CN211456136U - USB interface circuit and smart jack - Google Patents
USB interface circuit and smart jack Download PDFInfo
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- CN211456136U CN211456136U CN202020275187.7U CN202020275187U CN211456136U CN 211456136 U CN211456136 U CN 211456136U CN 202020275187 U CN202020275187 U CN 202020275187U CN 211456136 U CN211456136 U CN 211456136U
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Abstract
The utility model relates to a USB interface circuit and an intelligent socket, belonging to the technical field of chargers, comprising a USB terminal, wherein the USB terminal comprises a power supply positive pin and a power supply negative pin and is used for connecting a power supply; a threshold generation circuit for generating a voltage threshold; the comparator is used for comparing the USB interface voltage with the voltage threshold value and outputting the voltage according to the comparison result; the comparator comprises a first input end, a second input end and an output end; the first input end is connected with a power supply negative electrode pin of the USB terminal; the second input end is connected with the threshold value generating circuit; and the indicating lamp circuit is connected with the output end of the comparator and used for controlling the brightness according to the output result of the comparator, so that the problems of inaccurate indication and low sensitivity of the conventional USB charging indicating circuit are solved.
Description
Technical Field
The utility model relates to a USB interface circuit and smart jack belongs to charger technical field.
Background
In the prior art, an intelligent socket is often found, which has two-hole jacks, three-hole jacks, a key, a load indicator lamp and a USB interface, wherein the load indicator lamp is turned on or off along with the switch of an electronic load, so that the power supply state of the USB load is indicated through the light on or off or the color change.
As shown in fig. 1, for the existing USB charging circuit with a load charging indication function, a 1N5401 diode is used to perform on-off control on a triode through a voltage difference between two ends of the diode according to a principle that a voltage drop is generated after a load is conducted, so as to control on and off of a load indicator light; however, the USB charging circuit is generally suitable for low power loads, the USB output current is generally 200mA, and the voltage drop is as high as 0.8V, which causes a large voltage difference between the input voltage and the USB output voltage, and limits the selection range (voltage input parameter) of the current limiting IC.
However, there are two technical drawbacks in the above scheme:
(1) in the conventional USB charging circuit, when a load is full, the current is maintained to cause voltage difference, the current is in a constantly bright indicating state, the load can be damaged, and when the load current is large, the power consumption is obviously wasted, and the sensitivity is low;
(2) the USB output needs to meet the voltage output of 4.75V-5.1V, when the 1N5401 diode scheme is used, the voltage difference of the diode is 0.8V, the voltage output needs to be improved to be more than 5.8V, the voltage input range of the USB current-limiting chip is 2.7-5.5V, the two conflict, and accurate indication cannot be achieved.
SUMMERY OF THE UTILITY MODEL
The utility model aims at providing a USB interface circuit and smart jack to solve the current USB indicating circuit that charges and instruct inaccurate, the low problem of sensitivity.
In order to achieve the above purpose, the technical scheme of the utility model is that: the utility model provides a USB interface circuit, which comprises a USB terminal, wherein the USB terminal comprises a power supply anode pin and a power supply cathode pin and is used for connecting a power supply;
further comprising:
a threshold generation circuit for generating a voltage threshold;
the comparator is used for comparing the USB interface voltage with the voltage threshold value and outputting the voltage according to the comparison result;
the comparator comprises a first input end, a second input end and an output end; the first input end is connected with a power supply negative electrode pin of the USB terminal; the second input end is connected with the threshold value generating circuit;
and the indicator light circuit is connected with the output end of the comparator and used for controlling the brightness according to the output result of the comparator.
The utility model discloses an effective voltage that monitors USB terminal department to set up suitable voltage threshold value and carry out the comparison, guaranteed the pilot lamp and instructed the accuracy of the connection condition. By replacing the existing diode with the comparison chip, the high voltage difference generated by using the diode is reduced, and the selection range of the current-limiting IC is enlarged.
Furthermore, a power supply positive electrode pin of the USB terminal is connected with the power supply and is grounded through two capacitors connected in parallel; and a power supply negative electrode pin of the USB terminal is grounded through the sampling resistor.
Furthermore, the threshold generating circuit is a resistor voltage dividing circuit and comprises a first resistor and a second resistor which are sequentially connected in series, the first resistor is connected with a power supply positive electrode pin of the USB terminal and used for providing power supply voltage, and the second resistor is grounded; and the connecting end of the first resistor and the second resistor is connected with the second input end of the comparator.
Further, the indicator light circuit comprises an indicator light and a fourth resistor, and the indicator light is connected with the output end of the comparator through the fourth resistor.
Further, a power supply end of the comparator is connected with a power supply positive pin of the USB interface.
Further, the comparator adopts an LM358 chip.
