POE power supply power supply protection module, power supply system and power supply method

Abstract

The invention discloses a power supply protection module of a POE power supply, a power supply system and a power supply method, relates to the field of power supply protection of power supplies, and aims to solve the technical problem of insufficient power supply protection of a POE power supply circuit. The power supply protection module comprises a first starting circuit and a first discharging circuit; the power supply output end of the POE power supply is connected with the first port of the first starting circuit and the first port of the first discharging circuit. A second port of the first starting circuit is connected with a third port of the first discharging circuit; a third port of the first starting circuit is connected with a load; a second port of the first discharging circuit is connected with a first port of the first starting circuit; the first starting circuit is used for controlling the charging conduction time of the first starting circuit when current input of the POE power supply is received; and the first discharging circuit is used for controlling the first starting circuit to release the stored electric energy through the first discharging circuit when the current input of the POE power supply is not received.

Description

Technical Field

[0001] The present invention relates to the field of power supply protection, and in particular to a power supply protection module, a power supply system and a power supply method of a POE power supply. Background Art

[0002] In the existing technology, POE (Power over Ethernet) technology is widely used in wireless network power supply, outdoor network camera power supply, smart building power supply and IoT device power supply. At present, the power of POE power supply equipment is also constantly improving to broaden its scope of use. However, the POE efficiency of PD (Power Device) equipment powered by POE technology is difficult to exceed 90%. The existing solution is mainly to use ACF (Active Clamp Forward) circuit to improve the efficiency of POE power supply equipment.

[0003] However, in the existing scenario of using ACF circuit to improve POE efficiency, high-power PD devices (loads) are often equipped with capacitors of several hundred to thousands of microfarads for energy storage filtering. For ACF circuits, the presence of such capacitors will lead to the following risks: (1) At the moment of power-on, the capacitor is approximately equal to the short-circuit state, and the current charging the capacitor is very large, which will cause overcurrent protection of the PD device and thus fail to power on normally; (2) During power-off, the ACF synchronous rectification circuit will be backflowed by the reverse charging current of the capacitor, causing overshoot, which can easily damage the MOS tube and cause damage to the equipment; (3) After power-off, the capacitor cannot discharge quickly due to the disappearance of the load, and may even maintain a high voltage for a long time. This state will affect the reset timing and the next power-on timing of other modules, causing danger to the circuit and also causing a certain impact on the maintenance of the equipment. However, the existing technology has not well solved the above risks caused by insufficient power supply protection. Summary of the invention

[0004] The present invention provides a power supply protection module, a power supply system and a power supply method of a POE power supply, so as to solve the technical problem of insufficient power supply protection of the existing POE power supply circuit.

[0005] According to a first aspect of an embodiment of the present application, a power supply protection module of a POE power supply is provided, comprising a first starting circuit and a first discharge circuit;

[0006] The power output end of the POE power supply is connected to the first port of the first starting circuit and the first port of the first discharging circuit respectively;

[0007] The second port of the first startup circuit is connected to the third port of the first discharge circuit; the third port of the first startup circuit is connected to a load;

[0008] The second port of the first discharge circuit is connected to the first port of the first start-up circuit;

[0009] The first startup circuit is used to control the charging on-time of the first startup circuit when the first port of the first startup circuit receives the current input of the POE power supply, so as to control the voltage rising rate of the first startup circuit;

[0010] The first discharge circuit is used to control the first start-up circuit to release the electric energy stored during the power supply of the POE power supply through the first discharge circuit when the first port of the first discharge circuit does not receive the current input of the POE power supply.

[0011] The present application forms a power supply protection module of a POE power supply through a first startup circuit and a first discharge circuit. When the POE power supply needs to be used to power the load, the first startup circuit can control the charging conduction time of the first startup circuit, thereby controlling the rising rate of the voltage of the first startup circuit, and can ensure the stability of the POE power supply to the load, and prevent the surge current generated by instantaneous power-on from causing the overcurrent protection of the load and causing the load to fail to power on normally; the first discharge circuit can control the first startup circuit to release the electric energy stored during the POE power supply through the first discharge circuit when the POE power supply stops supplying power, and prevent the first startup circuit from incompletely releasing the electric energy and causing the first startup circuit voltage to fail to control the rising rate. Through the above circuit, the power supply protection of the power supply circuit of the POE power supply can be realized in the complete stage from the POE power supply starting to supply power to the load to the POE power supply stopping to supply power to the load.

[0012] In some embodiments of the present application, the first startup circuit includes a parallel capacitor group, a first resistor, a second resistor and a first transistor; the parallel capacitor group includes a plurality of capacitors connected in parallel;

[0013] The first port of the parallel capacitor group is connected to the first port of the first startup circuit; the second port of the parallel capacitor group is connected to the second port of the first startup circuit;

[0014] The first port of the first resistor is connected to the first port of the first startup circuit; the second port of the first resistor is connected to the second port of the first startup circuit;

[0015] The source of the first transistor is connected to the first port of the first startup circuit; the gate of the first transistor is connected to the second port of the first startup circuit; the drain of the first transistor is connected to the third port of the first startup circuit;

[0016] The second port of the first startup circuit is grounded through the second resistor.

