An intelligent power distribution device

Abstract

The utility model discloses an intelligent power distribution device, include: overcurrent protection circuit, prevent reverse connection protection circuit, one -way conducting element, first input port for connecting power supply, second input port and be used for connecting output load's output port, overcurrent protection circuit is used for when the output current of power supply is greater than the set threshold value, cut off the pass between power supply and output load, the first end of prevent reverse connection protection circuit connects output port, the second end of prevent reverse connection protection circuit connects the first end of one -way conducting element, and the second end of one -way conducting element connects the second input terminal, prevent reverse connection protection circuit is used for when the negative pole of power supply is connected to the first input port and the positive pole of power supply is connected to the second input port, increase the resistance of self, to reduce the current that flows through one -way conducting element. The utility model can solve the problem that the current that flows through one -way conducting element is too big when the positive pole and the negative pole of power supply are connected reversely, causes its damage.

Description

Technical Field

[0001] This utility model relates to the field of automotive power network management technology, and in particular to an intelligent power distribution device. Background Technology

[0002] In vehicle-mounted intelligent power distribution devices, overcurrent protection circuits can cut off the power supply and load path when the power output current is too high, in order to protect the main power network and related devices; unidirectional conduction elements are often used to provide a freewheeling path for inductive loads, to prevent overvoltage damage to devices caused by sudden current changes at the load end.

[0003] However, when the power supply polarity of an intelligent power distribution device is reversed—that is, the first input port is connected to the negative terminal and the second input port is connected to the positive terminal—an abnormal loop can form if there is a lack of targeted protection, causing excessive current to flow through the unidirectional conductive element. Since the current-carrying capacity of unidirectional conductive elements is limited, excessive current can easily cause them to break down and be damaged. This not only results in the loss of their original functions such as freewheeling but may also lead to secondary faults such as short circuits, seriously affecting the safety and reliability of the intelligent power distribution device. Utility Model Content

[0004] This invention provides an intelligent power distribution device that can solve the problem of excessive current flowing through unidirectional conductive elements, causing damage, when the positive and negative terminals of the power supply are reversed.

[0005] This utility model provides an intelligent power distribution device, including: an overcurrent protection circuit, a reverse connection protection circuit, a unidirectional conducting element, a first input port for connecting to a power supply, a second input port, and an output port for connecting to an output load; the input terminal of the overcurrent protection circuit is connected to the first input port, and the output terminal of the overcurrent protection circuit is connected to the output port. The overcurrent protection circuit is used to cut off the path between the power supply and the output load when the output current of the power supply exceeds a set threshold; the first terminal of the reverse connection protection circuit is connected to the output port, the second terminal of the reverse connection protection circuit is connected to the first terminal of the unidirectional conducting element, and the second terminal of the unidirectional conducting element is connected to the second input terminal; the reverse connection protection circuit is used to increase its own resistance when the first input port is connected to the negative terminal of the power supply and the second input port is connected to the positive terminal of the power supply, so as to reduce the current flowing through the unidirectional conducting element.

[0006] Optionally, the reverse connection protection circuit includes a PTC thermistor, with the first terminal of the PTC thermistor serving as the first terminal of the reverse connection protection circuit and the second terminal of the PTC thermistor serving as the second terminal of the reverse connection protection circuit.

[0007] Optionally, the reverse connection protection circuit includes N PTC thermistors, which are connected in series. The first terminal of the first PTC thermistor serves as the first terminal of the reverse connection protection circuit, and the second terminal of the last PTC thermistor serves as the second terminal of the reverse connection protection circuit. N is an integer greater than or equal to 2.

[0008] Optionally, the reverse connection protection circuit includes N PTC thermistors, which are connected in parallel to the output port and the first terminal of the unidirectional conducting element, where N is an integer greater than or equal to 2.

[0009] Optionally, the overcurrent protection circuit includes a current detection module, a switching module, and a control module; the first terminal of the current detection module serves as the input terminal of the overcurrent protection circuit, the second terminal of the current detection module is connected to the first terminal of the switching module, and the output terminal of the current detection module is connected to the input terminal of the control module. The current detection module is used to collect the output current of the power supply; the second terminal of the switching module serves as the output terminal of the overcurrent protection circuit, and the control terminal of the switching module is connected to the output terminal of the control module. The control module is configured to control the switching module to turn off when the output current exceeds a set threshold.

