Overcurrent protection device

Abstract

The utility model discloses an over-current protection device. The over-current protection device comprises a current amplification unit, a voltage amplification unit, a signal conversion unit and an over-current following unit, the signal conversion unit is used for receiving an external dimming reference signal, a first output end of the signal conversion unit is connected to a normal phase input end of the current amplification unit, and a second output end of the signal conversion unit is connected to a first end of the overcurrent following unit; the second end of the overcurrent following unit is connected to the negative phase input end of the voltage amplification unit, and the output end of the current amplification unit and the output end of the voltage amplification unit are externally connected with an external power supply. Based on the signal conversion unit and the overcurrent following unit, the overcurrent protection device can realize following switching of output voltage and overcurrent protection points and adaptive adjustment of overcurrent protection ranges of different output voltages. The utility model relates to the technical field of power supplies.

Description

Technical Field

[0001] The utility model relates to the technical field of power supplies, in particular to an overcurrent protection device. Background Art

[0002] In order to achieve constant current protection at the load end, usually two control circuits are set in the LED power supply model, namely a constant voltage control circuit and a constant current control circuit. When there is no overcurrent state at the load end, the constant voltage control circuit controls the stable output of the voltage. When the output current of the switching power supply is greater than the set overcurrent protection value, based on the constant current control circuit, the output current is maintained at a constant value, so as to achieve constant current protection.

[0003] At present, in order to reduce the number of series models, manufacturers adopt the method of integrating and designing power supplies with different output voltages, and carry out overcurrent protection on power supplies with different output voltages based on the obtained wide-range constant voltage integrated common model. However, the overcurrent protection value of this wide-range constant voltage integrated common model often can only follow the minimum output voltage, and there is a long-term overload risk when it works at the maximum output voltage.

[0004] Therefore, the problems existing in the prior art still need to be solved and optimized urgently. Summary of the Utility Model

[0005] The purpose of the utility model is to solve the technical problems existing in the related technologies to a certain extent.

[0006] For this reason, an object of an embodiment of the utility model is to provide an overcurrent protection device, which can realize the follow-up switching of the output voltage and the overcurrent protection point, and the adaptive adjustment of the overcurrent protection range of different output voltages.

[0007] To achieve the above technical purpose, in the first aspect, an embodiment of the utility model provides an overcurrent protection device, including: a current amplification unit, a voltage amplification unit, a signal conversion unit and an overcurrent following unit;

[0008] The signal conversion unit is used to receive an external dimming reference signal. The first output end of the signal conversion unit is connected to the positive-phase input end of the current amplification unit, and the second output end of the signal conversion unit is connected to the first end of the overcurrent following unit;

[0009] The second end of the overcurrent following unit is connected to the negative-phase input end of the voltage amplification unit, and the output ends of the current amplification unit and the voltage amplification unit are externally connected to an external power supply.

[0010] In addition, an overcurrent protection device according to an embodiment of the utility model may also have the following additional technical features:

[0011] Optionally, in an embodiment of the present utility model, the signal conversion unit includes a first potentiometer and a first resistor;

[0012] The first end of the first resistor is connected to an external dimming power supply, and the second end of the first resistor is connected to the first end of the first potentiometer;

[0013] The first end of the first potentiometer is connected to the first end of the overcurrent following unit, and the second end of the first potentiometer is connected to the positive input terminal of the current amplification unit.

[0014] Optionally, in an embodiment of the present utility model, the signal conversion unit includes a second potentiometer, a first amplifier, and a second resistor;

[0015] The fixed end of the second potentiometer is connected to an external dimming power supply, and the movable end of the second potentiometer is connected to the positive input terminal of the first amplifier;

[0016] The output terminal of the first amplifier is connected to the first end of the second resistor, and the output terminal of the first amplifier is connected to the negative input terminal of the first one;

[0017] The first end of the second resistor is connected to the first end of the overcurrent following unit, and the second end of the second resistor is connected to the positive input terminal of the current amplification unit.

