A detection circuit for detecting the output power of a USB power supply

Abstract

The present invention discloses a detection circuit for detecting the output power of a USB power supply, which includes a USB-C interface module, a filtering circuit, a dual-channel operational amplifier, and an output control circuit; wherein, the input end of the USB-C interface module is electrically connected to a charger of the USB-C interface or electrically connected to a charger of the USB-A interface through an interface conversion head; the USB-C interface module is also electrically connected to the output control circuit through the dual-channel operational amplifier; the dual-channel operational amplifier is used to compare the first real-time voltage signal input by the charger with a set reference voltage signal respectively, and then control the power output of the output control circuit according to the comparison result. The present invention can provide different output powers to the subsequent circuit according to different chargers, realize the adjustability of the power output, and improve the operability of the product.

Description

Technical Field

[0001] The present invention relates to the detection of power output of a power supply, and particularly to a detection circuit for detecting the output power of a USB power supply. Background Art

[0002] At present, with the popularization of USB Type-C technology, in order to be compatible with new and old technologies, generally a PD protocol IC is configured at the product end and matched with corresponding software programs to realize the management of power input and output. However, for mid- and low-end products, this method has too high a cost and a longer development cycle, which is not conducive to the research and development of products. At the same time, if the PD protocol IC is not configured, for users, they need to select a charger with a corresponding interface according to actual needs when choosing a charger. Then, for currently commonly used chargers, their default power input is 5V. Since the charging current capacity of the current charger cannot be judged, the product of the load cannot be flexibly adjusted, reducing the operability of the product itself. Summary of the Invention

[0003] In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a detection circuit for the output power of a USB power supply, which can solve the problems such as the inability to detect the output capacity of an external adapter and the inability of the product of the load to be adapted.

[0004] The purpose of the present invention is achieved by adopting the following technical solutions:

[0005] A detection circuit for detecting the output power of a USB power supply, comprising a USB-C interface module, a filter circuit, a dual-channel operational amplifier and an output control circuit; wherein, the input end of the USB-C interface module is electrically connected to a first charger or electrically connected to a second charger through an interface adapter; the first output end of the USB-C interface module is electrically connected to the first non-inverting input end of the dual-channel operational amplifier, and is used to provide a first real-time voltage signal to the dual-channel operational amplifier; the second output end of the USB-C interface module is electrically connected to the second inverting input end of the dual-channel operational amplifier through the filter circuit, and is used to provide a second real-time voltage signal to the dual-channel operational amplifier;

[0006] The first inverting input end, the second non-inverting input end and the third input end of the dual-channel operational amplifier are respectively used for inputting a first reference voltage signal, a second reference voltage signal and a third reference voltage signal;

[0007] The dual-channel operational amplifier is used to control the power output of the output control circuit according to the first comparison result between the first real-time voltage signal and the first reference voltage signal, and the second comparison result between the second real-time voltage signal and the second reference voltage signal; wherein, the charging interface of the first charger is a USB-C interface; the charging interface of the second charger is a USB-A interface.

[0008] Further, the dual-channel operational amplifier includes a first comparator; the positive input terminal of the first comparator is connected to the first real-time voltage signal, and the negative input terminal is connected to the first reference voltage signal, and is used to compare the first real-time voltage signal with the first reference voltage signal; wherein, when the first real-time voltage signal is greater than the first reference voltage signal, the first comparison result output by the first comparator is the voltage value of the third reference voltage signal and the charging interface of the currently connected charger is a USB-C interface; when the first real-time voltage signal is less than the first reference voltage signal, the first comparison result output by the first comparator is 0V and the charging interface of the currently connected charger is a USB-A interface.

[0009] Further, the dual-channel operational amplifier further includes a second comparator; the negative input terminal of the second comparator is connected to the second real-time voltage signal, and the positive input terminal inputs the second reference voltage signal, and is used to compare the second real-time voltage signal with the second reference voltage signal; wherein, when the second real-time voltage signal is greater than the second reference voltage signal, the second comparison result output by the second comparator is 0V and the current output capacity of the currently connected charger is greater than the second preset value; when the second real-time voltage signal is less than the second reference voltage signal, the second comparison result output by the second comparator is the voltage value of the third reference voltage signal and the current output capacity of the currently connected charger is less than the first preset value; wherein, the first preset value is less than the second preset value.