[0017] The present application combines a parallel capacitor group, a first resistor, a second resistor and a first transistor into a first starting circuit, which can control the voltage rising rate when using a POE power supply to power the load, ensure the smooth power supply of the load by the POE power supply, and avoid the surge current at the moment of power-on causing overcurrent protection of the load and resulting in failure to power on normally, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0018] In some embodiments of the present application, the first discharge circuit includes a third resistor, a fourth resistor, a fifth resistor and a second triode;

[0019] The first port of the third resistor is connected to the first port of the first discharge circuit; the second port of the third resistor is connected to the base of the second transistor;

[0020] The emitter of the second transistor is connected to the second port of the first discharge circuit;

[0021] The first port of the fourth resistor and the first port of the fifth resistor are connected to the collector of the second transistor;

[0022] The second port of the fourth resistor and the second port of the fifth resistor are connected to the third port of the first discharge circuit and are grounded at the same time.

[0023] The present application combines the third resistor, the fourth resistor, the fifth resistor and the second transistor into a first discharge circuit, which can release the electric energy stored in the soft start circuit during operation when the POE power supply ends, thereby preventing the first start circuit from failing to control the rising rate of the circuit voltage due to incomplete release of the electric energy of the first start circuit, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0024] In some embodiments of the present application, a current control circuit is also included;

[0025] The first port of the current control circuit is coupled to the power output terminal of the POE power supply; the second port of the current control circuit is coupled to the first port of the first startup circuit;

[0026] The current control circuit includes a first diode and a second diode;

[0027] The anode of the first diode is connected to the first port of the current control circuit; the cathode of the first diode is connected to the second port of the current control circuit;

[0028] The anode of the second diode is connected to the first port of the current control circuit; the cathode of the second diode is connected to the second port of the current control circuit;

[0029] The current control circuit is used to control the input current to flow from the first port of the current control circuit to the second port when the first port of the current control circuit receives the current input of the POE power supply; and to prevent the current returned by the load from flowing from the second port of the current control circuit to the first port of the current control circuit when the first port of the current control circuit does not receive the current input of the POE power supply.

[0030] The present application combines the first diode and the second diode into a current control circuit. When the POE power supply needs to be used to power the load, the direction of the current is fixed to flow from the POE power supply to the load, and when the POE power supply stops supplying power, the current returned from the load is prevented from flowing to the POE power supply, thereby preventing the current backflow when the POE power supply ends, thereby avoiding the problem of over-shock and breakdown of the POE power MOS tube caused by the current backflow, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0031] In some embodiments of the present application, a second discharge circuit is further included;

[0032] The first port of the second discharge circuit is connected to the power output terminal of the POE power supply; the second port of the second discharge circuit is connected to the load;

[0033] The second discharge circuit includes a discharge judgment circuit and a discharge control circuit;

[0034] The first port of the discharge judgment circuit is connected to the first port of the second discharge circuit; the second port of the discharge judgment circuit is connected to the second port of the second discharge circuit; the third port of the discharge judgment circuit is grounded;

[0035] The first port of the discharge control circuit is connected to the second port of the second discharge circuit; the second port of the discharge control circuit is connected to the second port of the discharge judgment circuit; the third port of the discharge control circuit is grounded;

[0036] The discharge judgment circuit is used to output a control signal through the second port of the discharge judgment circuit to control the discharge control circuit to work when the first port of the discharge judgment circuit does not receive the current input of the POE power supply;

[0037] The discharge control circuit is used to release the electric energy stored in the filter capacitor connected to the load during the power supply of the POE power supply through the discharge control circuit when the second port of the discharge control circuit receives the control signal of the discharge judgment circuit.

[0038] The present application adds a second discharge circuit consisting of a discharge judgment circuit and a discharge control circuit. When the POE power supply to the load ends, the discharge judgment circuit can judge the circuit state and control the working timing of the discharge control circuit to prevent abnormal discharge; the discharge control circuit can release the electric energy stored in the filter capacitor connected to the load during the circuit power supply period according to the control of the discharge judgment circuit, thereby avoiding the circuit timing abnormality problem caused by the difficulty of discharging the filter capacitor after the power supply ends, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0039] In some embodiments of the present application, the discharge determination circuit includes a sixth resistor, a seventh resistor, an eighth resistor and a third transistor;

[0040] The first port of the eighth resistor is connected to the first port of the discharge judgment circuit; the second port of the eighth resistor is connected to the base of the third transistor;

[0041] The emitter of the third triode is connected to the first port of the seventh resistor; the collector of the third triode is grounded;

[0042] The second port of the seventh resistor is connected to the second port of the discharge judgment circuit;

[0043] The second port of the discharge determination circuit is connected to the second port of the second discharge circuit through a sixth resistor.

