CN211699667U - Display device - Google Patents
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- CN211699667U CN211699667U CN202020236215.4U CN202020236215U CN211699667U CN 211699667 U CN211699667 U CN 211699667U CN 202020236215 U CN202020236215 U CN 202020236215U CN 211699667 U CN211699667 U CN 211699667U
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Abstract
The utility model provides a display device, this display device includes: the power panel at least comprises a voltage control circuit and a switch control circuit, and the power supply is connected with the first end of the voltage control circuit and the first end of the switch control circuit on the power panel; the second end of the voltage control circuit is connected with the second end of the switch control circuit, the third end of the switch control circuit is connected with the load, and the voltage control circuit is used for detecting the voltage output by the power supply and controlling the voltage of the second end of the voltage control circuit according to the voltage output by the power supply; the switch control circuit is used for controlling the switch control circuit to be switched on or switched off according to the voltage of the second end of the voltage control circuit, the voltage output by the power supply and the preset threshold voltage. The display device can accurately control the working state of the switch control circuit according to the change of the voltage output by the power supply, and the problem that other elements of the display device work abnormally due to the fact that the change range of the voltage output by the power supply is large is solved.
Description
Technical Field
The utility model relates to a power technical field especially relates to a display device.
Background
With the continuous development of electronic technology, the variety of electronic devices including display devices is increasing, such as televisions, smart phones, notebook computers, and the like; when people use the electronic equipment, the power panel of the electronic equipment is connected to the mains supply, and the mains supply supplies power to the display device of the electronic equipment, so that the performance of the power panel is very important for the electronic equipment.
Here, a television is taken as an example to describe in detail: fig. 1 is a schematic structural diagram of a power panel of a conventional television, and as shown in fig. 1, the power panel includes: the power supply system comprises a voltage conversion module and at least one switch control circuit, wherein an input end of the voltage conversion module is connected with a mains supply, an output end of the voltage conversion module is connected with the at least one switch control circuit, of course, an output end of the voltage conversion module can also be directly connected to a load, each switch control circuit in the at least one switch control circuit is connected with a load, and the load can be, for example, a USB interface, a WIFI module, a remote control module, a camera module and the like of an electronic device. In the case shown in fig. 1, the voltage conversion module is used to convert the commercial power into a dc voltage required by the load, for example, in a television, the voltage conversion module can convert the commercial power into a 5V voltage; the switch control circuit is used for controlling the on-off of the circuit according to the voltage output by the voltage conversion module, so that a load connected with the switch control circuit is protected, and the problem that the load works abnormally due to the abnormality of other loads is avoided, and the conditions of halt, screen splash and the like of the display device can be caused in serious cases.
However, in the situation shown in fig. 1, when one of the loads works abnormally, such as a short circuit, the normal operation of the other loads is affected, and thus the television may be crashed or become blurred, in order to solve the problem, a current limiting chip or a resettable fuse is connected in series to the front end of the load, wherein the structure of the power board connected in series to the current limiting chip or the resettable fuse is shown in fig. 2. However, the current limiting chip and the recoverable fuse depend on the current variation in the circuit, and if the current limiting chip or the recoverable fuse device itself has too large protection current selection, the current limiting chip cannot play a role in protection, and if the protection current selection is small, the load may not work normally, so that the parameter selection of the current limiting chip or the recoverable fuse is difficult, and if the selection is not appropriate, the electronic device including the display device may still not work normally, resulting in poor stability of the electronic device.
Therefore, how to ensure the normal operation of the electronic device including the display device and improve the stability of the electronic device is an urgent problem to be solved.
SUMMERY OF THE UTILITY MODEL
The utility model provides a display device to guarantee to include display device's electronic equipment normal work, improve electronic equipment's stability.
In a first aspect, the present invention provides a display device, wherein the display device includes: a power panel and a load; the power panel at least includes: a voltage control circuit and a switch control circuit;
the power supply is connected with the first end of the voltage control circuit and the first end of the switch control circuit on the power panel, and the power supply is used for supplying power to the load through the voltage control circuit and the switch control circuit on the power panel;
the second end of the voltage control circuit is connected with the second end of the switch control circuit, and the third end of the switch control circuit is connected with the load;
the voltage control circuit is used for detecting the voltage output by the power supply and controlling the voltage of the second end of the voltage control circuit according to the voltage output by the power supply; the switch control circuit is used for controlling the switch control circuit to be switched on or switched off according to the voltage of the second end of the voltage control circuit, the voltage output by the power supply and a preset threshold voltage; when the switch control circuit is switched on, the power supply supplies power to the load.
In some possible designs, the voltage control circuit includes: a first diode VD 1;
the power supply is respectively connected with the cathode of the first diode VD1 and the first end of the switch control circuit, and the anode of the first diode VD1 is connected with the second end of the switch control circuit.
In some possible designs, the first diode VD1 is a zener diode.
