A hysteresis dynamometer uses electromagnetic hysteresis — the lag between magnetic field and material magnetization — to generate a smooth, speed-independent braking torque. The steel rotor and pole structure create a frictionless magnetic air gap. Torque is precisely controlled by adjusting excitation current, enabling full torque delivery from zero RPM through maximum rated speed without any mechanical contact.
Sí. This is the key advantage of hysteresis dynamometers. Because torque is generated by the electromagnetic hysteresis effect rather than rotor motion, rated braking torque is available at zero RPM. This makes hysteresis dynos the standard choice for starting torque measurement, cogging torque testing, locked rotor tests, and servo motor evaluation.
EconoTest EC/ECO series covers torque from 0.1 Nuevo Méjico (EC0.1KB, EC0.1HB) a 30 Nuevo Méjico (EC30KB) and speeds up to 30,000 RPM (serie kb, air-cooled) o 25,000 RPM (Serie HB, air+water cooled). The complete model range includes: 0.1, 0.2, 0.3, 0.5, 1, 2, 3, 5, 7.5, 10, 15, 20, y 30 Nm models.
KB (estándar) series: accuracy ±0.5% full scale, velocidad máxima 30,000 RPM (modelos pequeños) hasta 4,000 RPM (30 Nm model); most KB models are air-cooled, while the 5, 7.5 y 15 Nm KB models are water-cooled. media pensión (alta precisión) series: accuracy ±0.2% full scale, maximum speed up to 25,000 RPM on most models, with air+water, refrigeración por agua+soplador o aire+soplador según el tamaño. Choose HB series for precision servo motor testing, cogging torque measurement, or applications where ±0.2% accuracy is required.
Hysteresis dynamometers are ideal for: AC motors, DC motors, BLDC motors, motores paso a paso, servomotores, and any motor where zero-speed or low-speed torque measurement is required. They are particularly suited for servo motor evaluation (bandwidth, par dentado, speed ripple) and for any motor requiring testing from free-run to locked rotor in a single setup.
Cooling varies by model. serie kb: air cooling on most models; the EC5KB, EC7.5KB and EC15KB are water-cooled. Serie HB: air+water cooling on the 0.1–3 Nm models, water+blower on EC5HB, air+blower on EC10HB, and air cooling on EC20HB. For extended test cycles or high-duty applications, water-cooled models are recommended. The cooling system is integrated and requires no external fan or pump for smaller air-cooled models.
Standard tests include: medición de par (rated, rotor bloqueado, breakdown), speed testing, power and efficiency, aumento de temperatura, vibración y ruido, load characteristics, cogging torque and torque ripple, capacidad de sobrecarga, starting performance, transient response, and harmonic analysis of voltage and current. The hysteresis dyno supports both steady-state and dynamic measurement requirements.
Hysteresis dynamometers operate without mechanical contact between rotor and stator, which means minimal wear and very low maintenance. No brushes, no friction surfaces, and no consumables need replacement in normal operation. Periodic checks of bearing condition and cooling water quality (for water-cooled models) are the primary maintenance tasks.