[0044] The present application combines the sixth resistor, the seventh resistor, the eighth resistor and the third transistor into a discharge judgment circuit, which can judge the circuit state, control the working timing of the discharge control circuit, prevent abnormal discharge, meet the circuit working requirements, and thus realize power supply protection for the power supply circuit of the POE power supply.

[0045] In some embodiments of the present application, the discharge control circuit includes a ninth resistor, a tenth resistor and a fourth transistor;

[0046] The gate of the fourth transistor is connected to the second port of the discharge judgment circuit; the source of the fourth transistor is connected to the first port of the discharge control circuit;

[0047] The first port of the ninth resistor and the first port of the tenth resistor are connected to the drain of the fourth transistor;

[0048] The second port of the ninth resistor and the second port of the tenth resistor are connected to the second port of the discharge control circuit.

[0049] The present application combines the ninth resistor, the tenth resistor and the fourth transistor into a discharge control circuit, which can release the electric energy stored in the filter capacitor connected to the load during the circuit power supply period according to the control of the discharge judgment circuit, thereby avoiding the circuit timing abnormality problem caused by the difficulty of discharging the filter capacitor after the power supply ends, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0050] According to a second aspect of the embodiments of the present application, a POE power supply system is provided, comprising a POE power supply, a load, and a power supply protection module of the POE power supply as described in the first aspect of the embodiments of the present application;

[0051] The POE power supply is connected to the load through the power supply protection module to supply power to the power supply protection module and the load.

[0052] According to a third aspect of the embodiments of the present application, a power supply method is provided, which is applicable to the power supply system of the POE power supply according to the second aspect of the embodiments of the present application, and the power supply method includes:

[0053] When the POE power supply starts to supply power, the power supply protection module controls the charging on time of the power supply protection module according to the preset capacitor charging and discharging parameters to control the voltage rising rate of the power supply protection module;

[0054] When the POE power source stops supplying power, the power supply protection module releases the electric energy stored during the period when the POE power source supplies power.

[0055] In this way, according to the working status of the POE power supply module, when the power supply starts, the power supply protection module controls the charging conduction time of the power supply protection module according to the preset capacitor charging and discharging parameters, thereby controlling the voltage rising rate of the power supply protection module, which can avoid the overcurrent protection of the load caused by the surge current generated by the instantaneous power-on of the POE power supply module, thereby avoiding the problem that the load cannot be powered on normally; when the power supply is stopped, the power supply protection module releases the electric energy stored during the power supply of the POE power supply, which can prevent the failure of controlling the voltage rising rate of the power supply protection module due to the incomplete release of the electric energy of the power supply protection module, thereby realizing the power supply protection of the power supply circuit of the POE power supply from the beginning to the end of the period from the POE power supply to the load.

[0056] In some embodiments of the present application, the power supply method further includes:

[0057] When the POE power supply starts to supply power, the power supply protection module controls the input current to flow from the POE power supply to the load through the power supply protection module;

[0058] When the POE power supply stops supplying power, the power supply protection module prevents the current returned by the load from flowing to the POE power supply through the power supply protection module.

[0059] In this way, when the POE power supply starts to supply power, the power supply protection module controls the input current to flow from the POE power supply to the load through the power supply protection module. When the POE power supply stops supplying power, the power supply protection module prevents the current returned by the load from flowing to the POE power supply through the power supply protection module. This can prevent current backflow when the POE power supply ends, thereby avoiding the problem of over-shock and breakdown of the POE power MOS tube caused by current backflow, thereby realizing power supply protection for the power supply circuit of the POE power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 : is a module schematic diagram showing a power supply protection module of a POE power supply in an embodiment of the present application;

[0061] Figure 2 : is another module schematic diagram of a power supply protection module of a POE power supply in an embodiment of the present application;

[0062] Figure 3 : is a circuit structure diagram of a power supply protection module of a POE power supply in an embodiment of the present application;

[0063] Figure 4 : is a module schematic diagram of a second discharge circuit shown in a power supply protection module of a POE power supply in an embodiment of the present application;

[0064] Figure 5 : is a circuit structure diagram of a second discharge circuit shown in a power supply protection module of a POE power supply in an embodiment of the present application;

[0065] Figure 6 : is a system connection diagram showing a power supply system of a POE power supply in an embodiment of the present application;

[0066] Figure 7 : is a flow chart showing a power supply method in an embodiment of the present application;

[0067] Among them, the specific reference numerals are:

[0068] 11-13: the first port to the third port of the first startup circuit 1;

[0069] 21-23: the first port to the third port of the first discharge circuit 2;

[0070] 51-52: a first port and a second port of the current control circuit 5;

[0071] 61-62: a first port and a second port of a second discharge circuit 6;

[0072] 71-73: the first port to the third port of the discharge determination circuit 7;

[0073] 81-83: the first port to the third port of the discharge control circuit 8;

[0074] 3: POE power supply; 4: load. DETAILED DESCRIPTION

[0075] The following will be combined with the drawings of the embodiments of the present application to clearly and completely describe the technical solutions of the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments shown in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0076] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, unless otherwise clearly and specifically defined, "multiple" and "several" mean two or more.

