Switch circuit and underwater equipment

Abstract

The present invention discloses a switch circuit and underwater equipment. The switch circuit includes: a voltage divider, a MOS tube, a controller and a physical switch, wherein: a power supply is connected to the source of the MOS tube and the input end of the voltage divider, a first output end of the voltage divider is connected to the input end of the controller and one end of the physical switch, an output end of the controller is connected to the gate of the MOS tube and the control end of the voltage divider, and a second output end of the voltage divider is connected to the other end of the physical switch and then grounded; when the physical switch is closed, the first output end of the voltage divider outputs a low-level signal to the controller, and the controller outputs a low-level signal to the gate of the MOS tube, thereby turning on the MOS tube; when the physical switch is disconnected, the first output end of the voltage divider outputs a high-level signal to the controller, and the controller stops outputting a signal to the gate of the MOS tube, thereby turning off the MOS tube. The embodiment of the present invention realizes that the MOS tube can be stably turned on, and reduces the power loss when the MOS tube is turned on.

Description

Technical Field

[0001] The embodiments of the present invention relate to circuit design technology, and in particular to a switch circuit and underwater equipment. Background Art

[0002] When the current MOS tube (Metal Oxide Semiconductor) switch circuit is used in an aqueous environment, since the electrodes of the physical switch are processed in a non-fully sealed manner, it may cause the resistance between the electrodes of the physical switch to decrease due to the conductivity of water after the electrodes come into contact with water. Accordingly, the voltage between the gate and the source may reach the turn-on voltage, thereby erroneously triggering the MOS tube to turn on.

[0003] In the prior art, in order to solve the problem of false triggering of the MOS tube when the MOS tube switch circuit is applied in a water environment, the following method is usually used: ensure that the absolute value of the voltage between the gate and the source is as small as possible, so that even if the MOS tube switch circuit encounters water, the MOS tube will not be falsely triggered to turn on because the voltage between the gate and the source has not reached the turn-on voltage. However, if the absolute value of the voltage between the gate and the drain is made smaller, the conduction impedance of the MOS tube will be larger when it is turned on, thereby increasing the heat and power consumption of the switch circuit. Summary of the invention

[0004] The present invention provides a switch circuit and underwater equipment to achieve stable conduction of a MOS tube and reduce heat and power consumption of the switch circuit.

[0005] In the first aspect, an embodiment of the present invention provides a switch circuit for use in an underwater environment, the switch circuit comprising: a voltage divider, a MOS tube, a controller and a physical switch, wherein: a power supply is connected to the source of the MOS tube and the input end of the voltage divider, a first output end of the voltage divider is connected to the input end of the controller and one end of the physical switch, an output end of the controller is connected to the gate of the MOS tube and the control end of the voltage divider, and a second output end of the voltage divider is connected to the other end of the physical switch and then grounded;

[0006] When the physical switch is closed, the first output end of the voltage divider outputs low-level information to the controller, and the controller outputs a low-level signal to the gate of the MOS tube, thereby turning on the MOS tube; when the physical switch is disconnected, the first output end of the voltage divider outputs a high-level signal to the controller, and the controller stops outputting signals to the gate of the MOS tube, thereby disconnecting the MOS tube.

[0007] Furthermore, the voltage divider includes a first resistor, a second resistor and a third resistor connected in series; one end of the first resistor serves as an input end of the voltage divider, the other end of the first resistor is connected to one end of the second resistor as a control end of the voltage divider, the other end of the second resistor is connected to one end of the third resistor as a first output end of the voltage divider, and the other end of the third resistor serves as a second output end of the fast search voltage divider.

[0008] Furthermore, the switch circuit also includes a decoupling capacitor; one end of the decoupling capacitor is connected to the power supply, and the other end of the decoupling capacitor is connected to the output end of the controller.

[0009] Furthermore, the capacitance value of the decoupling capacitor is 100nF to 10uF.

[0010] Furthermore, the physical switch is a single-pole single-throw switch.

[0011] Furthermore, the physical switch is a single-pole double-throw switch.

[0012] Furthermore, the MOS tube is a P-channel enhancement mode MOS tube.

[0013] Furthermore, the controller is a microprocessor.

[0014] Furthermore, the voltage value of the power supply is 5 to 24V.

[0015] In a second aspect, an embodiment of the present invention further provides an underwater device, which includes a switch circuit as described in any embodiment of the present invention.