[0010] Further, when the charging interface of the currently connected charger is a USB-A interface, the output control circuit outputs a high level;

[0011] When the charging interface of the currently connected charger is a USB-C interface: when the second comparison result is 0V, the output control circuit outputs a low level; when the second comparison result is the voltage value of the third reference voltage signal, the output control circuit outputs a high level.

[0012] Further, the first preset value is 1A, and the second preset value is 1.5A; the first reference voltage signal is less than the second reference voltage signal, and the second reference voltage signal is less than the third reference voltage signal.

[0013] Further, the first reference voltage signal is 0.2V, the second reference voltage signal is 0.67V, and the third reference voltage signal is 3.9V.

[0014] Further, the dual-channel operational amplifier includes chip IC1, chip U4, capacitor C35, capacitor C36, capacitor C37, capacitor C38, resistor R35, resistor R39, resistor R40, resistor R41, resistor R42, resistor R47, resistor R48, resistor R51, and resistor R52;

[0015] Among them, the port 1 of chip IC1 outputs the first comparison result, the port 7 outputs the second result, the port 2 accesses the first reference voltage signal, the port 5 inputs the second reference voltage signal, the port 8 inputs the third reference voltage signal, the port 3 accesses the first real-time voltage signal through resistor R55, the port 6 accesses the second real-time voltage signal, and the port 4 is grounded;

[0016] The port 8 of chip IC1 is also electrically connected to the port 3 of chip U4; the port 2 of chip U4 is grounded, the port 1 is grounded through resistor R52, the port 1 is also electrically connected to the port 3 of chip U4 through resistor R51, and the port 3 accesses the 5V power supply through resistor R41;

[0017] The port 3 of chip U4 is also grounded through capacitor C35, and the port 3 is grounded through resistor R39, resistor R47, and resistor R40 in sequence; one end of capacitor C36 is grounded and the other end is electrically connected to the port 3 of chip U4; one end of resistor R35 is connected between resistor R39 and the port 3 of chip U4, and the other end is grounded through resistor R48 and resistor R42 in sequence; one ends of capacitor C37 and capacitor C38 are both grounded, and the other ends are both connected between resistor R39 and resistor R47; the second reference voltage signal is connected between resistor R35 and resistor R48; capacitor C38 accesses the third reference voltage signal.

[0018] Further, the filtering circuit is an RC low-pass filtering circuit; among them, the RC low-pass filtering circuit includes resistor R16 and capacitor C53; one end of resistor R16 is electrically connected to the port 3 of chip IC1 through resistor R55 and the other end is electrically connected to the port 6 of chip IC1; one end of capacitor C53 is grounded and the other end is connected between resistor R16 and the port 6 of chip IC1; the first real-time voltage signal input from the port 3 of chip IC1 forms the second real-time voltage signal after being filtered by resistor R16 and capacitor C53 and is input to the port 6 of chip IC1.

[0019] Further, the output control circuit includes resistor R30, resistor R33, resistor R14, triode Q5, and triode Q6;

[0020] One end of the resistor R33 is electrically connected to the port 1 of the chip IC1, and the other end is electrically connected to the base of the triode Q6; the emitter of the triode Q6 is grounded, and the collector is electrically connected to the base of the triode Q5 through the resistor R27; one end of the resistor R14 is grounded, and the other end is connected between the resistor R33 and the base of the triode Q6; the emitter of the triode Q5 is electrically connected to the port 7 of the chip IC1, and the collector is electrically connected to the subsequent circuit of the device; one end of the resistor R30 is electrically connected to the emitter of the triode Q5, and the other end is connected between the resistor R27 and the base of the triode Q5.

[0021] Further, it further includes a controllable precision power supply, and the controllable precision power supply is electrically connected to the dual-channel operational amplifier for providing a first reference voltage signal, a second reference voltage signal, and a third reference voltage signal to the dual-channel operational amplifier.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] The present invention realizes the power supply modes of two USB chargers through the cooperation of the interface conversion head and the USB-C interface module. At the same time, when the charging interface of the charger is a USB-C interface, the power of the power supply output to the subsequent circuit is adjusted according to the current output capacity of the charger to improve the operability of the product. Description of the Drawings

[0024] Figure 1 It is a circuit module diagram of a detection circuit for the output power of a USB power supply provided by the present invention;

[0025] Figure 2 It is Figure 1 a circuit schematic diagram of the filter and the operational amplifier in

[0026] Figure 3 It is Figure 1 a circuit schematic diagram of the output control circuit in Detailed Embodiments

[0027] Next, in combination with the drawings and the specific embodiments, the present invention will be further described. It should be noted that on the premise of no conflict, the following described embodiments or technical features can be combined arbitrarily to form new embodiments.