[0077] In large-scale power supply application scenarios, POE power supplies are usually used in conjunction with ACF circuits to improve the power supply efficiency of POE power supply equipment. However, in high-power power supply scenarios using ACF circuits in conjunction with POE power supplies, high-power PD devices (loads) are usually equipped with capacitors of several hundred to thousands of microfarads for energy storage filtering. The presence of such capacitors will result in: (1) At the moment of power-on, the capacitor is approximately equal to the short-circuit state, and the current charging the capacitor is very large, which will cause overcurrent protection of the PD device and thus fail to power on normally; (2) During power-off, the ACF synchronous rectification circuit will be backflowed by the reverse charging current of the capacitor, causing overshoot, which can easily damage the MOS tube and cause damage to the equipment; (3) After power-off, the capacitor cannot discharge quickly due to the disappearance of the load, and may even maintain a high voltage for a long time. This state will affect the reset timing and the next power-on timing of other modules, causing circuit danger and also causing a certain impact on equipment maintenance.

[0078] Due to the above-mentioned coordination scenarios of the POE power supply and the ACF circuit, it should be understood that the POE power supply described throughout this application essentially includes the POE power supply device itself and the ACF circuit that is used to match it to improve the power supply efficiency of the POE power supply.

[0079] Based on the above technical background, this application proposes a POE power supply protection module, see Figure 1, is a module schematic diagram of a power supply protection module of a POE power supply provided in the present application, including a first starting circuit 1 and a first discharge circuit 2;

[0080] The power output end of the POE power supply 3 is connected to the first port 11 of the first starting circuit 1 and the first port 21 of the first discharge circuit 2 respectively;

[0081] The second port 12 of the first startup circuit 1 is connected to the third port 23 of the first discharge circuit 2; the third port 13 of the first startup circuit 1 is connected to the load 4;

[0082] The second port 22 of the first discharge circuit 2 is connected to the first port 11 of the first start-up circuit 1;

[0083] The first startup circuit 1 is used to control the charging on time of the first startup circuit 1 when the first port 11 of the first startup circuit 1 receives the current input of the POE power supply 3, so as to control the voltage rising rate of the first startup circuit 1;

[0084] The first discharge circuit 2 is used to control the first start-up circuit 1 to release the electric energy stored during the power supply of the POE power supply 3 through the first discharge circuit 2 when the first port 21 of the first discharge circuit 2 does not receive the current input of the POE power supply 3.

[0085] The present application forms a power supply protection module of a POE power supply through a first startup circuit and a first discharge circuit. When the POE power supply needs to be used to power the load, the first startup circuit can control the charging conduction time of the first startup circuit, thereby controlling the rising rate of the voltage of the first startup circuit, and can ensure the stability of the POE power supply to the load, and prevent the surge current generated by instantaneous power-on from causing the overcurrent protection of the load and causing the load to fail to power on normally; the first discharge circuit can control the first startup circuit to release the electric energy stored during the POE power supply through the first discharge circuit when the POE power supply stops supplying power, and prevent the first startup circuit from incompletely releasing the electric energy and causing the first startup circuit voltage to fail to control the rising rate. Through the above circuit, the power supply protection of the power supply circuit of the POE power supply can be realized in the complete stage from the POE power supply starting to supply power to the load to the POE power supply stopping to supply power to the load.

[0086] In some embodiments of this application, see Figure 2 , is another module schematic diagram of a power supply protection module of a POE power supply provided in the present application, which includes, in addition to a first starting circuit 1 and a first discharge circuit 2, a current control circuit 5 and a second discharge circuit 6;

[0087] The first port 51 of the current control circuit 5 is coupled to the power output terminal of the POE power supply 3; the second port 52 of the current control circuit 5 is coupled to the first port 11 of the first start-up circuit 1;

[0088] The first port 61 of the second discharge circuit 6 is connected to the power output terminal of the POE power supply 3 ; the second port 62 of the second discharge circuit 6 is connected to the load 4 .

[0089] In some embodiments of this application, see Figure 3 , which is a circuit structure diagram of a power supply protection module of a POE power supply provided in the present application, including a first starting circuit 1, a first discharge circuit 2 and a current control circuit 5.

[0090] In some embodiments of this application, see Figure 3 , the first startup circuit 1 includes a parallel capacitor group, a first resistor R1, a second resistor R2 and a first transistor Q1; the parallel capacitor group includes a plurality of capacitors C2 to C5 connected in parallel;

[0091] The first port of the parallel capacitor group is connected to the first port 11 of the first startup circuit 1; the second port of the parallel capacitor group is connected to the second port 12 of the first startup circuit 1;

[0092] The first port of the first resistor R1 is connected to the first port 11 of the first startup circuit 1; the second port of the first resistor R1 is connected to the second port 12 of the first startup circuit 1;

[0093] The source of the first transistor Q1 is connected to the first port 11 of the first startup circuit 1; the gate of the first transistor Q1 is connected to the second port 12 of the first startup circuit 1; the drain of the first transistor Q1 is connected to the third port 13 of the first startup circuit 1;

[0094] The second port 12 of the first startup circuit 1 is grounded through the second resistor R2.