[0016] The present invention solves the problems of false triggering and turning on of the MOS tube and large power loss when the MOS tube is turned on in the switch circuit applied to the underwater environment in the prior art, and realizes stable conduction of the MOS tube and reduces the power loss when the MOS tube is turned on. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a structural schematic diagram of a switch circuit in Embodiment 1 of the present invention;

[0018] Figure 2 It is a structural schematic diagram of a switch circuit in Embodiment 1 of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0020] Embodiment 1

[0021] Figure 1 This is a schematic diagram of a switch circuit provided in Embodiment 1 of the present invention. This embodiment is applicable to situations where the switch circuit is mis-conducted in an underwater environment and the power loss of the MOS tube is large, such as Figure 1 As shown, the switch circuit may specifically include: a voltage divider 1, a MOS tube 2, a controller 3 and a physical switch 4, and its structure and function are described below.

[0022] The power supply is connected to the source of the MOS tube 2 and the input end of the voltage divider 1, the first output end of the voltage divider 1 is connected to the input end of the controller 3 and one end of the physical switch 4, the output end of the controller 3 is connected to the gate of the MOS tube 2 and the control end of the voltage divider 1, and the second output end of the voltage divider 1 is connected to the other end of the physical switch 4 and then grounded;

[0023] When the physical switch 4 is closed, the first output end of the voltage divider 1 outputs a low-level signal to the controller 3, and the controller 3 outputs a low-level signal to the gate of the MOS tube 2, thereby turning on the MOS tube 2; when the physical switch 4 is disconnected, the first output end of the voltage divider 1 outputs a high-level signal to the controller 3, and the controller 3 stops outputting the signal to the gate of the MOS tube 2, thereby turning off the MOS tube 2.

[0024] In a specific embodiment of the present invention, the MOS transistor 3 is an insulated gate type in a field effect transistor. Specifically, it can be divided into an N-channel MOS transistor and a P-channel MOS transistor, and specifically, it can be divided into an N-channel enhancement MOS transistor, an N-channel depletion MOS transistor, a P-channel enhancement MOS transistor, and a P-channel depletion MOS transistor. The MOS transistor 2 can be used in a power supply circuit and a drive circuit to play a switch role, that is, when the MOS transistor 2 is turned on, the switch circuit is turned on, and when the MOS transistor 2 is turned off, the switch circuit is turned off. Taking the P-channel enhancement MOS transistor as an example, its conduction condition is: the gate voltage U G and source voltage U S The voltage between V GS =U G -U S Less than the turn-on voltage V T , that is, the conduction condition of the P-channel enhancement MOS tube is: V GS <V T . Turn-on voltage V T, also known as the threshold voltage, can represent the gate voltage U required to start forming a conductive channel between the source and the drain. G , and this turn-on voltage V T It is a negative value, indicating that when the P-channel enhancement MOS tube is turned on, the voltage value V between the gate and the source GS In addition, the P-channel enhancement MOS tube has the following characteristics: when the P-channel enhancement MOS tube is turned on, the greater the absolute value of the voltage between the gate and the source, that is, |V GS |The larger the on-resistance R DS (on) is smaller, on the contrary, the on-resistance R DS The larger the on-resistance R DS The larger the (on), the greater the power loss when the MOS tube 2 is turned on.

[0025] The voltage divider 1 can be understood as being composed of a plurality of resistors, which play a voltage dividing role in the circuit. When the physical switch 4 is used in series with other components, it can be used to control the on and off of the circuit. When the physical switch 4 is used in parallel with other components, the components connected in parallel can be short-circuited. The physical switch 4 can be a single-pole single-throw switch or a single-pole double-throw switch, etc., which can be determined according to actual conditions and is not specifically limited here.