In some possible designs, the switch control circuit includes: the charging circuit comprises a first resistor R1, a grounding switch K1, a charging submodule, a capacitor C1 and a state switching submodule;
wherein a first terminal of the voltage control circuit is connected to a first terminal of the first resistor R1, a first terminal of the capacitor C1, and a first terminal of the state switching submodule; the second end of the voltage control circuit is connected with the first end of the grounding switch K1;
a second end of the first resistor R1 is connected to a second end of the ground switch K1 and a first end of the charging submodule, and a second end of the charging submodule is connected to a second end of the capacitor C1;
the second end of the state switching submodule is connected with the second end of a capacitor C1, and the third end of the state switching submodule is connected with the load;
the first resistor R1 is used for controlling the voltage of the second end of the first resistor R1; the grounding switch K1 is used for controlling the grounding switch K1 to be switched on or off according to the voltage of the second end of the voltage control circuit and a first threshold voltage; the capacitor C1 is used for charging through the charging submodule and discharging through the charging submodule and the grounding switch K1; the state switching submodule is used for controlling the connection or disconnection between the power supply and the load according to the voltage at the two ends of the capacitor C1;
the preset threshold voltage comprises the first threshold voltage.
In some possible designs, the grounding switch K1 includes: a second resistor R2 and a transistor Q1;
the second end of the voltage control circuit is connected with the base electrode of the triode Q1 through the second resistor R2, the emitter electrode of the triode Q1 is grounded, and the collector electrode of the triode Q1 is respectively connected with the second end of the first resistor R1 and the first end of the charging submodule;
the second resistor R2 is used for adjusting the current input to the base of the triode Q1;
the transistor Q1 is used for controlling the conduction or the disconnection between the collector and the emitter of the transistor Q1 according to the input current.
In some possible designs, the transistor Q1 is an NPN transistor or a PNP transistor.
In some possible designs, the charging submodule includes a third resistor R3, and the third resistor R3 is used for adjusting the current charged and discharged by the capacitor C1.
In some possible designs, the state switching submodule includes: a metal oxide semiconductor field effect transistor (MOS) tube;
the grid electrode of the MOS tube is connected with the second end of the charging submodule and the second end of the capacitor C1, the source electrode of the MOS tube is connected with the first end of the capacitor C1, and the drain electrode of the MOS tube is connected to the load;
the MOS tube is used for controlling the MOS tube to be switched on or switched off according to the voltage at two ends of the capacitor C1 and a second threshold voltage; when the MOS tube is conducted, the power supply supplies power to the load; the preset threshold voltage comprises a second threshold voltage, and the second threshold voltage is the conduction voltage of the MOS tube.
In some possible designs, the switch control circuit further includes: a fourth resistor R4;
the second end of the grounding switch K1 is connected with the second end of the first resistor R1 and the first end of the charging submodule through the fourth resistor R4;
the fourth resistor R4 is used for adjusting the starting voltage of the capacitor C1 for charging and the ending voltage of the discharging.
In some possible designs, the MOS transistor is an N-type MOS transistor or a P-type MOS transistor.
The utility model provides a display device, wherein, display device includes: the power panel at least comprises a voltage control circuit and a switch control circuit, and the power supply is connected with the first end of the voltage control circuit and the first end of the switch control circuit on the power panel; the second end of the voltage control circuit is connected with the second end of the switch control circuit, the third end of the switch control circuit is connected with the load, and the voltage detection circuit is used for detecting the voltage output by the power supply and controlling the voltage of the second end of the voltage control circuit according to the voltage output by the power supply; the switch control circuit is used for controlling the switch control circuit to be switched on or switched off according to the voltage of the second end of the voltage control circuit, the voltage output by the power supply and the preset threshold voltage. The display device provided by the embodiment can accurately control the working state of the switch control circuit according to the change of the voltage output by the power supply, so that the problem that other elements of the display device work abnormally due to the fact that the change amplitude of the voltage output by the power supply is large is solved, and the stability of the display device is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without inventive labor.
Fig. 1 is a first schematic structural diagram of a power panel of a conventional television;
fig. 2 is a second schematic structural diagram of a power panel of a conventional television set;
fig. 3 is a third schematic structural diagram of a power panel of a conventional television set;
fig. 4 is a fourth schematic structural diagram of a power panel of a conventional television set;
FIG. 5 is a schematic diagram of the voltage variation at the load end when the display device is connected to an external device using the power panel shown in FIG. 3 or FIG. 4;
FIG. 6 is a schematic diagram showing voltage changes at the power output terminal and the load terminal when the display device is connected to an external device using the power panel shown in FIG. 3 or FIG. 4;
fig. 7 is a schematic structural diagram of a display device provided with a power panel according to an embodiment of the present invention;
fig. 8 is a schematic structural diagram of a circuit on a power board according to another embodiment of the present invention;
fig. 9 is a schematic structural diagram of a circuit on a power board according to another embodiment of the present invention;
fig. 10 is a schematic structural diagram of a circuit on a power board according to another embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
In the situation shown in fig. 1, when one of the loads works abnormally, for example, a short circuit occurs, the voltage at the output terminal of the voltage conversion module changes, which may affect the normal operation of other loads, and may cause the television to crash or screen splash in a serious case, in order to solve this problem, a current limiting chip or a recoverable fuse is connected in series at the front end of the load, wherein the structure of the power board connected with the current limiting chip or the recoverable fuse in series at the front end of the load is shown in fig. 2.
