Switching Power Supply Connection Detection
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Solution Overview
Problem
Conventional switching power supply systems fail to activate when the power storage component, such as a primary or secondary battery, is depleted, as they rely on voltage from the battery to restart operations and use photocouplers for signal transmission, which cannot operate without sufficient charge.
Innovation Solution
A switching power supply apparatus with a second switching element, an input/output conversion circuit, a transformer, a pulse generator, and a device connection state detection circuit that uses a waveform detection circuit to detect voltage or current changes in the transformer's winding wire, allowing for connection state detection even without power on the secondary side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the switching power supply apparatus uses photocoupler for signal transmission from secondary side to primary side, then the restart signal can be transmitted when voltage is applied from load device, but the system fails to operate when power storage component is depleted and cannot transmit signal
Solution Approach 1:
The patent introduces a transformer as an intermediary component to transmit the restart signal from the secondary side to the primary side. The transformer couples the two sides magnetically, allowing signal transmission without direct electrical connection. This resolves the contradiction because the transformer can operate with very low power requirements compared to photocoupler, enabling signal transmission even when the power storage component is depleted.
Solution Approach 2:
The patent replaces the photocoupler (optical system) with a transformer (electromagnetic system) for signal transmission. The transformer uses magnetic field coupling instead of light transmission, which has lower power consumption and can operate effectively when the power storage component is depleted, thus improving adaptability to different power storage states.
2Loss of energy
If the switching power supply apparatus stops operation to reduce power consumption when output side is unloaded, then power consumption is reduced, but the apparatus cannot detect connection state when power storage is depleted
Solution Approach 1:
The patent implements preliminary action by having the waveform detection circuit continuously monitor the transformer winding voltage or current even when the switching power supply apparatus is in stopped state. This allows the system to detect the connection state of the load device beforehand, so when power storage is depleted, the system can still identify that a device is connected and initiate restart procedures.
Solution Approach 2:
The waveform detection circuit uses the transformer's own electromagnetic field and inherent voltage/current characteristics to detect connection state, without requiring additional power from the depleted power storage component. The circuit leverages the existing magnetic coupling in the transformer to generate detectable signals that indicate whether a load device is connected, enabling self-diagnosis with minimal 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
Enables the switching power supply apparatus to detect connection states and control operations independently of the power storage component's charge level, ensuring continuous functionality even when batteries are empty.
Implementation Method 1
a waveform detection circuit that detects a voltage or current generated in a secondary winding wire of the transformer in response to a pulse signal
Data Source
AI summary
A switching power supply apparatus of the present disclosure is a device connection state detection circuit that detects a connection state in a load device connection terminal in a power supply system having the load device connection terminal. The device connection state detection circuit includes a transformer, a switching element, a pulse generator, and a waveform detection circuit. The waveform detection circuit detects a voltage or a current generated in a primary winding wire or a secondary winding wire of the transformer in accordance with operation of a pulse signal, compares the detected voltage or current with a preset reference value, and outputs an output signal in accordance with a comparison result, to an OFF terminal.