Safety protection circuit of adapter

Abstract

The utility model relates to a safety protection circuit of an adapter. Comprising an AC input end, an input filter rectification circuit, an AC output circuit, a PFC control circuit, a flyback circuit, an input overvoltage / undervoltage circuit, a PFC output short-circuit protection circuit, an over-temperature protection circuit, a 15V output control circuit and a 395V output control circuit. The first direct-current output circuit is used for outputting 395V direct-current voltage; the second direct-current output circuit is used for outputting 15V direct-current voltage; the safety of the adapter is improved, and the service life of the adapter is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of adapters, in particular to a safety protection circuit of an adapter. Background Art

[0002] As an AC-DC and strong-weak current conversion device, consumer power adapters need to adapt to various complex and harsh working environments and withstand various abnormal energy impacts that exceed the rated design specifications.

[0003] At the same time, stable output must be provided to ensure the usage requirements of subsequent terminal devices.

[0004] Therefore, the quality and reliability of power adapters have always been an important topic for power supply manufacturers to study and improve.

[0005] The existing power adapter is generally provided with a safety protection circuit of the adapter. However, the safety protection circuit of the existing adapter is relatively simple and can only protect the adapter in a single way, which in turn affects the service life of the adapter.

[0006] Therefore, in the utility model patent application, the applicant carefully studied a safety protection circuit of the adapter to solve the above problems. Utility Model Content

[0007] The utility model aims to overcome the deficiencies in the prior art and mainly aims to provide a safety protection circuit for an adapter, which improves the safety of the adapter and prolongs its service life.

[0008] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

[0009] A safety protection circuit of an adapter, comprising an AC input terminal, an input filter and rectifier circuit, an AC output circuit, a PFC control circuit, a flyback circuit, an input overvoltage / undervoltage circuit, a PFC output short-circuit protection circuit, an overtemperature protection circuit, a 15V output control circuit, a 395V output control circuit, a first DC output circuit for outputting a 395V DC voltage, and a second DC output circuit for outputting a 15V DC voltage;

[0010] The AC input end is connected to the input end of the input filter and rectifier circuit, and the output end of the input filter and rectifier circuit is connected to the PFC control circuit and the input overvoltage / undervoltage circuit respectively.

[0011] The PFC control circuit is respectively connected to the flyback circuit, the over-temperature protection circuit, the 395V output control circuit, the input over-voltage / under-voltage circuit, the AC output circuit and the PFC output short-circuit protection circuit;

[0012] The flyback circuit is respectively connected to an over-temperature protection circuit, an input over-voltage / under-voltage circuit, a PFC output short-circuit protection circuit, a 15V output control circuit and a 395V output control circuit;

[0013] The 395V output control circuit is respectively connected to the first DC output circuit and the PFC output short-circuit protection circuit; the 15V output control circuit is respectively connected to the second DC output circuit and the input overvoltage / undervoltage circuit.

[0014] As a preferred solution, the over-temperature protection circuit includes a comparator U12D, a resistor R146, a resistor R142, a thermistor R147, a resistor R144, a resistor R143, a resistor R141, a resistor R149 and a diode D28;

[0015] The resistor R146, thermistor R147 and resistor R144 are connected in series, the series node of thermistor R147 and resistor R144 is connected to the negative input terminal of comparator U12D, the non-series node of resistor R146 and the non-series node of resistor R142 are both used to connect to the 15V+ voltage terminal, and the non-series node of resistor R144 and the non-series node of resistor R143 are both connected to the ground terminal GND;

[0016] The resistor R142 and the resistor R143 are connected in series, and the series node of the resistor R142 and the resistor R143 is connected to the positive input terminal of the comparator U12D. The positive input terminal of the comparator U12D is connected to the output terminal of the comparator U12D through the resistor R141. The output terminal of the comparator U12D and one end of the resistor R149 are both connected to the cathode of the diode D28. The anode of the diode D28 is connected to the PFC control circuit. The other end of the resistor R149 is used to connect to the 15V+ voltage terminal.