In the following, two cases of serially connecting a current-limiting chip and a resettable fuse to the front end of a load are described in detail, where the load is a USB interface of a display device, and the operating voltage of the USB interface is 5V:
first, working principle when serial connection current limiting chip is connected to front end of USB interface
As shown IN fig. 3, when the display device normally operates, the 5V-IN node is IN a power-on state, the EN pin of the current-limiting chip is at a high level, and the OUT pin of the current-limiting chip outputs a 5V voltage signal. If the current in the circuit is increased at the moment that the USB interface on the 5V-OUT node is connected with external equipment, when the current is increased to the protective current of the current limiting chip, the current limiting chip is automatically turned off, and at the moment, the voltage of the 5V-OUT node is 0V; when the external device is inserted into the USB interface, the current in the circuit is gradually reduced, when the current is smaller than the protection current of the current-limiting chip, the current-limiting chip is conducted again, at the moment, the voltage of the 5V-OUT node is 5V, namely, the power supply supplies power for the USB interface at the moment.
Second, working principle when connecting recoverable fuse in series at front end of USB interface
The circuit structure of the power board when the USB interface front end is connected in series with the resettable fuse is shown in fig. 4. Wherein the resettable fuse is composed of a specially treated polymeric resin and conductive particles distributed in the polymeric resin. Under normal conditions, the polymer resin tightly binds the conductive particles outside the crystalline structure to form a chain-shaped conductive path, the restorable fuse is in a low-resistance state under normal conditions, and the crystal structure cannot be changed when the heat generated by current flowing through the restorable fuse is small; when a fault occurs in the circuit, such as a short circuit, the current flowing through the recoverable fuse is increased, the polymer resin can be melted by the heat generated by the current, the volume of the recoverable fuse is rapidly increased, and under the abnormal condition, the recoverable fuse is in a high-resistance state, and the current in the circuit can be rapidly reduced due to the high-resistance state of the recoverable fuse, so that the circuit is protected. When the fault is relieved, the crystal of the polymer resin is cooled and crystallized again, the volume is shrunk, the conductive particles form a conductive path again, and the fuse can be restored to be in a low-resistance state again.
When the external equipment is inserted into the USB interface, the current IN the circuit is increased, if the current is larger than the protection current of the restorable fuse, the restorable fuse is melted by the heat generated by the current, and the circuit is switched off, namely the 5V-IN node and the 5V-OUT node are IN a switched-off state; when the external equipment is inserted into the USB interface, the current IN the circuit is gradually reduced, when the current IN the circuit is smaller than the protection current of the restorable fuse, the restorable fuse cools and crystallizes again, the circuit is conducted, namely the 5V-IN node and the 5V-OUT node are IN a conducting state, and the power supply supplies power to the USB interface.
As can be seen from the above description, the current limiting chip and the resettable fuse depend on the current variation in the circuit, and if the protection current selection of the current limiting chip or the resettable fuse device is too large, the current limiting chip or the resettable fuse device cannot perform the protection function, and if the protection current selection is small, the load may not work normally, so that the parameter selection of the current limiting chip or the resettable fuse is difficult, and if the selection is not appropriate, the electronic device including the display device may still not work normally.
In addition, as shown in fig. 5, no matter the current-limiting chip or the recoverable fuse is connected in series at the front end of the USB interface, when an external device is plugged into the USB interface, the current change amplitude in the circuit is large, which causes a voltage return channel phenomenon at the 5V-OUT node (i.e., the load end). Referring to fig. 6, a curve 1 is a voltage variation curve of a 5V-IN node (power output end), a curve 2 is a voltage variation curve of a 5V-OUT node (load end), and if the 5V-IN node is connected with other loads, due to the voltage drop of the 5V-IN node, other loads may work abnormally, and IN severe cases, the display device may be halted, and screen splash may occur.
Based on there is the problem as above among the prior art, the utility model provides a display device to guarantee to include display device's electronic equipment normal work, improve electronic equipment's stability.
The display device provided by the present invention is described in detail by several specific embodiments below:
fig. 7 is a schematic structural diagram of a display device provided with a power board according to an embodiment of the present invention. As shown in fig. 7, the display device, such as a television, provided in this embodiment includes: power strip and load, the power strip includes at least: the power panel is used for supplying power to the load through the voltage control circuit and the switch control circuit. It should be noted that the power panel can also be used to supply power to other elements inside the display device, such as a WiFi module, a camera module, a remote control module, and so on.
The power panel can be further provided with an input port circuit, the input port circuit is connected with mains supply through a plug, and the input port circuit can convert alternating mains supply into direct current required by elements inside the display device. For example, the input port circuit may include a voltage conversion module capable of converting ac mains power into dc power required by elements inside the display device.
