CN110875607A - Charging system - Google Patents
Charging system Download PDFInfo
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- CN110875607A CN110875607A CN201810994889.8A CN201810994889A CN110875607A CN 110875607 A CN110875607 A CN 110875607A CN 201810994889 A CN201810994889 A CN 201810994889A CN 110875607 A CN110875607 A CN 110875607A
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Abstract
A charging system is used for charging a plurality of USB devices and comprises a control circuit, a power management chip and at least two USB interfaces, wherein the USB interfaces are used for connecting the USB devices, the control circuit is used for detecting whether the USB interfaces are connected with the USB devices or not, and the control circuit is used for outputting a quick charging signal when detecting that only one USB interface is connected with the USB devices; outputting a common charging signal when detecting that at least two USB charging interfaces are connected to the USB equipment; the power management chip is used for outputting a first voltage to a USB charging interface connected with the USB device when receiving the quick charging signal, and the power management chip is also used for outputting a second voltage to the USB charging interface connected with the USB device when receiving the quick charging signal. Therefore, the number of the USB devices can be automatically identified, different charging modes can be controlled accordingly, and the USB device charging system is convenient to use.
Description
Technical Field
The present invention relates to a charging system.
Background
At present, with the wide application of digital products such as mobile phones, the types of chargers matched with the digital products also appear endlessly. With low cost and high performance, there is a natural need for a Universal Serial Bus (USB) charging system that uses one set of power inputs but has multiple sets of interfaces.
Because of the high voltage fast charging, the charging system with a single power supply and multiple interfaces must include a Micro Control Unit (MCU) to detect the connection status of each interface and inform each interface whether to use fast charging. However, the use of MCU control requires considerable technical capability, complex Printed Circuit Board (PCB) routing and high cost. Therefore, how to provide a simpler charging system with multiple USB interfaces becomes one of the problems to be solved by researchers.
Disclosure of Invention
In view of the foregoing, there is a need for a charging system.
A charging system for charging a USB device, the charging system comprising:
the USB charging interfaces are used for connecting USB equipment;
the control circuit is used for detecting whether the USB charging interface is connected with the USB equipment or not; the control circuit is also used for outputting a quick charging signal when detecting that only one USB charging interface is connected to the USB equipment; outputting a common charging signal when detecting that at least two USB charging interfaces are connected to the USB equipment; and
the power management chip is used for outputting a first voltage to a USB charging interface connected with the USB equipment when receiving the quick charging signal; and the power management chip is also used for outputting a second voltage to a USB charging interface connected with the USB equipment when receiving the quick charging signal.
Further, the power management chip is electrically connected with a power supply to receive a supply voltage output by the power supply, and is used for converting the supply voltage into the first voltage or the second voltage.
Furthermore, the control circuit comprises a control unit, wherein the control unit is connected with the USB charging interface and is used for detecting whether the USB charging interface is connected with the USB device.
Furthermore, the charging system further comprises a resistor, the control circuit further comprises a voltage modulation circuit and a comparator, the positive input end of the comparator is grounded through the resistor, the reverse input end of the comparator is connected with the voltage modulation circuit, and the output end of the comparator is connected with the control unit.
Further, the control circuit further includes:
the number of the electronic switches is the same as that of the USB charging interfaces, the electronic switches correspond to the USB charging interfaces one by one, and the electronic switches are connected with the control unit;
when the control unit detects that the USB charging interface is connected with the USB equipment, the control unit sends a detection signal to the electronic switch corresponding to the USB charging interface connected with the USB equipment so as to control the electronic switch to be conducted.
Further, the control circuit further includes:
the number of the current sources is the same as that of the electronic switches, and the current sources are electrically connected in a one-to-one correspondence manner;
the electronic switch comprises a first end, a second end and a third end, wherein the first end of the electronic switch is connected with the control unit to receive the detection signal, the second end of the electronic switch is connected with the corresponding current source, and the third end of the electronic switch is connected between the positive input end of the comparator and the resistor.
Furthermore, the electronic switch is a field effect transistor, and the first end, the second end and the third end of the electronic switch are respectively a grid electrode, a source electrode and a drain electrode of the field effect transistor.
Further, the electronic switch is a triode, and the first end, the second end and the third end of the electronic switch are respectively a base electrode, a collector electrode and an emitter electrode of the triode.
Further, the first voltage is a direct current voltage of 9V, and the second voltage is a direct current voltage of 5V.
In the charging system, the control unit detects the number of the accessed USB devices, and correspondingly sends the quick charging signals or the common charging signals to the power management chip according to the number of the accessed USB devices. Therefore, the power management chip can output different charging modes according to the received quick charging signal or the received common charging signal, and the use is convenient.
