Electrical machines and transformers
DC motors, induction motors (slip, Kloss equation) and transformers: ratio, short circuit, part-load efficiency and voltage regulation.
Enter nameplate data, determine the operating point and cross-check with the manufacturer's curves or test report.
Calculators in this category
DC Motor Starting Resistor Calculator
Calculate the series resistance needed to limit the initial armature current of a DC motor at standstill.
Open calculator →Induction Motor Slip Calculator
Calculate synchronous speed and slip of an induction motor from supply frequency, pole pairs and rotor speed.
Open calculator →Transformer Short-Circuit Current Calculator
Calculate the prospective steady-state short-circuit current of a transformer from rated current and relative short-circuit impedance.
Open calculator →Transformer Efficiency Calculator at Partial Load
Calculate transformer efficiency at a given load from rated apparent power, power factor and no-load and short-circuit test losses.
Open calculator →DC motor back EMF
Calculate the back EMF E of a DC motor from armature voltage U, armature current IA and armature-circuit resistance RA: E = U − IA·RA. The calculator shows how the armature voltage splits into induced back EMF and resistive armature drop.
Open calculator →DC Motor Efficiency Calculator
Calculate shaft output power and overall efficiency of a DC motor from armature-circuit data and mechanical losses.
Open calculator →Transformer No-Load Current Calculator
Calculate the no-load current of a transformer relative to its rated current from the no-load test.
Open calculator →Kloss Equation Calculator for Induction Motors
Calculate the ratio of torque to breakdown torque of an induction motor at given slip and breakdown slip with the Kloss approximation.
Open calculator →Transformer Voltage Regulation Calculator
Calculate the relative secondary voltage change of a transformer at rated load from per-unit short-circuit voltage components and power factor.
Open calculator →Transformer Turns Ratio Calculator
Calculate the secondary voltage or turns ratio of an ideal transformer.
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