[0010] Optionally, the switching module includes a MOSFET; the MOSFET includes a gate, a source, and a drain; the gate of the MOSFET serves as the control terminal of the switching module, the drain of the MOSFET serves as the first terminal of the switching module, and the source of the MOSFET serves as the second terminal of the switching module.

[0011] Optionally, the MOSFET has a first freewheeling diode, the anode of which is connected to the source of the MOSFET, and the cathode of which is connected to the drain of the MOSFET.

[0012] Optionally, the overcurrent protection circuit also includes a drive module. The input terminal of the drive module is connected to the output terminal of the control module, and the output terminal of the drive module is connected to the control terminal of the switch module. The drive module is used to amplify the signal output by the control module.

[0013] Optionally, the current detection module includes a sensing resistor and an operational amplifier; the first end of the sensing resistor serves as the first end of the current detection module, and the second end of the sensing resistor serves as the second end of the current detection module; the first input end of the operational amplifier is connected to the first end of the sensing resistor, the second input end of the operational amplifier is connected to the second end of the sensing resistor, and the output end of the operational amplifier serves as the output end of the current detection module.

[0014] Optionally, the unidirectional conducting element includes a second freewheeling diode, with the cathode of the second freewheeling diode serving as the first terminal of the unidirectional conducting element and the anode of the second freewheeling diode serving as the second terminal of the unidirectional conducting element.

[0015] This utility model provides an intelligent power distribution device, including an overcurrent protection circuit, a reverse connection protection circuit, and a unidirectional conducting element. The overcurrent protection circuit monitors the power supply's output current in real time. When the output current exceeds a set threshold, it cuts off the path between the power supply and the output load, effectively preventing damage to the output load and the intelligent power distribution device itself caused by short circuits, overloads, and other faults, thus improving circuit safety. The reverse connection protection circuit, when the power supply's positive and negative terminals are reversed, utilizes its characteristics to increase its own resistance, reducing the current flowing through the unidirectional conducting element and preventing it from being broken down by excessive current during reverse connection. This solves the problem of easily damaging the freewheeling element in traditional devices when the power supply is reversed. The unidirectional conducting element provides a freewheeling path for inductive loads and wiring harnesses, preventing damage to the device due to negative voltage caused by sudden changes in inductor current when the path between the power supply and the output load 20 is disconnected. Simultaneously, the reverse connection protection circuit and the unidirectional conducting element work together to achieve targeted protection against reverse connection scenarios while ensuring the normal operation of the freewheeling function, balancing functionality and safety.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this utility model, nor is it intended to limit the scope of this utility model. Other features of this utility model will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of an intelligent power distribution device provided in an embodiment of this utility model;

[0019] Figure 2 The output port voltage and current waveforms are shown without a second freewheeling diode.

[0020] Figure 3 This describes the direction of the freewheeling current after adding a second freewheeling diode and a reverse connection protection circuit.

[0021] Figure 4 The output port voltage and current waveforms are shown after adding a second freewheeling diode and reverse connection protection circuit.

[0022] Figure 5 The provided diagram is a schematic diagram of a reverse connection protection circuit in one embodiment;

[0023] Figure 6The provided diagram shows the structure of the reverse connection protection circuit in yet another embodiment.

[0024] Figure 7 The provided diagram shows the structure of the reverse connection protection circuit in yet another embodiment.

[0025] Figure 8 The provided diagram is a schematic diagram of an overcurrent protection circuit in one embodiment;

[0026] Figure 9 The provided diagram is a structural schematic of a switch module in one embodiment;

[0027] Figure 10 The provided diagram shows the structure of an overcurrent protection circuit in yet another embodiment.

[0028] Figure 11 The provided diagram is a structural schematic of a current detection module in one embodiment;

[0029] Figure 12 This is a structural schematic diagram of another intelligent power distribution device provided in this embodiment of the utility model;

[0030] Figure 13 This is a schematic diagram showing the current flow direction when the power supply is connected in the positive direction;

[0031] Figure 14 This is a schematic diagram showing the current flow direction when the power supply is reversed;

[0032] Figure 15 This is a waveform diagram of the voltage and current at the output port when the power supply voltage is reversed without a PTC thermistor.