[0017] As a preferred solution, the first DC output circuit includes a coil LF2, a capacitor C1, a resistor R2, a capacitor C2, a fuse F104 and an output interface J4;

[0018] One end of the resistor R2 is connected to the ground terminal GND, the other end of the resistor R2 is connected to the ground terminal GND1, the two ends of the left side of the coil LF2 are respectively connected to the 395V output control circuit and the ground terminal GND1, and the two ends of the capacitor C1 are respectively connected to the two ends of the left side of the coil LF2;

[0019] One end of the right side of the coil LF2 is connected to pin 1 of the output interface J4, the other end of the right side of the coil LF2 is connected to pin 2 of the output interface J4 through the fuse F104, and both ends of the capacitor C2 are respectively connected to both ends of the right side of the coil LF2.

[0020] As a preferred solution, the 15V output control circuit includes a resistor R92, a resistor R93, a resistor R94, a MOS tube Q14, a MOS tube Q12 and a fuse F103;

[0021] One end of the fuse F103 is used to connect to the 15V+ voltage terminal, and the other end of the fuse F103 is connected to the source of the MOS tube Q14. The gate of the MOS tube Q14 is connected to the source of the MOS tube Q14 through the resistor R92. The drain of the MOS tube Q12 is connected to the gate of the MOS tube Q14. The gate of the MOS tube Q12 is connected to the input overvoltage / undervoltage circuit through the resistor R94. The source of the MOS tube Q12 is connected to the ground terminal GND. The drain of the MOS tube Q14 is connected to the source of the MOS tube Q12 through the resistor R93. The drain of the MOS tube Q14 is connected to the second DC output circuit.

[0022] Compared with the prior art, the utility model has obvious advantages and beneficial effects. Specifically, the cooperation of the input overvoltage / undervoltage circuit, the PFC output short-circuit protection circuit and the over-temperature protection circuit improves the safety of the adapter and prolongs its service life.

[0023] Secondly, multiple fuses are used to fully protect the input and output, extending the service life of the adapter.

[0024] In order to more clearly illustrate the structural features and effects of the present invention, it is described in detail below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a partial circuit schematic diagram of an embodiment of the utility model.

[0026] Figure 2 It is another partial circuit schematic diagram of an embodiment of the utility model.

[0027] Description of Figure Numbers:

[0028] 10. Input filter rectifier circuit

[0029] 21. PFC control circuit 22. Flyback circuit

[0030] 31. AC output circuit 32. First DC output circuit

[0031] 41. Input overvoltage / undervoltage circuit 42. PFC output short circuit protection circuit

[0032] 43. Over temperature protection circuit

[0033] 51. 395V output control circuit 52. 15V output control circuit. DETAILED DESCRIPTION

[0034] The utility model is further described below in conjunction with the accompanying drawings and specific implementation methods.

[0035] Please refer to Figure 1 and Figure 2 As shown, it shows the specific structure of the preferred embodiment of the utility model, which is a safety protection circuit of an adapter, including an AC input terminal, an input filter and rectifier circuit 10, an AC output circuit 31, a PFC control circuit 21, a flyback circuit 22, an input overvoltage / undervoltage circuit 41, a PFC output short-circuit protection circuit 42, an over-temperature protection circuit 43, a 15V output control circuit 52, a 395V output control circuit 51, a first DC output circuit 32 for outputting a 395V DC voltage, and a second DC output circuit 33 for outputting a 15V DC voltage;

[0036] The AC input end is connected to the input end of the input filter rectifier circuit 10, and the output end of the input filter rectifier circuit 10 is connected to the PFC control circuit 21 and the input overvoltage / undervoltage circuit 41 respectively.

[0037] The PFC control circuit 21 is respectively connected to the flyback circuit 22, the over-temperature protection circuit 43, the 395V output control circuit 51, the input over-voltage / under-voltage circuit 41, the AC output circuit 31 and the PFC output short-circuit protection circuit 42. Preferably, the PFC control circuit 21 is composed of a PFC chip IC1 of model PI SC2601F and its peripheral circuits.

[0038] The flyback circuit 22 is respectively connected to the over-temperature protection circuit 43, the input over-voltage / under-voltage circuit 41, the PFC output short-circuit protection circuit 42, the 15V output control circuit 52 and the 395V output control circuit 51; preferably, the flyback circuit 22 is composed of a flyback chip IC2 of model SC1155D and its peripheral circuits.

