Power supply device

Abstract

The application relates to a power supply device. The power supply device comprises a first power supply branch, a power over Ethernet branch and an auxiliary control circuit; the auxiliary control circuit comprises a voltage detection circuit and an auxiliary load circuit; the voltage detection circuit is connected with the first power supply branch, and the auxiliary load circuit is connected with the power over Ethernet branch; the voltage detection circuit is used for collecting the voltage of the first power supply branch to obtain a first power supply voltage, and when the first power supply voltage is higher than a preset threshold value, the auxiliary load circuit is controlled to provide a load condition for the power over Ethernet branch. The power supply stability can be improved without changing the original structure.

Description

Technical Field

[0001] This application relates to the field of power switching technology, and in particular to a power supply device. Background Technology

[0002] Today, some devices with high requirements for power supply stability, such as video recording equipment, are typically designed with redundant power supplies to ensure a seamless switch to another power supply in case one power supply fails, preventing power loss. However, different power supply methods provide different voltages. Under the Power over Ethernet (PoE) standard, when another power supply takes over, PoE may repeatedly cycle through power-on and power-off processes, potentially resulting in a situation where neither power supply provides power, making seamless switching impossible.

[0003] This shows that current redundant power supply methods still suffer from low power supply stability. Utility Model Content

[0004] Therefore, it is necessary to provide a power supply device that can improve power supply stability without changing the original structure, addressing the aforementioned technical problems.

[0005] This application provides a power supply device, which includes a first power supply branch, an Ethernet power supply branch, and an auxiliary control circuit; the auxiliary control circuit includes a voltage detection circuit and an auxiliary load circuit, wherein:

[0006] The voltage detection circuit is connected to the first power supply branch, and the auxiliary load circuit is connected to the Ethernet power supply branch.

[0007] The voltage detection circuit is used to collect the voltage of the first power supply branch to obtain the first power supply voltage, and when the first power supply voltage is higher than a preset threshold, control the auxiliary load circuit to provide load conditions for the Ethernet power supply branch.

[0008] In one embodiment, the power supply device further includes an isolated output circuit, wherein the first power supply branch or the Ethernet power supply branch is connected to the isolated output circuit to supply power to the target load device.

[0009] In one embodiment, the power supply device further includes an auxiliary control circuit voltage source circuit, the auxiliary control circuit being connected to the isolated output circuit via the auxiliary control circuit voltage source circuit; the auxiliary control circuit voltage source circuit is used to provide a voltage input source to the auxiliary control circuit based on the auxiliary winding voltage of the isolated output circuit.

[0010] In one embodiment, the power supply device includes a monitoring trigger circuit for monitoring the first power supply branch and the Ethernet power supply branch. When the first power supply branch or the Ethernet power supply branch is inserted, the voltage detection circuit is triggered to collect the voltage of the first power supply branch.

[0011] In one embodiment, the voltage detection circuit includes a first comparator and an enable circuit;

[0012] The first input terminal of the first comparator is used to input a reference voltage, and the second input terminal of the first comparator is connected to the first power supply branch;

[0013] The enabling circuit includes a first transistor, the base of which is connected to the output of the first comparator, the emitter of which receives the reference voltage, and the collector of which is connected to the auxiliary load circuit.

[0014] In one embodiment, the power supply device further includes a rectifier and filter circuit, through which the first power supply branch is connected to the second input terminal of the first comparator.

[0015] In one embodiment, the auxiliary load circuit includes a periodic signal generation circuit and a constant current source circuit. The periodic signal generation circuit is connected to the input voltage terminal and is used to generate a periodic signal based on the input voltage input to the input voltage terminal. The periodic signal is matched with the minimum power requirement of the Power over Ethernet branch. The constant current source circuit is used to provide load conditions for the Power over Ethernet branch based on the input voltage and the periodic signal.

[0016] In one embodiment,

[0017] The periodic signal generation circuit includes a hysteresis comparator circuit, a capacitor, and a third comparator; the hysteresis comparator circuit includes multiple loops composed of a second comparator and multiple resistors, used to charge the capacitor so that the capacitor generates a triangular wave signal, and outputs the triangular wave signal to the second input terminal of the third comparator.

[0018] The first input terminal of the third comparator is connected to the input voltage terminal and is used to generate a periodic signal based on the input voltage and the triangular wave signal.

[0019] In one embodiment,

[0020] The constant current source circuit includes a second transistor and a third transistor, wherein the base of the second transistor is connected to the periodic signal generating circuit, the collector of the second transistor is connected to the input voltage terminal and the base of the third transistor respectively, and the emitter of the second transistor is grounded.

[0021] The collector of the third transistor is connected to the Ethernet power supply branch, the emitter of the third transistor is connected to the ground terminal, and the ground terminal is connected to the ground terminal of the Ethernet power supply branch.

[0022] In one embodiment, the Power over Ethernet (PoE) branch includes a rectifier bridge circuit and a DC energy storage circuit.

[0023] The rectifier bridge circuit is connected to the collector of the third transistor and the DC energy storage circuit respectively, and is used to generate and output a preset voltage; the DC energy storage circuit is used to smooth the preset voltage before outputting it.