[0028] Based on the existing problems, the present invention provides a preferred embodiment, a detection circuit for the output power of a USB power supply, as Figure 1 shown, including an interface adapter, a USB-C interface module, a filter circuit, an operational amplifier, and an output control circuit.

[0029] Among them, the interface adapter is used to realize the conversion between the USB-A interface and the USB-C interface.

[0030] The input end of the USB-C interface module is electrically connected to the first charger, or is electrically connected to the second charger through an interface adapter.

[0031] Since a charger with a USB-A interface cannot be directly electrically connected to the USB-C interface module. Therefore, when the interface of the charger is a USB-A interface, it is electrically connected to the USB-C interface module through an interface adapter. When the charging interface is a USB-C interface, it is directly electrically connected to the USB-C interface module. That is, the first charger is a charger with a USB-C interface, and the second charger is a charger with a USB-A interface.

[0032] More specifically, in the actual use process, the USB-C interface module is generally implemented by using a USB-C SINK female socket. A USB-C interface is provided through the USB-C SINK female socket to realize connection with the first charger or connection with the second charger through an interface adapter.

[0033] Since chargers with different interfaces have different current output capabilities, when adjusting the power output of the subsequent circuit, it is first necessary to determine the interface type of the currently connected charger and the current output capability of the charger. Therefore, in this embodiment, an operational amplifier is set to implement the above determination.

[0034] Preferably, the operational amplifier in this embodiment is a dual-channel operational amplifier.

[0035] Even further, the first non-inverting input terminal of the dual-channel operational amplifier is electrically connected to the first output terminal of the USB-C interface module for obtaining a first real-time voltage signal.

[0036] The second inverting input terminal of the dual-channel operational amplifier is electrically connected to the second input terminal of the USB-C interface module through a filter circuit for obtaining a second real-time voltage signal.

[0037] A first reference voltage signal is input to the first inverting input terminal of the dual-channel operational amplifier, a second reference voltage signal is input to the second non-inverting input terminal, and a third reference voltage signal is input to the third input terminal.

[0038] Specifically, the dual-channel operational amplifier is used to compare the first real-time voltage signal with the first reference voltage signal to obtain a first comparison result for judging the interface type of the currently connected charger.

[0039] The dual-channel operational amplifier is used to compare the second real-time voltage signal with the second reference voltage signal to obtain a second comparison result for judging the current output capability of the currently connected charger.

[0040] More specifically, the dual-channel operational amplifier includes a first comparator A and a second comparator B. Among them, the first non-inverting input terminal of the first comparator A is electrically connected to the first input terminal of the USB-C interface module, and the first inverting input terminal inputs a first real-time voltage signal, which is used to compare the first real-time voltage signal with a first reference voltage to obtain a first comparison result.

[0041] The second inverting input terminal of the second comparator B is electrically connected to the second input terminal of the USB-C interface module through a filter circuit, and the second non-inverting input terminal inputs a second real-time voltage signal, which is used to compare the second real-time voltage signal with a second reference voltage signal to obtain a second comparison result.

[0042] That is to say, the first comparator A is used to judge the interface type of the currently connected charger; the second comparator B is used to judge the current output ability of the currently connected charger.

[0043] The input terminal of the output control circuit is electrically connected to the first output terminal and the second output terminal of the dual-channel operational amplifier, and is used to control the magnitude of the power supplied to the load according to the first comparison result and the second comparison result. Among them, the load such as the power amplifier module, the motor module, etc. can detect the output ability of the external adapter, so as to adjust the adaptability of the load and improve the operability of the product. For example, according to the magnitude of the output ability of the adapter, the power of products such as speakers and fans can be adjusted.

[0044] More specifically, when the first real-time voltage signal is greater than the first reference voltage signal, the first comparison result output by the first comparator is the voltage value of the third reference voltage signal, and the interface type of the currently connected charger is the USB-C interface.

[0045] On the contrary, when the first real-time voltage signal is less than the first reference voltage signal, the first comparison result output by the first comparator is 0V, and the charging interface of the currently connected charger is the USB-A interface.

[0046] Since the voltage signals provided by the USB-A interface charger and the USB-C interface charger are different, accordingly, different chargers with different interfaces can be distinguished by setting corresponding reference voltages.

