Standby Power Supply Circuit for 2-Wire Intercom Systems

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Solution Overview

Problem

Conventional 2-wire intercom systems face limitations in alternating current impedance, particularly at standby status, leading to reduced audio quality and limited device capacity due to the large size of inductors required for sufficient power supply and impedance.

Innovation Solution

A standby power supply circuit is introduced, comprising two separate power supply modules: one for standby and one for operation, utilizing a constant current circuit with a main and auxiliary path, along with a voltage regulator unit, to maintain high alternating current impedance and stable voltage, even under varying conditions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a coil inductor is used as the inductance component to provide sufficient impedance and power supply capacity, then the alternating current impedance is improved, but the size of the inductor becomes very large

Engineering Contradiction:
Improvealternating current impedanceVSAvoidsize of inductor
Core Design Contradiction:
ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent replaces the mechanical coil inductor with an electronic inductance circuit composed of active electronic components (transistors, capacitors, resistors). This substitution maintains the necessary alternating current impedance while eliminating the large physical size associated with traditional coil inductors, thereby resolving the contradiction between impedance reliability and component size.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If a single system power supply is used to serve all device loads, then the device complexity is reduced, but the alternating current impedance becomes insufficient when large numbers of devices are connected

Engineering Contradiction:
Improvepower supply structureVSAvoidalternating current impedance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent segments the single power supply system into multiple independent power supply modules, each serving specific device loads. This segmentation allows each module to maintain sufficient alternating current impedance independently, while the overall system complexity remains manageable due to the modular architecture. Each module can be optimized for its specific load requirements.

Inventive Principle:
Principle #1Segmentation

3Weight of stationary object

If electronic inductance circuit is used to replace coil inductor to reduce size, then the device complexity is reduced, but the alternating current impedance becomes limited especially for operation circuit

Engineering Contradiction:
Improvesize of inductance componentVSAvoidalternating current impedance
Core Design Contradiction:
Weight of stationary objectVSReliability

Solution Approach 1:

The patent employs parameter changes by dynamically adjusting the operating parameters of the electronic inductance circuit based on whether devices are in standby or operation mode. During standby mode, parameters are optimized for high impedance with minimal power consumption. During operation mode, parameters are adjusted to maintain sufficient impedance while supporting higher power demands, thus resolving the limitation of fixed-parameter electronic inductance circuits.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2745386B1Standby power supply circuit for 2-wire bus intercom system and apparatus thereof
Publication Date: 2018.12.19 ABB (SCHWEIZ) AG
  • EP2745386B1 patent drawingFigure 1~2a
  • EP2745386B1 patent drawingFigure 2b~2c
  • EP2745386B1 patent drawingFigure 2d~3

AI summary

A standby power supply circuit (300) for a 2-wire bus intercom system and an apparatus thereof. The standby power supply circuit (300) is separated into two power supply modules, in which the first power supply module is a power supply to a standby circuit (302) and the second power supply module is a power supply to an operation circuit (304). The power supply to the operation circuit (304) is switched off by a constant circuit switch (310) when a device load is at the standby status. The power supply to the standby circuit (302) comprises a constant current circuit (306) whose alternating current impedance is large. With the standby power supply circuit, the larger alternating current impedance for the 2-wire intercom system is achieved, which can offer sufficient power for many device loads both in the conditions of operation and standby status.