Switching Power Supply Standby Control With Optical Coupler Cutoff
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Solution Overview
Problem
Conventional switching power supplies experience high standby power consumption due to maximum bias currents on both the primary and secondary sides when in a standby state, limiting the ability to further reduce power usage.
Innovation Solution
A method and circuit configuration that detects load demand, switching between a first mode using an optical coupler circuit and a second mode with a driving pulse signal to reduce bias currents, specifically turning off the bias current of the optical coupler circuit when the load demand is low, thereby reducing standby power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If burst mode is used to reduce standby power consumption, then power consumption is reduced, but bias currents remain at maximum values preventing further reduction
Solution Approach 1:
The patent implements dynamic switching between two operational modes: first mode uses optical coupler circuit with maximum bias currents for stable feedback, while second mode turns off optical coupler bias currents to minimize power consumption. The system dynamically selects modes based on load conditions, resolving the contradiction between power savings and current stability.
Solution Approach 2:
The patent changes the bias current parameter from static maximum value to dynamic variable. In first mode, bias currents are maintained at maximum for reliability. In second mode, bias currents are reduced to near-zero for power savings. This parameter transformation allows the system to overcome the limitation of fixed bias current values.
2Reliability
If optical coupler circuit operates continuously, then feedback control is maintained, but power consumption increases due to continuous bias current flow
Solution Approach 1:
The patent implements periodic operation of the optical coupler circuit. Instead of continuous operation, the circuit alternates between active periods (first mode with feedback control) and idle periods (second mode with minimal power consumption). This periodic action maintains necessary feedback control while significantly reducing average power consumption.
Solution Approach 2:
The patent segments the operational timeline into distinct first mode and second mode periods. During first mode segments, optical coupler provides feedback control. During second mode segments, optical coupler is disabled for power savings. This temporal segmentation allows the system to achieve both reliable control and low power consumption at different times.
3Loss of energy
If bias currents are reduced to minimize power loss, then standby power consumption decreases, but control precision and stability deteriorate
Solution Approach 1:
The patent dynamically adjusts bias current levels based on operational requirements. During first mode, high bias currents ensure precise feedback control. During second mode, low bias currents minimize power loss. This dynamic adjustment resolves the contradiction by matching current levels to actual control needs rather than maintaining fixed high levels.
Solution Approach 2:
The patent transforms the bias current parameter from a fixed high value to a variable parameter that adapts to operational mode. In first mode, parameter is set for precision control. In second mode, parameter is reduced for energy efficiency. This parameter flexibility allows the system to overcome the trade-off between precision and power consumption.
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 approach effectively minimizes bias currents to zero, reducing quiescent loss and further lowering standby power consumption of the switching power supply.
Implementation Method 1
an optical coupler circuit being coupled between a primary side and a secondary side
Data Source
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AI summary
A standby method for a switching power supply, a switching power supply, and primary and secondary control circuits, which relate to the technical field of secondary feedback control. The method is applied to a switching power supply provided with an optical coupler circuit, and includes: upon detecting a mode control signal indicating that a load device power supply demand is greater than a preset value, entering, by the switching power supply, a first mode, and controlling output of the switching power supply by means of an optical coupler circuit; and upon detecting a mode control signal indicating that the load device power supply demand is less than or equal to the preset value, entering, by the switching power supply, a second mode, turning off a bias current of the optical coupler circuit, and controlling the output of the switching power supply by means of a driving pulse signal, so as to reduce bias currents of a primary side and a secondary side of the switching power supply, and reduce standby power consumption of the switching power supply. In this case, the bias current of the optical coupler circuit is turned off, so that the bias currents of the primary side and the secondary side are both 0, thereby reducing the bias current, reducing quiescent loss, and further reducing standby power consumption.