[0047] Furthermore, the first reference voltage is 0.2V and the third reference voltage is 3.9V.

[0048] More specifically, when the voltage value of the second real-time voltage signal is greater than the second reference voltage signal, the second comparison result output by the second comparator is 0V, and the current output ability of the currently connected charger is greater than the second preset value.

[0049] Conversely, when the voltage value of the second real-time voltage signal is less than the voltage value of the second reference voltage signal, the second comparison result output by the second comparator is the voltage value of the third reference voltage signal, and the current output capacity of the currently connected charger is less than the first preset value.

[0050] Specifically, the first preset value is 1A, and the second preset value is 1.5A. The voltage value of the second reference voltage signal is 0.67V.

[0051] As can be seen from the foregoing, when the interface of the currently connected charger is a USB-A interface, the voltage value of the first real-time voltage signal is 0.2V less than the voltage value of the first real-time voltage signal.

[0052] The second real-time voltage signal is the voltage signal filtered by the filter circuit. Therefore, the voltage value of the second real-time voltage signal will necessarily be less than 0.67V of the second reference voltage signal, and the second comparison result output by the second comparator will necessarily be the voltage value of the third reference voltage signal. Then, the current output magnitude of the currently connected charger will necessarily be less than the first preset value of 1A.

[0053] On the contrary, when the interface of the currently connected charger is a USB-C interface, the voltage value of the first real-time voltage signal is 0.2V greater than the voltage value of the first reference voltage signal. Since it is not clear about the magnitude relationship between the voltage value of the second real-time voltage signal and 0.67V of the second reference voltage signal, it is necessary to further judge through the second comparator B to obtain the current output capacity of the currently connected charger.

[0054] That is, when the first comparison result output by the first comparator A is 0V, the power supplied by the output control circuit to the subsequent circuit will not be affected by the output result of the second comparator B.

[0055] More preferably, this embodiment further includes a controllable precision voltage source. The controllable precision voltage source is used to provide the above three reference voltages. Specifically, the model of the controllable precision voltage source is TL431A.

[0056] In addition, the second real-time voltage signal is obtained by filtering the first real-time voltage signal. Since the voltage value of the first reference voltage signal is 0.2V, that is, the threshold voltage of the first comparator A is 0.2V and its voltage value is small, the first real-time voltage signal can be input to the first comparator A without filtering. Since the voltage value of the second reference voltage signal is 0.67V, that is, the threshold voltage of the second comparator B is 0.67V, in this embodiment, a filter circuit is added to filter the first real-time voltage signal and then input it to the second comparator B to ensure the stability of the signal.

[0057] Preferably, the filter circuit is a low-pass filter circuit.

[0058] As Figure 2 shown, the dual-channel operational amplifier includes chip IC1, chip U4, capacitor C35, capacitor C36, capacitor C37, capacitor C38, resistor R35, resistor R39, resistor R40, resistor R41, resistor R42, resistor R47, resistor R48, resistor R51, and resistor R52.

[0059] Among them, the port 1 of chip IC1 outputs the first comparison result, the port 7 outputs the second comparison result, the port 2 accesses the first reference voltage signal, the port 5 inputs the second reference voltage signal, the port 8 inputs the third reference voltage signal, the port 3 accesses the first real-time voltage signal through resistor R55, the port 6 accesses the second real-time voltage signal, and the port 4 is grounded.

[0060] The port 8 of chip IC1 is also electrically connected to the port 3 of chip U4.

[0061] The port 2 of chip U4 is grounded, the port 1 is grounded through resistor R52, the port 1 is also electrically connected to the port 3 of chip U4 through resistor R51, and the port 3 accesses the 5V power supply through resistor R41.

[0062] The port 3 of chip U4 is also grounded through capacitor C35, and the port 3 is grounded through resistor R39, resistor R47, and resistor R40 in sequence. One end of capacitor C36 is grounded and the other end is electrically connected to the port 3 of chip U4.

[0063] One end of resistor R35 is connected between resistor R39 and the port 3 of chip U4, and the other end is grounded through resistor R48 and resistor R42 in sequence.

[0064] One end of capacitor C37 and capacitor C38 is grounded, and the other end is connected between resistor R39 and resistor R47.

[0065] The second reference voltage signal is connected between resistor R35 and resistor R48; capacitor C38 accesses the third reference voltage signal.

[0066] More specifically, the low-pass filter circuit is an RC low-pass filter circuit, including resistor R16 and capacitor C53; one end of resistor R16 is electrically connected to the port 3 of chip IC1 through resistor R55 and the other end is electrically connected to the port 6 of chip IC1.

