WO2023134533A1

WO2023134533A1 - Protective circuit and biological sample preparation device

Info

Publication number: WO2023134533A1
Application number: PCT/CN2023/070657
Authority: WO
Inventors: 黄毓锐; 李凯; 刘勇军; 李成员
Original assignee: 深圳市瑞沃德生命科技有限公司
Priority date: 2022-01-17
Filing date: 2023-01-05
Publication date: 2023-07-20
Also published as: CN114498562A; CN114498562B; CN116488109A

Abstract

Embodiments of the present application provide a protective circuit, comprising: a control module; a first loop, the first loop comprising a constant current source and a resistance value detection module; and a second loop, the second loop comprising a power supply and an overcurrent detection module. The resistance value detection module detects load resistance values at two ends of the constant current source and sends said load resistance values to the control module; if the load resistance values are not within a preset range, the control module controls the power supply to not supply power; and if the load resistance values are within the preset range and the overcurrent detection module detects an overcurrent, the power supply does not supply power. In an embodiment of the present application, load resistance values at two ends of the constant current source in the first loop are detected; if the load resistance values are not within a preset range, no power will be supplied to the second loop; if the load resistance values are within the preset range, then it is determined, according to overcurrent detection by the second loop, whether to supply power to the second loop; and for the first loop in which the constant current source is excited, a short circuit of said first loop will not cause a large current, thereby achieving short circuit protection between any electrical loops.

Description

A protective circuit and biological sample preparation device

This application claims the priority of the Chinese patent application with the application number 202210047826.8 and the title of the invention "a protective circuit and biological sample preparation device" filed at the Chinese Patent Office on January 17, 2022, the entire contents of which are incorporated by reference in this application.

technical field

The present application relates to the technical field of short circuit protection, in particular to a protection circuit and a biological sample preparation device.

Background technique

After a short circuit occurs in the circuit, a large current will be generated, which will easily damage the chips and other components in the circuit or reduce its service life, which will have a great impact on the circuit. More seriously, the entire circuit may fail, resulting in loss of device functionality and a safety risk to users. Therefore, it is very necessary to carry out short-circuit protection on the circuit.

For equipment with multiple exposed metal terminals, improper use by the user or aging or failure of the circuit itself may cause a short circuit. There are two methods for performing short circuit protection in the prior art. One is to use insulating parts to cover the exposed metal terminals, and then remove them when the equipment needs to be used; the other is to design overcurrent protection. The first method is still unable to protect the short circuit caused by the aging of the circuit itself, failure and other reasons; the second method can only design overcurrent protection for each electric circuit corresponding to the metal terminal, between any metal terminals, any electric circuit The problem of short circuit between them still cannot be solved.

technical problem

The embodiment of the present application provides a protection circuit, which aims to solve the problem of short circuit between any metal terminals and between any electrical circuits of the equipment with exposed metal terminals in the prior art.

technical solution

In the first aspect, a protection circuit is provided, including:

control module;

The first loop, the first loop includes a constant current source and a resistance value detection module; and

The second loop, the second loop includes a power supply and an overcurrent detection module;

Among them, the resistance value detection module detects the load resistance value at both ends of the constant current source and sends it to the control module; if the load resistance value is not in the preset range, the control module controls the power supply to not supply power; if the load resistance value is in the preset range and the overcurrent detection The module detects overcurrent, and the power supply does not supply power.

In a second aspect, a biological sample preparation device is provided, including a housing, a plurality of motors, a plurality of experimental containers, a plurality of heating devices, and a plurality of protection circuits as described above;

Multiple motors are arranged in the casing, and the drive shafts of the multiple motors are respectively connected to multiple experimental containers to drive the multiple experimental containers to rotate;

Both ends of the constant current source of each first circuit form a first terminal, which is exposed to the shell;

The two nodes of each second loop form a second terminal and are exposed to the casing;

When each heating device clamps the experimental container for heating, it contacts with the first terminal to form a closed first loop, and contacts with the second terminal to form a closed second loop.