The utility model also provides an intelligent socket, which comprises an electric jack and a USB jack, wherein the USB jack is connected with a USB interface circuit and comprises a USB terminal, and the USB terminal comprises a power supply anode pin and a power supply cathode pin and is used for connecting a power supply;
further comprising:
a threshold generation circuit for generating a voltage threshold;
the comparator is used for comparing the USB interface voltage with the voltage threshold value and outputting the voltage according to the comparison result;
the comparator comprises a first input end, a second input end and an output end; the first input end is connected with a power supply negative electrode pin of the USB terminal; the second input end is connected with the threshold value generating circuit;
and the indicator light circuit is connected with the output end of the comparator and used for controlling the brightness according to the output result of the comparator.
The utility model discloses an effective voltage that monitors USB terminal department to set up suitable voltage threshold value and carry out the comparison, guaranteed the pilot lamp and instructed the accuracy of the connection condition. By replacing the existing diode with the comparison chip, the high voltage difference generated by using the diode is reduced, and the selection range of the current-limiting IC is enlarged.
Furthermore, a power supply positive electrode pin of the USB terminal is connected with the power supply and is grounded through two capacitors connected in parallel; and a power supply negative electrode pin of the USB terminal is grounded through the sampling resistor.
Furthermore, the threshold generating circuit is a resistor voltage dividing circuit and comprises a first resistor and a second resistor which are sequentially connected in series, the first resistor is connected with a power supply positive electrode pin of the USB terminal and used for providing power supply voltage, and the second resistor is grounded; and the connecting end of the first resistor and the second resistor is connected with the second input end of the comparator.
Further, the indicator light circuit comprises an indicator light and a fourth resistor, and the indicator light is connected with the output end of the comparator through the fourth resistor.
Further, a power supply end of the comparator is connected with a power supply positive pin of the USB interface.
Further, the comparator adopts an LM358 chip.
Drawings
FIG. 1 is a circuit diagram of a USB interface in the prior art;
fig. 2 is a schematic diagram of the power supply of the USB interface circuit in the embodiment of the USB interface circuit of the present invention;
fig. 3 is a schematic diagram of threshold comparison in the embodiment of the USB interface circuit of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention, i.e., the described embodiments are only some, but not all embodiments of the invention. The components of embodiments of the present invention, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the accompanying drawings, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiment of the present invention, all other embodiments obtained by the person skilled in the art without creative work belong to the protection scope of the present invention.
USB interface circuit embodiment:
the present embodiment provides a USB interface circuit, and the general concept of the interface circuit is: the voltage or the current flowing through the power supply pin in the USB terminal is obtained through the sampling resistor, and the sensitivity of the indicating circuit in the charging process is improved according to the adjustment of the comparison threshold.
Specifically, in this embodiment, the specific composition of the USB interface circuit is described by taking the detection of the voltage at the negative pin of the power supply of the USB terminal as an example.
In order to obtain the voltage at the power supply negative pin of the USB terminal, in this embodiment, a sampling resistor (R18) is disposed at the power supply negative pin, the current flowing through the power supply negative pin is detected by the sampling resistor (R18), and a voltage difference is formed by the sampling resistor (R18) to obtain the voltage value at the power supply negative pin.
As shown in fig. 2, the schematic diagram of the USB interface circuit in this embodiment includes a USB terminal, where the USB terminal includes a positive power pin and a negative power pin for connecting to a power supply. In this embodiment, the USB terminal is used as a power adapter terminal to connect to a power supply, and is equivalent to a socket for supplying power to a load having a matching plug. In fig. 2, when the USB interface circuit is connected to the power supply, the power supply is usually connected to the USB interface circuit through a corresponding voltage-reducing module or a current-limiting IC.
As shown in fig. 3, the USB interface circuit further includes a threshold generation circuit for generating a voltage threshold. In the embodiment, a resistor voltage-dividing circuit is used as a threshold generating circuit, and comprises a first resistor (R16) and a second resistor (R20) which are sequentially connected in series, wherein the first resistor (R16) is connected with a power supply positive electrode pin of the USB terminal and used for providing power supply voltage, and the second resistor (R20) is grounded; the connection end of the first resistor (R16) and the second resistor (R20) is connected with the second input end of the comparator. As another embodiment, another threshold generation circuit may be used, and for example, a constant current method or a constant voltage method may be used to obtain the threshold.
In this embodiment, the sensitivity of the USB indicating circuit is mainly adjusted by comparing the threshold value with one comparator. As shown IN FIG. 3, IN the present embodiment, the comparator includes a first input terminal (IN +), a second input terminal (IN-) and an output terminal (OUT 1); the first input end (IN +) is connected with a power supply negative electrode pin of the USB terminal; the second input terminal (IN-) is connected to a threshold generation circuit. The output terminal (OUT1) of the comparator is connected with an indicator light circuit for controlling the brightness according to the output result of the comparator.
