Power Supply Switching Circuit Battery Drain Reduction

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Solution Overview

Problem

Existing power supply switching circuits face challenges in reducing battery power consumption, particularly when switching between main and battery power supplies, leading to potential battery exhaustion due to unnecessary power supply from the battery.

Innovation Solution

A power supply switching circuit with a first control signal output unit using the main power supply when its voltage exceeds a reference, and a second control signal output unit using the battery when the main power supply voltage is lower, along with parasitic diode suppression and delay units to manage current flow and prevent backflow, ensuring efficient power switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a comparator and inverter are used to compare main power supply voltage and battery voltage, then power supply switching can be achieved, but battery power consumption increases and battery may be exhausted

Engineering Contradiction:

Improvepower supply switching reliabilityVSAvoidbattery power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the battery from the voltage comparison function, using it only for power supply switching control rather than continuous voltage comparison. The battery is taken out of the comparator input circuit, eliminating continuous battery power consumption while maintaining switching reliability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a voltage detection circuit as an intermediary that samples the main power supply voltage without requiring continuous battery power. This mediator enables voltage comparison functionality while preventing direct battery power consumption in the comparator.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If both AC power supply and battery are supplied to the circuit, then power supply switching can be controlled, but battery power is wasted when AC power supply voltage is higher than battery voltage

Engineering Contradiction:

Improvepower supply switching controlVSAvoidbattery power loss

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent extracts the battery from continuous operation during AC power supply mode, putting it into a standby state. The battery is taken out of active power supply mode when AC voltage is sufficient, preventing energy loss while maintaining switching control capability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent implements periodic voltage sampling of the main power supply rather than continuous comparison. This periodic action reduces battery power consumption during AC supply mode while maintaining the ability to detect when switching is needed.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS9811062B2Power supply switching circuit, electronic device, and control method of power supply switching circuit

Publication Date: 2017.11.07 SONY GROUP CORP

AI summary

There is provided a power supply switching circuit including a first control signal output unit that outputs a signal exceeding a predetermined potential using a main power supply as a first control signal when a power supply voltage of the main power supply exceeds a predetermined reference voltage, a second control signal output unit that outputs the signal exceeding the predetermined potential using a standby power supply from a battery as a second control signal when a potential of the first control signal does not exceed the predetermined potential, and a power supply output unit that outputs the main power supply when the first control signal exceeds the predetermined potential and outputs the standby power supply when the second control signal exceeds the predetermined potential.