[0033] Figure 16 This is a waveform diagram of the voltage and current at the output port when the power supply voltage is reversed after adding a PTC thermistor. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0036] Figure 1 This is a structural schematic diagram of an intelligent power distribution device provided in an embodiment of this utility model. Figure 1 As shown, the intelligent power distribution device 1 includes an overcurrent protection circuit 11, a reverse connection protection circuit 12, a unidirectional conduction element 13, a first input port IN1 for connecting to the power supply 10, a second input port IN2, and an output port OUT for connecting to the output load 20.

[0037] The input terminal of the overcurrent protection circuit 11 is connected to the first input port IN1, and the output terminal of the overcurrent protection circuit 11 is connected to the output port OUT. The overcurrent protection circuit 11 is used to cut off the path between the power supply 10 and the output load 20 when the output current of the power supply 10 is greater than a set threshold.

[0038] The first terminal of the reverse connection protection circuit 12 is connected to the output port OUT, the second terminal of the reverse connection protection circuit 12 is connected to the first terminal of the unidirectional conduction element 13, and the second terminal of the unidirectional conduction element 13 is connected to the second input terminal IN2.

[0039] The reverse connection protection circuit 12 is used to increase its own resistance when the first input port IN1 is connected to the negative terminal of the power supply 10 and the second input port IN2 is connected to the positive terminal of the power supply 10, so as to reduce the current flowing through the unidirectional conducting element 13.

[0040] Specifically, the overcurrent protection circuit 11 is an electronic protection circuit connected in series in the main power supply path. It is used to monitor the current flowing through it in real time. When the current exceeds a set threshold, the circuit will quickly activate and actively cut off the current path from its input to its output, thereby disconnecting the power supply 10 from the output load 20 and preventing damage to the output load 20 or the power distribution device itself caused by large currents generated by short circuits, overloads, or other faults.

[0041] The reverse connection protection circuit 12 is a protection circuit used to detect the polarity of the power input and automatically change its own conductivity when it detects that the power supply 10 is connected in reverse (positive and negative terminals reversed). When the power supply polarity is correct, it presents a low impedance state (does not affect the main path); when the positive terminal of the power supply 10 is mistakenly connected to the second input port IN2 or the negative terminal of the power supply 10 is mistakenly connected to the first input port IN1, the reverse connection protection circuit 12 increases its own resistance value, thereby reducing the reverse current flowing through the unidirectional conducting element 13, effectively preventing the reverse current from damaging the unidirectional conducting element 13.

[0042] Optionally, the unidirectional conducting element 13 includes a second freewheeling diode D2, with the cathode of the second freewheeling diode D2 serving as the first terminal of the unidirectional conducting element 13 and the anode of the second freewheeling diode D2 serving as the second terminal of the unidirectional conducting element 13.

[0043] Continue to refer to Figure 1 The working process of this intelligent power distribution device is as follows:

[0044] When the positive terminal of power supply 10 is connected to the first input port IN1 and the negative terminal of power supply 10 is connected to the second input port IN2, the output current of power supply 10 flows from the first input port IN1 into the input terminal of overcurrent protection circuit 11. If the output current is less than a set threshold, overcurrent protection circuit 11 remains on, and current flows from its output terminal to the output port OUT, supplying power to output load 20. At this time, reverse connection protection circuit 12 is connected to the output port OUT at its first terminal and to the second input port IN2 through unidirectional conducting element 13 at its second terminal. Under normal polarity, reverse connection protection circuit 12 is in a low-resistance state, allowing small current to pass through. Unidirectional conducting element 13 is in a reverse bias state, in a cutoff state, preventing current from flowing directly from the output port OUT to the second input port IN2.

[0045] Regardless of whether the power supply polarity is correct, if the current flowing through the overcurrent protection circuit 11 exceeds the set threshold, the overcurrent protection circuit 11 will immediately activate, disconnecting its internal switch and cutting off the main current path from the first input port IN1 to the output port OUT. The connection between the power supply 10 and the output load 20 will be interrupted, thereby protecting the output load and the intelligent power distribution device itself from overcurrent damage.

