CN215493808U - Voltage detection circuit - Google Patents
Voltage detection circuit Download PDFInfo
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- CN215493808U CN215493808U CN202121199044.3U CN202121199044U CN215493808U CN 215493808 U CN215493808 U CN 215493808U CN 202121199044 U CN202121199044 U CN 202121199044U CN 215493808 U CN215493808 U CN 215493808U
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Abstract
The utility model provides a voltage detection circuit, comprising: the sampling circuit rectifies the voltage of the alternating-current power line to obtain a negative voltage, and level conversion is carried out on the negative voltage subjected to filtering and voltage division in sequence to obtain a positive comparison voltage; the hysteresis comparison circuit compares the forward comparison voltage with a first preset voltage threshold and a second preset voltage threshold, outputs a high level signal when the forward comparison voltage is greater than the first preset voltage threshold and less than the second preset voltage threshold, and outputs a low level signal when the forward comparison voltage is greater than the second preset voltage threshold, wherein the first preset voltage threshold is less than the second preset voltage threshold, so that the voltage state of the alternating current power line is detected by a threshold comparison method, the interference of external factors is avoided, and the misjudgment is prevented.
Description
Technical Field
The utility model relates to the technical field of power supplies, in particular to a voltage detection circuit.
Background
With the continuous development of integrated circuits and the increase of system complexity, machines powered by double power supplies or even multiple power supplies are more and more popular. When any power supply fails, a normal power supply can be used for supplying power to the machine, so that whether the power supply is in a failure state or an undervoltage or overvoltage state needs to be judged, generally, switching points of double-voltage machines are detected through piezoresistors or voltage-regulator tubes, and the judgment points are prone to being inaccurate due to temperature and external factors, so that judgment errors are caused, and devices are damaged.
SUMMERY OF THE UTILITY MODEL
Therefore, the present invention is directed to a voltage detection circuit, which overcomes the defect that a voltage detection device in the prior art is susceptible to external factors and makes a misjudgment.
In order to achieve the purpose, the utility model provides the following technical scheme:
an embodiment of the present invention provides a voltage detection circuit, including: the sampling circuit is used for rectifying the voltage of the alternating current power line to obtain a negative voltage, and performing level conversion on the negative voltage subjected to filtering and voltage division sequentially to obtain a positive comparison voltage; the first input end of the hysteresis comparison circuit is connected with an external power supply, the hysteresis comparison circuit is used for comparing the forward comparison voltage with a first preset voltage threshold and a second preset voltage threshold, when the forward comparison voltage is greater than the first preset voltage threshold and smaller than the second preset voltage threshold, a high level signal is output, when the forward comparison voltage is greater than the second preset voltage threshold, a low level signal is output, and the first preset voltage threshold is smaller than the second preset voltage threshold.
In one embodiment, a sampling circuit includes: the voltage-stabilizing circuit comprises a rectifying circuit, a filter circuit, a voltage dividing circuit and a level conversion circuit, wherein the first end of the rectifying circuit is connected with an alternating current power line, the second end of the rectifying circuit is connected with the first end of the filter circuit and the first end of the voltage dividing circuit, and the rectifying circuit is used for rectifying the voltage of the alternating current power line to obtain negative voltage; the second end of the filter circuit is grounded, and the filter circuit is used for filtering negative voltage; the second end of the voltage division circuit is connected with the first input end of the level conversion circuit, the third end of the voltage division circuit is grounded, and the voltage division circuit is used for dividing the filtered negative voltage; the second input end of the level conversion circuit is grounded, the output end of the level conversion circuit is connected with the second input end of the hysteresis comparison circuit, and the level conversion circuit is used for carrying out level inversion on the divided negative voltage to obtain the positive comparison voltage.
In one embodiment, a rectifier circuit includes: and the cathode of the first diode is connected with the alternating current power circuit, and the anode of the first diode is connected with the first end of the filter circuit and the first end of the voltage division circuit.
