Single-Pin Optocoupler Interface Circuit for Bidirectional Bus Signaling

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Solution Overview

Problem

Existing interface circuits for bidirectional data communication between lighting control devices and buses require two separate pins on the microcontroller, increasing complexity and reducing efficiency.

Innovation Solution

A simplified interface circuit using a single pin for bidirectional communication via a transmission optocoupler and a receiving optocoupler, where the same node is used to supply a driver voltage for signal transmission and detect the status of the receiving optocoupler, allowing for efficient data exchange using an asymmetrical resistance network.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two separate pins are used for bidirectional communication with two optocouplers, then reliable data transmission and reception is achieved, but device complexity and pin count increase

Engineering Contradiction:
Improvedata transmission reliabilityVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines two separate communication channels (transmission and reception) into a single pin interface. The control circuit uses one pin to communicate bidirectionally with the operating device by switching between transmission and reception modes, eliminating the need for two separate pins while maintaining communication reliability through the use of two optocouplers configured for full-duplex operation on a single line

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single pin serves multiple functions by acting as both a transmission output and reception input depending on the operational mode. The control circuit implements multi-functionality by switching the pin's role between sending data to and receiving data from the operating device, thereby reducing pin count while maintaining full bidirectional communication capability

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

2Adaptability or versatility

If two separate pins are used for bidirectional communication, then full-duplex communication capability is achieved, but the number of required connections increases

Engineering Contradiction:
Improvecommunication capabilityVSAvoidnumber of pins
Core Design Contradiction:
Adaptability or versatilityVSQuantity of substance

Solution Approach 1:

The patent merges two separate communication pins into one by implementing time-division or mode-division multiplexing. The control circuit switches between transmission and reception modes, allowing a single pin to carry both outgoing and incoming data signals, thereby reducing the quantity of required connections from two pins to one while preserving full-duplex communication capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent adds a temporal or functional dimension to the single pin interface by implementing mode switching. Instead of using two pins simultaneously, the system uses one pin across different time periods or operational states (transmission mode vs. reception mode), effectively multiplying the pin's functionality through dimensional expansion of its operational space

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 solution reduces the number of pins required for bidirectional data communication, enhancing efficiency and simplifying the circuit design while maintaining effective data transmission and reception capabilities.

Implementation Method 1

bidirectional communication with a bus via a transmitting optocoupler and a receiving optocoupler

Methodology Applied
Scientific EffectOptical coupling: Light

Data Source

PatentEP2939505B1Interface circuit for signal transmission
Publication Date: 2018.07.11 TRIDONIC GMBH & CO KG
  • EP2939505B1 patent drawingFigure 1

AI summary

The invention relates to an interface circuit (1) for an operating device (2) of the domestic appliance technology, in particular for an operating device for lighting means (3), for bi-directional communication with a bus (4) via a respective transmitting opto-coupler (9) and a receiving opto-coupler (8), wherein a node point (P) of the interface circuit (1) is impinged upon with a driver voltage (VT) in such a way that the transmitting opto-coupler (9) switches through and thus sends a signal to the bus (4), and wherein, at the same node point (P), the state of the receiving opto-coupler (8) can be detected so that a signal can be received from the bus (4).