Resistor-Multiplexed Wake-Up Circuit for Zero-Standby Input Sensing

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Solution Overview

Problem

Existing circuits for activating electronic devices in vehicles face inefficiencies in power management during standby modes, leading to power drainage and requiring multiple wires for user input interfaces.

Innovation Solution

A sensing circuit with a first transistor and multiple switches connected to identifying resistors, which outputs characteristic voltages to activate a microcontroller efficiently, using a single wire interface and maintaining zero standby current, allowing for efficient user input detection and control signal transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing circuits are used to activate electronic devices, then user input detection is enabled, but power drainage occurs during standby modes

Engineering Contradiction:
Improveuser input detectionVSAvoidpower drainage during standby
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent extracts the activation function from the main controller, implementing it in a separate sensing circuit that operates independently during standby. This sensing circuit can detect user inputs and generate activation signals without requiring the main controller to be powered, thereby eliminating power drainage during standby while maintaining reliable user input detection.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a sensing circuit as an intermediary between the user input interface and the main controller. This intermediary circuit handles signal detection and controller activation without requiring continuous power to the main controller, thus preventing power drainage while ensuring reliable input detection through the sensing circuit's dedicated detection capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If existing circuits are used for user input interfaces, then multiple wires are required for connection, but circuit complexity increases

Engineering Contradiction:
Improveuser interface connectivityVSAvoidnumber of wires required
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent implements a single wire that serves multiple functions: it carries both the user input signal from the interface and the activation signal to the main controller. The sensing circuit processes the input signal and generates the activation signal on the same wire, eliminating the need for separate wires and reducing overall system complexity while maintaining ease of operation.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the input signal transmission function and the activation signal transmission function into a single wire connection. The sensing circuit combines these functions by detecting the input signal and generating the activation signal that is transmitted back through the same wire, thereby reducing the number of wires required and simplifying the user interface connectivity.

Inventive Principle:
Principle #5Merging (Combining)

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

The circuit effectively activates a microcontroller to sense user inputs while preventing power usage during standby, reducing power drainage and simplifying the user interface with a single wire connection, enabling efficient control of electronic devices like wireless transmitters.

Implementation Method 1

a first transistor configured to output an activation signal to the controller and a plurality of switches in connection with a base of the transistor

Methodology Applied
Scientific EffectTransistor switching:

Implementation Method 2

The first output node and the second output node are configured to output a characteristic voltage corresponding a ratio of each of the identifying resistors

Methodology Applied
Scientific EffectVoltage division: Ohm's Law

Data Source

PatentEP3259846B1Resistor multiplexed switch wake-up circuit
Publication Date: 2022.03.30 GENTEX CORP
  • EP3259846B1 patent drawingFigure 1

AI summary

A sensing circuit configured to activate a controller is disclosed. The circuit comprises a first transistor configured to output an activation signal to the controller and a plurality of switches in connection with a base of the transistor. Each of the switches is connected to an identifying resistor. A first output node and a second output node are in communication with the base of the transistor and each of the switches. The first output node and the second output node are separated across an additional identifying resistor. The first output node and the second output node are configured to output a characteristic voltage corresponding a ratio of each of the identifying resistors in response to an input received by one or more of the plurality of switches.