Beneficial effect

The embodiment of the present application detects the load resistance value at both ends of the constant current source in the first loop. If the load resistance value is not within the preset range, no power is supplied to the second loop. If the load resistance value is within the preset range, then according to the second loop The overcurrent detection judges whether to supply power to the second loop, and for the first loop that is excited as a constant current source, its short circuit will not cause a large current, thus realizing short circuit protection between any electrical loops.

Description of drawings

The above and/or additional aspects and advantages of the present application will become apparent and easy to understand from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

FIG. 1 is a schematic diagram of a protection circuit provided in Embodiment 1 of the present application;

FIG. 2 is a schematic diagram of another protection circuit provided in Embodiment 1 of the present application;

FIG. 3 is a schematic diagram of an overcurrent detection module provided in Embodiment 1 of the present application;

Fig. 4 is a schematic diagram of the biological sample preparation device provided in Example 2 of the present application.

Embodiments of the present invention

Embodiments of the present application are described in detail below, examples of which are shown in the drawings, wherein the same or similar reference numerals denote the same or similar modules or modules having the same or similar functions throughout. The embodiments described below by referring to the figures are exemplary, are only for explaining the present application, and should not be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents falling within the spirit and scope of the appended claims.

Embodiment one

FIG. 1 is a schematic diagram of a protection circuit provided in Embodiment 1 of the present application. As shown in FIG. 1 , the protection circuit includes a first loop 1 , a second loop 2 and a control module 3 .

In the embodiment of the present application, the first loop 1 includes a constant current source 11 and a resistance value detection module 12 . The constant current source 11 is the excitation source of the first loop 1, and the voltage for forming the circuit of the constant current source 11 is a low voltage that will not cause harm to the human body, such as 3.3V. Connected to both ends of the constant current source 11 is the first load resistor R1 , and the first load resistor R1 varies according to the load actually connected to the first loop 1 . The resistance value detecting module 12 detects the load resistance value at both ends of the constant current source 11 , that is, detects the resistance value of the first load resistor R1 , and sends it to the control module 3 . In some embodiments, other parameters of the first loop 1 may also be detected and sent to the control module 3 for subsequent short-circuit protection control, which is not limited here.

The second loop 2 includes a power supply 21 , an overcurrent detection module 22 and a switch module 23 . The power supply is the excitation source of the second loop 2, which can be a commonly used constant voltage power supply, such as a 12V DC voltage source, which is not limited here. Generally, the second load resistor R2 is connected to both ends of the power supply 21 , and the second load resistor R2 varies according to the load actually connected to the second loop 2 . In the embodiment of the present application, the switch module 23 is connected between the power supply end of the power supply 21 and the second load resistor R2. Preferably, the switch module 23 is composed of field effect transistors. An overcurrent detection module 22 is connected between the second load resistor R2 and the ground, and when only the second loop 2 is short-circuited, short-circuit protection for the second loop 2 is realized.

The control module 3 adjusts the closing or opening of the switch module 23 according to the received resistance value of the first load resistor R1 to control whether the power supply 21 supplies power to the second load resistor R2. If the resistance value of the first load resistor R1 is not within the preset range, the control module 3 turns off the switch module 23 and controls the power supply 21 not to supply power. If the resistance value of the first load resistor R1 is within a preset range and the overcurrent detection module 22 detects overcurrent, the control module 3 turns off the switch module 23 and controls the power supply 21 not to supply power. If the resistance value of the first load resistor R1 is within a preset range and the overcurrent detection module 22 does not detect overcurrent, the control module 3 closes the switch module 23 to control the power supply 21 to supply power. Preferably, the control module 3 outputs a PWM (Pulse width modulation, pulse width modulation) signal to the switch module 23 according to the first load resistance R1, the switch module 23 is closed, and the power supply 21 supplies power; the control module 3 does not send power to the switch module 23 according to the first load resistance R1 The switch module 23 outputs a PWM signal, the switch module 23 is turned off, and the power supply 21 does not supply power. The mode in which the control module 3 controls the switch module 23 to close or open is also referred to as a software control mode.