[0067] One end of capacitor C53 is grounded and the other end is connected between resistor R16 and the port 6 of chip IC1.

[0068] The first real-time voltage signal input at the port 3 of chip IC1 forms a second real-time voltage signal after being filtered by resistor R16 and capacitor C53 and is input to the port 6 of chip IC1.

[0069] Preferably, the output control circuit includes an AND gate circuit for outputting a logic high level / low level to drive the subsequent circuit. Specifically, as Figure 3 shown, the output control circuit includes resistor R30, resistor R33, resistor R14, transistor Q5, and transistor Q6.

[0070] One end of resistor R33 is electrically connected to port 1 of chip IC1, and the other end is electrically connected to the base of transistor Q6.

[0071] The emitter of transistor Q6 is grounded, and the collector is electrically connected to the base of transistor Q5 through resistor R27; one end of resistor R14 is grounded, and the other end is connected between resistor R33 and the base of transistor Q6.

[0072] The emitter of transistor Q5 is electrically connected to port 7 of chip IC1, and the collector is electrically connected to the subsequent circuit of the device.

[0073] One end of resistor R30 is electrically connected to the emitter of transistor Q5, and the other end is connected between resistor R27 and the base of transistor Q5.

[0074] That is, the conduction and cutoff of transistors Q5 and Q6 are controlled by the first comparison result output from port 1 of chip IC1 and the second comparison result output from port 7 to control whether the output control circuit outputs a high level or a low level.

[0075] From Figure 3 it can also be seen that:

[0076] When the first comparison result output by the first comparator A is 3.9V, transistors Q6 and Q5 are turned on:

[0077] When the second comparison result output by the second comparator B is 0V, the output control circuit outputs a low level (0V);

[0078] When the second comparison result output by the second comparator B is 3.9V, the output control circuit outputs a high level (3.9V).

[0079] When the first comparison result of the first comparator A is 0V, transistor Q6 is turned off, and the output control circuit will surely output a high level (3.9V).

[0080] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art based on the present invention fall within the scope of protection required by the present invention.

Claims

1. A detection circuit for detecting the output power of a USB power supply, characterized in that, It includes a USB-C interface module, a filter circuit, a dual-channel operational amplifier, and an output control circuit. Among them, the input end of the USB-C interface module is electrically connected to a first charger or electrically connected to a second charger through an interface adapter. The first output end of the USB-C interface module is electrically connected to the first non-inverting input end of the dual-channel operational amplifier for providing a first real-time voltage signal to the dual-channel operational amplifier. The second output end of the USB-C interface module is electrically connected to the second inverting input end of the dual-channel operational amplifier through the filter circuit for providing a second real-time voltage signal to the dual-channel operational amplifier. The first inverting input end, the second non-inverting input end, and the third input end of the dual-channel operational amplifier are respectively used for inputting a first reference voltage signal, a second reference voltage signal, and a third reference voltage signal. The dual-channel operational amplifier is used to control the power output of the power supply of the output control circuit according to a first comparison result between the first real-time voltage signal and the first reference voltage signal and a second comparison result between the second real-time voltage signal and the second reference voltage signal. Among them, the charging interface of the first charger is a USB-C interface; the charging interface of the second charger is a USB-A interface. The dual-channel operational amplifier includes a first comparator. The non-inverting input end of the first comparator is connected to the first real-time voltage signal, and the inverting input end is connected to the first reference voltage signal for comparing the first real-time voltage signal with the first reference voltage signal. Among them, when the first real-time voltage signal is greater than the first reference voltage signal, the first comparison result output by the first comparator is the voltage value of the third reference voltage signal and the charging interface of the currently connected charger is a USB-C interface; when the first real-time voltage signal is less than the first reference voltage signal, the first comparison result output by the first comparator is 0V and the charging interface of the currently connected charger is a USB-A interface. The dual-channel operational amplifier further includes a second comparator. The inverting input end of the second comparator is connected to the second real-time voltage signal, and the non-inverting input end inputs the second reference voltage signal for comparing the second real-time voltage signal with the second reference voltage signal. Among them, when the second real-time voltage signal is greater than the second reference voltage signal, the second comparison result output by the second comparator is 0V and the current output capacity of the currently connected charger is greater than a second preset value; when the second real-time voltage signal is less than the second reference voltage signal, the second comparison result output by the second comparator is the voltage value of the third reference voltage signal and the current output capacity of the currently connected charger is less than a first preset value. Among them, the first preset value is less than the second preset value.