Drawings
Fig. 1 is a block diagram of a preferred embodiment of a charging system connected to a USB device.
Fig. 2 is a circuit diagram of a preferred embodiment of the charging system.
Description of the main elements
USB charging interfaces 30a, 30b, 30c
Power management chip U1
Control unit U2
Comparator U3
Resistor R1
Electronic switches Q1, Q2, Q3
Current sources C1, C2, C3
The following detailed description will further illustrate the invention in conjunction with the above-described figures. Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the charging system of the present invention will be described in further detail and described with reference to the accompanying drawings and embodiments.
Referring to fig. 1 and 2, in a preferred embodiment of the present invention, a charging system 100 is used for charging a plurality of USB devices. In the present embodiment, three USB devices 200a, 200b, and 200c are taken as an example for convenience of description.
The charging system 100 includes a control circuit 10, a power management chip U1 and at least two USB charging interfaces. In the present embodiment, three USB charging interfaces 30a, 30b, and 30c are taken as an example for convenience of description.
The plurality of USB charging interfaces 30a, 30b, and 30c are used for electrically connecting the plurality of USB devices 200a, 200b, and 200 c.
The control circuit 10 is configured to detect whether the USB charging interfaces 30a, 30b, and 30c are connected to a USB device.
If only one USB charging interface is connected to the USB device, the control circuit 10 outputs a fast charging signal to the power management chip U1.
If it is detected that at least two USB charging interfaces are connected to the USB device, the control circuit 10 outputs a normal charging signal to the power management chip 20.
The power management chip U1 is used for outputting a first voltage to a USB charging interface connected to a USB device when receiving the quick charging signal.
The power management chip U1 is used for outputting a second voltage to the USB charging interface connected to the USB device when receiving the fast charging signal.
For example, if the control circuit 10 detects that only one USB charging interface 30a is connected to the USB device 200a, and the USB charging interface 30b is not connected to the USB device. At this time, the control circuit 10 will output a fast charging signal to the power management chip U1. When receiving the fast charging signal, the power management chip U1 outputs a first voltage to the USB charging interface 30a to perform fast charging for the USB device 200 a.
If the control circuit 10 detects that the USB charging interfaces 30a and 30b are respectively connected to the USB devices 200a and 200b, the control circuit 10 outputs a normal charging signal to the power management chip U1. When receiving the normal charging signal, the power management chip U1 outputs a second voltage to the USB charging interfaces 30a and 30b to perform normal charging for the USB devices 200a and 200 b.
In this embodiment, the first voltage is a 9V dc voltage, and the second voltage is a 5V dc voltage. In another alternative embodiment, the first voltage may also be a 12V dc voltage.
When the control circuit 10 detects that the USB charging interface is connected to the USB device, the control circuit 10 will automatically identify whether the connected USB device can support the fast charging mode.
For example, when the control circuit 10 detects that only one USB charging interface is connected to the USB device, the control circuit 10 will determine whether the connected USB device can support the fast charging mode.
If the connected USB device supports the fast charging mode, the control circuit 10 outputs a fast charging signal, and the fast charging signal controls the power management chip U1 to fast charge the connected USB device.
If the connected USB device does not support the fast charging mode, the control circuit 10 outputs a normal charging signal, and the normal charging signal controls the power management chip U1 to normally charge the connected USB device.
In this way, the charging system 100 can automatically identify the number of the USB devices connected thereto, and control different charging modes accordingly, thereby facilitating the use.
In a preferred embodiment, the power management chip U1 is electrically connected to a power source 40 to receive a supply voltage output by the power source 40. As such, the power management chip U1 may convert the supply voltage to the first voltage or the second voltage. The control unit U2 is connected to the USB charging interfaces 30a, 30b, and 30c, and is configured to detect whether the USB charging interfaces 30a, 30b, and 30c are connected to a USB device.
The control circuit 10 may include a voltage modulation circuit 12, a comparator U3, at least two electronic switches, and at least two current sources. In this embodiment, the number of the electronic switches Q1, Q2, and Q3 is three, and may be more than three. The number of the current sources C1, C2, and C3 is three, and may be more than three.
The positive input end of the comparator U3 is grounded through the resistor R1, the negative input end of the comparator U3 is connected with the voltage modulation circuit 12, and the output end of the comparator U3 is connected with the control unit U2. The voltage modulation circuit 12 is configured to output a reference voltage to an inverting input terminal of the comparator U3.