[0024] The aforementioned power supply device uses an auxiliary control circuit and a voltage detection circuit to monitor the power supply status in real time and triggers an auxiliary load circuit to provide load conditions for the Ethernet power supply branch. This maintains low impedance and ensures continuous activation of Ethernet power supply. When the power supply to the first power supply branch is interrupted, or when the voltage level of the Ethernet power supply branch is higher, the Ethernet power supply branch can immediately take over the power supply task. This ensures that the Ethernet power supply branch always maintains a load state and avoids power outages due to failure to meet the minimum load condition. This achieves seamless connection during power supply switching, eliminates the interruption period caused by power supply logic conflicts, and improves power supply stability without changing the original structure. Attached Figure Description

[0025] Figure 1 This is a structural block diagram of the power supply device in one embodiment;

[0026] Figure 2 This is a structural block diagram of the power supply device in another embodiment;

[0027] Figure 3 This is a flowchart illustrating the operation of the power supply device in one embodiment;

[0028] Figure 4 This is a flowchart illustrating the operation of the power supply device in another embodiment;

[0029] Figure 5 This is a block diagram of a voltage detection circuit in one embodiment;

[0030] Figure 6 This is a block diagram of the auxiliary load circuit in one embodiment. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0032] In one embodiment, such as Figure 1 As shown, a power supply device is provided, which includes a first power supply branch 100, an Ethernet power supply branch 200, and an auxiliary control circuit 300; the auxiliary control circuit 300 includes a voltage detection circuit 310 and an auxiliary load circuit 320, wherein:

[0033] The voltage detection circuit 310 is connected to the first power supply branch 100, and the auxiliary load circuit 320 is connected to the Ethernet power supply branch 200;

[0034] The voltage detection circuit 310 is used to collect the voltage of the first power supply branch 100 to obtain the first power supply voltage, and when the first power supply voltage is higher than a preset threshold, it controls the auxiliary load circuit 320 to provide load conditions for the Ethernet power supply branch 200.

[0035] The first power supply branch 100 can be a power supply branch connected to a DC power supply or an AC power supply. Further, the first power supply branch 100 may include a power input terminal, a voltage conversion module, and an output interface. For example, the power input terminal can be connected to AC power, an adapter, or other power sources. The voltage conversion module rectifies, transforms, filters, or performs one or more processes on the input voltage to adjust it to a stable output voltage required by the load device. The output interface is directly or indirectly connected to the power supply port of the load device to transmit the converted voltage to the load device. Further, the voltage conversion module may include a switching power supply module with an isolation transformer.

[0036] The Power over Ethernet (PoE) branch 200 can be a power supply branch that uses the Power over Ethernet (PoE) protocol for power supply. For example, the PoE branch 200 may include a data cable, a power identification module, and a power switch. The power identification module can be a combination of a resistor divider network and a protocol identification chip, used to detect the cable voltage and complete the PoE protocol handshake; its output is connected to the control terminal of the power switch. The power switch can be a transistor, MOSFET, relay, etc., with its main electrode connected in series between the data cable and the load port. The PoE branch 200 can monitor whether there is a preset threshold difference in the cable voltage through power identification to determine the power supply demand, and compare its impedance characteristics with the standard protocol to control the passing level signal, triggering the power switch to turn on or off.

[0037] The auxiliary control circuit 300 includes a voltage detection circuit 310 and an auxiliary load circuit 320.

[0038] The voltage detection circuit 310 is used to acquire the voltage of the first power supply branch 100 to obtain a first power supply voltage. When the first power supply voltage is higher than a preset threshold, it controls the auxiliary load circuit 320 to provide load conditions for the Ethernet power supply branch 200. For example, the voltage detection circuit 310 may include a voltage sampling unit, a comparator, and a signal output unit. The voltage sampling unit can be connected in parallel to the voltage node of the first power supply branch 100 through a voltage divider resistor network. The comparator can perform difference calculation between the sampled voltage and an internal reference voltage. The signal output unit generates a control signal through a level conversion circuit.

[0039] In this embodiment, the first power supply branch 100 and the Ethernet power supply branch 200 can be implemented using existing power supply circuits, and an auxiliary load circuit 320 is connected on this basis to provide load conditions for the Ethernet power supply branch 200.

[0040] For example, the auxiliary load circuit 320 may include a controllable load element and a drive circuit. When the voltage sampling obtains the voltage ratio signal of the first power supply branch 100 through the voltage divider resistor network, a threshold comparison is performed by a comparator, and a high-level signal or a low-level signal is output, thereby indicating the voltage state of the Ethernet power supply branch 200. The drive circuit may amplify or process the level signal to control the operation of the controllable load element. For example, the controllable load element may be an adjustable impedance module composed of semiconductor devices such as transistors, field-effect transistors, MOSFETs, or thyristors, and impedance adjustment can be achieved through a base drive circuit. The controllable load element may also be a transistor, and the load size can be controlled by adjusting the resistance value. Furthermore, the resistance value adjustment of the controllable load element can be achieved by changing the equivalent resistance value through a digital potentiometer, and the switching state switching can be achieved by adjusting the MOSFET conduction duty cycle through a PWM signal.

[0041] In this embodiment, the auxiliary load circuit 320 can be implemented through a grounding mechanism to achieve a load loop. Furthermore, the auxiliary load circuit 320 can obtain power from an isolated power supply and, with the aid of the Power over Ethernet protocol's grounding connection mechanism, achieve a complete power supply loop, thereby enabling continuous operation without the need for an additional power source.