In one embodiment, the filter circuit is an RC filter circuit, including: the first capacitor and the first resistor are connected in parallel, the first end of the first capacitor and the first resistor are connected with the second end of the rectifying circuit and the first end of the voltage dividing circuit respectively, and the second end of the first capacitor and the first resistor are connected in parallel and grounded.
In one embodiment, a voltage divider circuit includes: the first end of the second resistor and the second capacitor after being connected in parallel is connected with the first end of the filter circuit and the second end of the rectifying circuit through the third resistor respectively, the first end of the second resistor and the second capacitor after being connected in parallel is also connected with the first input end of the level conversion circuit, and the second end of the second resistor and the second capacitor after being connected in parallel is grounded.
In one embodiment, a level shift circuit includes: the voltage divider comprises a fourth resistor, a fifth resistor and a first comparator, wherein the positive phase input end of the first comparator is grounded, the negative phase input end of the first comparator is connected with the second end of the voltage dividing circuit through the fourth resistor, the negative phase input end of the first comparator is further connected with the output end of the first comparator through the fifth resistor, and the output end of the first comparator is further connected with the second input end of the hysteresis comparison circuit.
In one embodiment, a hysteresis comparison circuit includes: the controllable voltage divider circuit comprises a controllable voltage divider circuit, a hysteresis circuit and a comparison circuit, wherein a first end of the controllable voltage divider circuit is connected with an external power supply, and a second end of the controllable voltage divider circuit is connected with a first input end of the comparison circuit; the first input end of the comparison circuit is also connected with the output end of the comparison circuit through the hysteresis circuit, and the second input end of the comparison circuit is connected with the second end of the sampling circuit; when the voltage of the alternating current power line is higher than a first preset voltage threshold and is smaller than a second preset voltage threshold, the comparison circuit outputs a high level signal, the hysteresis circuit is in a conducting state, and the voltage of a first input end of the comparison circuit is the second preset voltage threshold; when the voltage of the alternating current power line is higher than the second preset voltage threshold, the comparison circuit outputs a low level signal, the hysteresis circuit is in a disconnected state, and the voltage of the first input end of the comparison circuit is the first preset voltage threshold.
In one embodiment, the controllable voltage divider circuit includes: the first end of the variable resistor is connected with an external power supply, the second end of the variable resistor is connected with the first end of the sixth resistor, the two ends of the sixth resistor are respectively connected with the first input end of the comparison circuit and the first end of the seventh resistor, and the second end of the seventh resistor is grounded.
In one embodiment, the hysteresis circuit includes: the first end of the eighth resistor is connected with the first input end of the comparison circuit, the second end of the eighth resistor is connected with the anode of the second diode, and the cathode of the second diode is connected with the output end of the comparison circuit.
In one embodiment, the comparison circuit includes: the positive phase input end of the second comparator is connected with the second end of the sampling circuit through the ninth resistor, the negative phase input end of the second comparator is grounded through the third capacitor, the positive power supply end and the negative power supply end of the second comparator are both connected with an external power supply, and the positive power supply end and the negative power supply end of the second comparator are grounded through the fourth capacitor and the fifth capacitor respectively.
In one embodiment, the voltage detection circuit further includes: and the first end of the display circuit is connected with the output end of the hysteresis comparison circuit, and the second end of the display circuit is grounded and is used for displaying a corresponding display state based on the high level signal and the low level signal output by the hysteresis comparison circuit.
In one embodiment, a display circuit includes: the first end of the first light-emitting diode and the first end of the second light-emitting diode which are connected in reverse parallel are connected with the output end of the hysteresis comparison circuit through the tenth resistor, and the second end of the first light-emitting diode and the second light-emitting diode which are connected in reverse parallel are grounded.
In one embodiment, the voltage detection circuit further includes: the first end of the sampling circuit is connected with an alternating current power line through a voltage transformation module, and the voltage transformation module is used for carrying out voltage reduction processing on the voltage of the alternating current power line.
