Anti-reverse insertion protection circuit and ultrasonic diagnostic apparatus

Abstract

This application relates to the technical field of electronic circuits, specifically to a reverse insertion protection circuit and an ultrasound diagnostic device. The reverse insertion protection circuit includes an input terminal, an output terminal, and a ground terminal connected to each other. The output terminal is used to connect to an electrical circuit. The input terminal and the ground terminal are used to connect to the positive and negative terminals of a power supply, respectively. A PMOS transistor, a first resistor, and a second resistor are connected sequentially between the input terminal and the ground terminal. The gate of the PMOS transistor is connected between the first and second resistors. The first and second resistors are used to adjust the voltage difference between the gate and source of the PMOS transistor so that the PMOS transistor conducts when the input terminal and the ground terminal are connected to the positive and negative terminals of the power supply. A diode is also connected between the input terminal and the output terminal. The diode is connected in parallel with the PMOS transistor, with the anode of the diode connected to the input terminal and the cathode connected to the output terminal.

Description

Technical Field

[0001] This application relates to the technical field of electronic circuits, specifically to a reverse insertion protection circuit and an ultrasonic diagnostic device. Background Technology

[0002] Ultrasound diagnostic equipment is an instrument that uses ultrasound signals to diagnose diseases in living organisms. In the process of manufacturing ultrasound diagnostic equipment, circuit boards and power supplies for providing power to the circuit boards are inevitably used. Current technology usually connects the power supply and the circuit board through a power adapter to power the circuit board.

[0003] If the operator is not careful when plugging in the power adapter, the adapter may be plugged in backwards, causing the positive and negative terminals of the power supply to be reversed with the positive and negative terminals of the circuit board. This can burn out many electronic components on the circuit board, damage the circuit board, and render the ultrasound diagnostic equipment unusable. Summary of the Invention

[0004] The purpose of this application is to overcome the defect that if the operator is not careful, the adapter may be plugged in backwards, causing the positive and negative terminals of the power supply to be reversed with the positive and negative terminals of the circuit board, resulting in the burning of many electronic components on the circuit board, damaging the circuit board, and causing the ultrasound diagnostic equipment to malfunction.

[0005] To address this, this application provides a reverse insertion protection circuit, comprising an input terminal, an output terminal, and a ground terminal connected to each other. The output terminal is used to connect to an electrical circuit. The input terminal and the ground terminal are used to connect to the positive and negative terminals of a power supply, respectively. A PMOS transistor, a first resistor, and a second resistor are connected sequentially between the input terminal and the ground terminal. The gate of the PMOS transistor is connected between the first resistor and the second resistor. The first resistor and the second resistor are used to adjust the voltage difference between the gate and source of the PMOS transistor so that the PMOS transistor conducts when the input terminal and the ground terminal are connected to the positive and negative terminals of the power supply. A diode is also connected between the input terminal and the output terminal. The diode is connected in parallel with the PMOS transistor, with the anode of the diode connected to the input terminal and the cathode of the diode connected to the output terminal.

[0006] Furthermore, the reverse insertion protection circuit also includes a first capacitor, one end of which is connected between a first resistor and a second resistor, and the other end of which is connected between the PMOS transistor and the first resistor.

[0007] Furthermore, the reverse insertion protection circuit also includes at least one third resistor, which is connected in parallel across the first and second resistors.

[0008] Furthermore, there are two third resistors connected in parallel. One end of each third resistor is connected to the output terminal, and the other end of each third resistor is connected to the ground terminal.

[0009] Furthermore, the reverse insertion protection circuit also includes a buffer circuit, which includes a fourth resistor and a second capacitor connected in series, and the buffer circuit is connected in parallel across the two ends of the PMOS transistor.

[0010] Furthermore, there are two fourth resistors, which are connected in parallel.

[0011] Furthermore, there are two second capacitors, which are connected in parallel.

[0012] Furthermore, the reverse insertion protection circuit also includes a fifth resistor, one end of which is connected between the first resistor and the second resistor, and the other end of which is connected to the gate of the PMOS transistor.

[0013] Furthermore, when the voltage difference between the gate and source of the PMOS transistor is greater than or equal to 1.2V, the PMOS transistor is turned on when its input terminal and ground terminal are connected to the positive and negative terminals of the power supply.

[0014] Secondly, this application also provides an ultrasound diagnostic device, which includes the aforementioned reverse insertion protection circuit.