The indicating lamp circuit comprises an indicating lamp and a fourth resistor, wherein the indicating lamp is connected with the output end of the comparator through the fourth resistor.
In this embodiment, a power supply end of the comparator is connected to the power supply positive pin of the USB interface. In another embodiment, in this embodiment, the power supply terminal of the comparator may be directly connected to a power supply.
In this embodiment, the working principle of the USB interface circuit is as follows: when the voltage difference between the two ends of the sampling resistor is detected to be higher than the voltage threshold value, the color change or the on-off change of the USB indicating lamp is used for power supply prompting.
Or when the plug of the USB load charging equipment is unplugged, the current flowing through the sampling resistor is 0, and is lower than the voltage threshold, the output of the comparator is turned off, and the indicator light is turned off or the color of the indicator light changes.
As a further improvement of this embodiment, in this embodiment, the indicator light may be displayed in a manner of changing the color of the light or changing the on/off state of the indicator light. Specifically, (1) the light on-off changes: the indicator lamp adopts red and blue double-color patch LEDs as the USB terminal and USB plug power-on and power-off state and network-on/network-off state indication. The red and blue light-emitting diodes are reversely connected in parallel, and when the USB intelligent socket is electrified, the light-emitting diodes display red light to prompt that the USB intelligent socket is in an electrified state; the light emitting diode displays blue light to prompt the load power supply. And changing the red and blue double text lamp into a warm white lamp. (2) Color change of the indicator light: only the color change of the light emitting diode is used to only change the load power supply prompt.
In this embodiment, the sensitivity of the indicating circuit is adjusted by adjusting the comparison between the first resistor (R16) and the second resistor (R20) to adjust the threshold of the comparator. By replacing the existing diode with the comparison chip, the problem that the difference between the input voltage and the USB output voltage is large due to high voltage difference generated by using the diode is solved, and the selection range of the current-limiting IC is enlarged.
In this embodiment, the comparator may adopt an LM358 operational amplifier (two-way), or may adopt a single-way operational amplifier, for example, OPA365aid bvr.
Smart jack embodiment:
in this embodiment, this smart jack includes electric jack and USB jack, the USB jack is connected with USB interface circuit. The specific contents of the USB interface circuit have been described in detail in the above embodiments of the USB interface circuit, and therefore, the details are not repeated herein.
The above description is only for the preferred embodiment of the present invention, and the present invention is not limited thereto, the protection scope of the present invention is defined by the claims, and all structural changes equivalent to the contents of the description and drawings of the present invention should be included in the protection scope of the present invention.
Claims (7)
1. A USB interface circuit comprises a USB terminal, wherein the USB terminal comprises a power supply positive electrode pin and a power supply negative electrode pin and is used for being connected with a power supply;
it is characterized by also comprising:
a threshold generation circuit for generating a voltage threshold;
the comparator is used for comparing the USB interface voltage with the voltage threshold value and outputting the voltage according to the comparison result;
the comparator comprises a first input end, a second input end and an output end; the first input end is connected with a power supply negative electrode pin of the USB terminal; the second input end is connected with the threshold value generating circuit;
and the indicator light circuit is connected with the output end of the comparator and used for controlling the brightness according to the output result of the comparator.
2. The USB interface circuit according to claim 1, wherein the power supply positive pin of the USB terminal is connected to the power supply and grounded through two capacitors connected in parallel; and a power supply negative electrode pin of the USB terminal is grounded through the sampling resistor.
3. The USB interface circuit according to claim 1, wherein the threshold generation circuit is a resistor divider circuit, and includes a first resistor and a second resistor connected in series in sequence, the first resistor is connected to the positive power pin of the USB terminal for providing a power voltage, and the second resistor is grounded; and the connecting end of the first resistor and the second resistor is connected with the second input end of the comparator.
4. The USB interface circuit of claim 1, wherein the indicator light circuit comprises an indicator light and a fourth resistor, and the indicator light is connected to the output terminal of the comparator through the fourth resistor.
5. The USB interface circuit according to claim 1, wherein the power terminal of the comparator is connected to the positive power terminal of the USB interface.
6. The USB interface circuit of claim 1, wherein the comparator is an LM358 chip.
7. A smart jack comprising an electrical jack and a USB jack, said USB jack having connected thereto a USB interface circuit according to any one of claims 1 to 6.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020275187.7U CN211456136U (en) | 2020-03-06 | 2020-03-06 | USB interface circuit and smart jack |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202020275187.7U CN211456136U (en) | 2020-03-06 | 2020-03-06 | USB interface circuit and smart jack |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211456136U true CN211456136U (en) | 2020-09-08 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202020275187.7U Active CN211456136U (en) | 2020-03-06 | 2020-03-06 | USB interface circuit and smart jack |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211456136U (en) |
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2020
- 2020-03-06 CN CN202020275187.7U patent/CN211456136U/en active Active
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