[0018] Optionally, in an embodiment of the present utility model, the overcurrent following unit includes a voltage division part, at least one switching part, and at least one comparison part, and each switching part corresponds to one comparison part;

[0019] The first end of the comparison part is connected to the second output terminal of the signal conversion unit, and the second end of the comparison part is connected to the first end of the switching part;

[0020] The second end of the switching part is connected to the voltage division end point of the voltage division part, and the voltage division end point of the voltage division part is connected to the negative input terminal of the voltage amplification unit.

[0021] Optionally, in an embodiment of the present utility model, the voltage division part includes a third resistor and a fourth resistor;

[0022] The first end of the third resistor is externally connected to a voltage division power supply, and the second end of the third resistor is connected to the negative input terminal of the voltage amplification unit;

[0023] The second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is grounded.

[0024] Optionally, in an embodiment of the present utility model, the switching part includes a fifth resistor and a switching transistor;

[0025] The first end of the fifth resistor is connected to the voltage division end point of the voltage division part, and the second end of the fifth resistor is connected to the drain of the switching transistor;

[0026] The gate of the switching transistor is connected to the second end of the comparison part, and the source of the switching transistor is grounded.

[0027] Optionally, in an embodiment of the present invention, the comparison part includes a sixth resistor, a seventh resistor, an eighth resistor, and a reference voltage regulator

[0028] The first end of the sixth resistor is connected to the second output end of the signal conversion unit, and the second end of the sixth resistor is connected to the reference end of the reference voltage regulator;

[0029] The anode of the reference voltage regulator is grounded, the cathode of the reference voltage regulator is connected to the first end of the seventh resistor, and the second end of the seventh resistor is externally connected to a comparison power supply;

[0030] The cathode of the reference voltage regulator is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the first end of the switching part.

[0031] Optionally, in an embodiment of the present invention, the comparison part includes a ninth resistor, a tenth resistor, a reference power supply, and a second amplifier;

[0032] The first end of the ninth resistor is connected to the second output end of the signal conversion unit, and the second end of the ninth resistor is connected to the negative-phase input end of the second amplifier;

[0033] The reference power supply is connected to the positive-phase input end of the second amplifier, the output end of the second amplifier is connected to the first end of the tenth resistor, and the second end of the tenth resistor is connected to the first end of the switching part.

[0034] Optionally, in an embodiment of the present invention, the current amplification unit includes a third amplifier, a first diode, a first capacitor, an eleventh resistor, and a twelfth resistor;

[0035] The positive-phase input end of the third amplifier is connected to the first output end of the signal conversion unit, and the output end of the third amplifier is connected to the first end of the twelfth resistor;

[0036] The second end of the twelfth resistor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the negative-phase input end of the third amplifier;

[0037] The output terminal of the third amplifier is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the negative electrode of the first diode, and the positive electrode of the first diode is externally connected to an external power supply.

[0038] Optionally, in an embodiment of the present invention, the voltage amplification unit includes a fourth amplifier, a second diode, a second capacitor, a thirteenth resistor, and a fourteenth resistor;

[0039] The non-inverting input terminal of the fourth amplifier is externally connected to an amplification power supply, the inverting input terminal of the fourth amplifier is connected to the second end of the overcurrent following unit, and the output terminal of the fourth amplifier is connected to the first end of the fourteenth resistor;

[0040] The second end of the fourteenth resistor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the inverting input terminal of the fourth amplifier;

[0041] The output terminal of the fourth amplifier is connected to the first end of the thirteenth resistor, the second end of the thirteenth resistor is connected to the negative electrode of the second diode, and the positive electrode of the second diode is externally connected to an external power supply.

[0042] The advantages and beneficial effects of the present invention will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present invention:

[0043] An overcurrent protection device disclosed in an embodiment of the present application, the overcurrent protection device includes a current amplification unit, a voltage amplification unit, a signal conversion unit, and an overcurrent following unit; the signal conversion unit is used to receive an external dimming reference signal, the first output terminal of the signal conversion unit is connected to the non-inverting input terminal of the current amplification unit, and the second output terminal of the signal conversion unit is connected to the first end of the overcurrent following unit; the second end of the overcurrent following unit is connected to the inverting input terminal of the voltage amplification unit, and the output terminals of the current amplification unit and the voltage amplification unit are externally connected to an external power supply. Based on the signal conversion unit and the overcurrent following unit, the overcurrent protection device can realize the follow-up switching of the output voltage and the overcurrent protection point, and the adaptive adjustment of the overcurrent protection range of different output voltages. Description of the Drawings

[0044] The drawings are used to provide a further understanding of the technical solutions of the present application, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solutions of the present application, and do not constitute a limitation to the technical solutions of the present application.