[0039] The 395V output control circuit 51 is respectively connected to the first DC output circuit 32 and the PFC output short circuit protection circuit 42; the 15V output control circuit 52 is respectively connected to the second DC output circuit 33 and the input overvoltage / undervoltage circuit 41.

[0040] In this embodiment, the over-temperature protection circuit 43 includes a comparator U12D, a resistor R146, a resistor R142, a thermistor R147, a resistor R144, a resistor R143, a resistor R141, a resistor R149 and a diode D28;

[0041] The resistor R146, thermistor R147 and resistor R144 are connected in series, the series node of thermistor R147 and resistor R144 is connected to the negative input terminal of comparator U12D, the non-series node of resistor R146 and the non-series node of resistor R142 are both used to connect to the 15V+ voltage terminal, and the non-series node of resistor R144 and the non-series node of resistor R143 are both connected to the ground terminal GND;

[0042] The resistor R142 and the resistor R143 are connected in series, and the series node of the resistor R142 and the resistor R143 is connected to the positive input terminal of the comparator U12D. The positive input terminal of the comparator U12D is connected to the output terminal of the comparator U12D through the resistor R141. The output terminal of the comparator U12D and one end of the resistor R149 are both connected to the cathode of the diode D28. The anode of the diode D28 is connected to the PFC control circuit 21. The other end of the resistor R149 is used to connect to the 15V+ voltage terminal.

[0043] In this embodiment, the first DC output circuit 32 includes a coil LF2, a capacitor C1, a resistor R2, a capacitor C2, a fuse F104 and an output interface J4;

[0044] One end of the resistor R2 is connected to the ground terminal GND, the other end of the resistor R2 is connected to the ground terminal GND1, the two ends of the left side of the coil LF2 are respectively connected to the 395V output control circuit 51 and the ground terminal GND1, and the two ends of the capacitor C1 are respectively connected to the two ends of the left side of the coil LF2;

[0045] One end of the right side of the coil LF2 is connected to pin 1 of the output interface J4, the other end of the right side of the coil LF2 is connected to pin 2 of the output interface J4 through the fuse F104, and both ends of the capacitor C2 are respectively connected to both ends of the right side of the coil LF2.

[0046] In this embodiment, the 15V output control circuit 52 includes a resistor R92, a resistor R93, a resistor R94, a MOS transistor Q14, a MOS transistor Q12 and a fuse F103;

[0047] One end of the fuse F103 is used to connect to the 15V+ voltage terminal, and the other end of the fuse F103 is connected to the source of the MOS tube Q14. The gate of the MOS tube Q14 is connected to the source of the MOS tube Q14 through the resistor R92. The drain of the MOS tube Q12 is connected to the gate of the MOS tube Q14. The gate of the MOS tube Q12 is connected to the input overvoltage / undervoltage circuit 41 through the resistor R94. The source of the MOS tube Q12 is connected to the ground terminal GND. The drain of the MOS tube Q14 is connected to the source of the MOS tube Q12 through the resistor R93. The drain of the MOS tube Q14 is connected to the second DC output circuit 33.

[0048] In this embodiment, the input filter rectifier circuit 10 includes a varistor VR1, a capacitor CY2, a magnetic bead B1, a capacitor CY1, a capacitor CX1, a coil LF1, a capacitor CY3, a capacitor CY4, a magnetic bead B2, an inductor L1, a fuse F102, a fuse F1, a rectifier tube BD1 and a capacitor CB1.

[0049] Fuse F1 is a 15A / 250V high-current chip fuse that protects all high-current inputs before rectifier tube BD1 and withstands currents exceeding 11A when the AC+DC output power is 1700W.

[0050] Fuse F102 uses a 3.5A / 250V high-current chip fuse to protect the input current circuit of the DC part after the rectifier tube BD1.

[0051] The key points of the design of the utility model are that the cooperation of the input overvoltage / undervoltage circuit, the PFC output short-circuit protection circuit and the over-temperature protection circuit improves the safety of the adapter and prolongs its service life;

[0052] Secondly, multiple fuses are used to fully protect the input and output, extending the service life of the adapter.

