Case Study 4: Directional Logic for Significant Temperature Extremes
A naval application required the ability to determine direction of target movement (in this case the propeller). Typically, this would be accomplished through the use of a dual channel zero speed sensor, however this application was outside the standard operating temperature range (-40C) and required the ability to operate in cryogenic temperatures.
The use of a pair of variable reluctance sensors, phased 90 degrees electrically, provided the customer with the directional feedback needed for the application. The sensors selected had an operating temperature range of -450 to +450F, allowing for reliable operation in the cryogenic temperatures.