The technical scheme of the utility model has the following advantages:
according to the voltage detection circuit provided by the utility model, the sampling circuit rectifies the voltage of the alternating current power line to obtain a negative voltage, and level conversion is carried out on the negative voltage subjected to filtering and voltage division in sequence to obtain a positive comparison voltage; the hysteresis comparison circuit compares the forward comparison voltage with a first preset voltage threshold and a second preset voltage threshold, outputs a high level signal when the forward comparison voltage is greater than the first preset voltage threshold and less than the second preset voltage threshold, and outputs a low level signal when the forward comparison voltage is greater than the second preset voltage threshold, wherein the first preset voltage threshold is less than the second preset voltage threshold, so that the voltage state of the alternating current power line is detected by a threshold comparison method, the interference of external factors is avoided, and the misjudgment is prevented.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings 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 other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a composition diagram of a specific example of a voltage detection circuit according to an embodiment of the present invention;
fig. 2 is a composition diagram of another specific example of the voltage detection circuit according to the embodiment of the present invention;
fig. 3 is a composition diagram of another specific example of the voltage detection circuit according to the embodiment of the present invention;
fig. 4 is a specific circuit structure diagram of the voltage detection circuit according to the embodiment of the present invention;
fig. 5 is a composition diagram of a specific example of the voltage detection circuit according to the embodiment of the present invention;
fig. 6 is a composition diagram of another specific example of the voltage detection circuit according to the embodiment of the present invention.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.
In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.
Examples
An embodiment of the present invention provides a voltage detection circuit, which is applied to an occasion where a power output voltage state needs to be determined, as shown in fig. 1, and includes: a sampling circuit 1 and a hysteresis comparison circuit 2.
As shown in fig. 1, a first end of a sampling circuit 1 according to an embodiment of the present invention is connected to an ac power line, a second end of the sampling circuit 1 is connected to a second input end of a hysteresis comparison circuit 2, and the sampling circuit 1 is configured to rectify an ac power line voltage to obtain a negative voltage, and perform level conversion on the negative voltage that is sequentially filtered and divided to obtain a positive comparison voltage.
Because the voltage of the alternating-current power line is alternating-current voltage, the negative voltage of the alternating-current power line is obtained by using the sampling circuit 1, then the peak in the negative voltage is filtered, and the peak is subjected to voltage reduction processing and then subjected to level conversion to obtain positive comparison voltage.
It should be noted that, in the embodiment of the present invention, the sampling circuit 1 may be used to directly rectify the voltage of the ac power line, obtain the forward voltage through rectification, filter the peak of the forward circuit, and then perform voltage reduction processing on the peak to obtain the forward comparison voltage.
As shown in fig. 1, a first input terminal of a hysteresis comparison circuit 2 according to an embodiment of the present invention is connected to an external power source, the hysteresis comparison circuit 2 is configured to compare a forward comparison voltage with a first preset voltage threshold and a second preset voltage threshold, output a high level signal when the forward comparison voltage is greater than the first preset voltage threshold and smaller than the second preset voltage threshold, and output a low level signal when the forward comparison voltage is greater than the second preset voltage threshold, where the first preset voltage threshold is smaller than the second preset voltage threshold.
The hysteresis comparison circuit 2 of the embodiment of the utility model can automatically set the first preset voltage threshold and the second preset voltage threshold, can reasonably set the parameters of components of the circuit, and can set the hysteresis difference (the difference value between the first preset voltage threshold and the second preset voltage threshold), thereby realizing that when the voltage of the alternating current power line is between the first preset voltage threshold and the second preset voltage threshold, a high level signal is output, and when the voltage of the alternating current power line is higher than the second preset voltage threshold, a low level signal is output, so as to represent the current running state of the alternating current power line.
In an embodiment, as shown in fig. 2, the voltage detection circuit further includes: the first end of the sampling circuit 1 is connected with an alternating current power line through a voltage transformation module 3, and the voltage transformation module 3 is used for carrying out voltage reduction processing on the voltage of the alternating current power line.
Because the ac power line is large, in order to prevent the voltage of the ac power line from damaging each component in the circuit, the voltage of the ac power line is stepped down by the voltage transformation module 3 and then transmitted to the sampling circuit 1, wherein the voltage transformation module 3 may be a high-frequency transformer, which is only used as an example and is not limited thereto.
