Introduction
When I started lecturing in 2002, drawing nice circuit diagrams was just a shlepp, until I discovered Circuit Macros. The PIC drawing language together with some basic circuit macros, made it an absolute delight to draw three, single-phase AC sources and three load impedances at exactly 120 to one another, to illustrate the symmetry of three-phase circuits. Below are some excerpts from one of the lectures I taught in 2003, Introduction to Balanced Three-Phase Circuits.
Drawing simple three-phase circuits
Click on any of the circuits below to display its source code
If it is a perfectly balanced three-phase supply, line and load,
the neutral current, , will be 0,
and a neutral conductor is not required.
As a matter of fact, the y-connected load doesn’t even have to have a neutral connection.
And neither does the supply.
Because there was zero current flowing in the neutral from the load back to the supply, the star point at the load will be “virtually” earthed.
The current in phase A, and the voltage drops over the Thévening equivalent impedance, the line impedance and the load impedance can easily be calculated as if it was a simple, series connected AC circuit.
Animating the above drawings
Because all the above drawings are precise, it makes them ideal for GIF animation,