[0045] Figure 1 It is a frame schematic diagram of an overcurrent protection device provided for an embodiment of the present invention;

[0046] Figure 2 The circuit schematic diagram of the first overcurrent protection device provided for an embodiment of the present utility model;

[0047] Figure 3 The circuit schematic diagram of the overcurrent following unit provided for an embodiment of the present utility model;

[0048] Figure 4 The circuit schematic diagram of the second overcurrent protection device provided for an embodiment of the present utility model;

[0049] Figure 5 The circuit schematic diagram of the third overcurrent protection device provided for an embodiment of the present utility model;

[0050] Figure 6 The circuit schematic diagram of the fourth overcurrent protection device provided for an embodiment of the present utility model. Specific embodiments

[0051] The embodiments of the present utility model will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present utility model, and should not be construed as a limitation to the present utility model.

[0052] In the description of the present utility model, it should be understood that the orientation or positional relationship indicated by terms such as "length", "upper", "lower", "front", "rear", "left", "right", "top", "inner", "outer", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present utility model, unless otherwise specified, the meaning of "a plurality" is two or more.

[0053] Currently, in order to reduce the number of series models, manufacturers adopt the method of integrating and designing power supplies with different output voltages. For example, a 100W constant voltage power supply integrates 12V, 15V, 20V, and 24V into the same power supply device, and their corresponding rated currents are 8.3A, 6.7A, 5A, and 4.2A respectively. Their corresponding overcurrent protection values calculated at the 120% overcurrent point are 9.96A, 8.04A, 6A, and 5.04A respectively. For this type of wide-range constant voltage integrated and shared model, its overcurrent protection value can only follow the minimum voltage, and there is a long-term overload risk when it operates at the maximum output voltage.

[0054] In view of this, in the embodiments of the present utility model application, an overcurrent protection device is provided. Based on an overcurrent following unit and a signal conversion unit, the device realizes that the overcurrent protection point changes following the change of the output voltage, and within the following range, according to the set value of the overcurrent protection point, the output voltage is switched in the form of a comparator to realize the adaptive switching adjustment of the overcurrent protection range.

[0055] Referring to Figure 1 , specifically, an overcurrent protection device in the embodiments of the present application includes: a current amplification unit, a voltage amplification unit, a signal conversion unit, and an overcurrent following unit;

[0056] The signal conversion unit is used to receive an external dimming reference signal. The first output end of the signal conversion unit is connected to the positive input end of the current amplification unit, and the second output end of the signal conversion unit is connected to the first end of the overcurrent following unit;

[0057] The second end of the overcurrent following unit is connected to the negative input end of the voltage amplification unit, and the output ends of the current amplification unit and the voltage amplification unit are externally connected to an external power supply.

[0058] In the embodiments of the present application, the current amplification unit is used to provide an output current to an external device, and the voltage amplification unit is used to provide an output voltage to an external device; the signal conversion unit is used to receive a dimming reference signal generated by an external dimming circuit, and after processing the dimming signal, generate a set signal VI and a following signal Vf. Among them, the set signal VI is input to the positive input end of the current amplification unit to set the overcurrent protection value of the power supply; the following signal Vf is input to the first end of the overcurrent following unit, which is used to control the operation of the overcurrent following unit to realize the adaptive switching of the power supply output voltage.

[0059] In some embodiments, the signal conversion unit includes a first potentiometer and a first resistor;

[0060] The first end of the first resistor is connected to an external dimming power supply, and the second end of the first resistor is connected to the first end of the first potentiometer;

[0061] The first end of the first potentiometer is connected to the first end of the overcurrent following unit, and the second end of the first potentiometer is connected to the positive input end of the current amplification unit.