The display device further includes, for example: a display panel, a driving board, a main board, a rear case, a base, etc., not all of which are shown in fig. 7. Wherein, display panel is used for presenting the picture to the user, and the drive plate is used for the drive display panel makes display panel present the picture, the utility model discloses in do not do the restriction to the type of display panel. The utility model discloses well display device's backshell, mainboard, base etc. can be similar with backshell, mainboard, base that display device includes among the prior art, the utility model discloses do not limit to the concrete type of above-mentioned display device's backshell, mainboard, base etc..
Fig. 8 is a schematic structural diagram of a circuit on a power board according to an embodiment of the present invention, as shown in fig. 8, the power board at least includes: a voltage control circuit 801 and a switch control circuit 802.
The first end of the power supply and voltage control circuit 801 and the first end of the switch control circuit 802 are connected, and the power supply supplies power to the load through the voltage control circuit 801 and the switch control circuit 802 on the power supply board. Illustratively, the power supply referred to herein may be the input port circuit shown in FIG. 7 described above.
The second terminal of the voltage control circuit 801 is connected to the second terminal of the switch control circuit 802, and the third terminal of the switch control circuit 802 is connected to the load.
The voltage control circuit 801 is used for detecting the voltage output by the power supply and controlling the voltage of the second end of the voltage control circuit 801 according to the voltage output by the power supply; the switch control circuit 802 is configured to control the switch control circuit 802 to be turned on or off according to the voltage at the second end of the voltage control circuit 801, the voltage output by the power supply, and a preset threshold voltage, where when the switch control circuit 802 is turned on, the power supply supplies power to the load 803, and when the switch control circuit 802 is turned off, the power supply does not supply power to the load 803.
On the basis of the embodiment shown in fig. 8, the voltage control circuit 801 and the switch control circuit 802 on the power panel may become a switch control protection circuit of the display device, and the switch control protection circuit can control the switch control circuit to be turned on or off, that is, between the power supply and the load, according to the voltage output by the power supply in the circuit and/or the voltage at the load terminal. Here, the working principle of the switch control protection circuit is described in detail by taking a load as a USB interface and a power supply as an input port circuit as an example:
before the input port circuit is not connected with the mains supply, the voltage of the output end of the input port circuit is 0V, and the output end of the input port circuit is not conducted with the USB interface, namely the USB interface is in a power-off state.
The input port circuit is connected with a mains supply through a plug, wherein the mains supply is alternating current, and the input port circuit can convert the alternating current mains supply into direct current required by a load, for example, 220V alternating current mains supply into 5V direct current required by a USB interface. At this time, the voltage at the output end of the input port circuit is 5V, the voltage control circuit 801 detects that the voltage at the output end of the input port circuit is 5V, and controls the voltage at the second end of the voltage control circuit 801 according to the voltage at the output end of the input port circuit; the switch control circuit 802 controls the output terminal of the input port circuit to be in a conducting state with the USB interface according to the voltage at the second terminal of the voltage control circuit 801, the voltage at the output terminal of the input port circuit, and the preset threshold voltage.
When the USB interface is plugged into the external device, the voltage of the USB interface decreases, and at this time, the voltage at the output terminal of the input port circuit also decreases accordingly. When the voltage at the output end of the input port circuit decreases, and the switch control circuit 802 cannot meet the conducting condition, the switch control circuit is in an off state, and the output end of the input port circuit and the USB interface are in an off state, that is, the USB interface is in a power-off state at this time.
Under the condition, the output end of the input port circuit is disconnected with the USB interface, and the voltage of the output end of the input port circuit cannot be further reduced, so that the problem that other elements of the display device work abnormally due to the fact that the voltage change amplitude of the output end of the input port circuit is large is solved, and the stability of the display device is improved.
Then, the voltage at the output terminal of the input port circuit is restored to 5V again, and the voltage control circuit 801 re-detects the voltage at the output terminal of the input port circuit and controls the voltage at the second terminal of the voltage control circuit 801; the switch control circuit 802 controls the switch control circuit 802 to be turned on again according to the voltage at the second end of the voltage control circuit 801, the voltage at the output end of the input port circuit, and the preset threshold voltage, so that the power supply supplies power to the load.
In this embodiment, the display device includes: the power panel at least comprises a voltage control module and a switch control circuit, and the power supply is connected with the first end of the voltage control circuit and the first end of the switch control circuit on the power panel; the second end of the voltage control circuit is connected with the second end of the switch control circuit, the third end of the switch control circuit is connected with the load, and the voltage detection circuit is used for detecting the voltage output by the power supply and controlling the voltage of the second end of the voltage control circuit according to the voltage output by the power supply; the switch control circuit is used for controlling the switch control circuit to be switched on or switched off according to the voltage of the second end of the voltage control circuit, the voltage output by the power supply and the preset threshold voltage. The display device provided by the embodiment can accurately control the working state of the switch control circuit according to the change of the voltage output by the power supply and/or the change of the voltage of the load terminal, so that the problem that other elements of the display device work abnormally due to large change amplitude of the voltage output by the power supply is avoided, and the stability of the display device is improved.