As an embodiment of the present application, as shown in FIG. 1 , the overcurrent detection module 22 is connected to the control module 3 . When the overcurrent detection module 22 outputs a preset level, it means that the overcurrent detection module 22 detects the overcurrent of the second circuit 2 , and the control module 3 does not output a PWM signal to the switch module 23 to turn off the switch module 23 . The software control method can stably disconnect the switch module 23, avoiding safety risks and false alarms caused by only momentary disconnection.

As another embodiment of the present application, as shown in FIG. 2 , FIG. 2 is a schematic diagram of another protection circuit provided in Embodiment 1 of the present application. The overcurrent detection module 22 is directly connected to the switch module 23 . After the overcurrent detection module 22 detects the overcurrent of the second circuit 2 , it outputs a preset level to turn off the switch module 23 , and controls the power supply 21 not to supply power. The method in which the overcurrent detection module 22 is directly connected to the switch module 23 to control its closing or opening is also referred to as a hardware control method. For the switch module 23 composed of field effect transistors, the hardware control method can quickly disconnect the switch module 23 to avoid safety risks caused by delayed disconnection.

Combining the characteristics of the software control mode and the hardware control mode, as shown in Figure 2, the embodiment of the present application adopts the software control mode and the hardware control mode at the same time, so that the protection circuit has a double overcurrent protection mechanism, which is safer, more stable and more reliable.

FIG. 3 is a schematic diagram of an overcurrent detection module provided in Embodiment 1 of the present application. As shown in FIG. 3 , the overcurrent detection module 22 includes a comparator 221 and a sampling resistor 222 . The sampling resistor 222 is connected between the second load resistor R2 and the ground. One input terminal of the comparator 221 is connected to the sampling resistor 222 to compare the voltage of the sampling resistor 222 relative to the ground. The output terminals of the comparator 221 are respectively connected to the control module 3 and the switch module 23 . When the second loop 2 is overcurrent, the comparator 221 detects that the voltage of the sampling resistor 222 is too large relative to the ground, and its output terminal outputs a low level (preset level) to the control module 3 and the switch module 23 .

In some specific scenarios, a total of four nodes at the two ends of the first load resistor R1 and the two ends of the second load resistor R2 are exposed as terminals, and the user connects different conductors according to actual needs, and the protection circuit automatically judges whether to start a short circuit Protect. The operating principle of the protection circuit in the embodiment of the present application is as follows.

In the first loop 1, when the two nodes corresponding to the first load resistor R1 are short-circuited, the resistance value of the first load resistor R1 detected by the resistance value detection module 12 is 0, and 0 is set as not in the preset range, and the control The module 3 turns off the switch module 23 and controls the power supply 21 not to supply power. Thus, the second loop 2 is disconnected; although the first loop 1 is still closed, because it is excited by a constant current source, it will not generate a large current, so the short circuit in this case will not cause damage to the first loop 1 .

In the second loop 2, when the two nodes corresponding to the second load resistance R2 are short-circuited, the resistance value detection module 12 detects that the first load resistance R1 is not in the preset range, and then judges based on the above situation; the resistance value detection module 12 Detecting that the first load resistance R1 is within a preset range and the overcurrent detection module 22 does not detect overcurrent, the control module 3 closes the switch module 23 to control the power supply 21 to supply power; the resistance value detection module 12 detects the first load resistance R1 In the preset range and the overcurrent detection module 22 detects overcurrent, the overcurrent detection module 22 quickly outputs a preset level to the switch module 23 so that the switch module 23 is disconnected, and the overcurrent detection module 22 also outputs to the control module 3 After receiving the preset level, the control module 3 does not send a PWM signal to the switch module 23 to disconnect it, and the power supply 21 does not supply power. As a result, the second circuit 2 is disconnected.