[0095] Illustratively, the first starting circuit 1 of the present application can control the charging time of the parallel capacitor group by configuring the capacitor charging and discharging parameters of the parallel capacitor group, thereby controlling the rising rate of the Vgs voltage of the first transistor Q1, and further controlling the rising rate of the voltage of the first starting circuit 1, thereby ensuring that the voltage of the POE power supply 3 is stable when supplying power to the load 4 through the first starting circuit 1.

[0096] The present application combines a parallel capacitor group, a first resistor, a second resistor and a first transistor into a first starting circuit, which can control the voltage rising rate when using a POE power supply to power the load, ensure the smooth power supply of the load by the POE power supply, and avoid the surge current at the moment of power-on causing overcurrent protection of the load and resulting in failure to power on normally, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0097] In some embodiments of this application, see Figure 3 , the first discharge circuit 2 includes a third resistor R3, a fourth resistor R5, a fifth resistor R6 and a second transistor Q2;

[0098] The first port of the third resistor R3 is connected to the first port 21 of the first discharge circuit 2; the second port of the third resistor R3 is connected to the base of the second transistor Q2;

[0099] The emitter of the second transistor Q2 is connected to the second port 22 of the first discharge circuit 2;

[0100] The first port of the fourth resistor R5 and the first port of the fifth resistor R6 are connected to the collector of the second transistor Q2;

[0101] The second port of the fourth resistor R5 and the second port of the fifth resistor R6 are connected to the third port 23 of the first discharge circuit 2 and are grounded at the same time.

[0102] Exemplarily, during the period when the POE power supply 3 continuously supplies power to the first discharge circuit 2, the voltage of the POE power supply 3 is continuously applied to the base of the second transistor Q2, the Vbe voltage of the second transistor Q2 approaches 0V, and the second transistor Q2 is cut off. At this time, the first discharge circuit 2 neither works nor acts as an additional load; and after the POE power supply 3 stops supplying power to the first discharge circuit 2, the voltage of the POE power supply 3 approaches 0V, and the parallel capacitor group in the first starting circuit 1 is continuously charged during the period when the POE power supply 3 supplies power, so the voltage of the parallel capacitor group approaches the supply voltage of the POE power supply 3. Therefore, the Vbe voltage of the second transistor Q2 is obviously greater than the turn-on voltage, and the second transistor Q2 is turned on. At this time, the first discharge circuit 2 works to release the electric energy of the parallel capacitor group in the first starting circuit 1 through the fourth resistor R5 and the fifth resistor R6, thereby preventing the incomplete release of the electric energy of the first starting circuit from causing the first starting circuit to fail to control the rising rate of the circuit voltage.

[0103] The present application combines the third resistor, the fourth resistor, the fifth resistor and the second transistor into a first discharge circuit, which can release the electric energy stored in the soft start circuit during operation when the POE power supply ends, thereby preventing the first start circuit from failing to control the rising rate of the circuit voltage due to incomplete release of the electric energy of the first start circuit, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0104] In some embodiments of this application, see Figure 3 , the current control circuit 5 includes a first diode D1 and a second diode D2;

[0105] The anode of the first diode D1 is connected to the first port 51 of the current control circuit 5; the cathode of the first diode D1 is connected to the second port 52 of the current control circuit 5;

[0106] The anode of the second diode D2 is connected to the first port 51 of the current control circuit 5; the cathode of the second diode D2 is connected to the second port 52 of the current control circuit 5;

[0107] The current control circuit 5 is used to control the input current to flow from the first port 51 of the current control circuit 5 to the second port 52 when the first port 51 of the current control circuit 5 receives the current input of the POE power supply 3; and to prevent the current returned by the load 4 from flowing from the second port 52 of the current control circuit 5 to the first port 51 of the current control circuit 5 when the first port 51 of the current control circuit 5 does not receive the current input of the POE power supply 3.

[0108] Exemplarily, the unidirectional conduction characteristics of the first diode D1 and the second diode D2 can fix the direction of current flow from the POE power supply 3 to the load 4 when the POE power supply 3 supplies power to the load 4, and prevent the current returning from the load 4 from flowing to the POE power supply 3 when the POE power supply 3 stops supplying power; at the same time, by connecting the first diode D1 and the second diode D2 in parallel, the on-state internal resistance of the current control circuit 5 can be reduced, and the first diode D1 and the second diode D2 can be prevented from heating up, thereby improving the working efficiency of the current control circuit 5.