[0062] In some embodiments, the signal conversion unit includes a second potentiometer, a first amplifier, and a second resistor;

[0063] The fixed end of the second potentiometer is connected to an external dimming power supply, and the movable end of the second potentiometer is connected to the positive input end of the first amplifier;

[0064] The output terminal of the first amplifier is connected to the first end of the second resistor, and the output terminal of the first amplifier is connected to the negative-phase input terminal of the first one;

[0065] The first end of the second resistor is connected to the first end of the overcurrent following unit, and the second end of the second resistor is connected to the positive-phase input terminal of the current amplification unit.

[0066] In some embodiments, the overcurrent following unit includes a voltage division part, at least one switching part, and at least one comparison part, and each switching part corresponds to one comparison part;

[0067] The first end of the comparison part is connected to the second output terminal of the signal conversion unit, and the second end of the comparison part is connected to the first end of the switching part;

[0068] The second end of the switching part is connected to the voltage division end point of the voltage division part, and the voltage division end point of the voltage division part is connected to the negative-phase input terminal of the voltage amplification unit.

[0069] In some embodiments, the voltage division part includes a third resistor and a fourth resistor;

[0070] The first end of the third resistor is externally connected to a voltage division power supply, and the second end of the third resistor is connected to the negative-phase input terminal of the voltage amplification unit;

[0071] The second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is grounded.

[0072] In some embodiments, the switching part includes a fifth resistor and a switching transistor;

[0073] The first end of the fifth resistor is connected to the voltage division end point of the voltage division part, and the second end of the fifth resistor is connected to the drain of the switching transistor;

[0074] The gate of the switching transistor is connected to the second end of the comparison part, and the source of the switching transistor is grounded.

[0075] In some embodiments, the comparison part includes a sixth resistor, a seventh resistor, an eighth resistor, and a reference voltage regulator

[0076] The first end of the sixth resistor is connected to the second output terminal of the signal conversion unit, and the second end of the sixth resistor is connected to the reference terminal of the reference voltage regulator;

[0077] The anode of the reference voltage regulator is grounded, the cathode of the reference voltage regulator is connected to the first end of the seventh resistor, and the second end of the seventh resistor is externally connected to a comparison power supply;

[0078] The cathode of the reference voltage regulator is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the first end of the switching unit.

[0079] In some embodiments, the comparison unit includes a ninth resistor, a tenth resistor, a reference power supply, and a second amplifier;

[0080] The first end of the ninth resistor is connected to the second output end of the signal conversion unit, and the second end of the ninth resistor is connected to the negative-phase input end of the second amplifier;

[0081] The reference power supply is connected to the positive-phase input end of the second amplifier, the output end of the second amplifier is connected to the first end of the tenth resistor, and the second end of the tenth resistor is connected to the first end of the switching unit.

[0082] In some embodiments, the current amplification unit includes a third amplifier, a first diode, a first capacitor, an eleventh resistor, and a twelfth resistor;

[0083] The positive-phase input end of the third amplifier is connected to the first output end of the signal conversion unit, and the output end of the third amplifier is connected to the first end of the twelfth resistor;

[0084] The second end of the twelfth resistor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the negative-phase input end of the third amplifier;

[0085] The output end of the third amplifier is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the negative electrode of the first diode, and the positive electrode of the first diode is externally connected to an external power supply.

[0086] In some embodiments, the voltage amplification unit includes a fourth amplifier, a second diode, a second capacitor, a thirteenth resistor, and a fourteenth resistor;

[0087] The positive-phase input end of the fourth amplifier is externally connected to an amplification power supply, the negative-phase input end of the fourth amplifier is connected to the second end of the overcurrent following unit, and the output end of the fourth amplifier is connected to the first end of the fourteenth resistor;

[0088] The second end of the fourteenth resistor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the negative-phase input end of the fourth amplifier;

[0089] The output end of the fourth amplifier is connected to the first end of the thirteenth resistor, the second end of the thirteenth resistor is connected to the negative electrode of the second diode, and the positive electrode of the second diode is externally connected to an external power supply.

[0090] The present application will be explained below with reference to specific embodiments.

[0091] First Embodiment

[0092] Referring to Figure 2 and Figure 3 , Figure 2 is a circuit schematic diagram of an overcurrent protection device provided by an embodiment of the present application.