[0042] This embodiment provides a power supply device that uses an auxiliary control circuit 300 and a voltage detection circuit 310 to monitor the power supply status in real time and triggers an auxiliary load circuit 320 to provide load conditions for the Ethernet power supply branch 200. This maintains low impedance and ensures continuous activation of Ethernet power supply. When the power supply to the first power supply branch 100 is interrupted, or when the voltage level of the Ethernet power supply branch 200 is higher, the Ethernet power supply branch 200 can immediately take over the power supply task, ensuring that the Ethernet power supply branch 200 always maintains a load state and avoids power outages due to failure to meet the minimum load condition. This achieves seamless connection during power supply switching, eliminates the interruption period caused by power supply logic conflicts, and improves power supply stability without changing the original structure.

[0043] In one embodiment, the power supply device further includes an isolated output circuit, with the first power supply branch or the Power over Ethernet branch connected to the isolated output circuit to supply power to the target load device.

[0044] The isolation output circuit is used to connect the power supply branch to the target load device, and can be physically isolated to form an electrical isolation barrier.

[0045] For example, the isolated output circuit may include devices such as magnetic isolation components and optocouplers, as well as components such as filter capacitors and voltage regulator modules. Magnetic isolation components, such as high-frequency transformers, can be connected to the power supply branch via the primary winding and to the load device via the secondary winding, with the two windings separated by insulating material. The voltage regulator module can be a linear regulator, a switching regulator, or other voltage regulator used to adjust the input voltage to the stable value required by the load. By transferring energy through electromagnetic induction and filtering out input voltage fluctuations through the voltage regulator module, continuity and stability of power transmission can be achieved.

[0046] The power supply device provided in this embodiment forms an electrical isolation barrier through an isolated output circuit, which can eliminate the potential risks of ground loops and voltage conflicts when two power supplies are connected in parallel. This improves the stability and safety of the power supply while enhancing the reliability of the system under complex electromagnetic environments and grounding conditions.

[0047] In one embodiment, the power supply device further includes an auxiliary control circuit voltage source circuit, which is connected to the isolation output circuit. The auxiliary control circuit voltage source circuit is used to provide a voltage input source for the auxiliary control circuit based on the auxiliary winding voltage of the isolation output circuit.

[0048] The auxiliary control circuit voltage source circuit may include a voltage acquisition module for acquiring voltage from the auxiliary winding of the isolation output circuit; the auxiliary control circuit voltage source circuit may also include a rectification and filtering module for converting AC or pulsating voltage into a smooth DC voltage, thereby eliminating high-frequency components and fluctuations in the acquired voltage; the auxiliary control circuit voltage source circuit may also include a voltage regulation output module for adjusting the voltage after eliminating fluctuations and high-frequency components to the target stable value, thereby providing a final stable power supply for the auxiliary control circuit.

[0049] As a component of the isolated output circuit, the auxiliary winding's voltage output is independent of the main winding's load state, and the two remain isolated in the electrical path. Therefore, fluctuations in the main power supply can be prevented from directly affecting the control circuit's power supply.

[0050] This embodiment provides a power supply device that obtains a stable reference voltage from the auxiliary winding of the isolated output circuit through a voltage acquisition module. Based on the voltage of the auxiliary winding of the isolated output circuit, it provides a voltage input source for the auxiliary control circuit. This enables the auxiliary control circuit to achieve self-sufficiency and high reliability in power supply, avoiding the risk of control failure due to main power supply failure. When the current power supply branch fails, if the Ethernet power supply branch is still effective, the isolated output circuit can switch to Ethernet power supply to maintain operation. Its auxiliary winding can continue to provide energy to the voltage source circuit, ensuring the continuous operation of the control circuit. Thus, without adding an additional power supply module, it achieves the technical effect of continuing to perform voltage detection and load control functions even when the current power supply fails, ensuring accurate and reliable power supply switching.

[0051] In one embodiment, the power supply device includes a monitoring trigger circuit for monitoring a first power supply branch and an Ethernet power supply branch. When the first power supply branch or the Ethernet power supply branch is inserted, the trigger voltage detection circuit collects the voltage of the first power supply branch.

[0052] It is understandable that the auxiliary control device is designed to address situations where seamless switching may not be possible when two power supply branches exist. Therefore, when there is only one power supply branch, there is no possibility of switching power supply branches. In this case, if the load is continuously supplied to the Ethernet power supply branch, it may cause additional energy consumption.

[0053] In this embodiment, the first power supply branch and the Ethernet power supply branch are monitored by a monitoring trigger circuit. When the first power supply branch or the Ethernet power supply branch is inserted, that is, when the number of current power supply branches increases from one to multiple, the voltage monitoring circuit can be triggered to collect voltage, thereby preparing for possible power supply branch switching in the future.

[0054] The monitoring trigger circuit may include two independent detection modules, each connected to the physical interface of a corresponding power supply branch. The first detection module may be connected to the physical interface of the first power supply branch, and the second detection module may be connected to the physical interface of the Power over Ethernet branch. Both can be implemented using one or more components such as a contact switch and a voltage presence detection circuit. For example, the contact switch can determine the completion of the physical connection by the closure of its mechanical contacts, and the voltage presence detection circuit can determine the validity of the power supply by sampling the voltage signal at the interface.

[0055] The monitoring trigger circuit may also include logic gate circuits. When any detection module recognizes a valid access signal, the logic gate circuit can trigger the enable signal of the voltage detection circuit by outputting a control signal. This allows the voltage detection circuit to start detecting the first power supply branch only after the monitoring trigger circuit confirms that the power supply branch is connected, thus avoiding continuous monitoring in the unconnected state.