[0026] When the switch circuit composed of the above components is applied to an underwater environment, the following problem may occur: the problem of the switch circuit being turned on due to the conductivity of water. Specifically, due to the conductivity of water, the resistance between the electrodes of the physical switch 4 becomes smaller. Since the input end of the voltage divider 1 is connected to the input voltage, the first output end of the voltage divider 1 is connected to one end of the physical switch 4, and the second output end of the voltage divider 1 is connected to the other end of the physical switch 4 and then grounded, now since the resistance between the electrodes of the physical switch 4 becomes smaller, the total resistance in the circuit becomes smaller, the current in the circuit increases, and the voltage at the control end of the voltage divider 1 increases. Since the gate of the MOS tube 2 is connected to the control end of the voltage divider 1, the gate voltage U of the MOS tube 2 is G It also increases accordingly, and because the source of MOS tube 2 is also connected to the input voltage, and the input voltage is a positive voltage, that is, U S is a positive voltage and remains constant. In this case, the voltage between the gate and the source is V GS The voltage V between the gate and the source decreases accordingly for the P-channel enhancement MOS tube. GS The conduction condition of MOS tube 2 may be met, that is, V GS <V T, which will turn on the MOS tube 2, and thus turn on the switch circuit. It is generally believed that the switch circuit conduction in the above case is a false trigger conduction, and it is necessary to try to prevent the above situation from happening. In addition, there is also the problem of how to reduce the power loss of the MOS tube 2 when the MOS tube 2 is turned on. It should be noted that the conduction of the switch circuit under normal circumstances specifically refers to: when the physical switch 4 is closed, the MOS tube 2 is triggered to turn on, thereby turning on the switch circuit. In addition, it should be noted that due to the conductivity of water, the resistance between the electrodes of the physical switch 4 will become smaller, but the physical switch 4 will not be closed, that is, there is still resistance between the electrodes of the physical switch 4, and the voltage between the electrodes is not zero, but relative to the situation where the switch circuit is not used underwater, the resistance between the electrodes of the physical switch 4 becomes smaller, and at this time, the physical switch 4 is still in the disconnected state. In order to achieve that the switch circuit is triggered to turn on only under normal circumstances, and in other situations, such as the false trigger conduction situation, the switch circuit will not be turned on, and when the MOS tube 2 is turned on, the power loss of the MOS tube 2 is reduced, the following technical solutions can be specifically adopted:

[0027] The power supply is connected to the source of the MOS tube 2 and the input end of the voltage divider 1, the first output end of the voltage divider 1 is connected to the input end of the controller 3 and one end of the physical switch 4, the output end of the controller 3 is connected to the gate of the MOS tube 2 and the control end of the voltage divider 1, and the second output end of the voltage divider 1 is connected to the other end of the physical switch 4 and then grounded. In this way, when the switch circuit is applied to an underwater environment, it can be divided into the following two cases:

[0028] (1) The physical switch 4 is in an off state, so that the first output end of the voltage divider 1 outputs a high-level signal. Since the input end of the controller 3 is connected to the first output end of the voltage divider 1, the input end of the controller 3 can receive the high-level signal. When the input end of the controller 3 receives the high-level signal, the output end of the controller 3 stops outputting a signal to the gate of the MOS tube 2 connected to the input end. That is, at this time, the gate voltage of the MOS tube 2 is not controlled by the controller 3. Since the voltage divider 1 can be composed of a plurality of resistors connected in series, and the input end of the voltage divider 1 is connected to an input voltage, which is a positive voltage, the voltage of the control end of the voltage divider 1 is also a positive value. Since the gate of the MOS tube 2 is connected to the control end of the voltage divider 1, the gate voltage U G That is, it is the positive value, and since the source of MOS tube 2 is also connected to the input voltage, that is, U S is a positive voltage and remains constant. In this case, the voltage V between the gate and the source is GS Still not less than the turn-on voltage V T , that is, the conditions required for the MOS tube 2 to be turned on are not met, the MOS tube 2 will not be turned on, and then the switch circuit cannot be turned on.

[0029] (2) The physical switch 4 is in a closed state, so that one end of the physical switch 4 is grounded, that is, the first output end of the voltage divider 1 is grounded, and the end outputs a low-level signal and outputs a low-level signal to the controller 3, that is, the input end of the controller 3 can detect the low-level signal. When the input end of the controller 3 detects the low-level signal, the output end of the controller 3 will output a low-level signal. Since the output end of the controller 3 is connected to the gate of the MOS tube 2, the gate of the MOS tube 2 can receive the low-level signal, that is, the gate voltage U G Pulled down to a low level, since the source of MOS tube 2 is connected to the input voltage, and the input voltage is a positive voltage, that is, U S is a positive voltage and remains constant, which makes the voltage V between the gate and the source GS =U G -U S =-U S , that is, V GS =-U S , in other words, the voltage V between the gate and source GS reaches the minimum value, that is, |V GS | reaches the maximum value. According to the above, |V GS |The larger the on-resistance R DS The smaller the on-resistance R DS The larger the (on), the greater the power loss when the MOS tube 2 is turned on. GS | is the maximum value, correspondingly, the on-resistance R DS (on) is the minimum value, thereby reducing the power loss when the MOS tube 2 is turned on. In addition, due to the on-resistance R DS The reduction of the (on) value also increases the overcurrent capability of the switching circuit accordingly.