Fig. 9 is a schematic structural diagram of a switch control protection circuit according to an embodiment of the present invention; as shown in fig. 9, based on the embodiment shown in fig. 8, the voltage control circuit 801 includes: a first diode VD1, wherein the power source is connected to the cathode of the first diode VD1 and the first end of the switch control circuit 802, respectively, and the anode of the first diode VD1 is connected to the second end of the switch control circuit 802.
Optionally, the first diode VD1 is a zener diode. For example, the first diode VD1 may be a BZT52C3V9 model diode. Of course, in practical application, the utility model discloses do not do specific restriction to the model of diode, it as long as can play the effect that detects the voltage of the negative pole of first diode VD1 and control the anodal voltage of first diode VD1 can.
The first diode VD1 is specifically used for controlling the voltage of the positive electrode of the first diode VD1 when the voltage at the output end of the input port circuit is greater than or equal to the cutoff voltage of the first diode VD 1.
Accordingly, the switch control circuit 802 is configured to control the switch control circuit 802 to turn on or off according to the voltage of the anode of the first diode VD1, the voltage at the output terminal of the input port circuit, and the preset threshold voltage.
In the scheme, the voltage control circuit 801 is composed of diodes, the operation of the diodes depends on the change of voltage in the circuit, and the sensitivity is high, so that the voltage output by the power supply can be accurately detected, and the voltage at the second end of the voltage control circuit can be accurately controlled; the voltage control circuit in the scheme has the advantages of simple structure, fewer required components and lower cost.
Alternatively, as shown with reference to fig. 9, the switch control circuit 802 includes: a first resistor R1, a grounding switch K1, a charging submodule 8021, a capacitor C1 and a state switching submodule 8022.
A cathode of the first diode VD1 is connected to a first terminal of the first resistor R1, a first terminal of the capacitor C1, and a first terminal of the state switching submodule 8022; the anode of the first diode VD1 is connected with the first end of the grounding switch K1; a second end of the first resistor R1 is connected to a second end of the ground switch K1 and a first end of the charging submodule 8021, and a second end of the charging submodule 8021 is connected to a second end of the capacitor C1; a second terminal of state switching submodule 8022 is connected to a second terminal of capacitor C1, and a third terminal of state switching submodule 8022 is connected to load 803.
The first resistor R1 is used to control the voltage at the second end of the first resistor R1.
The ground switch K1 is used for controlling the ground switch K1 to turn on or off according to the voltage at the second end of the voltage control circuit 801 and the first threshold voltage. Specifically, the grounding switch K1 is used for controlling the grounding switch K1 to be turned on or off according to the voltage of the anode of the first diode VD1 and the first threshold voltage.
In one possible implementation, the grounding switch K1 includes: a second resistor R2 and a transistor Q1; the anode of the first diode VD1 is connected to the base of the transistor Q1 through the second resistor R2, the emitter of the transistor Q1 is grounded, and the collector of the transistor Q1 is connected to the second end of the first resistor R1 and the first end of the charging submodule 8021.
The second resistor R2 is used to adjust the current inputted to the base of the transistor Q1. That is to say, in this embodiment, the second resistor R2 can play a role of current limiting to ensure the current flowing into the base of the transistor Q1, so as to prevent the collector of the transistor Q1 from being broken down due to too large current.
The transistor Q1 is used to control the conduction or the cut-off between the collector and the emitter of the transistor Q1 according to the current input to the base of the transistor Q1. The current input to the base of the transistor Q1 can be determined according to the voltage of the anode of the first diode VD1 and the second resistor R2.
Optionally, the first threshold voltage is a cut-off voltage of the transistor Q1. Specifically, if the voltage of the positive electrode of the first diode VD1 is greater than the cut-off voltage of the transistor Q1, the base current input to the transistor Q1 satisfies the conduction condition of the transistor Q1, and the emitter and the collector of the transistor Q1 are conducted; if the voltage of the positive electrode of the first diode VD1 is less than or equal to the cut-off voltage of the transistor Q1, the base current input to the transistor Q1 cannot satisfy the on condition of the transistor Q1, and the emitter and the collector of the transistor Q1 are disconnected.
Alternatively, the transistor Q1 may be an NPN transistor or a PNP transistor. The utility model discloses do not limit to the concrete type of triode.
And a capacitor C1 for charging through the charging submodule 8021 and discharging through the charging submodule 8021 and the grounding switch K1.
Specifically, the capacitor C1 is discharged through the charging submodule 8021 and the grounding switch K1, wherein when the capacitor C1 is discharged, the grounding switch K1 is in a conducting state; in the discharging process of the capacitor C1, the voltage difference between the two ends of the capacitor C1 increases continuously, and when the voltage difference between the two ends of the capacitor C1 satisfies the turn-on condition of the state switching submodule, the state switching submodule 8022 switches the state between the power supply and the load 803 to a conducting state, and at this time, the power supply supplies power to the load 803. It is understood that the capacitor C1 is discharged through the charging submodule 8021 and the grounding switch K1, so that the state switching submodule 8022 can switch the state between the power supply and the load 803 from off to on.
