Intelligent current detection circuit

Abstract

The utility model provides a current intelligent detection circuit, and belongs to the field of power supply protection circuits. The current intelligent detection circuit comprises a power supply input module, the power supply input module is provided with a resettable fuse with over-current protection, the current intelligent detection circuit further comprises a differencing module, a main control module and an indication module, a first input end of the differencing module is connected with a voltage input end of the resettable fuse, and a second input end of the differencing module is connected with a voltage output end of the resettable fuse. The second input end of the differencing module is connected with the voltage output end of the resettable fuse, the output end of the differencing module is connected with the input end of the master control module, the output end of the master control module is connected with the input end of the indication module, and the master control module can receive the level of the output end of the differencing module and send the level to the resettable fuse. And a control level signal is output to the indication module for alarming. The self-recovery fuse has the beneficial effects that the self-recovery characteristic of a circuit is reserved, and equipment users can know the state of the self-recovery fuse in time.

Description

Technical Field

[0001] This utility model relates to the field of power protection circuits, specifically to a current intelligent detection circuit. Background Technology

[0002] With the development of the times and technology, all kinds of electronic devices have emerged in our lives, from small watches to large cars and industrial equipment, which have greatly improved productivity and quality of life. However, as the load on equipment increases and the operating time becomes longer, there are also extremely high requirements for the safety of power supplies, especially for overcurrent protection of circuits.

[0003] Currently, two common solutions are used in mainstream designs. The first is to use a series-connected resettable fuse (PPTC) in the power supply path. During an overcurrent, its internal resistance increases dramatically, and it automatically resets after the fault is cleared. This solution is low-cost, simple, and reliable. However, the PPTC is limited by its inherent characteristics, and its performance degrades after repeated triggering, causing instability and potential safety hazards. The second solution uses a current-limiting IC to detect the current, which has the functions of current-limiting output and overcurrent shutdown. However, this solution is relatively expensive, and its high integration leads to power limitations. Utility Model Content

[0004] To address the problems in the existing technology, this utility model provides an intelligent current detection circuit that can perform timely and accurate safety checks on overcurrent protection circuits using self-resetting fuses, avoiding performance degradation caused by repeated triggering of the self-resetting fuse and resulting in unstable safety hazards.

[0005] This utility model discloses an intelligent current detection circuit, including a power input module equipped with a self-resetting fuse for overcurrent protection. The intelligent current detection circuit also includes a difference module, a main control module, and an indicator module. The first input terminal of the difference module is connected to the voltage input terminal of the self-resetting fuse, the second input terminal of the difference module is connected to the voltage output terminal of the self-resetting fuse, the output terminal of the difference module is connected to the input terminal of the main control module, and the output terminal of the main control module is connected to the input terminal of the indicator module. The main control module can receive the voltage level of the output terminal of the difference module and output a control level signal to the indicator module for alarm.

[0006] Furthermore, the power input module also includes a power input interface, a transient suppression unit, and a filtering unit. The positive output terminal of the power input interface is connected in series with the self-resetting fuse and then connected to one end of the transient suppression unit and the filtering unit, respectively. The other ends of the transient suppression unit and the filtering unit are respectively connected to the negative power supply terminal.

[0007] Furthermore, the difference calculation module includes an operational amplifier U15A. The non-inverting input terminal of the operational amplifier U15A is connected to one end of resistor R125 and one end of resistor R163, respectively. The other end of resistor R125 is connected to the voltage output terminal of the resettable fuse, and the other end of resistor R163 is grounded. The inverting input terminal of the operational amplifier U15A is connected to one end of resistor R164 and one end of resistor R168, respectively. The other end of resistor R164 is connected to the voltage input terminal of the resettable fuse, and the other end of resistor R168 is connected to the output terminal of the operational amplifier U15A.

[0008] Furthermore, the main control module includes a main control chip U14, a crystal oscillator unit and a storage unit connected to the main control chip. The main control chip U14 is provided with a first ADC pin for acquiring current detection information and a second ADC pin for acquiring overcurrent count. A detection path is provided between the first ADC pin and the output terminal of the difference module, and an overcurrent count path is provided between the second ADC pin and the output terminal of the difference module.

[0009] Furthermore, the detection path includes a resistor R123 and a diode D1 connected in series. One end of the resistor R123 is connected to the output terminal of the operational amplifier U15A, and the cathode of the diode D1 is connected to the first ADC pin of the main control chip U14. The overcurrent counting path includes a resistor R170 and a diode D21 connected in series. One end of the resistor R170 is connected to the output terminal of the operational amplifier U15A, and the cathode of the diode D21 is connected to the second ADC pin of the main control chip U14.

[0010] Furthermore, the indicator module is an audible, visual, and electrical alarm structure.

[0011] Furthermore, the indicator module is a dual indicator light, one of which indicates the overcurrent protection status of the resettable fuse, and the other indicator light reminds the user to replace the resettable fuse.