[0056] This embodiment provides a power supply device that, through the physical connection status sensing function of the monitoring trigger circuit, enables the voltage detection circuit to be activated only when the power supply branch is actually connected. Furthermore, when the voltage of the first power supply branch exceeds a preset threshold, the auxiliary load circuit is used to provide load conditions for the Ethernet power supply branch. This upgrades redundant power supply monitoring from passive continuous detection to active event-driven response, avoiding misjudgments caused by environmental interference or loose connections, and reducing the static power consumption of the auxiliary control circuit. This significantly improves power supply stability and resource utilization efficiency while reducing energy consumption.

[0057] In one embodiment, the voltage detection circuit includes a first comparator and an enable circuit;

[0058] The first input terminal of the first comparator is used to input the reference voltage, and the second input terminal of the first comparator is connected to the first power supply branch.

[0059] The enabling circuit includes a first transistor, the base of which is connected to the output of a first comparator, the emitter of which receives a reference voltage, and the collector of which is connected to an auxiliary load circuit.

[0060] The first comparator compares a reference voltage with the input voltage of the first power supply branch to determine whether the voltage of the first power supply branch exceeds a threshold. The first input terminal of the first comparator is connected to a preset reference voltage as a judgment standard, and the second input terminal can be connected to the output terminal of the first power supply branch to obtain a real-time voltage signal. In one specific embodiment, the reference voltage can be a preset voltage or determined by the auxiliary winding voltage of the isolated output circuit. Furthermore, the first comparator can amplify the voltage difference at the differential input terminal to obtain the comparison result.

[0061] The enabling circuit includes a first transistor, which can control whether the auxiliary load circuit provides load conditions to the Power over Ethernet branch by controlling the on or off state of the first transistor.

[0062] The base of the first transistor is connected to the output of the first comparator to receive the comparison result. The emitter of the first transistor is connected to an independent reference voltage source, while the collector is connected to the control terminal of the auxiliary load circuit, forming a transmission path for the enable signal. The threshold voltage of the first transistor matches the output level of the comparator; for example, a transistor, MOSFET, or JFET can be used to ensure the reliability of the switching operation. In one specific embodiment, the reference voltage source connected to the emitter of the first transistor can be the same as the reference voltage source of the voltage detection circuit.

[0063] In this embodiment, the voltage monitoring circuit samples the voltage of the first power supply branch, and the first comparator compares the sampled voltage with a reference voltage using a threshold comparison, outputting the comparison result. The switching state of the transistor controls whether the auxiliary load circuit provides load conditions to the Ethernet power supply branch. During the threshold comparison stage, the first comparator can eliminate noise interference by amplifying the input voltage difference and output a stable level signal to control the base voltage of the transistor. During the enable signal generation stage, when the transistor is on, the reference voltage connected to the transmitter forms a loop through the collector and emitter, providing a stable reference level to the auxiliary load circuit; when it is off, the signal path is blocked to avoid reverse current or invalid interference.

[0064] This embodiment provides a power supply device that uses a first comparator to perform digital threshold judgment on the voltage of the power supply branch, and combines a first transistor to convert the logic signal into a stable switching control. The enable circuit ensures the anti-interference capability of signal transmission through an independent reference voltage source. At the same time, the direct coupling between the comparator and the transistor reduces signal delay, enabling accurate identification of the power supply status, thereby improving the system stability and reliability in redundant power supply scenarios.

[0065] In one embodiment, the power supply device further includes a rectifier and filter circuit, and the first power supply branch is connected to the second input terminal of the first comparator through the rectifier and filter circuit.

[0066] The rectifier and filter circuit can be a structure used to convert the original voltage of the first power supply branch into a smooth DC signal, so that the smooth DC signal can be effectively used to power the load device and to provide an effective voltage signal for the voltage detection circuit.

[0067] For example, a rectifier-filter circuit may include at least a rectifier unit and a filter unit. The rectifier unit may be used to convert an AC signal into a DC signal, and for example, this can be accomplished using the unidirectional conduction characteristic of a diode. The filter unit may be a combination circuit including a capacitor and an inductor, used to suppress voltage switching through charging and discharging characteristics, thereby enabling signal smoothing.

[0068] The power supply device provided in this embodiment converts the original voltage signal of the first power supply branch into a smooth DC signal through a rectifier and filter circuit. The pre-signal processing can effectively improve the anti-interference capability and input signal compatibility of the voltage detection link, enabling the first comparator to make threshold judgment based on a more stable input signal, thereby reducing the probability of false triggering, improving detection accuracy, and achieving the technical effect of enhancing the system's environmental adaptability.

[0069] In one embodiment, the auxiliary load circuit includes a periodic signal generation circuit and a constant current source circuit. The periodic signal generation circuit is connected to the input voltage terminal and is used to generate a periodic signal based on the input voltage input to the input voltage terminal. The periodic signal is matched with the minimum power requirement of the Power over Ethernet (PoE) branch. The constant current source circuit is used to provide load conditions for the PoE branch based on the input voltage and the periodic signal.

[0070] The periodic signal generation circuit can be a signal source that generates periodic signals of a specific frequency or pulse width. In this embodiment, by generating periodic signals, a reference timing can be provided for the load of the constant current source circuit. The periodic signal generation circuit can generate periodic signals by using an oscillator in conjunction with logic gate circuits or a dedicated signal generation chip. For example, the periodic signal generation circuit may include a signal generation module based on an RC oscillator and a timer, or it may include a circuit using a dedicated PWM signal generation chip. The input voltage value is obtained through a voltage sampling network, and the signal parameters are dynamically adjusted according to a pre-stored power demand curve, for example, reducing the pulse width when the input voltage increases to maintain a constant total power.

