\right]$

$R_{th} = 0.1$ $I_N = 120$

Along the curve

②

Domain of the variable — blue

R_{th}_{\min} = 0.1,\quad R_{th}_{\max} = 40

$R_{th} \in \left[0.1, 40\right]$

$R_{th} = 0.1$ $R_{th} = 0.1$

Along the curve

③

Response curve — green

I_N=V_{th}/R_{th}

$R_{th} \in \left[0.1, 40\right]$

$R_{th} = 0.1$ $I_N = 120$

Along the curve

④

Rate of change — amber

\frac{\mathrm{d}I_N}{\mathrm{d}R_{th}}

$R_{th} \in \left[0.1, 40\right]$

$R_{th} = 0.351$ $I_N^{\prime} = -199.4$

Along the curve

Lecture brief

Historical brief

Ohm (1827), Kirchhoff (1845) and Maxwell’s circuit reduction still run every board: RLC transients, transformers, skin effect and three-phase power. The sheets are those network laws, not a SPICE deck. This sheet (ELC-40 — Norton current) is the form associated with Norton current. Working symbols: $V_{th}$ , $R_{th}$ $\rightarrow$ $I_N$ . Norton source from Thévenin. Pedagogical SI sheet with a live model and a swept parameter.

Purpose

Purpose: compute

I_N

from

V_{th}

R_{th}

in Electrical via

I_N=V_{th}/R_{th}

Norton source from Thévenin. Use it when a real electrical question must be answered in SI before a code check.

Live realistic example

In symbols

Live case. Given

V_{th} = 12.000\,\mathrm{V}

R_{th} = 4.000\,\mathrm{Ω}

, the governing relation

I_N=V_{th}/R_{th}

yields

I_N = 3.000\,\mathrm{A}

. One governing identity, SI units, a single sweep on the sheet. Move a slider: the numbers are this situation, not a canned story.

Calculator

Inputs

Vth V_{th}12 VRth R_{th}4 Ω

Outputs

Norton I_N3.000 A

Reading speed

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Narration of this film

One governing identity, SI units, a single sweep on the sheet.

Norton source from Thévenin. Pedagogical SI sheet with a live model and a swept parameter.

Reading speed

Watch on YouTube