[0012] Compared with the prior art, the beneficial effects of this utility model are: by adding differential detection on both sides of the self-resetting fuse, this utility model completes current detection and overcurrent protection with minimal modification. This utility model is simple to modify, cost-controllable, and effective. Furthermore, the main control module can adopt the main control of the power supply, further reducing costs.

[0013] This invention retains the self-recovery characteristic of the circuit while also allowing equipment users to understand the real-time circuit status of the power supply. An indicator module alerts users to overcurrent or the need to replace the resettable fuse, thus facilitating circuit maintenance and improving circuit safety. Furthermore, thanks to the powerful capabilities of the main control chip, it can also generate readable fault logs for maintenance personnel to analyze. Attached Figure Description

[0014] To more clearly illustrate the solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 This is a structural block diagram of the present utility model;

[0016] Figure 2 This is a schematic diagram of an embodiment of the present invention;

[0017] Figure 3 This is a circuit schematic diagram of an embodiment of the power input module;

[0018] Figure 4 A circuit schematic diagram of an embodiment of the difference module;

[0019] Figure 5 This is a circuit schematic diagram of an embodiment of the main control module and the indicator module. Detailed Implementation

[0020] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, and accompanying drawings are used to distinguish different objects, not to describe a particular order.

[0021] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment to other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention can be combined with other embodiments.

[0022] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0023] like Figure 1 As shown, the intelligent current detection circuit of this utility model includes a power input module, which is equipped with a self-resetting fuse for overcurrent protection. The intelligent current detection circuit also includes a difference module, a main control module, and an indicator module. The first input terminal of the difference module is connected to the voltage input terminal of the self-resetting fuse, the second input terminal of the difference module is connected to the voltage output terminal of the self-resetting fuse, the output terminal of the difference module is connected to the input terminal of the main control module, and the output terminal of the main control module is connected to the input terminal of the indicator module. The main control module can receive the level of the output terminal of the difference module and output a control level signal to the indicator module for alarm.

[0024] This invention connects a self-resetting fuse (PPTC) in series at the power input position. During overcurrent, the resistance increases dramatically. A differential module detects the voltage difference across the PPTC, triggering the fuse and outputting its status to the main control module and a counter. The main control module then controls the indicator module to output the current indication. Simultaneously, the counter reports the count result to the main control module, which writes the result into its memory. When the count reaches a critical number, the main control module can control the indicator module's status to output a PPTC replacement reminder. This invention effectively prevents PPTC failure or damage, ensuring the safe operation of the equipment.

[0025] like Figure 2 and Figure 3 As shown in the figure, as an embodiment of the present invention, the power input module further includes a power input interface, a transient suppression unit and a filtering unit. The positive output terminal of the power input interface is connected in series with the self-resetting fuse and then connected to one end of the transient suppression unit and the filtering unit, respectively. The other end of the transient suppression unit and the filtering unit are respectively connected to the negative terminal of the power supply.

[0026] The transient suppression unit in this example uses a transient suppression diode D2. Other components such as electrostatic discharge tubes and ferrite beads can also be used. The filter unit in this example consists of multiple capacitors connected in parallel. Other components such as a combination of inductors and capacitors can also be used.

[0027] like Figure 4As shown, the difference calculation module in this example includes operational amplifier U15A. The non-inverting input terminal of operational amplifier U15A is connected to one end of resistor R125 and one end of resistor R163, respectively. The other end of resistor R125 is connected to the voltage output terminal of resettable fuse F3, and the other end of resistor R163 is grounded. The inverting input terminal of operational amplifier U15A is connected to one end of resistor R164 and one end of resistor R168, respectively. The other end of resistor R164 is connected to the voltage input terminal of resettable fuse F3, and the other end of resistor R168 is connected to the output terminal of operational amplifier U15A. Of course, the components of the difference calculation module in this example can also be configured and calculated according to actual conditions.

[0028] Furthermore, the main control module includes a main control chip U14, a crystal oscillator unit and a storage unit connected to the main control chip. The main control chip U14 is provided with a first ADC pin for acquiring current detection information and a second ADC pin for acquiring overcurrent count. A detection path is provided between the first ADC pin and the output terminal of the difference module, and an overcurrent count path is provided between the second ADC pin and the output terminal of the difference module.

[0029] The cumulative count setting in the main control chip U14 of this example is set according to the selected PPTC specification. The detection path in this example includes a resistor R123 and a diode D1 connected in series. One end of the resistor R123 is connected to the output terminal of the operational amplifier U15A, and the cathode of the diode D1 is connected to the first ADC pin of the main control chip U14. The overcurrent counting path includes a resistor R170 and a diode D21 connected in series. One end of the resistor R170 is connected to the output terminal of the operational amplifier U15A, and the cathode of the diode D21 is connected to the second ADC pin of the main control chip U14.

[0030] In this example, the indicator module is a dual indicator light composed of LEDs D24 and D25. LED D24 is used to indicate the overcurrent protection status of the resettable fuse, and LED D25 is used to remind the user to replace the resettable fuse.