[0015] The technical solution of this application has at least the following advantages:

[0016] 1. The reverse insertion protection circuit of this application works in conjunction with a first resistor, a second resistor, and a PMOS transistor to ensure that the PMOS transistor conducts when its input terminal and ground terminal are connected to the positive and negative terminals of the power supply. If the positive terminal of the power supply is connected to the ground terminal and the negative terminal is connected to the input terminal, the PMOS transistor will not conduct, thus providing the reverse insertion protection function. If the PMOS transistor fails, the diode connected in parallel with the PMOS transistor can also provide the reverse insertion protection function when the positive and negative terminals of the power supply are reversed. This can prevent electronic components on the circuit board from being burned out due to the reverse connection of the positive and negative terminals of the power supply, thereby improving the stability of the ultrasound diagnostic equipment.

[0017] 2. The first capacitor serves as a filter, making the current and voltage of the electrical circuit more stable; the third resistor improves the charging and discharging speed of the anti-reverse insertion circuit when the power is off, thereby ensuring the safe and stable operation of the electrical circuit and improving the response speed of the ultrasound diagnostic equipment.

[0018] 3. The inclusion of two third resistors allows for adjustment of the circuit's charging and discharging speed by working together with the two third resistors.

[0019] 4. When the positive and negative terminals of the power supply are reversed, the instantaneous parasitic inductance and capacitance of the anti-reverse connection circuit oscillate, resulting in a large instantaneous voltage in the circuit. This may cause the circuit board to overheat and damage the inductors and capacitors, thus affecting the service life of the ultrasound diagnostic equipment. More seriously, excessive voltage may lead to safety accidents such as fires, thereby increasing the risk of using the ultrasound diagnostic equipment. The buffer circuit can reduce the instantaneous voltage of the circuit when the positive and negative terminals of the power supply are reversed, making the circuit more stable, reducing the possibility of circuit board overheating and damage to inductors and capacitors, extending the service life of the ultrasound diagnostic equipment, and reducing the risk of using the ultrasound diagnostic equipment.

[0020] 5. The buffer circuit of this application reduces the instantaneous voltage of the circuit when the positive and negative terminals of the power supply are reversed by connecting a fourth resistor and a second capacitor in series. The arrangement of two fourth resistors and two second capacitors in parallel facilitates the adjustment of the resistance value of the fourth resistor and the capacitance value of the second capacitor to adjust the value of reducing the instantaneous voltage of the circuit when the positive and negative terminals of the power supply are reversed.

[0021] 6. The fifth resistor is a reserved resistor for the debugging circuit. The reserved resistor is used to enable the ultrasound diagnostic equipment to start slowly, which reduces the impact on the power grid, reduces the burden on the transformer and circuit, thereby extending the service life of the ultrasound diagnostic equipment and protecting it from damage. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of an anti-reverse insertion protection circuit provided in an exemplary embodiment of this application. Detailed Implementation

[0024] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0027] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0028] Example 1

[0029] Example 1 provides a reverse insertion protection circuit, referring to... Figure 1 The reverse insertion protection circuit includes an input terminal 1, an output terminal 2, and a ground terminal 3 connected to each other. The output terminal 2 is used to connect to the power supply circuit. The input terminal 1 and the ground terminal 3 are used to connect to the positive and negative terminals of the power supply, respectively. A PMOS transistor 4, a first resistor R1, and a second resistor R2 are connected in sequence between the input terminal 1 and the ground terminal 3. The gate G of the PMOS transistor 4 is connected between the first resistor R1 and the second resistor R2. The first resistor R1 and the second resistor R2 are used to adjust the voltage difference between the gate G and the source S of the PMOS transistor 4 so that the PMOS transistor 4 conducts when the input terminal 1 and the ground terminal 3 are connected to the positive and negative terminals of the power supply. A diode is also connected between the input terminal 1 and the output terminal 2. The diode is connected in parallel with the PMOS transistor 4. The positive terminal of the diode is connected to the input terminal 1, and the negative terminal of the diode is connected to the output terminal 2.

[0030] The aforementioned reverse insertion protection circuit works in conjunction with the first resistor R1, the second resistor R2, and the PMOS transistor 4. This ensures that the PMOS transistor 4 conducts when its input terminal 1 and ground terminal 3 are connected to the positive and negative terminals of the power supply. If the positive terminal of the power supply is connected to the ground terminal 3 and the negative terminal is connected to the input terminal 1, the PMOS transistor 4 will not conduct, thus providing reverse insertion protection. If the PMOS transistor 4 fails, the diode connected in parallel with the PMOS transistor 4 will also provide reverse insertion protection even if the positive and negative terminals of the power supply are reversed. This prevents electronic components on the circuit board from burning out due to reversed power supply polarity, thereby improving the stability of the ultrasound diagnostic equipment.

