Laboratory Stirring Systems

G. K. Heller stirring systems offer a wide range of features and capabilities including:

• Feedback circuitry on all models to maintain speed even when viscosity changes
  
• Standard horsepower ratings from 1/40 to 1/4 horsepower. Has 50/60 Hz operation
  
• A selection of propellers & paddles from 1-1/2" to 6" diameter
  
• Reference circuitry maintains speed even with voltage fluctuations of ±10%
  
• Cord connections between drive motors & controls increase convenience & allow placement away from hostile environments
  

G.K. Heller stirrers filter the drive current for better performance featuring:

• This filtering process eliminates the objectionable pulsing action common to unfiltered DC current
  
• Reduces motor heating
  
• Allows the use of a smaller motor for the same power rating
  
• Ensures smooth rotation for precise stirring
  
• Lengthens motor brush life
  
• Prevents demagnetization of permanent-magnet motor fields

A favorite with chemists and lab technicians everywhere. Totally enclosed, 1/40 hp, permanent magnet motor with two output shafts for maximum speeds of 4,000 and 333 rpm. The armature shaft provides high speeds for mixing light materials, while the geared shaft generates 3.6 lb. - in. (4.2 kg-cm) of torque at slower speeds for stirring more viscous mixtures. Continuously variable speed control.

Combines today's permanent-magnet motor technology with solid state electronics. Totally enclosed, 1/17 hp, cool, and quiet-running motors with direct-drive and geared options. Models available with speeds up to 2,500 rpm and torques up to 12 lb. - in. (13.8 kg-cm). Continuously variable speed control.

• Actual speeds are displayed and maintained by a synthetic tachogenerator. (Speed is kept within less than 1% of the base speed from no load to more than 100% of full load regardless of AC line voltage fluctuations of ±10%.)
  
• Viscosity measurement is easier thanks to a controller with a digital readout switchable between speed and torque.
  
• Data on shear stress, shear rate, velocity gradients, and viscosity is accumulated easily with external DC voltage signals for speed and torque (for strip or X-Y recorders) available through an output port on the rear of the control.
  
• Operator convenience and safety is increased with cord connections between drive motors and controls to allow control placement away from hostile environments.

1/4 hp, totally enclosed, permanent-magnet DC motor. Direct drive model provides speeds up to 2,500 rpm and 6.3 lb. - in. (7.3 kg-cm) of torque for more viscous applications. A variety of gearing options allow for even higher torque output (up to 90 lb. - in.) without putting undue stress on the motor.