[0046] When the positive and negative terminals of power supply 10 are incorrectly connected—that is, the positive terminal of power supply 10 is connected to the second input port IN2 and the negative terminal is connected to the first input port IN1—current will flow into the intelligent power distribution device from the second input port IN2. At this time, the reverse connection protection circuit 12 will detect this reverse connection of the power supply polarity, and its own resistance will increase, exhibiting a high impedance state. At this time, the unidirectional conducting element 13 is in a forward bias state, specifically manifested as the second freewheeling diode D2 being turned on. However, since the reverse connection protection circuit 12, which is connected in series with the second freewheeling diode D2, has become a high-impedance state, according to Ohm's law, the current in this series branch will be limited due to the high resistance of the reverse connection protection circuit 12, thereby reducing the current flowing through the second freewheeling diode D2 and preventing the unidirectional conducting element 13 from being damaged due to excessive current.

[0047] Because the output load 20 at the output port OUT of the intelligent power distribution device is generally an inductive load, and the wiring harness at the rear is also an inductive load, the thinner and longer the wire diameter of the harness, the greater the inductance. When the inductive load is disconnected, because the inductor current cannot change abruptly, if there is no freewheeling circuit, the voltage at the output terminal will be pulled to a very low negative voltage. The larger the inductance, the greater the negative voltage formed. The negative voltage formed at the output port OUT is directly proportional to the inductance and the rate of decrease of the current.

[0048] If there is no freewheeling current, the voltage and current waveforms at the output port OUT are as follows: Figure 2 As shown, assuming the short-circuit protection is triggered at 200A, without the second freewheeling diode D2, the inductive load will pull the voltage at the output port OUT to a very low negative voltage. If it exceeds -40V, it may damage the components in the overcurrent protection circuit 11.

[0049] To address the negative voltage at the output port OUT caused by a sudden drop in current from 200A to 0A on the output load 20, a second freewheeling diode D2 is added to the output port OUT relative to ground. When the connection between the power supply 10 and the output load 20 is broken, the current in the output load 20 can form a loop through the output load 20, the second freewheeling diode D2, and the rear end of the output load 20, thus preventing the negative voltage generated when the connection between the power supply 10 and the output load 20 is broken. However, if the second freewheeling diode D2 is added to the output port OUT, it will burn out if the polarity of the power supply 10 is reversed. The reverse connection protection circuit 12 for the intelligent power distribution output port provided in this embodiment of the invention satisfies both the freewheeling function for inductive loads and the reverse connection protection for the output port OUT. Figure 3 This refers to the direction of the freewheeling current after adding a second freewheeling diode and a reverse connection protection circuit. Figure 4 This is a waveform diagram of the voltage and current at the output port after adding a second freewheeling diode and a reverse connection protection circuit.

[0050] This utility model provides an intelligent power distribution device, including an overcurrent protection circuit 11, a reverse connection protection circuit 12, and a unidirectional conducting element 13. The overcurrent protection circuit 11 monitors the output current of the power supply 10 in real time. When the output current exceeds a set threshold, it cuts off the path between the power supply 10 and the output load 20, effectively preventing damage to the output load and the intelligent power distribution device itself caused by short circuits, overloads, or other faults, thus improving the safety of circuit operation. The reverse connection protection circuit 12, when the positive and negative terminals of the power supply are reversed, can increase its own resistance to reduce the current flowing through the unidirectional conducting element 13, preventing the unidirectional conducting element 13 from being broken down by excessive current during reverse connection. This solves the problem of easy damage to the freewheeling element in traditional devices when the power supply is reversed. The unidirectional conducting element 13 can provide a freewheeling path for inductive loads and wiring harnesses, preventing damage to the device due to negative voltage caused by sudden changes in inductor current when the path between the power supply 10 and the output load 20 is disconnected. At the same time, the reverse connection protection circuit 12 works in conjunction with the unidirectional conducting element 13 to achieve targeted protection against reverse connection scenarios while ensuring the normal operation of the freewheeling function, thus balancing functionality and safety.