[0031] Of course, the indicator module in this example can also be set as a buzzer, display module, or other sound, light, and electrical alarm structure.

[0032] The working principle of this utility model is as follows:

[0033] The input power supply voltage, after passing through a resettable fuse, outputs VSYS to power the load. The differential module, primarily composed of operational amplifiers, calculates the voltage difference between VSYS and DCIN using operational amplifier U15A. Under normal circumstances, the output result is transmitted to the main control chip U14 (SOC) via its two ADC pins: OC_DET is the status input, and COUNT is the counting input. When the current flowing through PPTC is normal, the voltage values ​​of DCIN and VSYS are equal. The result calculated by operational amplifier U15A is 0V, at which point the main control chip U14 controls the green indicator light D24 to flash.

[0034] When the current flowing through the PPTC is too large, its internal resistance increases, so the DCIN voltage is less than VSYS. The output level is calculated to be greater than 0V by U15A. After the SOC detects this level through the ADC pin of OC_DET, it controls the LED D24 to stay on as an alarm. At the same time, the SOC also counts the count through the ADC pin of COUNT and records it internally to the storage device. When the number of counts in the storage device reaches the dangerous count, the SOC controls the red LED D25 to stay on, reminding relevant personnel to replace the PPTC.

[0035] If the device with the power supply circuit installed has a human-machine interface display window, the SOC can also directly report the fault to the system or upper-level application, allowing users or maintenance personnel to perform safety maintenance on the device more directly.

[0036] As can be seen from the above, this utility model retains the self-recovery characteristic of the circuit while allowing equipment users to understand the real-time circuit status of the power supply circuit. The indicator module alerts users to overcurrent or the need to replace the resettable fuse, thus facilitating circuit maintenance and improving circuit safety. Furthermore, this utility model achieves current detection and overcurrent protection with minimal modifications. The modifications are simple, cost-effective, and highly efficient.

[0037] The specific embodiments described above are preferred embodiments of this utility model, and are not intended to limit the specific scope of this utility model. The scope of this utility model includes but is not limited to the specific embodiments described above. All equivalent changes made in accordance with this utility model are within the protection scope of this utility model.

Claims

1. A current intelligent detection circuit, characterized in that: The system includes a power input module equipped with a self-resetting fuse for overcurrent protection. The intelligent current detection circuit further includes a difference module, a main control module, and an indicator module. The first input terminal of the difference module is connected to the voltage input terminal of the self-resetting fuse, the second input terminal of the difference module is connected to the voltage output terminal of the self-resetting fuse, the output terminal of the difference module is connected to the input terminal of the main control module, and the output terminal of the main control module is connected to the input terminal of the indicator module. The main control module can receive the level of the output terminal of the difference module and output a control level signal to the indicator module for alarm.

2. The intelligent current detection circuit according to claim 1, characterized in that: The power input module further includes a power input interface, a transient suppression unit, and a filtering unit. The positive output terminal of the power input interface is connected in series with the self-resetting fuse and then connected to one end of the transient suppression unit and the filtering unit, respectively. The other ends of the transient suppression unit and the filtering unit are connected to the negative power supply.

3. The intelligent current detection circuit according to claim 1, characterized in that: The difference calculation module includes an operational amplifier U15A. The non-inverting input terminal of the operational amplifier U15A is connected to one end of resistor R125 and one end of resistor R163, respectively. The other end of resistor R125 is connected to the voltage output terminal of a resettable fuse, and the other end of resistor R163 is grounded. The inverting input terminal of the operational amplifier U15A is connected to one end of resistor R164 and one end of resistor R168, respectively. The other end of resistor R164 is connected to the voltage input terminal of a resettable fuse, and the other end of resistor R168 is connected to the output terminal of the operational amplifier U15A.

4. The intelligent current detection circuit according to claim 3, characterized in that: The main control module includes a main control chip U14, a crystal oscillator unit and a storage unit connected to the main control chip. The main control chip U14 is provided with a first ADC pin for acquiring current detection information and a second ADC pin for acquiring overcurrent count. A detection path is provided between the first ADC pin and the output terminal of the difference module, and an overcurrent count path is provided between the second ADC pin and the output terminal of the difference module.

5. The intelligent current detection circuit according to claim 4, characterized in that: The detection path includes a resistor R123 and a diode D1 connected in series. One end of the resistor R123 is connected to the output terminal of the operational amplifier U15A, and the cathode of the diode D1 is connected to the first ADC pin of the main control chip U14. The overcurrent counting path includes a resistor R170 and a diode D21 connected in series. One end of the resistor R170 is connected to the output terminal of the operational amplifier U15A, and the cathode of the diode D21 is connected to the second ADC pin of the main control chip U14.

6. The intelligent current detection circuit according to any one of claims 1-5, characterized in that: The indicator module is a combination of audible, visual, and electrical alarm structures.

7. The intelligent current detection circuit according to claim 6, characterized in that: The indicator module has two indicator lights: one light indicates the overcurrent protection status of the resettable fuse, and the other light reminds the user to replace the resettable fuse.

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