For the first loop 1 and the second loop 2, when any node at both ends of the second load resistor R2 is short-circuited with any node at both ends of the first load resistor R1, it is equivalent to connecting an additional resistor in parallel at both ends of the first load resistor R1 , so that the load resistance at both ends of the constant current source is not only the first load resistance R1, the actual load resistance value at both ends of the constant current source is set to be out of the preset range, the control module 3 disconnects the switch module 23, and controls the power supply 21 No power supplied. Thus, the second loop 2 is disconnected; and the power supply 21 will not form a new loop with the components in the first loop 1 to cause damage to them.

For the first loop 1 and the second loop 2, when the two ends of the first load resistor R1 and the two ends of the second load resistor R2 are all short-circuited, it is equivalent to the short-circuit of the two nodes corresponding to the first load resistor R1 In the case of the same, short-circuit protection can also be carried out.

Further, when the two ends of the first load resistor R1 are not connected to conductors, the resistance value of the first load resistor R1 detected by the resistance value detection module 12 is infinite, and the infinite value is set to be out of the preset range, and the control module 3 makes the switch The module 23 is disconnected, and the power supply 21 is controlled not to supply power. Thus, both the first circuit 1 and the second circuit 2 are disconnected. For the four exposed nodes, since the first loop 1 is a low voltage that will not cause harm to the human body, the switch module 23 in the second loop 2 is disconnected, that is, the power supply 21 is disconnected from the second load resistor R2, so the user touches To the four nodes, there is no security risk.

In some embodiments, the first loop 1 further includes a resistive temperature sensor 13 , the resistive temperature sensor 13 is used as the first load resistor R1 , connected in parallel to both ends of the constant current source 11 , and connected to the first loop 1 . The resistance value exhibited by the resistance temperature sensor 13 itself varies with the temperature it senses. The second loop 2 also includes a heating film connected into the second loop 2 as a second load resistor R2. According to the scene, the above-mentioned preset range is reasonably set, that is, the resistance value detection module 2 can be used to judge whether the resistive temperature sensor 13 and the heating film are in a normal working state, and whether the first loop 1 and the second loop 2 where they are located are short-circuited. Judging whether the load resistance value at both ends of the constant current source 11 is in the preset range can also be converted to judging whether the temperature sensed by the resistive temperature sensor 3 is in the preset range, and then judging whether the resistive temperature sensor 13 and the heating film are in normal operation state.

Embodiment two

In many experiments in biology, it is usually necessary to simulate the body temperature of organisms or maintain a specific temperature during the preparation of biological samples to facilitate the conduct of biological experiments. And it is required that the heating of a single experimental container will not affect other operations of the biological experiment.

For example, when preparing a single-cell suspension, operations such as cutting and grinding tissues are performed in experimental containers, and at the same time, the biological samples in each experimental container are maintained at different specific temperatures by heating equipment. During this process, the maintained temperature should not fluctuate too much, otherwise, the biological sample may be denatured, which will affect the results of the biological experiment. Therefore, in addition to heating, the heating equipment also needs to sense the temperature of the experimental container in real time and feed it back to the controller in the equipment to adjust the heating power and achieve stable heating. After the preparation of the single cell suspension is completed, the heating equipment and the experimental container need to be removed, and the single cell suspension in the experimental container needs to be poured out. To start the next single-cell suspension preparation, the heating device and experimental vessels are reloaded on the device. Therefore, the heating device needs to adapt to such usage scenarios of repeated plugging and unplugging.

Fig. 4 is a schematic diagram of the biological sample preparation device provided in Example 2 of the present application. As shown in FIG. 4 , the biological sample preparation device includes a casing, a plurality of motors, a plurality of experimental containers, a plurality of heating devices, and a plurality of protection circuits described in Embodiment 1 (not shown in the figure). In the embodiment of the present application, the structure of the protection circuit is the same as that of the first embodiment, including all the features described in the first embodiment, and will not be repeated here.