[0051] Figure 5 This provides a schematic diagram of a reverse connection protection circuit in one embodiment. For example... Figure 5 As shown, optionally, the reverse connection protection circuit 12 includes a PTC thermistor R1, with the first end of the PTC thermistor R1 serving as the first end of the reverse connection protection circuit 12, and the second end of the PTC thermistor R1 serving as the second end of the reverse connection protection circuit 12.

[0052] Specifically, when the first input port IN1 is connected to the positive terminal of power supply 10 and the second input port IN2 is connected to the negative terminal of power supply 10, the main current path is IN1->overcurrent protection circuit 11->OUT->output load 20->(return to the negative terminal of power supply 10). The current flowing through the reverse connection protection circuit 12 (OUT->R1->one-way conducting element 13->IN2) is extremely small or zero (because the one-way conducting element 13 is in a reverse bias cutoff state). The PTC thermistor R1 is at room temperature and exhibits a low resistance value, having almost no effect on the main circuit.

[0053] When the first input port IN1 is connected to the negative terminal of power supply 10 and the second input port IN2 is connected to the positive terminal of power supply 10, an abnormal current path is formed: from IN2 -> unidirectional conducting element 13 -> PTC thermistor R1 -> IN1. At this time, the unidirectional conducting element 13 is forward biased and conducts. A large current begins to flow through the PTC thermistor R1. A characteristic of PTC thermistors is that their resistance increases sharply as their temperature rises due to current flow. Therefore, when a reverse current flows through the PTC thermistor R1 and causes it to heat up, the resistance of the PTC thermistor R1 will significantly increase to a near-open-circuit high-resistance state. According to Ohm's law, under relatively fixed power supply voltage, the increase in the resistance of the PTC thermistor R1 will reduce the reverse current flowing through this branch (i.e., through the unidirectional conducting element 13), reducing it to a safe level. This embodiment utilizes the positive temperature coefficient characteristic of the PTC thermistor R1 (i.e., resistance increases with temperature) to automatically increase its resistance when an abnormally large current occurs due to reverse power connection, thereby effectively reducing the current flowing through the series-connected unidirectional conducting element 13 and preventing the unidirectional conducting element 13 from being damaged due to overcurrent.

[0054] Figure 6 This provides a schematic diagram of the reverse connection protection circuit in yet another embodiment. For example... Figure 6 As shown, optionally, the reverse connection protection circuit 12 includes N PTC thermistors R1 connected in series. The first end of the first PTC thermistor R1 serves as the first end of the reverse connection protection circuit 12, and the second end of the last PTC thermistor R1 serves as the second end of the reverse connection protection circuit 12. N is an integer greater than or equal to 2.

[0055] Figure 7 This provides a schematic diagram of the reverse connection protection circuit in yet another embodiment. For example... Figure 7 As shown, optionally, the reverse connection protection circuit 12 includes N PTC thermistors R1, which are connected in parallel to the output port OUT and the first terminal of the unidirectional conducting element 13, where N is an integer greater than or equal to 2. Figure 6 and Figure 7 The specific working process of the reverse connection protection circuit 12 is as follows: Figure 5 The same applies, please refer to the above. Figure 5 The explanation of the reverse connection protection circuit 12 will not be repeated here in this embodiment.

[0056] Figure 8 This provides a schematic diagram of an overcurrent protection circuit in one embodiment. For example... Figure 8 As shown, optionally, the overcurrent protection circuit 11 includes a current detection module 110, a switching module 111, and a control module 112.

[0057] The first terminal of the current detection module 110 serves as the input terminal of the overcurrent protection circuit 11. The second terminal of the current detection module 110 is connected to the first terminal of the switch module 111. The output terminal of the current detection module 110 is connected to the input terminal of the control module 112. The current detection module 110 is used to collect the output current of the power supply 10.

[0058] The second terminal of the switch module 111 serves as the output terminal of the overcurrent protection circuit 11. The control terminal of the switch module 111 is connected to the output terminal of the control module 112. The control module 112 is configured to control the switch module 111 to turn off when the output current is greater than a set threshold.

[0059] Specifically, the current detection module 110 is used to collect the output current of the power supply 10 in real time and convert the current signal into a voltage signal that can be recognized by the control module 112.