[0071] A constant current source circuit can be a circuit that converts a periodic signal and a time-varying input voltage into a stable current output. A constant current source circuit can include at least two input terminals to simultaneously respond to voltage and signal inputs. For example, a constant current source circuit can be a circuit including a switching transistor, implemented by controlling the switching transistor. In a specific embodiment, the constant current source circuit can analyze the timing characteristics of the periodic signal, output a current pulse of a preset amplitude in each signal cycle, and simultaneously adjust the on-resistance of the switching device according to the input voltage to maintain constant current characteristics, thereby injecting the current pulse into the Power over Ethernet branch to form a continuous load.

[0072] This embodiment provides a power supply device that generates dynamically adapted timing signals through a periodic signal generation circuit to control the output characteristics of a constant current source circuit. The periodic signal generation circuit dynamically adjusts signal parameters through voltage sampling and parameter calculation, while the constant current source circuit matches the current amplitude with the pulse period. By replacing continuous energy consumption with a periodic load, and under the premise of meeting the minimum power maintenance conditions of the Power over Ethernet protocol, the energy required to determine the minimum load condition can be effectively reduced, unnecessary energy loss can be reduced, and the effects of improving power supply stability and optimizing system energy efficiency can be achieved.

[0073] In one embodiment,

[0074] The periodic signal generation circuit includes a hysteresis comparator circuit, a capacitor, and a third comparator. The hysteresis comparator circuit includes multiple loops consisting of a second comparator and multiple resistors, used to charge the capacitor so that the capacitor generates a triangular wave signal, and outputs the triangular wave signal to the second input terminal of the third comparator.

[0075] The first input terminal of the third comparator is connected to the input voltage terminal, and is used to generate a periodic signal based on the input voltage and the triangular wave signal.

[0076] The hysteresis comparator circuit can be an auxiliary capacitor circuit for generating triangular waves. Furthermore, the hysteresis comparator circuit can be a feedback loop composed of a second comparator and multiple resistors to achieve hysteresis function, thereby dynamically controlling the charging and discharging path of the capacitor to generate a stable triangular wave signal.

[0077] In one specific embodiment, the hysteresis comparator circuit can be connected to the resistor network through the positive feedback mechanism of the second comparator. The charging and discharging path is controlled by the switching of the output state of the hysteresis comparator circuit. The charging and discharging rate can be determined by combining the resistance value and the capacitance value. For example, slow charging can be achieved by using a high resistance value resistor, and fast discharging can be achieved by using a low resistance value resistor.

[0078] The first input of the third comparator is connected to the input voltage terminal, and the second input receives a triangular wave signal. It can be used to compare the voltages at the two input terminals in real time and output a pulse sequence. For example, the output waveform can be a pulse width modulation (PWM) signal.

[0079] The third comparator can be used to compare the input voltage with the instantaneous value of the triangular wave point by point. In a specific embodiment, it can output a high level when the input voltage is higher than the triangular wave and a low level when it is lower, thereby converting the static input voltage into a dynamic pulse signal.

[0080] This embodiment provides a power supply device that uses the hysteresis characteristic of the hysteresis comparator circuit to charge and discharge the capacitor, thereby achieving stable generation of a triangular wave. The third comparator generates a periodic signal with an adjustable duty cycle by comparing the input voltage with the triangular wave in real time. While maintaining the stability of the triangular wave oscillation, dynamic parameter adaptation ensures that the periodic signal always meets the power requirements of the Ethernet power supply branch, thereby improving the system's dynamic response capability, reducing energy loss, and enhancing anti-interference reliability.

[0081] In one embodiment,

[0082] The constant current source circuit includes a second transistor and a third transistor. The base of the second transistor is connected to the periodic signal generating circuit, the collector of the second transistor is connected to the input voltage terminal and the base of the third transistor, and the emitter of the second transistor is grounded.

[0083] The collector of the third transistor is connected to the Power over Ethernet branch, and the emitter of the third transistor is connected to the ground terminal, which is connected to the ground terminal of the Power over Ethernet branch.

[0084] In this circuit, the second transistor can function as a signal-driven switch, receiving the periodic signal output from the periodic signal generation circuit through its base. Its collector is connected to both the input voltage terminal and the base of the third transistor, while its emitter is grounded, forming a reference circuit. The second transistor's conduction state can be controlled by its base voltage, and its collector voltage serves as the base driving source for the third transistor. The collector voltage of the second transistor is both the base driving source for the third transistor and a direct sampling point for the input voltage, converting the timing information of the periodic signal into a voltage driving signal.

[0085] In one specific embodiment, the second transistor can be a bipolar junction transistor (BJT) structure, achieving a switching function through the threshold voltage characteristic between its base and collector. When the periodic signal is high, the base voltage drives the second transistor to conduct, applying a positive voltage to the base of the third transistor via the collector. When the periodic signal is low, the second transistor is off, and the base voltage of the third transistor drops. Through the coordinated relationship between the base voltage and the collector voltage, precise control of the turn-on timing of the third transistor can be achieved.

[0086] The collector of the third transistor is connected to the Power over Ethernet (PoE) branch, or further, it can be connected to the output terminal of the PoE branch. The emitter of the third transistor forms a path with the ground terminal of the PoE branch through the ground terminal.