[0093] In Figure 2 , the signal conversion unit 101 includes a first resistor R15 and a first potentiometer VR1. One end of the first resistor is externally connected to an external dimming power supply. The overcurrent following unit 103 includes a voltage division part 1021, a switching part 1022, and a comparison part 1023. The voltage division part includes a third resistor R7 and a fourth resistor R8. The first end of the third resistor is externally connected to a voltage division power supply V0, and the second end of the third resistor serves as the voltage division end of the voltage division part; the switching part includes a fifth resistor R9 and a switching transistor Q1. The fifth resistor is connected in series with the switching transistor, and the switching transistor can be a MOS transistor; the comparison part includes a sixth resistor R14, a seventh resistor R13, an eighth resistor R12, and a reference voltage regulator SHR1. The reference voltage regulator can specifically be any one of a TL431 chip, a TL432 chip, an AS431 chip, an AS432 chip, etc. The current amplification unit 103 includes a third amplifier U1B, a first diode D1A, a first capacitor C5, an eleventh resistor R2, and a twelfth resistor R5. The voltage amplification unit 104 includes a fourth amplifier U1D, a second diode D1B, a second capacitor C6, a thirteenth resistor R3, and a fourteenth resistor R4.

[0094] It can be understood that adjusting the first potentiometer VR1 or the dimming reference signal VDIM can control different maximum output currents of the power supply, thereby setting different overcurrent protection values. At the same time, the potential of the following signal Vf is sampled and compared through the reference terminal R of the reference voltage regulator SHR1. The output current range is controlled by Figure 2 the first resistor R15, the first potentiometer VR1, and the resistors R10 and the sampling resistor J100 in the attached circuit in, and accordingly, the sampling point voltages at different output currents can be obtained.

[0095] When adjusting the first potentiometer VR1 or the dimming reference signal VDIM to change the output current of the power supply, the voltage value at the sampling point changes accordingly. Specifically, when the potential at the sampling point is greater than the reference voltage of the reference voltage regulator SHR1, the reference voltage regulator SHR1 is pulled low, causing the switching transistor Q1 to turn off and the output voltage of the power supply to drop; conversely, when the potential at the sampling point is less than the reference voltage of the reference voltage regulator SHR1, the switching transistor Q1 turns on and the output voltage of the power supply rises. Different output voltages of the power supply can be adjusted through the fourth resistor R8 of the voltage division part and the fifth resistor R9 of the switching part. By reasonably setting the resistance value and adjusting the reference voltage of the reference voltage regulator corresponding to the overcurrent protection point through voltage division, the follow-up switching of different voltages and currents and the self-adaptation of the overcurrent points of different voltages are realized, that is, the follow-up switching of the output voltage and the overcurrent protection point and the self-adaptive adjustment of the overcurrent protection range of different output voltages are realized.

[0096] It should be noted that referring to Figure 4 , Figure 4 the number of the switching part and the comparison part of the overcurrent follow-up unit in Figure 2 is both 2. Specifically, if there are three or more output voltage switches, then based on the fourth resistor R8 and the fifth resistor R9 in Figure 4 , the switching part and the comparison part can be set in parallel. The reference voltages corresponding to the reference voltage regulators in each comparison part are different. For example, a voltage dividing resistor R16 can be added to the reference terminal of the reference voltage regulator of the newly added comparison part to realize the flexible switching of multiple output voltages. The rest of the content is similar to the foregoing content about Figure 2 , and the content of more switching parts and comparison parts is similar to the foregoing content. This application will not elaborate here.

[0097] Second Embodiment

[0098] Referring to Figure 5 , Figure 5 is the circuit schematic diagram of another overcurrent protection device provided by the embodiment of the present application.

[0099] In Figure 5 , Figure 5 the signal conversion unit label in Figure 5 is 105, which includes a second potentiometer VR2, a first amplifier U2B and a second resistor R19. Among them, the first amplifier is used to isolate the load effect, and the resistors R17, R18 and R20 act as loads in the signal conversion unit. These load resistors can be equivalent to the second resistor. The overcurrent follow-up unit includes a voltage division part, a switching part and a comparison part. Among them, Figure 2 the voltage division part in Figure 5 is the same as the voltage division part in Figure 2 , Figure 5The comparison unit of the overcurrent following unit in China is labeled 106, and includes a ninth resistor R23, a tenth resistor R24, a second amplifier U1C, and a reference power supply. Among them, the reference power supply includes resistors R21 and R22, and the reference power supply is used to provide a voltage-dividing reference signal to the second amplifier U1C; the rest of the content is the same as that described above Figure 2 The content is the same.