In a specific embodiment, as shown in fig. 3, the sampling circuit 1 includes: a rectifier circuit 11, a filter circuit 12, a voltage divider circuit 13, and a level shifter circuit 14.
As shown in fig. 3, a first end of a rectifier circuit 11 according to an embodiment of the present invention is connected to an ac power line, a second end of the rectifier circuit 11 is connected to a first end of a filter circuit 12 and a first end of a voltage divider circuit 13, and the rectifier circuit 11 is configured to rectify an ac power line voltage to obtain a negative voltage.
Specifically, as shown in fig. 4, the rectifier circuit 11 of the embodiment of the present invention includes: a first diode D1, a cathode (IN terminal) of the first diode D1 is connected to the ac power line, and an anode of the first diode D1 is connected to the first terminal of the filter circuit 12 and the first terminal of the voltage divider circuit 13.
In fig. 4, the cathode of the first diode D1 is connected to the ac power line, so that a negative voltage can be obtained, but if the anode of the first diode D1 is connected to the ac power line, a positive voltage can be obtained by rectifying the ac power line, and in this case, the level shift circuit 14 is not required to shift the level of the divided positive voltage.
The rectifier circuit 11 according to the embodiment of the present invention is not limited to the circuit formed by the first diode D1, and may be a bridge rectifier circuit, which is not limited herein.
As shown in fig. 3, the second terminal of the filter circuit 12 according to the embodiment of the present invention is grounded, and the filter circuit 12 is used for filtering the negative voltage.
Specifically, as shown in fig. 4, the filter circuit 12 according to the embodiment of the present invention is an RC filter circuit, and includes: the rectifier circuit comprises a first capacitor C1 and a first resistor R1, wherein a first end of the first capacitor C1 connected in parallel with the first resistor R1 is connected with a second end of the rectifier circuit 11 and a first end of the voltage division circuit 13, respectively, and a second end of the first capacitor C1 connected in parallel with the first resistor R1 is grounded.
As shown in fig. 4, the first resistor R1 and the first capacitor C1 form a first-order RC filter circuit, and the embodiment of the utility model may also be a second-order RC filter circuit or other filter circuits with the same function, which is not limited herein.
As shown in fig. 3, a second terminal of the voltage divider 13 according to the embodiment of the present invention is connected to a first input terminal of the level shifter circuit 14, a third terminal of the voltage divider 13 is grounded, and the voltage divider 13 is configured to divide the filtered negative voltage.
Specifically, as shown in fig. 4, the voltage divider circuit 13 according to the embodiment of the present invention includes: a second resistor R2, a third resistor R3, and a second capacitor C2, wherein a first end of the second resistor R2 connected in parallel with the second capacitor C2 is connected to a first end of the filter circuit 12 and a second end of the rectifier circuit 11 through a third resistor R3, a first end of the second resistor R2 connected in parallel with the second capacitor C2 is further connected to a first input end of the level shifter circuit 14, and a second end of the second resistor R2 connected in parallel with the second capacitor C2 is grounded.
According to the embodiment of the utility model, the voltage division ratio can be set by setting the resistance values of the second resistor R2 and the third resistor R3, so that the amplitude of the divided negative voltage is controlled.
As shown in fig. 3, a second input terminal of the level shift circuit 14 according to the embodiment of the present invention is grounded, an output terminal of the level shift circuit 14 is connected to the second input terminal of the hysteresis comparison circuit 2, and the level shift circuit 14 is configured to perform level inversion on the divided negative voltage to obtain a positive comparison voltage.
Specifically, as shown in fig. 4, the level shift circuit 14 includes: a fourth resistor R4, a fifth resistor R5, and a first comparator U1, wherein a non-inverting input terminal of the first comparator U1 is grounded, an inverting input terminal of the first comparator U1 is connected to the second terminal of the voltage divider circuit 13 through the fourth resistor R4, an inverting input terminal of the first comparator U1 is further connected to an output terminal thereof through the fifth resistor R5, and an output terminal of the first comparator U1 is further connected to the second input terminal of the hysteresis comparator circuit 2.