[0031] Specifically, refer to Figure 1 The source S of PMOS transistor 4 has multiple interfaces, and the drain D of PMOS transistor 4 also has multiple interfaces. The drain D of PMOS transistor 4 is connected to the input terminal 1, and the source D of PMOS transistor 4 is connected to the end of the first resistor R1 that is away from the second resistor R2.

[0032] In some embodiments, the voltage input to input terminal 1 can be 19V, the resistance of the first resistor R1 can be 12KΩ, the resistance of the second resistor R2 can be 20KΩ, and the voltage output to the power circuit from output terminal 2 is equal to the voltage input to input terminal 1. When the voltage difference between the gate and source of PMOS transistor 4 is greater than or equal to 1.2V, PMOS transistor 4 conducts when input terminal 1 and ground terminal 3 are connected to the positive and negative terminals of the power supply. The values ​​of the first resistor R1 and the second resistor R2 can also be other values, as long as the voltage difference between the gate and source of PMOS transistor 4 is greater than 1.2V when the positive and negative terminals of the power supply are normally connected to the reverse insertion protection circuit, that is, the PMOS transistor can conduct when the positive and negative terminals of the power supply are normally connected to the reverse insertion protection circuit.

[0033] In some embodiments, refer to Figure 1The reverse insertion protection circuit also includes a first capacitor C1. One end of the first capacitor C1 is connected between the first resistor R1 and the second resistor R2, and the other end of the first capacitor C1 is connected between the PMOS transistor 4 and the first resistor R1. The first capacitor C1 acts as a filter, making the current and voltage of the electrical circuit more stable. Specifically, the capacitance value of the first capacitor C1 is preferably 10nF, but it can also be other values ​​as long as it can effectively filter the circuit. The reverse insertion protection circuit also includes at least one third resistor R3, which is connected in parallel across the first resistor R1 and the second resistor R2. The third resistor R3 can increase the charging and discharging speed of the reverse insertion protection circuit when the power is off, thereby ensuring the safe and stable operation of the electrical circuit and improving the response speed of the ultrasound diagnostic equipment. Specifically, one end of the third resistor R3 is connected between the first resistor R1 and the output terminal 2, and the other end of the third resistor R3 is connected between the ground terminal 3 and the second resistor R2. The resistance value of the third resistor R3 is preferably 2KΩ, but the resistance value of the third resistor R3 can also be other values, as long as it can achieve a better improvement in the charging and discharging speed of the circuit.

[0034] In some embodiments, two third resistors R3 are provided, connected in parallel. One end of each third resistor R3 is connected to the output terminal 2, and the other end of each third resistor R3 is connected to the ground terminal 3. The arrangement of two third resistors R3 facilitates the adjustment of the circuit's charging and discharging speed by adjusting the two resistors in tandem. Specifically, the resistance values ​​of the two third resistors R3 are preferably the same, but the resistance values ​​can also be set differently, as long as the charging and discharging speed of the circuit is improved, thereby increasing the response speed of the acoustic diagnostic device.

[0035] In some embodiments, refer to Figure 1 The reverse insertion protection circuit also includes a buffer circuit, which consists of a fourth resistor R4 connected in series and a second capacitor C2 connected in parallel across the PMOS transistor 4. Specifically, one end of the fourth resistor R4 is connected to the drain D of the PMOS transistor 4, the other end of the fourth resistor R4 is connected to one end of the second capacitor C2, and the end of the second capacitor C2 furthest from the fourth resistor R4 is connected to the source S of the PMOS transistor 4.

[0036] When the positive and negative terminals of the power supply are reversed, the instantaneous parasitic inductance and capacitance of the anti-reverse connection circuit oscillate, resulting in a large instantaneous voltage in the circuit. This may cause the circuit board to overheat and damage the inductors and capacitors, thus affecting the service life of the ultrasound diagnostic equipment. More seriously, excessive voltage may lead to fires and other safety accidents, thereby increasing the risk of using the ultrasound diagnostic equipment. The buffer circuit can reduce the instantaneous voltage of the circuit when the positive and negative terminals of the power supply are reversed, making the circuit more stable, reducing the possibility of circuit board overheating and damage to inductors and capacitors, extending the service life of the ultrasound diagnostic equipment, and reducing the risk of using the ultrasound diagnostic equipment.

