From a connection table to a trustworthy schematic

Write the electrical intent first

A schematic is a representation of connections, values, and device models. A drawing that looks connected may contain two different nets, and two distant labels may intentionally name one net. Begin with a connection table before placing symbols. For the RC example, list V1 between supply and 0 at 3.3 V, R1 between supply and out at 10 kΩ, and C1 between out and 0 at 100 nF.

In ALcad or another schematic editor, use the available component placement, wire, label, and value controls to express that table. Check capacitor polarity if the selected physical part is polarized. Ground names the reference node; it does not imply a protective-earth connection. Record symbol pin ordering when converting the drawing to a netlist.

Audit before requesting an analysis

Follow each node with your eyes and verify all intended terminals. Check that a crossing wire is actually joined when intended, and that unjoined crossings remain separate. Inspect displayed values and exported numeric units: 100 nF must become 100n or 1e-7 F, not 100 μF. A standard SPICE suffix M means milli; use MEG for mega when needed.

The nominal settled DC output is 3.3 V with an unloaded ideal capacitor. The step time constant is 1 ms and corner is 159.154943 Hz. These three predictions provide a connection audit independent of the drawing's visual polish.

Keep execution evidence specific

If your editor exposes netlist export or simulation, compare its generated connections and analysis settings with the course deck. Only describe an analysis as executed after reading its actual output and status. This lesson does not guarantee ALcad support for a particular import, engine, or analysis; standalone SPICE remains the reproducible reference path provided here.

Save the schematic and a plain connection list with assumptions, expected values, and tool/version. Reopen and confirm the values are retained. A saved picture proves the drawing exists; numerical result files separately establish an analysis. The ngspice documentation documents netlist units and element conventions.