[0109] The present application combines the first diode and the second diode into a current control circuit. When the POE power supply needs to be used to power the load, the direction of the current is fixed to flow from the POE power supply to the load, and when the POE power supply stops supplying power, the current returned from the load is prevented from flowing to the POE power supply, thereby preventing the current backflow when the POE power supply ends, thereby avoiding the problem of over-shock and breakdown of the POE power MOS tube caused by the current backflow, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0110] In some embodiments of the present application, a POE power supply protection module provided by the present application further includes a second discharge circuit 6, see Figure 4 , is a module schematic diagram of the second discharge circuit provided in this application.

[0111] In some embodiments of this application, see Figure 4 , the second discharge circuit 6 includes a discharge judgment circuit 7 and a discharge control circuit 8;

[0112] The first port 71 of the discharge judgment circuit 7 is connected to the first port 61 of the second discharge circuit 6; the second port 72 of the discharge judgment circuit 7 is connected to the second port 62 of the second discharge circuit 6; the third port 73 of the discharge judgment circuit 7 is grounded;

[0113] The first port 81 of the discharge control circuit 8 is connected to the second port 62 of the second discharge circuit 6; the second port 82 of the discharge control circuit 8 is connected to the second port 72 of the discharge judgment circuit 7; the third port 83 of the discharge control circuit 8 is grounded;

[0114] The discharge judgment circuit 7 is used to output a control signal through the second port 72 of the discharge judgment circuit 7 to control the discharge control circuit 8 to work when the first port 71 of the discharge judgment circuit 7 does not receive the current input of the POE power source 3;

[0115] The discharge control circuit 8 is used to release the electric energy stored in the filter capacitor connected to the load 4 during the power supply of the POE power supply 3 through the discharge control circuit 8 when the second port 82 of the discharge control circuit 8 receives the control signal of the discharge judgment circuit 7.

[0116] In some embodiments of this application, see Figure 5 , is a circuit structure diagram of the second discharge circuit provided in the present application, including a discharge judgment circuit 7 and a discharge control circuit 8.

[0117] In some embodiments of this application, see Figure 5 , the discharge judgment circuit 7 includes a sixth resistor R4, a seventh resistor R7, an eighth resistor R8 and a third transistor Q4;

[0118] The first port of the eighth resistor R8 is connected to the first port 71 of the discharge judgment circuit 7; the second port of the eighth resistor R8 is connected to the base of the third transistor Q4;

[0119] The emitter of the third transistor Q4 is connected to the first port of the seventh resistor R7; the collector of the third transistor Q4 is grounded;

[0120] The second port of the seventh resistor R7 is connected to the second port 72 of the discharge determination circuit 7;

[0121] The second port 72 of the discharge determination circuit 7 is connected to the second port 62 of the second discharge circuit 6 through the sixth resistor R4.

[0122] The present application combines the sixth resistor, the seventh resistor, the eighth resistor and the third transistor into a discharge judgment circuit, which can judge the circuit state, control the working timing of the discharge control circuit, prevent abnormal discharge, meet the circuit working requirements, and thus realize power supply protection for the power supply circuit of the POE power supply.

[0123] In some embodiments of the present application, the discharge control circuit 8 includes a ninth resistor R9, a tenth resistor R10 and a fourth transistor Q3;

[0124] The gate of the fourth transistor Q3 is connected to the second port 72 of the discharge judgment circuit 7; the source of the fourth transistor Q3 is connected to the first port 81 of the discharge control circuit 8;

[0125] The first port of the ninth resistor R9 and the first port of the tenth resistor R10 are connected to the drain of the fourth transistor Q3;

[0126] The second port of the ninth resistor R9 and the second port of the tenth resistor R10 are connected to the second port 82 of the discharge control circuit 8 .

[0127] The present application combines the ninth resistor, the tenth resistor and the fourth transistor into a discharge control circuit, which can release the electric energy stored in the filter capacitor connected to the load during the circuit power supply period according to the control of the discharge judgment circuit, thereby avoiding the circuit timing abnormality problem caused by the difficulty of discharging the filter capacitor after the power supply ends, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0128] Exemplarily, the second discharge circuit 6 releases the electric energy stored in the filter capacitor connected to the load 4 during the circuit power supply period through the discharge judgment circuit 7 and the discharge control circuit 8 when the POE power supply 3 ends supplying power, thereby avoiding the circuit timing abnormality problem caused by the difficulty of the filter capacitor to discharge after the power supply ends. Specifically, during the period when the POE power supply 3 continues to supply power, the Vbe voltage across the third transistor Q4 approaches 0V, and the third transistor Q4 is in the cut-off state. At this time, the Vgs voltage of the fourth transistor Q3 also approaches 0V, and the fourth transistor Q3 is also in the cut-off state, and the second discharge circuit 6 does not work; after the POE power supply 3 stops supplying power, the voltage of the POE power supply 3 approaches 0V, and the voltage drop rate of the load 4 due to the filter capacitor connected to it is slower than the voltage drop rate of the POE power supply 3, so the Vbe voltage of the third transistor Q4 The voltage is greater than the turn-on voltage, the third triode Q4 is turned on, so that current flows through the discharge judgment circuit 7, and therefore current flows through the sixth resistor R4 and the seventh resistor R7, so that the fourth triode Q3 has a Vgs voltage greater than the Vgs(th) voltage due to the voltage division of the sixth resistor R4 and the seventh resistor R7, and the fourth triode Q3 is turned on, so that the electric energy of the filter capacitor connected to the load 4 is released through the ninth resistor R9 and the tenth resistor R10, thereby avoiding the circuit timing abnormality problem caused by the difficulty in discharging the filter capacitor after the power supply is ended.