[0100] It can be understood that adjusting the second potentiometer VR2 or the dimming reference signal (VDIM) can control different maximum output currents, thereby setting different overcurrent protection values. The following signal Vf is obtained by sampling the voltage-dividing potential on the second potentiometer VR2. The second amplifier U1C is used as a comparator to compare the potential of the following signal Vf. The inverting input terminal of the second amplifier U1C is connected to the following signal Vf, and the non-inverting input terminal is connected to the voltage-dividing reference signal provided by the reference power supply. Different reference potentials can be adjusted through resistors R21 and R22. The output current range is controlled by resistor R17, resistor R18, second potentiometer VR2, second resistor R19, resistor R10, and sampling resistor J100.

[0101] When adjusting the second potentiometer VR2 or the dimming reference signal VDIM to increase the output current of the power supply, the potential of the sampling point of the following signal Vf becomes higher at this time. When the potential of the sampling point of Vf is greater than the set potential of the non-inverting input terminal of the second amplifier U1C, the output terminal of the second amplifier U1C outputs a low level, thereby causing the switching transistor Q1 to turn off, and the output voltage of the power supply decreases through voltage feedback. On the contrary, when the potential of the sampling point of the following signal Vf is less than the set potential of the positive input terminal of the second amplifier U1C, the output terminal of the second amplifier U1C outputs a high level, and the switching transistor Q1 conducts, causing the output voltage of the power supply to rise. Different output voltages of the power supply can be adjusted through the fourth resistor R8 and the fifth resistor R9, thereby realizing the following switching of different voltages and currents, and the overcurrent points of different voltages are self-adaptive. In addition, compared with Figure 2 The overcurrent protection device shown Figure 5 The overcurrent protection device shown can not only realize the following switching of the output voltage and the overcurrent protection point, and the self-adaptive adjustment of the overcurrent protection range of different output voltages, but also avoid the reference temperature drift phenomenon of the reference voltage regulator in high-temperature or low-temperature environments, and the overcurrent protection effect is better.

[0102] It should be noted that referring to Figure 6 , Figure 6 The number of the switching unit and the comparison unit of the overcurrent following unit in is 2, and its content is similar to the description above Figure 4 It can be simply inferred, and this application will not elaborate here.

[0103] In the description of this specification, the descriptions referring to terms such as "one embodiment", "another embodiment" or "certain embodiments" etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0104] Although the embodiments of the present utility model have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model, and the scope of the present utility model is defined by the claims and their equivalents.

Claims

1. An overcurrent protection device, characterized in that, Comprising: a current amplification unit, a voltage amplification unit, a signal conversion unit, and an overcurrent following unit; The signal conversion unit is configured to receive an external dimming reference signal. A first output terminal of the signal conversion unit is connected to a non-inverting input terminal of the current amplification unit, and a second output terminal of the signal conversion unit is connected to a first end of the overcurrent following unit; A second end of the overcurrent following unit is connected to a non-inverting input terminal of the voltage amplification unit, and output terminals of the current amplification unit and the voltage amplification unit are externally connected to an external power supply.

2. The overcurrent protection device according to claim 1, wherein The signal conversion unit includes a first potentiometer and a first resistor; A first end of the first resistor is connected to an external dimming power supply, and a second end of the first resistor is connected to a first end of the first potentiometer; The first end of the first potentiometer is connected to the first end of the overcurrent following unit, and a second end of the first potentiometer is connected to the non-inverting input terminal of the current amplification unit.