[0030] By adopting the above technical solution, when the switch circuit is applied to an underwater environment, only when the physical switch 4 is closed, the MOS tube 2 is turned on, thereby turning on the switch circuit, and when the MOS tube 2 is turned on, the conduction impedance R DS (on) is the minimum value, which reduces the power loss when the MOS tube 2 is turned on to the greatest extent and enhances the overcurrent capacity of the switch circuit. In other cases, such as the false triggering and turning on case mentioned above, the MOS tube 2 will not be turned on, and thus the switch circuit will not be turned on.

[0031] According to the technical solution of this embodiment, when the physical switch is closed, the first output end of the voltage divider outputs a low-level signal to the controller. When the controller detects the low-level signal, the controller outputs a low-level signal to the gate of the MOS tube, thereby turning on the MOS tube; when the physical switch is disconnected, the first output end of the voltage divider outputs a high-level signal to the controller. When the controller detects the high-level signal, the controller stops outputting the signal to the gate of the MOS tube, thereby turning off the MOS tube, thereby solving the problems of false triggering and turning on the MOS tube and large power loss when the MOS tube is turned on in the switch circuit used in the underwater environment in the prior art, achieving stable conduction of the MOS tube and reducing the power loss when the MOS tube is turned on.

[0032] Optionally, based on the above technical solution, Figure 2 As shown, the voltage divider 1 may specifically include a first resistor 11, a second resistor 12 and a third resistor 13 connected in series;

[0033] One end of the first resistor 11 serves as the input end of the voltage divider 1, the other end of the first resistor 11 is connected to one end of the second resistor 12 as the control end of the voltage divider 1, the other end of the second resistor 12 is connected to one end of the third resistor 13 as the first output end of the voltage divider 1, and the other end of the third resistor 13 serves as the second output end of the voltage divider 1.

[0034] In a specific embodiment of the present invention, the voltage divider 1 is specifically composed of a first resistor 11, a second resistor 12 and a third resistor 13 connected in series, in order to solve the problem that when the switch circuit is applied to an underwater environment, due to the conductivity of water, the gate voltage U of the MOS tube 2 G Increases, and accordingly, the voltage V between the gate and source of MOS tube 2 GS For P-channel enhancement MOS tubes, the voltage V between the gate and the source is reduced. GS The conduction condition of MOS tube 2 may be met, that is, V GS <V T , which will turn on the MOS tube 2 and the switch circuit. It is generally believed that the switch circuit is turned on due to false triggering. The resistance values ​​of the first resistor 11, the second resistor 12 and the third resistor 13 can be adjusted so that even if the gate voltage U G Increases, and accordingly, the voltage V between the gate and source of MOS tube 2 GS decrease, it will not make V GS Satisfy the conduction condition of MOS tube 2, that is, V GS <V T In other words, in the above case, the voltage V between the gate and source of MOS tube 2 is GS Still greater than or equal to the turn-on voltage V T, thereby ensuring that the MOS tube 2 will never be turned on when the physical switch 4 is turned off.

[0035] It should be noted that the specific resistance values ​​of the first resistor 11, the second resistor 12 and the third resistor 13 need to be determined according to the turn-on voltage V T The turn-on voltage V of different types of MOS tubes 2 is set. T Different, no specific limitation is made here.

[0036] Optionally, based on the above technical solution, Figure 2 As shown, the switch circuit may further include a decoupling capacitor 5;

[0037] One end of the decoupling capacitor 5 is connected to the power supply, and the other end of the decoupling capacitor 5 is connected to the output end of the controller 3 .

[0038] In a specific embodiment of the present invention, the switch circuit may further include a decoupling capacitor 5, which can prevent the voltage V between the gate and the source from GS A mutation occurs, thereby ensuring that the MOS tube 2 can be stably turned on.

[0039] Optionally, based on the above technical solution, the specific optional range of the capacitance value of the decoupling capacitor 5 can be 100nF to 10uF.

[0040] Optionally, based on the above technical solution, Figure 2 As shown, the physical switch 4 may specifically be a single-pole single-throw switch 41 .

[0041] Optionally, based on the above technical solution, the physical switch 4 may specifically be a single-pole double-throw switch.

[0042] Optionally, based on the above technical solution, the MOS transistor 2 may be a P-channel enhancement type MOS transistor.

[0043] Optionally, based on the above technical solution, the controller 3 may specifically be a microprocessor.

[0044] Optionally, based on the above technical solution, the voltage value of the power supply can specifically be 5 to 24V.