The electronic switches are in the same number with the USB charging interfaces in one-to-one correspondence, and the current sources are in the same number with the electronic switches in one-to-one correspondence and are electrically connected. The electronic switches Q1, Q2, Q3 each include a first terminal, a second terminal, and a third terminal.
A first terminal of the electronic switch Q1 is connected to the control unit U2 for receiving a detection signal, a second terminal of the electronic switch Q1 is connected to the current source C1, and a third terminal of the electronic switch Q1 is connected between the positive input terminal of the comparator U3 and a resistor R1.
A first terminal of the electronic switch Q2 is connected to the control unit U2 for receiving a detection signal, a second terminal of the electronic switch Q2 is connected to the current source C2, and a third terminal of the electronic switch Q2 is connected between the positive input terminal of the comparator U3 and the resistor R1.
A first terminal of the electronic switch Q3 is connected to the control unit U2 for receiving a detection signal, a second terminal of the electronic switch Q3 is connected to the current source C3, and a third terminal of the electronic switch Q3 is connected between the positive input terminal of the comparator U3 and the resistor R1.
In this embodiment, the electronic switches Q1, Q2, and Q3 are all field effect transistors, and the first, second, and third terminals of the electronic switches Q1, Q2, and Q3 are corresponding to the gate, source, and drain of the transistor. In another embodiment, the electronic switches Q1, Q2, Q3 are all transistors, and the first, second and third terminals of the electronic switches Q1, Q2, Q3 correspond to the base, collector and emitter of the transistors.
In other preferred embodiments, the charging system 100 may further include a plurality of control circuits 10, and the control circuits 10 are connected in parallel between the power management chip U1 and the resistor R1.
The basic working principle of the invention is as follows: the voltage received by the positive input terminal of the comparator U3 is: the resistance of the resistor R1 is multiplied by the current flowing through the resistor R1.
The output currents of the current sources C1, C2, and C3 are all denoted as I, the resistance value of the resistor R1 is denoted as R, the voltage received by the positive input terminal of the comparator U3 is denoted as V1, and the reference voltage output by the voltage modulation circuit 12 is denoted as V2.
When only one USB charging interface is connected to the USB device, at this time, the voltage V1 received by the positive input end of the comparator U3 satisfies the following formula: v1 ═ r × I.
When two USB charging interfaces are connected to a USB device, at this time, the voltage V1 received by the positive input end of the comparator U3 satisfies the following formula: v1 ═ r (I + I) ═ 2r ═ I.
When three USB charging interfaces are connected to a USB device, at this time, the voltage V1 received by the positive input end of the comparator U3 satisfies the following formula: v1 ═ r (I + I) ═ 3r ═ I.
In the present embodiment, the reference voltage outputted by the voltage modulation circuit 12 satisfies the following relationship: r I < V2<2r I.
In operation, when the control unit U2 detects that only one USB device (e.g., the USB device 200a) is connected to the USB charging interface (e.g., the USB charging interface 30a), the control unit U2 controls the electronic switch Q1 to be turned on. The output current of the current source C1 then flows through the resistor R1 to generate a voltage, which generates a voltage V1 ═ R ═ I at the positive input terminal of the comparator U3.
At this time, the voltage of the positive input terminal of the comparator U3 is less than the voltage of the negative input terminal, and the output terminal of the comparator U3 outputs a low level signal to the power management chip U1. The power management chip U1 outputs 9V dc voltage to the USB charging interface 30a according to the low level signal, so as to perform fast charging on the USB device 200 a.
When the control unit U2 detects that two USB devices (e.g., USB devices 200a and 200b) are connected to the USB charging interfaces (e.g., USB charging interfaces 30a and 30b), the control unit U2 controls the electronic switches Q1 and Q2 to be turned on correspondingly. Then, the current sources C1 and C2 output currents and flow through the resistor R1 to generate a voltage, so that the voltage V1 is 2R I at the positive input terminal of the comparator U3.
At this time, the voltage of the positive input terminal of the comparator U3 is greater than the voltage of the negative input terminal, and the output terminal of the comparator U3 outputs a high level signal to the power management chip U1. The power management chip U1 outputs a dc voltage of 5V to the USB charging interfaces 30a and 30b according to the high level signal, so as to charge the USB devices 200a and 200 b.
When the control unit U2 detects that three USB devices (e.g., USB devices 200a, 200b, 200c) are connected to the USB charging interfaces (e.g., USB charging interfaces 30a, 30b, 30c), the control unit U2 controls the electronic switches Q1, Q2, and Q3 to be turned on. At this time, the current sources C1, C2, and C3 output currents and flow through the resistor R1 to generate a voltage, so that the voltage V1 is 3R I at the positive input terminal of the comparator U3.
