Circuit Analysis & Fundamentals

The foundation of electrical engineering, worked in full: Ohm's law and the power wheel, series and parallel resistance, voltage and current dividers, series/parallel capacitance and inductance, RC and RL time constants with charge/discharge curves, RLC resonance with Q and bandwidth, stored energy in capacitors and inductors, AC impedance and phasors, Thévenin and Norton equivalents, the delta–wye transformation, and the Wheatstone bridge. Every tool shows the symbolic relationship, the numbers substituted in, and a labeled schematic of your circuit, and states its conventions (passive sign convention, RMS vs peak, ω = 2πf) explicitly. These are analysis and teaching tools — for understanding and preliminary analysis, not a substitute for full circuit design or code-compliant installation work — and they cross-link up into the Signals, Control, and Communications toolkits.

Ohm's Law Calculator & Power Wheel

Solve for voltage, current, resistance, or power from any two known values.

Resistor Series/Parallel Network Calculator

Equivalent resistance for up to six resistors in series or in parallel.

Voltage Divider Calculator

Output voltage of a two-resistor divider from the input and both resistors — or solve for the resistor that gives a target output. Shows the divider schematic and loading caveat.

Current Divider Calculator

Branch currents when a total current splits between two parallel resistors — with the inverse-ratio rule, the shared node voltage, and a labeled schematic.

Series/Parallel Capacitance & Inductance Calculator

Equivalent capacitance or inductance for series or parallel combinations — with the inverse-vs-resistor rules made explicit so you never mix them up.

RC / RL Time Constant Calculator

Time constant τ of an RC or RL circuit, the fraction charged/discharged at any time t, and the time to reach a target percentage — with a live charge/discharge curve.

RLC Resonance Calculator

Resonant frequency, quality factor Q, bandwidth, and damping for a series or parallel RLC circuit — with the resonance curve and half-power points drawn.

Capacitor & Inductor Energy Calculator

Energy stored in a capacitor (½CV²) or an inductor (½LI²), plus the stored charge or flux linkage — with the quadratic energy curve drawn.

AC Impedance & Phasor Calculator

Complex impedance of a series or parallel R-L-C combination at a chosen frequency — magnitude, phase, and both rectangular and polar forms, with the impedance-vs-frequency curve.

Thévenin / Norton Equivalent Calculator

Thévenin voltage and resistance, and the Norton current, for the classic source-behind-R1-with-R2-across-the-terminals network — plus load power and the maximum-power-transfer point.

Delta–Wye (Δ–Y) Conversion Calculator

Convert a three-resistor network between delta (Δ) and wye (Y / star) form in either direction, with both schematics drawn and the transformation steps shown.

Wheatstone Bridge Calculator

Balance condition and unknown resistance, or the bridge output (galvanometer) voltage of an unbalanced bridge — with the bridge schematic and the Vg-vs-Rx curve.