It should be noted that the level shift circuit 14 according to the embodiment of the present invention is not limited to use the first comparator U1 to invert the level of the divided negative voltage to obtain the positive comparison voltage, and may also use the not logic chip to invert the divided negative voltage to obtain the positive comparison voltage, which is not limited herein.
In one embodiment, as shown in fig. 5, the hysteresis comparator circuit 2 includes: controllable bleeder circuit 21, hysteresis circuit 22, comparator circuit 23.
As shown in fig. 5, a first terminal of the controllable voltage dividing circuit 21 according to the embodiment of the present invention is connected to an external power source, and a second terminal of the controllable voltage dividing circuit 21 is connected to a first input terminal (in1 terminal) of the comparing circuit 23.
Specifically, as shown in fig. 4, the controllable voltage dividing circuit 21 includes: the voltage limiting circuit comprises a variable resistor W1, a sixth resistor R6 and a seventh resistor R7, wherein a first end (P1 end) of the variable resistor is connected with an external power supply, a second end of the variable resistor is connected with a first end of the sixth resistor, two ends of the sixth resistor are respectively connected with a first input end of a comparison circuit 23 and a first end of the seventh resistor, a second end of the seventh resistor is grounded, and the voltage of the external power supply is limited by adjusting the resistance value of the controllable resistor.
As shown in fig. 5, the first input terminal (terminal in 1) of the comparison circuit 23 according to the embodiment of the present invention is further connected to the output terminal (terminal out) thereof through the hysteresis circuit 22, and the second input terminal (terminal in 2) of the comparison circuit 23 is connected to the second terminal of the sampling circuit 1.
Specifically, as shown in fig. 4, the hysteresis circuit 22 of the embodiment of the present invention includes: an eighth resistor R8 and a second diode D2, wherein a first end of the eighth resistor is connected to the first input terminal of the comparator 23, a second end of the eighth resistor is connected to an anode of the second diode, and a cathode of the second diode is connected to the output terminal of the comparator 23.
Specifically, as shown in fig. 4, the comparison circuit 23 of the embodiment of the present invention includes: the sampling circuit comprises a second comparator U2, a ninth resistor R9, a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5, wherein a positive phase input end of the second comparator U2 is connected with a second end of the controllable voltage division circuit 21, a positive phase input end of the second comparator U2 is further connected with an output end of the second comparator U2 through a hysteresis circuit 22, an inverting phase input end of the second comparator U2 is connected with a second end of the sampling circuit 1 through the ninth resistor R9, an inverting phase input end of the second comparator U2 is further grounded through the third capacitor C3, a positive power source end and a negative power source end of the second comparator U2 are both connected with an external power supply, and the positive power source end and the negative power source end of the second comparator U2 are respectively grounded through the fourth capacitor C4 and the fifth capacitor C5.
In one embodiment, as shown in fig. 6, the voltage detection circuit further includes: and the display circuit 4 is connected with the output end of the hysteresis comparison circuit 2 at a first end, grounded at a second end, and used for displaying a corresponding display state based on the high level signal and the low level signal output by the hysteresis comparison circuit 2.
Specifically, as shown in fig. 4, the display circuit 4 of the embodiment of the present invention includes: the first light-emitting diode LD1, the second light-emitting diode LED2 and the tenth resistor R10, wherein a first end of the first light-emitting diode LD1 and a second end of the second light-emitting diode LED2 which are connected in reverse parallel are connected with the output end of the hysteresis comparison circuit 2 through the tenth resistor R10, and a second end of the first light-emitting diode LD1 and the second light-emitting diode LED2 which are connected in reverse parallel are grounded.
In the embodiment of the present invention, when the voltage of the ac power line is higher than the first preset voltage threshold and is smaller than the second preset voltage threshold, the comparison circuit 23 outputs a high level signal, the hysteresis circuit 22 is in a conducting state, the voltage at the first input end of the comparison circuit 23 is the second preset voltage threshold, that is, when the input voltage at the second input end of the second comparator U2 is smaller than the input voltage at the first input end, the second comparator U2 outputs a low level signal, the second diode is conducting, and at this time, the voltage at the first input end of the second comparator U2 is determined by the controllable resistor, the sixth resistor, the seventh resistor, the eighth resistor, and the tenth resistor.