The capacitor C1 can be charged through the charging submodule 8021 and the first resistor R1, wherein the grounding switch K1 is in an off state when the capacitor C1 is charged; in the charging process of the capacitor C1, the voltage difference between the two ends of the capacitor C1 is continuously decreased, and when the voltage difference between the two ends of the capacitor C1 cannot satisfy the on condition of the state switching submodule, the state switching submodule 8022 switches the state between the power supply and the load 803 to the off state, and at this time, the power supply does not supply power to the load 803. It is understood that the capacitor C1 is charged by the charging submodule 8021 and the first resistor R1, so that the state switching submodule 8022 can switch the state between the power source and the load from on to off.
In one possible implementation, the charging submodule 8021 includes a third resistor R3, and the third resistor R3 is used for adjusting the charging and discharging currents of the capacitor C1. The larger the resistance of the third resistor R3 is, the smaller the charging and discharging current of the capacitor C1 is, and the longer the charging and discharging time of the capacitor C1 is; the smaller the resistance of the third resistor R3 is, the larger the current charged and discharged by the capacitor C1 is, and the shorter the charging and discharging time of the capacitor C1 is.
In this scheme, the charging speed of the capacitor C1 affects the power-down duration of the load 803, and the discharging speed of the capacitor C1 affects the power-up duration of the input port circuit supplying power to the load 803.
And a state switching submodule 8022 for controlling the connection or disconnection between the power supply and the load 803 according to the voltage across the capacitor C1.
In one possible implementation, the state switching sub-module 8022 includes: and a MOS tube. The gate of the MOS transistor is connected to the second end of the capacitor C1, and the drain of the MOS transistor is connected to the load 803. The MOS tube is used for controlling the MOS tube to be switched on or switched off according to the voltage at two ends of the capacitor C1; when the MOS transistor is turned on, the power supply supplies power to the load 803; when the MOS transistor is turned off, the power supply does not supply power to the load 803.
Optionally, the MOS transistor may be an NPN type MOS transistor or a PNP type MOS transistor. The utility model discloses in, do not limit to the concrete model of MOS pipe.
Here, taking the load 803 as an example of a USB interface, the turn-on voltage of the first diode VD1 is 3.9V, the turn-off voltage of the transistor Q1 is 0.7V, and the turn-on voltage of the MOS transistor is 1.3V, which describes in detail the operation process of the switch control protection circuit shown in this embodiment:
when the input port circuit is not connected with the mains supply, the voltage of the output end of the input port circuit is 0V, the base electrode of the triode Q1 is at a low level, the triode Q1 is in a cut-off state (namely, an off state), and at the moment, the MOS transistor is in the off state, namely, the USB interface is in a power-off state.
When the input port circuit is connected with a mains supply, the voltage of the output end of the input port circuit is 5V, the voltage of the positive electrode of the first diode VD2 is 1.1V, at the moment, the voltage of the positive electrode of the first diode VD1 is greater than the cut-off voltage of the triode Q1, the current input to the base electrode of the triode Q1 meets the conduction condition of the triode Q1, and the emitter and the collector of the triode Q1 are conducted; at this time, the voltage at the second end of the first resistor R1 is 0V, the voltage at the second end of the capacitor C1 is also 0V, and accordingly, Vgs of the MOS transistor is 5V, which is greater than the turn-on voltage of the MOS transistor, that is, Vgs satisfies the turn-on condition of the MOS, the MOS transistor is turned on, and at this time, the power supply supplies power to the load 803. Wherein, Vgs represents the voltage between the gate and the source of the MOS tube.
When the external device is connected to the USB interface, the voltage of the drain of the MOS transistor is reduced, and accordingly, the voltage of the output terminal of the input port circuit is also reduced, when the voltage of the output terminal of the input port circuit is reduced to the sum of the on voltage of the first diode VD1 and the off voltage of the transistor Q1, that is, the voltage of the output terminal of the input port circuit is reduced to 4.6V, the first diode VD1 is in an on state, the voltage of the positive electrode of the first diode VD1 is 0.7V, and the voltage of the positive electrode of the first diode VD1 is equal to the off voltage of the transistor Q1, so that the current input to the base of the transistor Q1 cannot meet the on condition of the transistor Q1, and the emitter and the collector of the transistor Q1 are in an off state.
At this time, the voltage of the first terminal of the first resistor R1 is equal to the voltage of the output terminal of the input port circuit.