In the embodiment of the present application, multiple motors are arranged in the casing, and their drive shafts are respectively connected to multiple experimental containers for preparing single-cell suspension, and drive the experimental containers to rotate. A plurality of protection circuits are arranged in the casing, and each protection circuit corresponds to an experimental container and a heating device. In the protection circuit, the two ends of the constant current source of the first loop 1 are exposed to the shell for the connection of the resistive temperature sensor in the heating equipment; the two ends of the second load resistor R2 of the second loop 2 are exposed to the shell as two nodes , for the heating film in the heating device to connect to it. In order to make the structure of the heating equipment small and compact, the two ends of the constant current source of the first loop 1 form a first terminal exposed to the shell, and the two ends of the second load resistor R2 of the second loop 2 serve as two nodes to form a second terminal exposed to the shell . Both the first terminal and the second terminal are two-section pin terminals. The heating device only needs to reserve two interfaces to be connected to the first terminal and the second terminal. When each heating device clamps the experimental container for heating, the resistance temperature sensor contacts with the first terminal to form a closed first loop 1 , and the heating film contacts with the second terminal to form a closed second loop 2 .

In the embodiment of the present application, the biological sample preparation device further includes a microcontroller. The microcontroller controls multiple heating films respectively according to the temperatures measured by multiple resistive temperature sensors, so as to stably maintain the biological samples in multiple experimental containers at the same or different specific temperatures. The control module 3 in the protection circuit multiplexes the microcontroller of the biological sample preparation device to realize short-circuit protection.

Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limitations on the present application, and those skilled in the art can make the above-mentioned The embodiments are subject to changes, modifications, substitutions and variations.

Claims

A protection circuit, characterized in that it comprises:

control module;

A first loop, the first loop includes a constant current source and a resistance value detection module; and

A second loop, the second loop includes a power supply and an overcurrent detection module;

Wherein, the resistance value detection module detects the load resistance value at both ends of the constant current source and sends it to the control module; if the load resistance value is not within a preset range, the control module controls the power supply to not supply power; If the load resistance value is within a preset range and the overcurrent detection module detects overcurrent, the power supply does not supply power.
The protection circuit according to claim 1, wherein the first loop further comprises a resistive temperature sensor, and the resistive temperature sensor is connected in parallel to both ends of the constant current source.
The protection circuit according to claim 1, wherein the overcurrent detection module includes a comparator and a sampling resistor.
The protection circuit according to any one of claims 1-3, wherein the second loop further includes a switch module composed of field effect transistors; the switch module is connected to the power supply, and the control module The power supply is controlled by closing or opening the switch module.
The protection circuit according to claim 4, wherein the control module outputs a pulse width modulation signal to the switch module according to the load resistance value, the switch module is closed, and the power supply supplies power; the control When the module does not output a pulse width modulation signal to the switch module according to the load resistance value, the switch module is turned off, and the power supply does not supply power.
The protection circuit according to claim 5, wherein the overcurrent detection module is connected to the switch module; when the overcurrent detection module outputs a preset level, the switch module is disconnected.
The protection circuit according to claim 5, wherein the overcurrent detection module is connected to the control module; when the overcurrent detection module outputs a preset level, the control module does not output to the switch module A pulse width modulated signal to turn off the switch module.
A biological sample preparation device, characterized in that it includes a housing, multiple motors, multiple experimental containers, multiple heating devices, and multiple protection circuits according to any one of claims 1-7;

The multiple motors are arranged in the housing, and the drive shafts of the multiple motors are respectively connected to the multiple experimental containers to drive the multiple experimental containers to rotate;

Both ends of the constant current source of each of the first loops form a first terminal, which is exposed to the housing;

Two nodes of each of the second loops form a second terminal and are exposed to the housing;

When each heating device clamps the experimental container for heating, it contacts with the first terminal to form a closed first loop, and contacts with the second terminal to form a closed second loop.
The biological sample preparation device according to claim 8, wherein the first terminal and the second terminal are two-section pin terminals.
The biological sample preparation device according to claim 8, wherein the control module is a microcontroller of the biological sample preparation device.