Inductive Rotary Encoder Power Management via Pulse-Triggered Circuit

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Solution Overview

Problem

Rotary encoders, particularly inductive ones, face challenges in minimizing power consumption during operation, especially when switching between normal and low-power modes, which can lead to increased energy usage and reduced efficiency.

Innovation Solution

A rotary encoder design featuring a first component group with an impulse wire, detector, and electronic circuit, and a second group with a magnet and code element, where the circuit is powered by a voltage pulse generated during relative movement, allowing the circuit to disconnect from the voltage source after position information is stored, minimizing energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the rotary encoder operates in normal mode with continuous power supply, then the operational reliability is improved, but the power consumption increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by switching the rotary encoder between normal operational mode and low-power mode. The control unit activates the encoder components only when measurement is required and returns them to low-power state when idle, creating a periodic on-off pattern that reduces average power consumption while maintaining reliability during active periods

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies dynamics by making the power supply state changeable rather than static. The system dynamically transitions between two operational states (normal mode with full power and low-power mode with reduced consumption) based on operational needs, allowing the power consumption to adapt to actual measurement requirements

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If the circuit remains connected to the voltage source continuously, then the operational readiness is improved, but the energy waste increases

Engineering Contradiction:
Improveoperational readinessVSAvoidenergy waste
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The control unit implements periodic connection and disconnection of the circuit from the voltage source. During normal operation, the circuit is connected and ready to measure. When measurement is not required, the circuit is disconnected to eliminate energy waste, creating a periodic connection pattern that balances readiness with energy conservation

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent extracts the circuit from the voltage source when measurement is not required. By physically disconnecting or electrically isolating the circuit from the power supply during idle periods, the system removes the energy-consuming component from the active system, eliminating waste while maintaining the ability to re-engage when needed

Inventive Principle:
Principle #2Taking out (Extraction)

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

This configuration ensures that the rotary encoder only consumes energy during actual rotary movements and reduces power consumption by disconnecting from the voltage source after position information is stored, enhancing operational efficiency and enabling seamless switching between operating modes.

Implementation Method 1

When the magnet approaches the impulse wire by a corresponding relative rotary movement, a voltage pulse can be generated by the impulse wire

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

Depending on the relative position of the code element to the at least one detector, a signal can be generated by the latter

Methodology Applied
Scientific EffectInductive coupling: Electromagnetic Induction

Data Source

PatentEP1959240B1Rotary encoder and method for its operation
Publication Date: 2014.06.04 DR JOHANNES HEIDENHAIN GMBH
  • EP1959240B1 patent drawingFigure 1~2
  • EP1959240B1 patent drawingFigure 3
  • EP1959240B1 patent drawingFigure 4

AI summary

The invention relates to a rotary encoder comprising a first and a second component group (1, 2). The first component group (1) has a pulse wire (1.1), a detector (1.211, 1.212; 1.211', 1.212'; 1.211", 1.212") and a circuit (1.5). The second component group (2) comprises a magnet (2.23) and a code element (2.21; 2.21'; 2.21"). When the magnet (2.23) approaches the impulse wire (1.1), a voltage pulse (Π) can be generated by the impulse wire (1.1). Depending on the relative position, a signal (Σ1.211, Σ1.222; Σ1.211', Σ1.222'; Σ1.211", Σ1.222") can be generated by the detector (1.211, 1.212; Σ1.211', Σ1.222'; Σ1.211", Σ1.222"), whereby a logic circuit (1.51), based on the signal (Σ1.211, Σ1.222; Σ1.211', Σ1.222'; Σ1.211", Σ1.222") a position information (P) can be determined which can be stored in a non-volatile memory (1.52). The circuit (1.5), triggered by the voltage pulse (Π), is supplied with a voltage from a voltage source (1.7) can be actuated. At the latest after the position information (P) has been stored in the memory (1.52), it can be disconnected from the voltage source (1.7).