Circuits & power reference

Electrical

Circuit analysis and power quality reference — Ohm's law, resistor networks, and power factor with real UK reactive-charge context.

Electrical Circuit

Ohm's law solver — voltage, current, resistance and power from any two — plus series and parallel resistor networks.

V = I·R · P = V·I
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Resistor Colour Code Calculator

4-band decode and encode — pick colours for ohms, or type a resistance for the nearest standard bands. IEC 60062.

digit · digit · multiplier · tolerance
Open

Power Factor Calculator

Power triangle solver, UK-focused quick-select operating points, capacitor correction sizing, and a UK DNO reactive-charge estimator.

S² = P² + Q² · PF = P/S
Open

Transformer Calculator

Turns ratio solver with directly modifiable, visually-exact coil turns, plus a sourced efficiency-vs-load model.

V₁/V₂ = N₁/N₂ = I₂/I₁
Open

Motor Starting & Inrush

Six to eight times running current before the shaft moves — and what star-delta, soft starters and drives really cost you in torque.

Istart ∝ V · Tstart ∝ V²
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Battery Sizing & Runtime

What a bank really delivers once depth of discharge, the Peukert effect and inverter losses have all taken their cut — which is never the number on the label.

V · Ah · DoD · t = H(C/IH)k
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Wire Gauge & Voltage Drop Calculator

The right AWG for your current and distance, and the actual voltage drop — real NEC ampacity and resistance tables.

V = 2 × dist × I × R/1000
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Results from every tool here are for reference only. Check them against other sources before relying on them for a real decision.