[0129] The present application adds a second discharge circuit consisting of a discharge judgment circuit and a discharge control circuit. When the POE power supply to the load ends, the discharge judgment circuit can judge the circuit state and control the working timing of the discharge control circuit to prevent abnormal discharge; the discharge control circuit can release the electric energy stored in the filter capacitor connected to the load during the circuit power supply period according to the control of the discharge judgment circuit, thereby avoiding the circuit timing abnormality problem caused by the difficulty of discharging the filter capacitor after the power supply ends, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0130] According to the second aspect of the implementation method of the present application, the present application also proposes a POE power supply system, see Figure 6 , is a connection diagram of a POE power supply system provided in the present application, including a POE power supply, a load and a power supply protection module of the POE power supply as described above;

[0131] The POE power supply is connected to the load through the power supply protection module to supply power to the power supply protection module and the load.

[0132] According to the third aspect of the implementation of the present application, the present application also proposes a power supply method, which is applicable to the power supply system of the POE power supply as described above, see Figure 7, is a flow chart of a power supply method provided in the present application, including steps S701 to S702, each step is as follows:

[0133] Step S701: When the POE power supply starts to supply power, the power supply protection module controls the charging on time of the power supply protection module according to the preset capacitor charging and discharging parameters to control the voltage rising rate of the power supply protection module;

[0134] Step S702: When the POE power source stops supplying power, the power supply protection module releases the electric energy stored during the period when the POE power source supplies power.

[0135] In some embodiments of the present application, the power supply method further includes:

[0136] When the POE power supply starts to supply power, the power supply protection module controls the input current to flow from the POE power supply to the load through the power supply protection module;

[0137] When the POE power supply stops supplying power, the power supply protection module prevents the current returned by the load from flowing to the POE power supply through the power supply protection module.

[0138] In this way, when the POE power supply starts to supply power, the power supply protection module controls the input current to flow from the POE power supply to the load through the power supply protection module. When the POE power supply stops supplying power, the power supply protection module prevents the current returned by the load from flowing to the POE power supply through the power supply protection module. This can prevent current backflow when the POE power supply ends, thereby avoiding the problem of over-shock and breakdown of the POE power MOS tube caused by current backflow, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0139] In some embodiments of the present application, the power supply method further includes:

[0140] When the POE power supply stops supplying power, the power supply protection module releases the electric energy stored in the filter capacitor connected to the load during the period of supplying power by the POE power supply through the power supply protection module.

[0141] In this way, when the POE power supply module stops supplying power, the second discharge circuit of the power supply protection module releases the electric energy stored in the filter capacitor during the system power supply period, which can avoid the circuit timing abnormality problem caused by the difficulty of discharging the filter capacitor after the power supply ends, thereby realizing power supply protection for the power supply circuit of the POE power supply.

[0142] The present application controls the charging on time of the power supply protection module according to the preset capacitor charging and discharging parameters when the power supply starts, based on the working state of the POE power supply module, so as to control the voltage rising rate of the power supply protection module, and can avoid the overcurrent protection of the load caused by the surge current generated by the instantaneous power-on of the POE power supply module, thereby avoiding the problem that the load cannot be powered on normally; when the power supply is stopped, the power supply protection module releases the electric energy stored during the power supply of the POE power supply, and can prevent the failure of controlling the voltage rising rate of the power supply protection module due to the incomplete release of the electric energy of the power supply protection module, thereby realizing the power supply protection of the power supply circuit of the POE power supply from the beginning to the end of the period from the POE power supply to the load.

[0143] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A power supply protection module for a POE power supply, characterized in that: comprising a first starting circuit and a first discharging circuit; The power output end of the POE power supply is respectively connected to the first port of the first starting circuit and the first port of the first discharging circuit; The second port of the first startup circuit is connected to the third port of the first discharge circuit; the third port of the first startup circuit is connected to a load; The second port of the first discharge circuit is connected to the first port of the first start-up circuit; The first startup circuit is used to control the charging on-time of the first startup circuit when the first port of the first startup circuit receives the current input of the POE power supply, so as to control the voltage rising rate of the first startup circuit; The first discharge circuit is used to control the first start-up circuit to release the electric energy stored during the power supply of the POE power supply through the first discharge circuit when the first port of the first discharge circuit does not receive the current input of the POE power supply.