[0060] Switch module 111 refers to a switch that can be controlled to open or close via an electrical signal. Switch module 111 can be a unidirectional switch, such as a switch that conducts unidirectionally by connecting a bidirectional switch and a diode in series, or a bidirectional switch, such as a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT) with an anti-parallel freewheeling diode. It is understood that the specific type of switch module 111 can be selected and configured according to actual application scenarios, and this invention does not limit its specific type.

[0061] The control module 112 may include a microcontroller. Optionally, the control module 112 may include a microcontroller, or a digital signal processor (DSP) or a field-programmable gate array (FPGA).

[0062] Continue to refer to Figure 8 The operation of the overcurrent protection circuit 11 is as follows:

[0063] Under normal operating conditions, the output current of power supply 10 flows to switch module 111 via current detection module 110. Switch module 111 is in a conducting state under the control of control module 112, and the current flows to output load 20 (such as vehicle inductive load, wiring harness, etc.) through switch module 111. Current detection module 110 collects the output current of power supply 10 in real time and converts it into a voltage signal, which is then transmitted to control module 112. Control module 112 determines that the output current is less than a set threshold and keeps switch module 111 conducting.

[0064] In overcurrent protection mode, when the current detection module 110 detects that the output current of the power supply 10 exceeds a set threshold, the control module 112 determines that the output current is greater than the set threshold through the amplified voltage signal and immediately outputs a shutdown control signal to control the switch module 111 to turn off, disconnecting the power supply 10 from the output load 20. At the moment the switch module 111 turns off, because the output load 20 is an inductive load, the inductor current cannot change abruptly. Without protection, an extremely high overvoltage pulse will be generated on the load side, which, when superimposed with the power supply voltage, may exceed the maximum withstand voltage of the switch module 111, causing damage.

[0065] Figure 9 This provides a structural schematic diagram of a switch module in one embodiment. For example... Figure 9 As shown, optionally, the switching module 111 includes a MOSFET M1; the MOSFET M1 includes a gate, a source, and a drain.

[0066] The gate of MOSFET M1 serves as the control terminal of switch module 111, the drain of MOSFET M1 serves as the first terminal of switch module 111, and the source of MOSFET M1 serves as the second terminal of switch module 111.

[0067] Optionally, continue to refer to Figure 6 The MOSFET M1 includes a first freewheeling diode D1. The anode of the first freewheeling diode D1 is connected to the source of the MOSFET M1, and the cathode of the first freewheeling diode D1 is connected to the drain of the MOSFET M1. This configuration can suppress the reverse electromotive force, protect the MOSFET M1, and improve the reliability and lifespan of the switching module 111.

[0068] Figure 10 This provides a schematic diagram of the overcurrent protection circuit in yet another embodiment. For example... Figure 10 As shown, optionally, the overcurrent protection circuit 11 also includes a drive module 113. The input terminal of the drive module 113 is connected to the output terminal of the control module 112, and the output terminal of the drive module 113 is connected to the control terminal of the switch module 111. The drive module 113 is used to amplify the signal output by the control module 112.

[0069] Specifically, the control signal output by the control module 112 has a problem of "insufficient power," such as low voltage and current, which cannot directly drive the switch module 111 to work normally. At this time, the role of the drive module 113 is to amplify the control signal to give it sufficient power, thereby effectively controlling the on / off state of the switch module 111.

[0070] For example, suppose the control module 112 outputs a weak 5V, 1mA signal, while the switch module requires a 12V, 100mA signal to trigger its action. The drive module 113 converts the 5V / 1mA signal to 12V / 100mA, ensuring that the switch module 111 can accurately execute the control module's instructions, thereby guaranteeing the reliability of the overcurrent protection circuit 11.

[0071] Figure 11 This provides a schematic diagram of the current detection module in one embodiment. For example... Figure 11 As shown, optionally, the current detection module 110 includes a detection resistor R2 and an operational amplifier U1.

[0072] The first terminal of the sensing resistor R2 serves as the first terminal of the current sensing module 110, and the second terminal of the sensing resistor R2 serves as the second terminal of the current sensing module 110. The first input terminal of the operational amplifier U1 is connected to the first terminal of the sensing resistor R2, the second input terminal of the operational amplifier U1 is connected to the second terminal of the sensing resistor R2, and the output terminal of the operational amplifier U1 serves as the output terminal of the current sensing module 110.