2. The detection circuit for detecting the output power of the USB power supply according to claim 1, wherein, If the charging interface of the currently connected charger is a USB-A interface, the output control circuit outputs a high level. When the charging interface of the currently connected charger is a USB-C interface: when the second comparison result is 0V, the output control circuit outputs a low level; when the second comparison result is the voltage value of the third reference voltage signal, the output control circuit outputs a high level.

3. The detection circuit for detecting the output power of the USB power supply according to claim 1, wherein The first preset value is 1A, and the second preset value is 1.5A; The first reference voltage signal is less than the second reference voltage signal, and the second reference voltage signal is less than the third reference voltage signal.

4. The detection circuit for detecting the output power of the USB power supply according to claim 3, characterized in that, The first reference voltage signal is 0.2V, the second reference voltage signal is 0.67V, and the third reference voltage signal is 3.9V.

5. The detection circuit for detecting the output power of the USB power supply according to claim 1, characterized in that, The dual-channel operational amplifier includes chip IC1, chip U4, capacitor C35, capacitor C36, capacitor C37, capacitor C38, resistor R35, resistor R39, resistor R40, resistor R41, resistor R42, resistor R47, resistor R48, resistor R51, and resistor R52; Among them, the port 1 of chip IC1 outputs the first comparison result, the port 7 outputs the second result, the port 2 accesses the first reference voltage signal, the port 5 inputs the second reference voltage signal, the port 8 inputs the third reference voltage signal, the port 3 accesses the first real-time voltage signal through resistor R55, the port 6 accesses the second real-time voltage signal, and the port 4 is grounded; The port 8 of chip IC1 is also electrically connected to the port 3 of chip U4; the port 2 of chip U4 is grounded, the port 1 is grounded through resistor R52, the port 1 is also electrically connected to the port 3 of chip U4 through resistor R51, and the port 3 accesses the 5V power supply through resistor R41; The port 3 of chip U4 is also grounded through capacitor C35, and the port 3 is grounded through resistor R39, resistor R47, and resistor R40 in sequence; one end of capacitor C36 is grounded and the other end is electrically connected to the port 3 of chip U4; one end of resistor R35 is connected between resistor R39 and the port 3 of chip U4, and the other end is grounded through resistor R48 and resistor R42 in sequence; one end of capacitor C37 and capacitor C38 is grounded, and the other end is connected between resistor R39 and resistor R47; the second reference voltage signal is connected between resistor R35 and resistor R48; capacitor C38 accesses the third reference voltage signal.

6. The detection circuit for detecting the output power of the USB power supply according to claim 5, wherein, The filtering circuit is an RC low-pass filtering circuit; among them, the RC low-pass filtering circuit includes resistor R16 and capacitor C53; one end of resistor R16 is electrically connected to the port 3 of chip IC1 through resistor R55 and the other end is connected to the port 6 of chip IC1; one end of capacitor C53 is grounded and the other end is connected between resistor R16 and the port 6 of chip IC1; the first real-time voltage signal input to the port 3 of chip IC1 forms a second real-time voltage signal after being filtered by resistor R16 and capacitor C53 and is input to the port 6 of chip IC1.

7. The detection circuit for detecting the output power of the USB power supply according to claim 5, characterized in that, The output control circuit includes resistor R30, resistor R33, resistor R14, triode Q5, and triode Q6; Among them, one end of the resistor R33 is electrically connected to the port 1 of the chip IC1, and the other end is electrically connected to the base of the triode Q6; the emitter of the triode Q6 is grounded, and the collector is electrically connected to the base of the triode Q5 through the resistor R27; one end of the resistor R14 is grounded, and the other end is connected between the resistor R33 and the base of the triode Q6; the emitter of the triode Q5 is electrically connected to the port 7 of the chip IC1, and the collector is electrically connected to the subsequent circuit of the device; one end of the resistor R30 is electrically connected to the emitter of the triode Q5, and the other end is connected between the resistor R27 and the base of the triode Q5.

8. The detection circuit for detecting the output power of a USB power supply according to claim 1, characterized in that, It further includes a controllable precision power supply, which is electrically connected to the dual-channel operational amplifier and is used to provide a first reference voltage signal, a second reference voltage signal, and a third reference voltage signal to the dual-channel operational amplifier.

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