Battery-Powered Rotary Encoder With Low-Power Storage Mode

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Solution Overview

Problem

Rotary encoders with batteries discharge quickly when stored without an external power supply, limiting their usability to a short time after activation due to high current consumption in active mode.

Innovation Solution

A rotary encoder design with a switchable mode between active and storage modes, utilizing a semiconductor switch to reduce power consumption to less than 50% of active mode, allowing extended storage without significant battery discharge, and automatically switching to active mode with an external power supply.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If the encoder operates in active mode without external power supply, then the rotary position can be detected continuously, but the battery discharges quickly and the encoder can only be used for a short time

Engineering Contradiction:
Improvedetection time without power supplyVSAvoidbattery current consumption
Core Design Contradiction:
Duration of action of moving objectVSUse of energy by moving object

Solution Approach 1:

The encoder dynamically switches between active mode and storage mode based on power availability. The microcontroller monitors the power interface and transitions the detection unit between operational and low-power states, optimizing battery usage while maintaining detection capability when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes its operational parameters by switching between two distinct modes: active mode with full detection functionality and higher current consumption, and storage mode with minimal functionality and reduced current consumption. This parameter switching resolves the contradiction between continuous detection and battery preservation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the encoder is stored in active mode for extended periods, then the position detection remains ready, but the battery becomes significantly discharged

Engineering Contradiction:
Improveposition detection readinessVSAvoidbattery charge loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

Instead of continuous operation, the encoder employs periodic activation. The system transitions to storage mode during extended periods without power, consuming minimal energy while maintaining the capability to be quickly reactivated. This periodic switching between states prevents battery depletion while preserving detection readiness.

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If the detection unit is continuously powered, then accurate position detection is maintained, but power consumption increases

Engineering Contradiction:
Improveposition detection accuracyVSAvoiddetection unit power consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The detection unit is extracted from continuous operation and activated only when needed. The microcontroller controls the switching of the detection unit between active and dormant states, separating the continuous monitoring function from the actual detection operation to reduce overall power consumption while maintaining measurement precision when active.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP4242594B1Rotary encoder
Publication Date: 2025.09.24 BAUMER GERMANY GMBH & CO KG
  • EP4242594B1 patent drawingFigure 1

AI summary

Rotary encoder for detecting the position of an input shaft, comprising the input shaft, a rotation unit with codings non-rotatably connected to the input shaft, a detection unit with which the positions of the codings on the rotation unit can be detected and output as coding signals, a processing unit with which the position of the input shaft can be determined from the coding signals, a power interface for supplying the rotary encoder with an external voltage source, a data interface for transmitting the detected position of the input shaft to the environment of the rotary encoder, a battery, wherein the rotary encoder can be operated in an active mode without electrical energy from the external voltage source by means of the battery.wherein the rotary encoder includes an electrical switch and in a storage mode of the rotary encoder the electrical switch is open and the electrical supply of the sensing unit with electrical energy from the battery is interrupted, so that during the storage mode the electrical power for the storage mode of the rotary encoder is less than the discharge of the battery during the active mode of the rotary encoder.