speed sensors : type GE12x                      NORIS A.C. tachogenerators of the Series GE.. are maintenance-free             speed-measuring devices using permanent-magnet excitation.             They are designed to provide an A.C. voltage signal that is             proportional to a speed of their drive shaft. It is possible to use             either voltage or frequency as the measured variable.             Tachogenerators are used where a direct supply is desired for             indicating instruments, monitoring or processing devices. Drive is             either direct from the take-off shaft by means of couplings or             indirectly via belt-and-pulley or friction wheel arrangements.             Tachogenerators are working without operating voltage.             主要特点            • Heavy-duty tachogenerator            • Straightforward application            • Suitable for extremely rigorous operating conditions            • NORIS tachogenerators are maintenance-free            • Rugged construction            • A.C. voltage output            • Meets CE requirements            • Noise-immune signal transmission            • No radio interference            • Direct or indirect drive possible            • Protection class: IP66 (from 3000 rpm up: IP54)            • Choice of mechanical connections for speed sensing            • Flanges and brackets available for mounting            • Suitable evaluation devices available             GENERAL NOTES ON TYPE GE120-.., GE121-.., GE122-..             Method of operation            The drive shaft rotates a permanent magnet in a stationary conductor             and induces a voltage in the latter whose amount and frequency are             proportional to the speed of the drive shaft. The GE12x-.. is of 12             the pole type having 6 pairs of poles so that the frequency of the             alternating voltage is 1/10 of the input speed.             Details            • There are three speed-range variants available of this series:            • GE120 for full-scale speed range 60 ... 1,000 rpm            • GE121 for full-scale speed range 150 ... 2,500 rpm            • GE122 for full-scale speed range 500 ... 6,000 rpm            • Electrical termination by screw terminals            • Output is an approximately sinusoidal A.C. voltage            • High electric output for multiple indicator operation            • Extremely long life through extra-sturdy suspension of drive shaft            • Direct drive possible via fl exible couplings            • Indirect drive possible via V-belt pulleys or friction wheels            • Wheels or pulleys can be mounted directly on the shaft            • Extremely high protection class (up to 3,000 rpm) and rugged             construction