In the embodiment of the present invention, when the voltage of the ac power line is higher than the second preset voltage threshold, the comparison circuit 23 outputs a low level signal, the hysteresis circuit 22 is in the off state, the voltage at the first input terminal of the comparison circuit 23 is the first preset voltage threshold, that is, when the input voltage at the second input terminal of the second comparator U2 is greater than the input voltage at the first terminal, the second comparator U2 outputs a high level signal, the second diode is turned off, and at this time, the voltage at the first input terminal of the second comparator U2 is determined by the controllable resistor, the sixth resistor, and the seventh resistor.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of the utility model may be made without departing from the spirit or scope of the utility model.
Claims (13)
1. A voltage detection circuit, comprising: a sampling circuit and a hysteresis comparison circuit, wherein,
the first end of the sampling circuit is connected with an alternating current power line, the second end of the sampling circuit is connected with the second input end of the hysteresis comparison circuit, the sampling circuit is used for rectifying the voltage of the alternating current power line to obtain a negative voltage, and level conversion is carried out on the negative voltage which is subjected to filtering and voltage division in sequence to obtain a positive comparison voltage;
the first input end of the hysteresis comparison circuit is connected with an external power supply, the hysteresis comparison circuit is used for comparing the forward comparison voltage with a first preset voltage threshold value and a second preset voltage threshold value, when the forward comparison voltage is greater than the first preset voltage threshold value and less than the second preset voltage threshold value, a high level signal is output, when the forward comparison voltage is greater than the second preset voltage threshold value, a low level signal is output, and the first preset voltage threshold value is less than the second preset voltage threshold value.
2. The voltage detection circuit of claim 1, wherein the sampling circuit comprises: a rectifying circuit, a filter circuit, a voltage divider circuit, and a level shifter circuit, wherein,
the first end of the rectifying circuit is connected with the alternating current power line, the second end of the rectifying circuit is connected with the first end of the filter circuit and the first end of the voltage dividing circuit, and the rectifying circuit is used for rectifying the voltage of the alternating current power line to obtain negative voltage;
the second end of the filter circuit is grounded, and the filter circuit is used for filtering the negative voltage;
the second end of the voltage division circuit is connected with the first input end of the level conversion circuit, the third end of the voltage division circuit is grounded, and the voltage division circuit is used for dividing the filtered negative voltage;
the second input end of the level conversion circuit is grounded, the output end of the level conversion circuit is connected with the second input end of the hysteresis comparison circuit, and the level conversion circuit is used for carrying out level inversion on the divided negative voltage to obtain a positive comparison voltage.
3. The voltage detection circuit according to claim 2, wherein the rectifier circuit includes:
and the cathode of the first diode is connected with the alternating current power line, and the anode of the first diode is connected with the first end of the filter circuit and the first end of the voltage division circuit.
4. The voltage detection circuit of claim 2, wherein the filter circuit is an RC filter circuit comprising: a first capacitor, a first resistor, wherein,
the first end of the first capacitor connected with the first resistor in parallel is connected with the second end of the rectifying circuit and the first end of the voltage dividing circuit respectively, and the second end of the first capacitor connected with the first resistor in parallel is grounded.
5. The voltage detection circuit of claim 2, wherein the voltage divider circuit comprises: a second resistor, a third resistor, a second capacitor, wherein,
the first end of the second resistor and the second capacitor after being connected in parallel is respectively connected with the first end of the filter circuit and the second end of the rectifying circuit through a third resistor, the first end of the second resistor and the second capacitor after being connected in parallel is also connected with the first input end of the level conversion circuit, and the second end of the second resistor and the second capacitor after being connected in parallel is grounded.