[0053] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A safety protection circuit for an adapter, characterized in that: It includes an AC input terminal, an input filter and rectifier circuit, an AC output circuit, a PFC control circuit, a flyback circuit, an input overvoltage / undervoltage circuit, a PFC output short-circuit protection circuit, an over-temperature protection circuit, a 15V output control circuit, a 395V output control circuit, a first DC output circuit for outputting a 395V DC voltage, and a second DC output circuit for outputting a 15V DC voltage; The AC input end is connected to the input end of the input filter rectifier circuit, and the output end of the input filter rectifier circuit is connected to the PFC control circuit and the input overvoltage / undervoltage circuit respectively. The PFC control circuit is respectively connected to the flyback circuit, the over-temperature protection circuit, the 395V output control circuit, the input over-voltage / under-voltage circuit, the AC output circuit and the PFC output short-circuit protection circuit; The flyback circuit is respectively connected to an over-temperature protection circuit, an input over-voltage / under-voltage circuit, a PFC output short-circuit protection circuit, a 15V output control circuit and a 395V output control circuit; The 395V output control circuit is respectively connected to the first DC output circuit and the PFC output short-circuit protection circuit; the 15V output control circuit is respectively connected to the second DC output circuit and the input overvoltage / undervoltage circuit.

2. The safety protection circuit of the adapter according to claim 1, characterized in that: The over-temperature protection circuit includes a comparator U12D, a resistor R146, a resistor R142, a thermistor R147, a resistor R144, a resistor R143, a resistor R141, a resistor R149 and a diode D28; The resistor R146, thermistor R147 and resistor R144 are connected in series, the series node of thermistor R147 and resistor R144 is connected to the negative input terminal of comparator U12D, the non-series node of resistor R146 and the non-series node of resistor R142 are both used to connect to the 15V+ voltage terminal, and the non-series node of resistor R144 and the non-series node of resistor R143 are both connected to the ground terminal GND; The resistor R142 and the resistor R143 are connected in series, and the series node of the resistor R142 and the resistor R143 is connected to the positive input terminal of the comparator U12D, and the positive input terminal of the comparator U12D is connected to the output terminal of the comparator U12D through the resistor R141. The output terminal of the comparator U12D and one end of the resistor R149 are both connected to the cathode of the diode D28, and the anode of the diode D28 is connected to the PFC control circuit. The other end of the resistor R149 is used to connect to the 15V+ voltage terminal.

3. The safety protection circuit of the adapter according to claim 1, characterized in that: The first DC output circuit includes a coil LF2, a capacitor C1, a resistor R2, a capacitor C2, a fuse F104 and an output interface J4; One end of the resistor R2 is connected to the ground terminal GND, the other end of the resistor R2 is connected to the ground terminal GND1, the two ends of the left side of the coil LF2 are respectively connected to the 395V output control circuit and the ground terminal GND1, and the two ends of the capacitor C1 are respectively connected to the two ends of the left side of the coil LF2; One end of the right side of the coil LF2 is connected to pin 1 of the output interface J4, the other end of the right side of the coil LF2 is connected to pin 2 of the output interface J4 through the fuse F104, and both ends of the capacitor C2 are respectively connected to both ends of the right side of the coil LF2.

4. The safety protection circuit of the adapter according to claim 1, characterized in that: The 15V output control circuit includes a resistor R92, a resistor R93, a resistor R94, a MOS tube Q14, a MOS tube Q12 and a fuse F103; One end of the fuse F103 is used to connect to the 15V+ voltage terminal, and the other end of the fuse F103 is connected to the source of the MOS tube Q14. The gate of the MOS tube Q14 is connected to the source of the MOS tube Q14 through the resistor R92. The drain of the MOS tube Q12 is connected to the gate of the MOS tube Q14. The gate of the MOS tube Q12 is connected to the input overvoltage / undervoltage circuit through the resistor R94. The source of the MOS tube Q12 is connected to the ground terminal GND. The drain of the MOS tube Q14 is connected to the source of the MOS tube Q12 through the resistor R93. The drain of the MOS tube Q14 is connected to the second DC output circuit.

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