[0037] In some embodiments, refer to Figure 1 There are two fourth resistors R4 connected in parallel, and two second capacitors C2 connected in parallel. The series connection of the fourth resistors R4 and the second capacitors C2 reduces the instantaneous voltage in the circuit when the power supply polarity is reversed. The parallel connection of the two fourth resistors R4 and the two parallel second capacitors C2 allows for adjustment of the resistance value of the fourth resistors R4 and the capacitance value of the second capacitors C2 to regulate the reduction of the instantaneous voltage in the circuit when the power supply polarity is reversed.

[0038] In some embodiments, the reverse insertion protection circuit further includes a fifth resistor R5. One end of the fifth resistor R5 is connected between the first resistor R1 and the second resistor R2 and is connected to the first capacitor C1. The other end of the fifth resistor R5 is connected to the gate of the PMOS transistor 4. The fifth resistor R5 is a reserved resistor for the debugging circuit. The reserved resistor is used to enable the ultrasound diagnostic equipment to start slowly, reducing the impact on the power grid, reducing the burden on the transformer and circuit, thereby extending the service life of the ultrasound diagnostic equipment and protecting it from damage.

[0039] Example 2

[0040] Example 2 provides an ultrasound diagnostic device, which includes the reverse insertion protection circuit of Example 1 and an adapter for connecting to the reverse insertion protection circuit to supply power to the power circuit. The ultrasound diagnostic device can be an ultrasound cart or a portable ultrasound diagnostic device. The device has a circuit board for processing various data to achieve diagnostic functions; this circuit board is the power circuit. In this application, the ultrasound diagnostic device prevents conduction when the adapter is inserted incorrectly due to the reverse insertion protection circuit, thereby preventing electronic components on the circuit board from burning out due to reversed power supply polarity and improving the stability of the ultrasound diagnostic device.

[0041] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this application.

Claims

1. A reverse insertion protection circuit, characterized by, The device includes an interconnected input terminal, an output terminal, and a ground terminal. The output terminal is used to connect to an electrical circuit. The input terminal and the ground terminal are used to connect to the positive and negative terminals of a power supply, respectively. A PMOS transistor, a first resistor, and a second resistor are connected sequentially between the input terminal and the ground terminal. The gate of the PMOS transistor is connected between the first resistor and the second resistor. The first resistor and the second resistor are used to adjust the voltage difference between the gate and source of the PMOS transistor so that the PMOS transistor conducts when the input terminal and the ground terminal are connected to the positive and negative terminals of the power supply. A diode is also connected between the input terminal and the output terminal. The diode is connected in parallel with the PMOS transistor, with the anode of the diode connected to the input terminal and the cathode of the diode connected to the output terminal. The reverse insertion protection circuit also includes a fifth resistor and at least one third resistor. The third resistor is connected in parallel across the first and second resistors. One end of the fifth resistor is connected between the first and second resistors, and the other end of the fifth resistor is connected to the gate of the PMOS transistor.

2. The protection circuit against reverse insertion according to claim 1, characterized in that, It also includes a first capacitor, one end of which is connected between a first resistor and a second resistor, and the other end of which is connected between a PMOS transistor and a first resistor.

3. The protection circuit against reverse insertion according to claim 1, characterized in that, There are two third resistors connected in parallel. One end of each third resistor is connected to the output terminal, and the other end of each third resistor is connected to the ground terminal.

4. The protection circuit against reverse insertion according to claim 1, characterized in that, It also includes a buffer circuit, which includes a fourth resistor and a second capacitor connected in series, and the buffer circuit is connected in parallel across the two ends of the PMOS transistor.

5. The reverse insertion protection circuit according to claim 4, wherein There are two fourth resistors, which are connected in parallel.

6. The anti-reverse insertion protection circuit according to claim 4, characterized in that, There are two second capacitors, which are connected in parallel.

7. The anti-reverse insertion protection circuit according to claim 1, characterized in that, When the voltage difference between the gate and source of the PMOS transistor is greater than or equal to 1.2V, the PMOS transistor is turned on when its input terminal and ground terminal are connected to the positive and negative terminals of the power supply.

8. An ultrasound diagnostic device, characterized in that, Includes a reverse insertion protection circuit as described in any one of claims 1-7.

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