6. The voltage detection circuit of claim 2, wherein the level shift circuit comprises: a fourth resistor, a fifth resistor, a first comparator, wherein,
the positive phase input end of the first comparator is grounded, the negative phase input end of the first comparator is connected with the second end of the voltage division circuit through a fourth resistor, the negative phase input end of the first comparator is further connected with the output end of a fifth resistor, and the output end of the first comparator is further connected with the second input end of the hysteresis comparison circuit.
7. The voltage detection circuit of claim 1, wherein the hysteresis comparison circuit comprises: a controllable voltage dividing circuit, a hysteresis circuit, and a comparison circuit, wherein,
the first end of the controllable voltage division circuit is connected with an external power supply, and the second end of the controllable voltage division circuit is connected with the first input end of the comparison circuit;
the first input end of the comparison circuit is also connected with the output end of the hysteresis circuit through the hysteresis circuit, and the second input end of the comparison circuit is connected with the second end of the sampling circuit;
when the voltage of the alternating current power line is higher than the first preset voltage threshold and is smaller than the second preset voltage threshold, the comparison circuit outputs a high level signal, the hysteresis circuit is in a conducting state, and the voltage of a first input end of the comparison circuit is the second preset voltage threshold;
when the voltage of the alternating current power line is higher than the second preset voltage threshold, the comparison circuit outputs a low level signal, the hysteresis circuit is in a disconnected state, and the voltage of a first input end of the comparison circuit is the first preset voltage threshold.
8. The voltage detection circuit of claim 7, wherein the controllable voltage divider circuit comprises: a variable resistor, a sixth resistor, a seventh resistor, wherein,
the first end of the variable resistor is connected with an external power supply, the second end of the variable resistor is connected with the first end of the sixth resistor, two ends of the sixth resistor are respectively connected with the first input end of the comparison circuit and the first end of the seventh resistor, and the second end of the seventh resistor is grounded.
9. The voltage detection circuit of claim 7, wherein the hysteresis circuit comprises: an eighth resistor and a second diode, wherein,
the first end of the eighth resistor is connected with the first input end of the comparison circuit, the second end of the eighth resistor is connected with the anode of the second diode, and the cathode of the second diode is connected with the output end of the comparison circuit.
10. The voltage detection circuit of claim 7, wherein the comparison circuit comprises: a second comparator, a ninth resistor, a third capacitor, a fourth capacitor and a fifth capacitor, wherein,
the positive phase input end of the second comparator is connected with the second end of the controllable voltage division circuit, the positive phase input end of the second comparator is further connected with the output end of the controllable voltage division circuit through the hysteresis circuit, the reverse phase input end of the second comparator is connected with the second end of the sampling circuit through the ninth resistor, the reverse phase input end of the second comparator is further grounded through the third capacitor, the positive power supply end and the negative power supply end of the second comparator are both connected with an external power supply, and the positive power supply end and the negative power supply end of the second comparator are grounded through the fourth capacitor and the fifth capacitor respectively.
11. The voltage detection circuit of claim 1, further comprising:
and the first end of the display circuit is connected with the output end of the hysteresis comparison circuit, and the second end of the display circuit is grounded and is used for displaying a corresponding display state based on the high level signal and the low level signal output by the hysteresis comparison circuit.
12. The voltage detection circuit of claim 11, wherein the display circuit comprises: a first light emitting diode, a second light emitting diode and a tenth resistor, wherein,
the first end of the first light-emitting diode and the first end of the second light-emitting diode which are connected in reverse parallel are connected with the output end of the hysteresis comparison circuit through a tenth resistor, and the second end of the first light-emitting diode and the second light-emitting diode which are connected in reverse parallel are grounded.
13. The voltage detection circuit of claim 1, further comprising:
the first end of the sampling circuit is connected with the alternating current power line through a voltage transformation module, and the voltage transformation module is used for carrying out voltage reduction processing on the voltage of the alternating current power line.
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| CN202121199044.3U CN215493808U (en) | 2021-05-31 | 2021-05-31 | Voltage detection circuit |
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| CN202121199044.3U CN215493808U (en) | 2021-05-31 | 2021-05-31 | Voltage detection circuit |
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