2. A POE power supply protection module according to claim 1, characterized in that: The first startup circuit includes a parallel capacitor group, a first resistor, a second resistor and a first transistor; the parallel capacitor group includes a plurality of capacitors connected in parallel; The first port of the parallel capacitor group is connected to the first port of the first startup circuit; the second port of the parallel capacitor group is connected to the second port of the first startup circuit; The first port of the first resistor is connected to the first port of the first startup circuit; the second port of the first resistor is connected to the second port of the first startup power supply; The source of the first transistor is connected to the first port of the first startup circuit; the gate of the first transistor is connected to the second port of the first startup circuit; the drain of the first transistor is connected to the third port of the first startup circuit; The second port of the first startup circuit is grounded through the second resistor.

3. The power supply protection module of a POE power supply according to claim 1, characterized in that: The first discharge circuit includes a third resistor, a fourth resistor, a fifth resistor and a second triode; The first port of the third resistor is connected to the first port of the first discharge circuit; the second port of the third resistor is connected to the base of the second transistor; The emitter of the second transistor is connected to the second port of the first discharge circuit; The first port of the fourth resistor and the first port of the fifth resistor are connected to the collector of the second transistor; The second port of the fourth resistor and the second port of the fifth resistor are connected to the third port of the first discharge circuit and are grounded at the same time.

4. The power supply protection module of a POE power supply according to claim 1, characterized in that: Also included is a current control circuit; The first port of the current control circuit is coupled to the power output terminal of the POE power supply; the second port of the current control circuit is coupled to the first port of the first startup circuit; The current control circuit includes a first diode and a second diode; The anode of the first diode is connected to the first port of the current control circuit; the cathode of the first diode is connected to the second port of the current control circuit; The anode of the second diode is connected to the first port of the current control circuit; the cathode of the second diode is connected to the second port of the current control circuit; The current control circuit is used to control the input current to flow from the first port of the current control circuit to the second port when the first port of the current control circuit receives the current input of the POE power supply; and to prevent the current returned by the load from flowing from the second port of the current control circuit to the first port of the current control circuit when the first port of the current control circuit does not receive the current input of the POE power supply.

5. The power supply protection module of a POE power supply according to claim 1, characterized in that: Also comprising a second discharge circuit; The first port of the second discharge circuit is connected to the power output terminal of the POE power supply; the second port of the second discharge circuit is connected to the load; The second discharge circuit includes a discharge judgment circuit and a discharge control circuit; The first port of the discharge judgment circuit is connected to the first port of the second discharge circuit; the second port of the discharge judgment circuit is connected to the second port of the second discharge circuit; the third port of the discharge judgment circuit is grounded; The first port of the discharge control circuit is connected to the second port of the second discharge circuit; the second port of the discharge control circuit is connected to the second port of the discharge judgment circuit; the third port of the discharge control circuit is grounded; The discharge judgment circuit is used to output a control signal through the second port of the discharge judgment circuit to control the discharge control circuit to work when the first port of the discharge judgment circuit does not receive the current input of the POE power supply; The discharge control circuit is used to release the electric energy stored in the filter capacitor connected to the load during the power supply of the POE power supply through the discharge control circuit when the second port of the discharge control circuit receives the control signal of the discharge judgment circuit.

6. A POE power supply protection module according to claim 5, characterized in that: The discharge judgment circuit includes a sixth resistor, a seventh resistor, an eighth resistor and a third transistor; The first port of the eighth resistor is connected to the first port of the discharge judgment circuit; the second port of the eighth resistor is connected to the base of the third transistor; The emitter of the third triode is connected to the first port of the seventh resistor; the collector of the third triode is grounded; The second port of the seventh resistor is connected to the second port of the discharge judgment circuit; The second port of the discharge determination circuit is connected to the second port of the second discharge circuit through a sixth resistor.

7. A POE power supply protection module according to claim 5, characterized in that: The discharge control circuit includes a ninth resistor, a tenth resistor and a fourth transistor; The gate of the fourth transistor is connected to the second port of the discharge judgment circuit; the source of the fourth transistor is connected to the first port of the discharge control circuit; The first port of the ninth resistor and the first port of the tenth resistor are connected to the drain of the fourth transistor; The second port of the ninth resistor and the second port of the tenth resistor are connected to the second port of the discharge control circuit.

8. A POE power supply system, characterized in that: A POE power supply, a load and a power supply protection module of the POE power supply according to any one of claims 1 to 7; The POE power supply is connected to the load through the power supply protection module to supply power to the power supply protection module and the load.

9. A power supply method, characterized in that: Applicable to the power supply system of the POE power supply as claimed in claim 8, the power supply method comprising: When the POE power supply starts to supply power, the power supply protection module controls the charging on time of the power supply protection module according to the preset capacitor charging and discharging parameters to control the voltage rising rate of the power supply protection module; When the POE power source stops supplying power, the power supply protection module releases the electric energy stored during the period when the POE power source supplies power.

10. A power supply method according to claim 9, characterized in that: The power supply method further comprises: When the POE power supply starts to supply power, the power supply protection module controls the input current to flow from the POE power supply to the load through the power supply protection module; When the POE power supply stops supplying power, the power supply protection module prevents the current returned by the load from flowing to the POE power supply through the power supply protection module.

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