[0045] In a specific embodiment of the present invention, the models of the physical switch 4, the controller 3 and the P-channel enhancement mode MOS tube can be selected according to actual conditions, and are not specifically limited here. In addition, the voltage value of the power supply can also be set according to actual conditions, and is not specifically limited here.

[0046] In addition, it should be noted that Figure 2As shown, the MOS tube 2 may specifically include a parasitic diode 21. For a P-channel enhancement type MOS tube, the cathode of the parasitic diode 21 is connected to the source of the MOS tube 2, and the anode of the parasitic diode 21 is connected to the drain of the MOS tube 2. The parasitic diode 21 may be used to prevent the source of the MOS tube 2 and the drain of the MOS tube 2 from being reversely connected. The MOS tube 2 may specifically further include a PN junction 22. The drain of the MOS tube 2 is an output terminal. The above-mentioned parasitic diode 21 and the PN junction 22 are both formed in the process flow of manufacturing the MOS tube 2. Figure 2 In which R1, R2 and R3 represent the first resistor 11, the second resistor 12 and the third resistor 13 respectively, C1 represents the decoupling capacitor 5, SW1 represents the single-pole single-throw switch 41, and MCU represents the microprocessor.

[0047] In addition, it should be noted that the physical switch 4 can be closed by program instructions or manually. Of course, it can be understood that the specific closing method of the physical switch 4 can be selected according to actual conditions and is not specifically limited here.

[0048] In addition, it should be noted that Figure 2 The middle MOS tube 2 is a P-channel enhancement type MOS tube.

[0049] Embodiment 2

[0050] Embodiment 2 of the present invention provides an underwater device, which includes the switch circuit described in the embodiment of the present invention. This embodiment is applicable to the situation where the switch circuit is mis-conducted in an underwater environment and the power loss of the MOS tube is large.

[0051] In a specific embodiment of the present invention, the underwater device may be an underwater robot or an underwater camera or other device equipped with a switch circuit.

[0052] The technical solution of this embodiment solves the problems of false triggering of the MOS tube and large power loss when the MOS tube is turned on, which exist in the switching circuit used in the underwater environment in the prior art, by adopting the switching circuit including the one described above. On the basis of achieving stable conduction of the MOS tube and reducing the power loss when the MOS tube is turned on, the safety of the underwater equipment is further improved and the power loss of the underwater equipment is reduced.

[0053] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A switch circuit for use in an underwater environment, characterized in that: include: A voltage divider, a MOS tube, a controller and a physical switch, wherein: a power supply is connected to the source of the MOS tube and the input end of the voltage divider, a first output end of the voltage divider is connected to the input end of the controller and one end of the physical switch, an output end of the controller is connected to the gate of the MOS tube and the control end of the voltage divider, and a second output end of the voltage divider is connected to the other end of the physical switch and then grounded; When the physical switch is closed, the first output end of the voltage divider outputs a low-level signal to the controller, and the controller outputs a low-level signal to the gate of the MOS tube, thereby turning on the MOS tube; when the physical switch is disconnected, the first output end of the voltage divider outputs a high-level signal to the controller, the gate voltage of the MOS tube is not controlled by the controller, and the controller stops outputting signals to the gate of the MOS tube, thereby disconnecting the MOS tube.

2. The switch circuit according to claim 1, characterized in that: The voltage divider includes a first resistor, a second resistor and a third resistor connected in series; one end of the first resistor serves as an input end of the voltage divider, the other end of the first resistor is connected to one end of the second resistor as a control end of the voltage divider, the other end of the second resistor is connected to one end of the third resistor as a first output end of the voltage divider, and the other end of the third resistor serves as a second output end of the voltage divider.

3. The switch circuit according to claim 1 or 2, characterized in that: It also includes a decoupling capacitor; one end of the decoupling capacitor is connected to the power supply, and the other end of the decoupling capacitor is connected to the output end of the controller.

4. The switch circuit according to claim 3, characterized in that: The capacitance value of the decoupling capacitor is 100nF to 10uF.

5. The switch circuit according to claim 1, characterized in that: The physical switch is a single-pole single-throw switch.

6. The switch circuit according to claim 1, characterized in that: The physical switch is a single-pole double-throw switch.

7. The switch circuit according to claim 1, characterized in that: The MOS tube is a P-channel enhancement type MOS tube.

8. The switch circuit according to claim 1, characterized in that: The controller is a microprocessor.

9. The switch circuit according to claim 1, characterized in that: The voltage value of the power supply is 5-24V.

10. An underwater device, characterized in that: Comprising a switching circuit as described in any one of claims 1 to 9.

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