The SS461A (461A 461 is a temperature compensated Digital Hall-effect Sensor IC designed to respond to alternating North and South poles or to a South-pole only.
 
Specifications: 
Product Category:    Board Mount Hall Effect/Magnetic Sensors
Type:    Bipolar    
Operating Supply Current:    10 mA    
Maximum Output Current:    20 mA    
Operating Point Min/Max:    10 G to 85 G    
Release Point Min/Max (Brp):    - 85 G to - 10 G    
Operating Supply Voltage:    12 V
Supply Voltage - Max:    30 V    
Supply Voltage - Min:    3.8 V    
Unit Weight:    120 mg
 
Application areas:
Non-contact switch, automatic ignition, brake circuit, position, speed detection and control, safety alarm device, textile control system, Brushless DC motors, encoders, sewing equipment, textile machinery, household appliances, safety alarm devices and other automation control fields.
 
Resources: 
1. SS461A Datasheet (PDF)