3. The overcurrent protection device according to claim 1, characterized in that The signal conversion unit includes a second potentiometer, a first amplifier, and a second resistor; A fixed end of the second potentiometer is connected to an external dimming power supply, and a movable end of the second potentiometer is connected to a non-inverting input terminal of the first amplifier; An output terminal of the first amplifier is connected to a first end of the second resistor, and the output terminal of the first amplifier is connected to a non-inverting input terminal of the first [amplifier]; The first end of the second resistor is connected to the first end of the overcurrent following unit, and a second end of the second resistor is connected to the non-inverting input terminal of the current amplification unit.

4. The overcurrent protection device according to claim 1, characterized in that, The overcurrent following unit includes a voltage division part, at least one switching part, and at least one comparison part, and each switching part corresponds to one comparison part; A first end of the comparison part is connected to the second output terminal of the signal conversion unit, and a second end of the comparison part is connected to a first end of the switching part; A second end of the switching part is connected to a voltage division end point of the voltage division part, and the voltage division end point of the voltage division part is connected to a non-inverting input terminal of the voltage amplification unit.

5. The overcurrent protection device according to claim 4, characterized in that, The voltage division part includes a third resistor and a fourth resistor; A first end of the third resistor is externally connected to a voltage division power supply, and a second end of the third resistor is connected to a non-inverting input terminal of the voltage amplification unit; The second end of the third resistor is connected to a first end of the fourth resistor, and a second end of the fourth resistor is grounded.

6. The overcurrent protection device according to claim 4, characterized in that, The switching part includes a fifth resistor and a switching transistor; A first end of the fifth resistor is connected to the voltage division end point of the voltage division part, and a second end of the fifth resistor is connected to a drain of the switching transistor; A gate of the switching transistor is connected to the second end of the comparison part, and a source of the switching transistor is grounded.

7. The overcurrent protection device according to claim 4, characterized in that The comparison part includes a sixth resistor, a seventh resistor, an eighth resistor, and a reference voltage regulator A first end of the sixth resistor is connected to the second output terminal of the signal conversion unit, and a second end of the sixth resistor is connected to a reference terminal of the reference voltage regulator; An anode of the reference voltage regulator is grounded, a cathode of the reference voltage regulator is connected to a first end of the seventh resistor, and a second end of the seventh resistor is externally connected to a comparison power supply; The cathode of the reference voltage regulator is connected to the first end of the eighth resistor, and the second end of the eighth resistor is connected to the first end of the switching unit.

8. The overcurrent protection device according to claim 4, wherein The comparison unit includes a ninth resistor, a tenth resistor, a reference power supply, and a second amplifier; The first end of the ninth resistor is connected to the second output end of the signal conversion unit, and the second end of the ninth resistor is connected to the negative-phase input end of the second amplifier; The reference power supply is connected to the positive-phase input end of the second amplifier, the output end of the second amplifier is connected to the first end of the tenth resistor, and the second end of the tenth resistor is connected to the first end of the switching unit.

9. The overcurrent protection device according to claim 1, characterized in that, The current amplification unit includes a third amplifier, a first diode, a first capacitor, an eleventh resistor, and a twelfth resistor; The positive-phase input end of the third amplifier is connected to the first output end of the signal conversion unit, and the output end of the third amplifier is connected to the first end of the twelfth resistor; The second end of the twelfth resistor is connected to the first end of the first capacitor, and the second end of the first capacitor is connected to the negative-phase input end of the third amplifier; The output end of the third amplifier is connected to the first end of the eleventh resistor, the second end of the eleventh resistor is connected to the negative electrode of the first diode, and the positive electrode of the first diode is externally connected to an external power supply.

10. The overcurrent protection device according to claim 1, characterized in that, The voltage amplification unit includes a fourth amplifier, a second diode, a second capacitor, a thirteenth resistor, and a fourteenth resistor; The positive-phase input end of the fourth amplifier is externally connected to an amplification power supply, the negative-phase input end of the fourth amplifier is connected to the second end of the overcurrent following unit, and the output end of the fourth amplifier is connected to the first end of the fourteenth resistor; The second end of the fourteenth resistor is connected to the first end of the second capacitor, and the second end of the second capacitor is connected to the negative-phase input end of the fourth amplifier; The output end of the fourth amplifier is connected to the first end of the thirteenth resistor, the second end of the thirteenth resistor is connected to the negative electrode of the second diode, and the positive electrode of the second diode is externally connected to an external power supply.

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