[0087] In one specific embodiment, the third transistor can be a transistor, a MOSFET with high current carrying capacity, etc., and can achieve constant current output by adjusting its on-resistance. When the third transistor is turned on, the input voltage forms a loop through its collector and ground, generating current flowing from the Ethernet power supply branch. When the input voltage fluctuates, the change in the collector voltage of the second transistor dynamically adjusts the base-collector voltage of the third transistor, thereby changing its on-resistance. Since the emitter of the third transistor is grounded, the collector voltage can remain stable according to the relationship between the on-resistance and the load current, forming an adaptive current control mechanism, thereby compensating for the impact of input voltage fluctuations on the output current without the need for additional feedback circuitry.

[0088] The power supply device provided in this embodiment converts the periodic signal timing into a voltage drive signal through a second transistor to control the conduction timing of a third transistor. Through the adaptive current regulation mechanism of the third transistor and the dynamic compensation function formed by the voltage linkage between the two transistors, it can achieve the effects of accurately controlling the periodic characteristics of the output current, automatically adapting to input voltage fluctuations, and improving the robustness of the system.

[0089] In one embodiment, the Power over Ethernet (PoE) branch includes a rectifier bridge circuit and a DC energy storage circuit.

[0090] The rectifier bridge circuit is connected to the collector of the third transistor and the DC energy storage circuit respectively, and is used to generate and output a preset voltage; the DC energy storage circuit is used to smooth the preset voltage before outputting it.

[0091] The rectifier bridge circuit serves as the front-end voltage conversion circuit in the Power over Ethernet (PoE) branch. It can be constructed using semiconductor diodes, integrated bridge modules, or other components to form a port structure. The positive output terminal is connected to the input terminal of the PoE line, while the negative output terminal is connected to the collector of the third transistor and the DC energy storage circuit, respectively. This converts the input AC or variable polarity voltage into a unidirectional pulsating DC voltage. The rectifier bridge circuit and the third transistor are electrically coupled through their collector terminals, allowing the constant current source circuit to provide load conditions for the PoE branch. In one specific embodiment, the AC input terminal of this circuit can be connected to the PoE branch, its output terminal is connected to the positive terminal of the filter capacitor in the DC energy storage circuit, and the collector of the third transistor is electrically connected to the negative output terminal of the rectifier bridge.

[0092] The third transistor can be a semiconductor switching device such as a transistor, MOSFET, or IGBT, comprising a base, collector, and emitter. In this embodiment, the conduction state of the third transistor can be controlled by the base voltage, dynamically adjusting the current flowing through the device. The collector of the third transistor is connected to the input voltage terminal of the constant current source circuit, while the emitter is connected to the ground terminal of the DC energy storage circuit, forming a constant current source control loop together with the second transistor. In a specific embodiment, the base of the third transistor receives a voltage signal from the second transistor via a signal line, its emitter is connected to the output terminal of the Ethernet power supply branch, and its collector is connected to the output terminal of the rectifier bridge circuit. By adjusting the base voltage, the input voltage can be converted into a constant current output to the ground loop, maintaining the stability of the load current.

[0093] The DC energy storage circuit can be a filter network including capacitors, inductors, and resistors. Further, it can integrate large-capacity electrolytic capacitors or supercapacitors to smooth the pulsating DC voltage after rectification, eliminate voltage ripple, and maintain stable output voltage. The input terminal of the DC energy storage circuit is connected to the positive output terminal of the rectifier bridge circuit, and the output terminal is connected to the target load device. In one specific embodiment, the electrolytic capacitor is connected in parallel with the inductor in series to form an LC filter circuit, and its ground terminal is connected to the emitter of the third transistor. During power supply switching, the energy storage element releases stored energy to suppress voltage drops, thereby improving power supply continuity.

[0094] This embodiment provides a power supply device that converts AC components into DC voltage through a rectifier bridge circuit, smooths voltage fluctuations through a DC energy storage circuit, and uses a third transistor to regulate current based on the base voltage. This enables the constant current source circuit to form a stable load condition during power supply, which not only eliminates the risk of power interruption but also achieves precise matching of power demand, thereby improving system stability and power supply continuity in redundant power supply scenarios.

[0095] To more clearly illustrate the technical solution of this application, a detailed embodiment is also provided.

[0096] In one embodiment, such as Figure 2 As shown, a power supply device is provided, including a first power supply branch, an Ethernet power supply branch, an auxiliary control device, and an auxiliary control circuit voltage source circuit.

[0097] The first power supply branch is the adapter power supply branch, and the Ethernet power supply branch uses the PoE protocol for power supply. The auxiliary control circuit consists of an adapter voltage detection module circuit, a subsequent circuit enable module circuit, a PWM waveform generation circuit, and a periodic constant current source circuit.

[0098] It is understandable that the auxiliary control circuit operates for the Power over Ethernet (PoE) branch. The auxiliary control circuit only needs a voltage source to power it when PoE is plugged in; when only the adapter is plugged in, the auxiliary control circuit does not need to function, and there is no need for a power supply voltage source. In this embodiment, the voltage source circuit of the auxiliary control circuit uses the voltage of the auxiliary winding Aux of the DC-DC isolated converter as the input source of the auxiliary control circuit. In conventional technology, the reference ground of the auxiliary control circuit is PoE_GND, while the reference ground of the auxiliary winding Aux voltage is Power_GND2, therefore a path cannot usually be formed. The applicant discovered through research that when the PoE is inserted for detection, identification, and power supply, the RTN transistor in the PD section will turn on, thus connecting the reference ground POE_GND and the reference ground Power_GND1 together; the PoE power supply switch will also turn on, thus connecting the reference ground Power_GND1 and the reference ground Power_GND2 together. Therefore, the reference grounds POE_GND and Power_GND2 will form a path, creating a voltage source from Aux to POE_GND, thereby powering the auxiliary control circuit.

