Battery-Free Displacement Encoder Using Magnetic Induction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing displacement measurement systems for rotary and linear encoders face challenges such as limited battery life, high cost, temperature sensitivity, and vulnerability to vibrations, particularly when using battery-powered systems or reed relays for turn counting.
Innovation Solution
A system that uses a first machine-sensible element and a plurality of second machine-sensible elements to generate pulses for an electrical counter, eliminating the need for a battery by harnessing magnetic induction, and employing sensors and a pulse generator to accurately count displacement periods and fractions without external power, making it insensitive to vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a battery is used to power the turn counting system, then the system can maintain operation during power interruptions, but the battery has limited lifetime and requires replacement
Solution Approach 1:
The patent removes the battery from the encoder system entirely. Instead of using a battery-powered memory system, the invention uses a passive optical storage medium (such as a CD-ROM or DVD) that stores position information without requiring power. The turn counting information is transferred to this external storage medium through an optical interface, eliminating the need for battery replacement while maintaining reliability during power interruptions.
Solution Approach 2:
The patent introduces an intermediary optical storage system between the encoder and the turn counting function. Rather than directly powering the memory, the system uses light to transfer data to an external optical medium, which then serves as the storage mechanism. This intermediary approach allows persistent storage without requiring a battery within the encoder.
2Reliability
If a battery is installed in the encoder, then turn counting can be maintained during power interruptions, but the battery cannot be placed in high temperature environments
Solution Approach 1:
The patent extracts the temperature-sensitive battery component from the encoder and replaces it with a temperature-resistant optical storage system. The optical medium and associated optics can operate in high temperature environments without the thermal limitations of battery chemistry, while still providing persistent turn counting capability during and after power interruptions.
3Use of energy by moving object
If reed relays are used for turn counting without a battery, then the system can operate without external power, but the reed relays are sensitive to vibrations and have limited lifetime
Solution Approach 1:
The patent replaces the mechanical reed relay system with an optical detection and storage system. Instead of using magnetic fields to actuate mechanical relays, the invention uses optical elements (such as transparent and opaque segments on a rotating member) to modulate light, which is then detected by photodetectors and stored on an optical medium. This substitution eliminates vibration sensitivity and mechanical wear while maintaining energy independence.
4Use of energy by moving object
If ferroelectric memories are used to store turn counting data, then the system can operate without a battery, but the memories are not available in small sizes
Solution Approach 1:
The patent uses an optical storage medium as an intermediary between the encoder and the turn counting storage function. The optical medium (CD-ROM, DVD, or similar) provides large storage capacity in a compact form factor that can be externally mounted or integrated without increasing the encoder's internal volume. This allows battery-free operation with adequate storage capacity for turn counting data.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise measurement of displacement without a battery, reducing costs and improving reliability across various temperatures and vibration levels, allowing for the use of non-volatile memory for storing position data.
Implementation Method 1
A system that uses a first machine-sensible element and a plurality of second machine-sensible elements to generate pulses for an electrical counter, eliminating the need for a battery by harnessing magnetic induction
Data Source
AI summary
Apparatus and method for measuring displacements of a rotary or linearly-displaceable member by counting periods of displacement thereof along a predetermined displacement path, including a pulse generator located at a pulse-generation station proximate to the displacement path; and an electrical circuit controlled by the pulse generator to actuate a first sensor to sense the status of the displaceable member at the particular instant one of said second machine-sensible elements passes through the pulse-generation station, and to increment a counter in accordance with said status determination. In the described preferred embodiments, the second machine-sensible elements are magnetic elements; and the pulse generator includes a coil, a magnetic core magnetically coupled to the coil, and a spring-mounting for the magnetic core causing the core to move from an initial position in one direction with respect to the coil when aligned with one of the second machine-sensible elements, and to be returned in the opposite direction by the spring to its initial position, whereby the coil generates pulses during such movements of the magnetic core.