• Powermag Control Systems Private Limited

Variable speed drives

Powermag Control Systems (P) Ltd makes variable speed drives that work based on Eddy current principle.The adjustable speed drive is operated by electromagnetic induction without any physical contact. The primary elements include an AC motor, an eddy current clutch, a tacho generator and a separate small solid-state electronic controller. The eddy current clutch has a drum driven at constant speed by the AC motor. Torque is transmitted from the drum to the rotor/shaft through an adjustable magnetic field produced by the clutch coil. The eddy current variable speed drive has an integral tacho generator mounted around the output shaft to give voltage and frequency proportional to speed. The Eddy current drives have a 34:1 speed range and can transmit up to 250 per cent of the rated motor torque intermittently. The tachometer is used for speed reference feedback and allows typical regulation of 0.5 to 1 percent. These drives accelerate high inertia loads quickly and handle intermittent overloads without increasing horsepower rating and eliminate external cooling fans. Application: Various industrial applications like cement, rubber, chemical, plastic, paper, wire drawing, mining, thermal power plants, blowers, extruders, pumps, screw feeders, conveyors, etc. Technical specifications: Parameter: 0.2 to 11 kw. Cooling: air cooled-self ventilated. Coil volts: 85 V DC (Maximum). Tacho volts: 30V AC rms, 500mA at 1500 rpm Tacho frequency: 600 Hz (near sine) at 1500 rpm. Protection: IP-21. Insulation: class F. Temperature: rise limited to Class B. Ambient: 50 degree Celsius. Altitude: Up to 1000mts above sea level.