[0099] The adapter voltage detection module detects the voltage after rectification and filtering in the adapter power supply branch. Input 1 is the rectified and filtered voltage of the adapter, and input 2 is the threshold voltage, which can be generated by the voltage source from Aux to POE_GND. In one specific embodiment, the threshold voltage is less than the minimum value of the input voltage of the PD section. When POE is inserted and the adapter voltage is greater than the threshold, a low-level signal is output to enable the subsequent auxiliary control circuits, namely the PWM generator circuit and the periodic constant current source circuit. Otherwise, the subsequent control circuits do not operate to achieve low-power standby of the auxiliary control circuits.

[0100] The PWM generator circuit is used to generate a PWM square wave signal to drive the subsequent constant current source circuit to work periodically. The periodic operation of the constant current source can effectively reduce power consumption. For example, if the duty cycle of the PWM is D and the power consumption of the constant current source is P, then the power consumption of the periodic constant current source is P' = D × P.

[0101] A periodic constant current source circuit is connected between the PoE output and PoE_GND to periodically consume the current of the PSE, ensuring that the PSE does not lose power. Furthermore, the consumption of the periodic constant current source circuit meets the requirement that the PSE output load current is not less than 10mA or that at least 10mA of current is consumed for at least 60ms within every 300ms.

[0102] The above auxiliary control circuitry enables seamless switching between adapter and PoE power supply while maintaining low power consumption. For example... Figure 3As shown, when the POE switches to the adapter, power is supplied by POE, the adapter voltage detection module operates, and the post-stage auxiliary control circuit does not operate; the adapter is inserted; it is determined whether the adapter voltage is greater than the threshold voltage, if not, POE continues to supply power, and the post-stage auxiliary control circuit does not operate; if yes, the post-stage auxiliary control circuit of the detection module operates, and the constant current source periodically consumes PSE current; the one with higher voltage between the adapter and POE takes over the power supply, and the PSE does not lose power; after POE is unplugged, the adapter takes over the power supply seamlessly, and the voltage source circuit of the auxiliary control circuit is cut off.

[0103] As Figure 4 shown, when the adapter switches to POE, power is supplied by the adapter, and the voltage source of the auxiliary control circuit is cut off; POE is inserted; the PSE performs identification, detection and power-on, the voltage source of the auxiliary control circuit is generated, and the voltage detection module operates; it is determined whether the adapter voltage is greater than the threshold voltage, if not, POE takes over the power supply, and the post-stage auxiliary control circuit of the detection module does not operate; if yes, the post-stage auxiliary control circuit of the detection module operates, and the constant current source periodically consumes PSE current; the one with higher voltage between the adapter and POE takes over the power supply, and the PSE does not lose power; after the adapter is unplugged, POE takes over the power supply seamlessly, and the voltage source circuit of the auxiliary control circuit operates.

[0104] In a specific embodiment, appropriate selection of resistance values can meet the requirements of low standby power consumption and low operating power consumption.

[0105] As Figure 5 shown, the adapter voltage detection circuit may include a first comparator (COMP1) and resistors, and the post-stage power enable circuit may include a transistor Q1, wherein the transistor Q1 may be any tube or semiconductor device that meets the requirements. The base of the transistor Q1 is connected to the output terminal of the first comparator via a resistor R5, and the collector is connected to the reference ground POE_GND. The reference voltage Vref is generated by the voltage of the auxiliary winding Aux, and is input to the positive (+) terminal of the first comparator via a resistor R1. The negative (-) terminal of the first comparator is input with the voltage obtained after the sampled voltage Adapter of the rectified and filtered adapter passes through a resistor R3. The positive terminal and the negative terminal of the first comparator are also grounded to POE_GND via a resistor R2 and a resistor R4 respectively. The output of the first comparator is connected to the post-stage power enable circuit to control whether the post-stage control circuit is powered on. When the adapter voltage < Vref, the first comparator outputs a high level, which is output to the transistor Q1 via the resistor R5, the transistor Q1 does not turn on, and Aux_1 has no power; when the adapter voltage > Vref, the first comparator outputs a low level, the transistor Q1 turns on, and Aux_1 supplies power to the post-stage auxiliary control circuit.

[0106] As Figure 6As shown, the PWM signal generation circuit includes comparator 2 (COMP2), comparator 3 (COMP3), multiple resistors, and capacitor C1. Comparator 2 forms a hysteresis comparator circuit. The output terminal of comparator 2 is connected to the negative terminals of comparator 2 and comparator 3 respectively through resistor R11. When comparator 2 outputs low and high, resistors R7, R8, R9, and R10 form different loops, generating two voltage thresholds to charge capacitor C1, producing a voltage triangular wave at the positive terminal of capacitor C1. The positive terminal of capacitor C1 is connected to the negative (-) terminal of comparator 3, and the positive (+) terminal of comparator 3 is connected to the bias voltage generated by the voltage divider of resistors R12 and R13 (midpoint of resistors R12 and R13), thus comparator 3 outputs a PWM wave. Adjusting the bias voltage generated by resistors R12 and R13, as well as the resistor and capacitor parameters of the hysteresis comparator circuit of comparator 2, can change the duty cycle of the PWM wave.