[0073] Specifically, when current flows through the circuit, a voltage difference is generated across the sensing resistor R2. Operational amplifier U1 captures this voltage difference through its two input terminals, amplifies it internally, and outputs a voltage signal that is directly proportional to the voltage difference (i.e., the circuit current). Control module 112 can use this voltage signal to determine the magnitude of the current in the circuit, providing a basis for overcurrent protection and other functions.

[0074] Figure 12 This is a structural schematic diagram of another intelligent power distribution device provided in an embodiment of this utility model. (See diagram below.) Figure 12 As shown, the intelligent power distribution device 1 includes an overcurrent protection circuit 11, a reverse connection protection circuit 12, a unidirectional conduction element 13, a first input port IN1 for connecting to the power supply 10, a second input port IN2, and an output port OUT for connecting to the output load 20.

[0075] The reverse connection protection circuit 12 includes a PTC thermistor R1. The first end of the PTC thermistor R1 serves as the first end of the reverse connection protection circuit 12, and the second end of the PTC thermistor R1 serves as the second end of the reverse connection protection circuit 12.

[0076] The overcurrent protection circuit 11 includes a current detection module 110, a switching module 111, and a control module 112. The current detection module 110 includes a detection resistor R2 and an operational amplifier U1. The switching module 111 includes a MOSFET M1, which has a first freewheeling diode D1. The overcurrent protection circuit 11 also includes a drive module 113. The unidirectional conducting element 13 includes a second freewheeling diode D2.

[0077] refer to Figure 12 The working process of the intelligent power distribution device 1 is as follows:

[0078] When the positive terminal of power supply 10 is connected to the first input port IN1 and the negative terminal of power supply 10 is connected to the second input port IN2, the output current of power supply 10 flows from the first input port IN1 into the input terminal of overcurrent protection circuit 11. If the output current is less than a set threshold, control module 112 outputs a conduction control signal to control MOSFET M1 to conduct, and the current flows from the output terminal of overcurrent protection circuit 11 to the output port OUT, supplying power to output load 20. At this time, since the first terminal of PTC thermistor R1 is connected to the output port OUT and the second terminal is connected to the second input port IN2 through unidirectional conducting element 13, under normal polarity, PTC thermistor R1 is in a low-resistance state, allowing a small current to pass through. For example, at room temperature, the resistance value of PTC thermistor R1 is 10Ω. The second freewheeling diode D2 is in a reverse bias state, in a cutoff state, preventing current from flowing directly from the output port OUT to the second input port IN2. Figure 13 This is a schematic diagram showing the current flow direction when the power supply is connected in the positive direction. For example... Figure 13 As shown, the current path is IN1->overcurrent protection circuit 11->OUT->output load 20->loop back to the negative terminal of power supply 10.

[0079] Figure 14 This is a schematic diagram showing the current flow direction when the power supply is reversed. For example... Figure 14 As shown, when the positive and negative terminals of power supply 10 are incorrectly connected—that is, the positive terminal of power supply 10 is connected to the second input port IN2 and the negative terminal is connected to the first input port IN1—current will flow from the second input port IN2 into the intelligent power distribution device, then to the PTC thermistor R1, and finally to the first input port IN1. Initially, the resistance of the PTC thermistor R1 is small, and the current is 14V / 10Ω = 1.4A. However, as the reverse connection time increases, due to the larger current, the temperature of the PTC thermistor R1 rises, and the resistance of the PTC thermistor increases accordingly. Consequently, the current decreases, eventually reaching equilibrium without damaging the second freewheeling diode D2.

[0080] Figure 15 This is a waveform diagram of the output port voltage and current when the power supply voltage is reversed without a PTC thermistor. For example... Figure 15 As shown, when the power supply voltage is reversed, the current at the output port exceeds 5A, which will break down the second freewheeling diode D2. Figure 16 This is a waveform diagram of the output port voltage and current when the power supply voltage is reversed after adding a PTC thermistor. For example... Figure 16 As shown, when the power supply voltage is reversed, the current at the output port is less than or equal to 1.4A, which will not break down the second freewheeling diode D2.

