Basic Circuit Laws
Every basic circuit laws calculator on CalcEngines — unit converters, derived indices and interpretive tools, each with its formula, a worked example and the reference intervals it is judged against.
10 calculators in this section
- Current Divider CalculatorHow a current splits between resistors in parallel: the current in every branch, its share as a percentage, the voltage across the group and the power each resistor has to get rid of — for up to six branches, with the two-resistor shortcut and the sign of it that everybody gets wrong.
- Delta-Wye Transformation CalculatorConvert a three-terminal resistor network between its delta (Δ, mesh) and wye (Y, star) forms in either direction, for unequal arms or balanced ones — and check the answer against the resistance you would actually measure between the terminals.
- Load Line CalculatorThe graphical method that explains every nonlinear-device bias problem: a device's own I-V curve crossed with the straight line a supply and a series resistor impose, and the operating point where they meet — for a diode, an LED, a zener in reverse, or an NTC thermistor whose curve moves with its own self-heating.
- Ohm’s Law CalculatorEnter any two of voltage, current, resistance and power and get the other two, with units scaled automatically from µA to kA and mΩ to MΩ — plus the full wheel of twelve Ohm's-law formulas.
- Resistor Power Rating CalculatorThe power a resistor really dissipates from its resistance and either the voltage across it or the current through it, the next standard wattage to buy after derating, what the manufacturer's derating curve allows at your ambient temperature, and how hot the part itself gets.
- Series and Parallel Resistor CalculatorTotal resistance of up to six resistors in series or in parallel, with the voltage across and current through each one, the power every resistor has to get rid of, and the nearest single standard value to the combination.
- Thévenin and Norton Equivalent CalculatorReplace a source and its resistor network with one voltage source and one resistance — or one current source and the same resistance — and see exactly what the equivalent predicts under any load: voltage, current, power, and the load that draws the most power from it.
- Two-Loop Mesh Current CalculatorTwo loops with their own sources and a resistor in common, solved by Kirchhoff's voltage law and Cramer's rule — with the matrix, the determinant and both cofactors printed, the branch currents including the shared one, the power in every element, and a power-balance check on the answer.
- Voltage Divider CalculatorOutput voltage of a two-resistor divider, how much a load pulls it down, the current and power in each resistor — and a design mode that picks a standard E24 or E96 pair for the voltage you want.
- Wheatstone Bridge CalculatorThe general four-arm bridge: the exact output voltage when it is out of balance, the balance condition R1·R4 = R2·R3 and the unknown resistance it gives you, the Thévenin resistance the detector sees, the sensitivity in volts per ohm, and what a real detector with its own resistance actually reads.