[0107] The constant current source circuit includes transistors Q2 and Q3 and multiple resistors. Transistors Q2 and Q3 can be any other suitable transistors or semiconductor devices. The output of comparator 3 is connected to the base of transistor Q2 through resistor R14. The collector of transistor Q3 is connected to the POE input voltage +48_POE, and the emitter of transistor Q3 is connected to the feedback resistor Rf to adjust the constant current source current. When the PWM signal is high, transistor Q2 is on, transistor Q3 is off, and the constant current source is not working. When the PWM signal is low, transistor Q2 is off, the Vb voltage turns on transistor Q3, and the on-state current of transistor Q3 is (Vb-Vf) / Rf, which is the constant current source current, thus drawing current from the PSE.

[0108] This embodiment provides a power supply device that, by adding a controllable constant current source circuit to the PSE input, ensures that the PSE power supply meets protocol requirements, avoiding power cut-off due to insufficient minimum load conditions, and enabling seamless switching between the adapter and PoE. Through access detection and PWM signal control, the auxiliary control circuit only operates after the PoE is plugged in and powered on; that is, the voltage source of the auxiliary control circuit is enabled only after the PoE is powered on. Furthermore, the subsequent auxiliary control circuit only operates and generates a PWM periodic signal when the adapter voltage is higher than a preset threshold, periodically drawing current from the PSE. The average current is also very low, meeting protocol requirements and ensuring the PSE does not lose power while meeting low power consumption requirements. By drawing power from the DC-DC isolated power supply Aux, after the PSE is plugged in and powered on, an Aux→POE_GND voltage source is automatically generated according to the power supply logic, effectively providing a voltage source for the auxiliary control circuit.

[0109] Each module in the aforementioned power supply device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0110] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0111] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0112] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A power supply device, characterized in that, The power supply device includes a first power supply branch, an Ethernet power supply branch, and an auxiliary control circuit; the auxiliary control circuit includes a voltage detection circuit and an auxiliary load circuit, wherein: The voltage detection circuit is connected to the first power supply branch, and the auxiliary load circuit is connected to the Ethernet power supply branch. The voltage detection circuit is used to collect the voltage of the first power supply branch to obtain the first power supply voltage, and when the first power supply voltage is higher than a preset threshold, control the auxiliary load circuit to provide load conditions for the Ethernet power supply branch.

2. The power supply device according to claim 1, characterized in that, The power supply device further includes an isolated output circuit, wherein the first power supply branch or the Ethernet power supply branch is connected to the isolated output circuit to supply power to the target load device.

3. The power supply device according to claim 2, characterized in that, The power supply device further includes an auxiliary control circuit voltage source circuit, and the auxiliary control circuit is connected to the isolated output circuit through the auxiliary control circuit voltage source circuit; the auxiliary control circuit voltage source circuit is used to provide a voltage input source for the auxiliary control circuit based on the auxiliary winding voltage of the isolated output circuit.

4. The power supply device according to claim 1, characterized in that, The power supply device includes a monitoring trigger circuit for monitoring the first power supply branch and the Ethernet power supply branch. When the first power supply branch or the Ethernet power supply branch is inserted, the voltage detection circuit is triggered to collect the voltage of the first power supply branch.

5. The power supply device according to claim 1, characterized in that, The voltage detection circuit includes a first comparator and an enable circuit; The first input terminal of the first comparator is used to input a reference voltage, and the second input terminal of the first comparator is connected to the first power supply branch; The enabling circuit includes a first transistor, the base of which is connected to the output of the first comparator, the emitter of which receives the reference voltage, and the collector of which is connected to the auxiliary load circuit.

6. The power supply device according to claim 5, characterized in that, The power supply device further includes a rectifier and filter circuit, and the first power supply branch is connected to the second input terminal of the first comparator through the rectifier and filter circuit.

7. The power supply device according to claim 1, characterized in that, The auxiliary load circuit includes a periodic signal generation circuit and a constant current source circuit. The periodic signal generation circuit is connected to the input voltage terminal and is used to generate a periodic signal based on the input voltage input to the input voltage terminal. The periodic signal is matched with the minimum power requirement of the Power over Ethernet branch. The constant current source circuit is used to provide load conditions for the Power over Ethernet branch based on the input voltage and the periodic signal.

8. The power supply device according to claim 7, characterized in that, The periodic signal generation circuit includes a hysteresis comparator circuit, a capacitor, and a third comparator; the hysteresis comparator circuit includes multiple loops composed of a second comparator and multiple resistors, used to charge the capacitor so that the capacitor generates a triangular wave signal, and outputs the triangular wave signal to the second input terminal of the third comparator. The first input terminal of the third comparator is connected to the input voltage terminal and is used to generate a periodic signal based on the input voltage and the triangular wave signal.

9. The power supply device according to claim 7, characterized in that, The constant current source circuit includes a second transistor and a third transistor, wherein the base of the second transistor is connected to the periodic signal generating circuit, the emitter of the second transistor is connected to the input voltage terminal and the base of the third transistor respectively, and the emitter of the second transistor is grounded. The collector of the third transistor is connected to the Ethernet power supply branch, and the emitter of the third transistor is connected to the ground terminal, which is connected to the ground terminal of the Ethernet power supply branch.

10. The power supply device according to claim 9, characterized in that, The Power over Ethernet (PoE) branch includes a rectifier bridge circuit and a DC energy storage circuit. The rectifier bridge circuit is connected to the collector of the third transistor and the DC energy storage circuit respectively, and is used to generate and output a preset voltage; the DC energy storage circuit is used to smooth the preset voltage before outputting it.

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