[0081] It should be noted that in this embodiment of the present invention, the green curve represents the current waveform and the red curve represents the voltage waveform.

[0082] The specific embodiments described above do not constitute a limitation on the scope of protection of this utility model. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. An intelligent power distribution device, characterized in that, include: Overcurrent protection circuit, reverse connection protection circuit, unidirectional conduction element, first input port for connecting the power supply, second input port and output port for connecting the output load; The input terminal of the overcurrent protection circuit is connected to the first input port, and the output terminal of the overcurrent protection circuit is connected to the output port. The overcurrent protection circuit is used to cut off the path between the power supply and the output load when the output current of the power supply is greater than a set threshold. The first end of the reverse connection protection circuit is connected to the output port, the second end of the reverse connection protection circuit is connected to the first end of the unidirectional conduction element, and the second end of the unidirectional conduction element is connected to the second input port. The reverse connection protection circuit is used to increase its own resistance when the first input port is connected to the negative terminal of the power supply and the second input port is connected to the positive terminal of the power supply, so as to reduce the current flowing through the unidirectional conducting element.

2. The intelligent power distribution device according to claim 1, characterized in that, The reverse connection protection circuit includes a PTC thermistor, with the first end of the PTC thermistor serving as the first end of the reverse connection protection circuit and the second end of the PTC thermistor serving as the second end of the reverse connection protection circuit.

3. The intelligent power distribution device according to claim 1, characterized in that, The reverse connection protection circuit includes N PTC thermistors, which are connected in series. The first terminal of the first PTC thermistor serves as the first terminal of the reverse connection protection circuit, and the second terminal of the last PTC thermistor serves as the second terminal of the reverse connection protection circuit. N is an integer greater than or equal to 2.

4. The intelligent power distribution device according to claim 1, characterized in that, The reverse connection protection circuit includes N PTC thermistors, which are connected in parallel to the output port and the first end of the unidirectional conduction element, where N is an integer greater than or equal to 2.

5. The intelligent power distribution device according to claim 1, characterized in that, The overcurrent protection circuit includes a current detection module, a switching module, and a control module; The first terminal of the current detection module serves as the input terminal of the overcurrent protection circuit, the second terminal of the current detection module is connected to the first terminal of the switch module, the output terminal of the current detection module is connected to the input terminal of the control module, and the current detection module is used to collect the output current of the power supply. The second terminal of the switch module serves as the output terminal of the overcurrent protection circuit. The control terminal of the switch module is connected to the output terminal of the control module. The control module is configured to control the switch module to turn off when the output current is greater than the set threshold.

6. The intelligent power distribution device according to claim 5, characterized in that, The switching module includes a MOSFET; the MOSFET includes a gate, a source, and a drain. The gate of the MOSFET serves as the control terminal of the switching module, the drain of the MOSFET serves as the first terminal of the switching module, and the source of the MOSFET serves as the second terminal of the switching module.

7. The intelligent power distribution device according to claim 6, characterized in that, The MOSFET has a first freewheeling diode, the anode of which is connected to the source of the MOSFET, and the cathode of which is connected to the drain of the MOSFET.

8. The intelligent power distribution device according to claim 5, characterized in that, The overcurrent protection circuit also includes a drive module. The input terminal of the drive module is connected to the output terminal of the control module, and the output terminal of the drive module is connected to the control terminal of the switch module. The drive module is used to amplify the signal output by the control module.

9. The intelligent power distribution device according to claim 5, characterized in that, The current detection module includes a detection resistor and an operational amplifier; The first end of the detection resistor serves as the first end of the current detection module, and the second end of the detection resistor serves as the second end of the current detection module. The first input terminal of the operational amplifier is connected to the first terminal of the detection resistor, the second input terminal of the operational amplifier is connected to the second terminal of the detection resistor, and the output terminal of the operational amplifier serves as the output terminal of the current detection module.

10. The intelligent power distribution device according to claim 1, characterized in that, The unidirectional conducting element includes a second freewheeling diode, the cathode of which serves as the first terminal of the unidirectional conducting element, and the anode of which serves as the second terminal of the unidirectional conducting element.

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