For the capacitor C1, before the voltage at the output terminal of the input port circuit decreases, the transistor Q1 is in a conducting state, the voltage at the second terminal of the capacitor C1 is 0V, and since the voltage at the second terminal of the capacitor C1 cannot change suddenly, the capacitor C1 is charged through the first resistor R1 and the third resistor R3 during the voltage decrease at the output terminal of the input port circuit, so that the voltage at the second terminal of the capacitor C1 is rapidly increased from 0V to 4.6V.
In the above process, since the USB interface is connected to the external device, the voltage at the output end of the input port circuit is reduced, and the capacitor C1 is charged to turn off the MOS transistor in the process of reducing the voltage at the output end of the input port circuit. Under the condition that the MOS tube is turned off, the voltage of the source electrode of the MOS tube is the same as the voltage of the output end of the input port circuit, the voltage of the drain electrode of the MOS tube is 0V, namely, the power supply is disconnected with the load 803, and the voltage of the output end of the input port circuit cannot be further reduced along with the change of the voltage of the load end, so that the problems that the voltage reduction amplitude of the output end of the input port circuit is large and other elements of the display device work abnormally due to the fact that external equipment is connected are solved, and the stability of the display device is improved.
Further, the voltage of the source of the MOS transistor is restored to 5V, that is, the voltage of the output end of the input port circuit is restored to 5V. When the voltage at the output terminal of the input port circuit is greater than 4.6V, i.e., the voltage at the output terminal of the input port circuit is greater than the turn-on voltage of the first diode VD1 and the turn-off voltage of the transistor Q1, the first diode VD1 and the transistor Q1 are turned back on. When the triode Q1 is turned on, the voltage at the second end of the capacitor C1 is 0V, and since the voltage at the two ends of the capacitor C1 cannot change suddenly, the capacitor C1 discharges through the triode Q1; in the discharging process of the capacitor C1, the voltage difference between the two ends of the capacitor C1 is continuously increased, and when the voltage difference between the two ends of the capacitor C1 meets the turn-on voltage of the MOS transistor, namely Vgs meets the turn-on voltage of the MOS transistor, the MOS transistor is turned on, and at the moment, the power supply supplies power for the USB interface.
In the process that the voltage of the source of the MOS transistor is restored from 4.6V to 5V, due to the characteristics of the capacitor, the voltage at the two ends of the capacitor C1 cannot suddenly change, therefore, in the process that the voltage at the output end of the input port circuit is restored from 4.6V to 5V, the capacitor C1 slowly discharges through the triode Q1, that is, the power supply supplies power to the USB interface slowly, in such a case, the slow power supply avoids the problem that the voltage at the output end of the input port circuit is reduced again due to the fact that the instantaneous current of the load 803 is too large, and further causes power supply abnormality of other elements of the display device, and further improves the stability of the display device.
Fig. 10 is a schematic structural diagram of a switch control protection circuit according to another embodiment of the present invention. Referring to fig. 10, in addition to the embodiment shown in fig. 9, the switch control circuit 802 further includes: and a fourth resistor R4.
The second terminal of the ground switch K1 is connected to the second terminal of the first resistor R1 and the first terminal of the charging submodule 8021 through the fourth resistor R4. That is, the collector of the transistor Q1 is connected to the second terminal of the first resistor R1 and the first terminal of the second resistor R2 through the fourth resistor R4.
In this embodiment, the fourth resistor R4 is used to adjust the charging start voltage and the discharging end voltage of the capacitor C1. The charging start voltage and the discharging end voltage of the capacitor C1 can affect the charging and discharging time of the capacitor C1.
As can be seen from the description of the embodiment shown in fig. 8, the third resistor R3 can adjust the charging and discharging current of the capacitor C1, thereby adjusting the charging and discharging speed of the capacitor C1; in the present embodiment, the fourth resistor R4 is provided, and the fourth resistor R4 and the third resistor R3 jointly adjust the charging and discharging speed of the capacitor C1.
In this embodiment, the fourth resistor R4 is disposed in the switch control circuit 802, so that the charging and discharging speed of the capacitor C1 can be adjusted, thereby avoiding the problem that the voltage at the output terminal of the input port circuit changes due to the change of the voltage on the load, and further other elements of the display device work abnormally, and improving the stability of the display device.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (10)
1. A display device, comprising: a power panel and a load; the power panel at least includes: a voltage control circuit and a switch control circuit;
the power supply is connected with the first end of the voltage control circuit and the first end of the switch control circuit on the power panel, and the power supply is used for supplying power to a load through the voltage control circuit and the switch control circuit on the power panel; the second end of the voltage control circuit is connected with the second end of the switch control circuit, and the third end of the switch control circuit is connected with the load;
the voltage control circuit is used for detecting the voltage output by the power supply and controlling the voltage of the second end of the voltage control circuit according to the voltage output by the power supply; the switch control circuit is used for controlling the switch control circuit to be switched on or switched off according to the voltage of the second end of the voltage control circuit, the voltage output by the power supply and a preset threshold voltage; when the switch control circuit is switched on, the power supply supplies power to the load.
