Electronic linear tape measure using a low power induced current

Abstract

An electronic linear tape measure using a low power induced current position transducer. The tape measure includes an enclosure case with a lateral slot through which the tape blade can be pulled. The tape blade is wound inside the enclosure case on a tape reel which is mounted on an axis support that has a spring loaded rewind mechanism. Also included are a tape lock, a keypad for various functions, and a conventional LCD display for displaying measured lengths. The signal processing and display electronics of the electronic tape measure are connected to the active portion of the transducer. The display provides an indication of the relative position between the elements of the transducer that coincides with the length of tape that has been pulled from the enclosure case. The relatively insensitive nature of the low power induced current position transducer to contaminants, tape damage and mechanical shock allows construction of an electronic tape measure with the preferred, historically proven, form that functions with greatly improved reliability when operating in a traditional environment. Additionally, the low power consumption of the induced current position transducer significantly increases the practicality of an electronic tape measure.