At this time, the voltage of the positive input terminal of the comparator U3 is greater than the voltage of the negative input terminal, and the output terminal of the comparator U3 outputs a high signal to the power management chip U1. The power management chip U1 outputs a dc voltage of 5V to the USB charging interfaces 30a, 30b, and 30c according to the high level signal, so as to perform normal charging for the USB devices 200a, 200b, and 200 c.
By analogy, if more USB devices are connected to the USB charging interfaces, the voltage at the positive input end of the comparator U3 will increase in sequence to be greater than the voltage at the negative input end. Thus, the control unit U2 outputs a normal charge signal to the power management chip U1. And the power management chip U1 outputs 5V direct-current voltage corresponding to the ordinary charging signal to carry out ordinary charging on the USB equipment.
The charging system 100 may detect the number of the connected USB devices through the control unit U2, and send a fast charging signal or a normal charging signal to the power management chip according to the number of the connected USB devices.
Therefore, the power management chip U1 can output different charging modes according to the received quick charging signal or the received common charging signal, and is convenient to use.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited, although the present invention is described in detail with reference to the preferred embodiments. It will be understood by those skilled in the art that various modifications and equivalent arrangements can be made without departing from the spirit and scope of the present invention. Moreover, based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without any creative effort will fall within the protection scope of the present invention.
Claims (9)
1. A charging system for charging a USB device, the charging system comprising:
the USB charging interfaces are used for connecting USB equipment;
the control circuit is used for detecting whether the USB charging interface is connected with the USB equipment or not; the control circuit is also used for outputting a quick charging signal when detecting that only one USB charging interface is connected to the USB equipment; outputting a common charging signal when detecting that at least two USB charging interfaces are connected to the USB equipment; and
the power management chip is used for outputting a first voltage to a USB charging interface connected with the USB equipment when receiving the quick charging signal; and the power management chip is also used for outputting a second voltage to a USB charging interface connected with the USB equipment when receiving the quick charging signal.
2. The charging system of claim 1, wherein the power management chip is electrically connected to a power source to receive a supply voltage output by the power source, the power management chip to convert the supply voltage to the first voltage or the second voltage.
3. The charging system of claim 2, wherein the control circuit comprises a control unit, and the control unit is connected to the USB charging interface and configured to detect whether the USB charging interface is connected to a USB device.
4. The charging system of claim 3, further comprising a resistor, wherein the control circuit further comprises a voltage modulation circuit and a comparator, a positive input terminal of the comparator is grounded through the resistor, a negative input terminal of the comparator is connected to the voltage modulation circuit, and an output terminal of the comparator is connected to the control unit.
5. The charging system of claim 4, wherein the control circuit further comprises:
the number of the electronic switches is the same as that of the USB charging interfaces, the electronic switches correspond to the USB charging interfaces one by one, and the electronic switches are connected with the control unit;
when the control unit detects that the USB charging interface is connected with the USB equipment, the control unit sends a detection signal to the electronic switch corresponding to the USB charging interface connected with the USB equipment so as to control the electronic switch to be conducted.
6. The charging system of claim 5, wherein the control circuit further comprises:
the number of the current sources is the same as that of the electronic switches, and the current sources are electrically connected in a one-to-one correspondence manner;
the electronic switch comprises a first end, a second end and a third end, wherein the first end of the electronic switch is connected with the control unit to receive the detection signal, the second end of the electronic switch is connected with the corresponding current source, and the third end of the electronic switch is connected between the positive input end of the comparator and the resistor.
7. The charging system of claim 6, wherein the electronic switch is a field effect transistor, and the first terminal, the second terminal and the third terminal of the electronic switch are a gate, a source and a drain of the field effect transistor, respectively.
8. The charging system of claim 6, wherein the electronic switch is a transistor, and the first terminal, the second terminal, and the third terminal of the electronic switch are a base, a collector, and an emitter of the transistor, respectively.
9. The charging system of claim 1, wherein the first voltage is a 9V dc voltage and the second voltage is a 5V dc voltage.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201810994889.8A CN110875607B (en) | 2018-08-29 | 2018-08-29 | Charging system |
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| CN201810994889.8A CN110875607B (en) | 2018-08-29 | 2018-08-29 | Charging system |
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| CN110875607A true CN110875607A (en) | 2020-03-10 |
| CN110875607B CN110875607B (en) | 2022-04-22 |
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| CN113629802A (en) * | 2021-07-15 | 2021-11-09 | 深圳天德钰科技股份有限公司 | Power supply device |
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| CN110875607B (en) | 2022-04-22 |
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