2. The display device according to claim 1, wherein the voltage control circuit comprises: a first diode VD 1;
the power supply is respectively connected with the cathode of the first diode VD1 and the first end of the switch control circuit, and the anode of the first diode VD1 is connected with the second end of the switch control circuit.
3. The display device according to claim 2, wherein the first diode VD1 is a zener diode.
4. The display device according to any one of claims 1 to 3, wherein the switch control circuit comprises: the charging circuit comprises a first resistor R1, a grounding switch K1, a charging submodule, a capacitor C1 and a state switching submodule;
wherein a first terminal of the voltage control circuit is connected to a first terminal of the first resistor R1, a first terminal of the capacitor C1, and a first terminal of the state switching submodule; the second end of the voltage control circuit is connected with the first end of the grounding switch K1;
a second end of the first resistor R1 is connected to a second end of the ground switch K1 and a first end of the charging submodule, and a second end of the charging submodule is connected to a second end of the capacitor C1;
the second end of the state switching submodule is connected with the second end of the capacitor C1, and the third end of the state switching submodule is connected with the load;
the first resistor R1 is used for controlling the voltage of the second end of the first resistor R1; the grounding switch K1 is used for controlling the grounding switch K1 to be switched on or off according to the voltage of the second end of the voltage control circuit and a first threshold voltage; the capacitor C1 is used for charging through the charging submodule and discharging through the charging submodule and the grounding switch K1; the state switching submodule is used for controlling the connection or disconnection between the power supply and the load according to the voltage at the two ends of the capacitor C1;
the preset threshold voltage comprises the first threshold voltage.
5. The display device according to claim 4, wherein the ground switch K1 includes: a second resistor R2 and a transistor Q1;
the second end of the voltage control circuit is connected with the base electrode of the triode Q1 through the second resistor R2, the emitter electrode of the triode Q1 is grounded, and the collector electrode of the triode Q1 is respectively connected with the second end of the first resistor R1 and the first end of the charging submodule;
the second resistor R2 is used for adjusting the current input to the base of the triode Q1;
the transistor Q1 is used for controlling the conduction or the disconnection between the collector and the emitter of the transistor Q1 according to the input current.
6. The display device according to claim 5, wherein the transistor Q1 is an NPN transistor or a PNP transistor.
7. The display device as claimed in claim 4, wherein the charging submodule comprises a third resistor R3, and the third resistor R3 is used for adjusting the current for charging and discharging the capacitor C1.
8. The display device according to claim 4, wherein the status switching sub-module comprises: a metal oxide semiconductor field effect transistor (MOS) tube;
the grid electrode of the MOS tube is connected with the second end of the charging submodule and the second end of the capacitor C1, the source electrode of the MOS tube is connected with the first end of the capacitor C1, and the drain electrode of the MOS tube is connected to the load;
the MOS tube is used for controlling the MOS tube to be switched on or switched off according to the voltage at two ends of the capacitor C1 and a second threshold voltage; when the MOS tube is conducted, the power supply supplies power to the load; the preset threshold voltage comprises a second threshold voltage, and the second threshold voltage is the conduction voltage of the MOS tube.
9. The display device according to claim 4, wherein the switch control circuit further comprises: a fourth resistor R4;
the second end of the grounding switch K1 is connected with the second end of the first resistor R1 and the first end of the charging submodule through the fourth resistor R4;
the fourth resistor R4 is used for adjusting the starting voltage of the capacitor C1 for charging and the ending voltage of the discharging.
10. The display device according to claim 8, wherein the MOS transistor is an N-type MOS transistor or a P-type MOS transistor.
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| CN202020236215.4U CN211699667U (en) | 2020-03-02 | 2020-03-02 | Display device |
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| CN202020236215.4U CN211699667U (en) | 2020-03-02 | 2020-03-02 | Display device |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112947655A (en) * | 2021-01-26 | 2021-06-11 | 厦门天马微电子有限公司 | Voltage stabilizing circuit, voltage stabilizing method and display device |
| CN113920953A (en) * | 2021-11-15 | 2022-01-11 | 京东方科技集团股份有限公司 | Electrophoretic display device, control method, and computer-readable storage medium |
| CN117392951A (en) * | 2023-12-05 | 2024-01-12 | 上海视涯技术有限公司 | Power supply detection circuit, silicon-based display panel and display device |
-
2020
- 2020-03-02 CN CN202020236215.4U patent/CN211699667U/en active Active
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112947655A (en) * | 2021-01-26 | 2021-06-11 | 厦门天马微电子有限公司 | Voltage stabilizing circuit, voltage stabilizing method and display device |
| CN113920953A (en) * | 2021-11-15 | 2022-01-11 | 京东方科技集团股份有限公司 | Electrophoretic display device, control method, and computer-readable storage medium |
| CN117392951A (en) * | 2023-12-05 | 2024-01-12 | 上海视涯技术有限公司 | Power supply detection circuit, silicon-based display panel and display device |
| CN117392951B (en) * | 2023-12-05 | 2024-03-19 | 上海视涯技术有限公司 | Power supply detection circuit, silicon-based display panel and display device |
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