CN217848932U

CN217848932U - Voltage band-pass device and power supply circuit

Info

Publication number: CN217848932U
Application number: CN202220340886.4U
Authority: CN
Inventors: 沈继光; 冯文斌; 廖庆; 朱赞林; 钟声
Original assignee: Guangzhou Asensing Technology Co Ltd
Current assignee: Guangzhou Asensing Technology Co Ltd
Priority date: 2022-02-18
Filing date: 2022-02-18
Publication date: 2022-11-18
Anticipated expiration: 2032-02-18

Abstract

The application provides a voltage band-pass device and a power supply circuit, and relates to the technical field of voltage detection. The first voltage selection module is electrically connected with the second voltage selection module, and the first voltage selection module and the second voltage selection module are respectively electrically connected with the power supply input end, the state output end and the voltage stabilization module; the first voltage selection module is used for being conducted when the voltage of the power supply input end is larger than a first voltage value, the second voltage selection module is used for being conducted when the voltage of the power supply input end is larger than a second voltage value, and the first voltage value is larger than the second voltage value; the state output end is used for outputting a first signal when the first voltage selection module and the second voltage selection module are both switched on or switched off; the state output end is also used for outputting a second signal when the first voltage selection module is switched off and the second voltage selection module is switched on. The application provides a voltage band-pass ware and power supply circuit has with low costs and uses more nimble advantage.

Description

Voltage band-pass device and power supply circuit

Technical Field

The application relates to the technical field of voltage detection, in particular to a voltage band-pass device and a power circuit.

Background

In recent years, electronic voltage products are increasing, and there is always a problem of unstable voltage during power supply design, and circuits need to face overvoltage or undervoltage situations. When the input voltage is higher than the maximum voltage that the electronic product can bear, the electronic product can be burnt, and when the voltage is lower than the normal working minimum voltage, the circuit can have the problem of uncertain state. Therefore, the input voltage needs to be detected and protected.

At present, a TVS transistor is one of important protection means, but the TVS transistor has limitations, and when an input voltage overvoltage always exists, the TVS transistor is burned out and cannot be recovered, and the influence caused by the undervoltage cannot be avoided. In addition, the MCU can be used for detecting the voltage to realize the detection and protection of the input voltage, but the MCU has the problems of high cost, inflexible detection and the like.

In summary, the detection and protection of the input voltage in the prior art have the problems of high cost and inflexibility.

Disclosure of Invention

An object of the application is to provide a voltage band-pass device and a power supply to solve the problems of high cost and inflexibility when detecting and protecting input voltage in the prior art.

In order to achieve the above purpose, the embodiments of the present application employ the following technical solutions:

in one aspect, an embodiment of the present application provides a voltage band-pass device, where the voltage band-pass device includes a power input terminal, a first voltage selection module, a second voltage selection module, a voltage stabilization module, and a state output terminal, where the first voltage selection module is electrically connected to the second voltage selection module, and the first voltage selection module and the second voltage selection module are respectively electrically connected to the power input terminal, the state output terminal, and the voltage stabilization module; wherein, the first and the second end of the pipe are connected with each other,

the first voltage selection module is used for being conducted when the voltage of the power supply input end is larger than a first voltage value, the second voltage selection module is used for being conducted when the voltage of the power supply input end is larger than a second voltage value, and the first voltage value is larger than the second voltage value;

the state output end is used for outputting a first signal when the first voltage selection module and the second voltage selection module are both switched on or switched off;

the state output end is also used for outputting a second signal when the first voltage selection module is switched off and the second voltage selection module is switched on.

Optionally, the first voltage selection module includes a first voltage detection unit and a first switch unit, the first voltage detection unit is electrically connected to the power input terminal and the first switch unit respectively, and the first switch unit is further electrically connected to the power input terminal, the voltage stabilization module and the status output terminal; wherein, the first and the second end of the pipe are connected with each other,

the first voltage detection unit is used for detecting the voltage of the power supply input end;

the first switch unit is used for conducting when the voltage of the power supply input end is larger than the first voltage value.

Optionally, the first voltage detection unit includes a first resistor and a second resistor, one end of the first resistor connected in series with the second resistor is electrically connected to the power input end, the other end of the first resistor is grounded, and the first switch unit is connected between the first resistor and the second resistor.

Optionally, the first switch unit includes a first switch tube, a second switch tube and a third resistor, a first end of the first switch tube is connected to the voltage stabilizing module, a control end of the first switch tube is electrically connected to the first voltage detecting unit, a second end of the first switch tube is electrically connected to one end of the third resistor and a control end of the second switch tube, the first end of the second switch tube and the other end of the third resistor are electrically connected to the state output terminal, and the second end of the second switch tube is electrically connected to the power input terminal.

Optionally, the first switch tube includes an NPN triode, the second switch tube includes a PNP triode, an emitter of the first switch tube is connected to the voltage stabilizing module, a base of the first switch tube is electrically connected to the first voltage detecting unit, a collector of the first switch tube is electrically connected to one end of the third resistor and the base of the second switch tube, respectively, the emitter of the second switch tube and the other end of the third resistor are electrically connected to the state output terminal, and a collector of the second switch tube is electrically connected to the power input terminal.

Optionally, the second voltage selection module includes a second voltage detection unit and a second switch unit, the second voltage detection unit is electrically connected to the power input terminal and the second switch unit respectively, and the second switch unit is further electrically connected to the power input terminal, the voltage stabilization module, and the status output terminal; wherein the content of the first and second substances,

the second voltage detection unit is used for detecting the voltage of the power supply input end;

the second switch unit is used for conducting when the voltage of the power supply input end is larger than the second voltage value.

Optionally, the second voltage detection unit includes a fourth resistor and a fifth resistor, one end of the fourth resistor connected in series with the fifth resistor is electrically connected to the power input end, the other end of the fourth resistor is grounded, and the second switch unit is connected between the first resistor and the second resistor.

Optionally, the first voltage selection module includes a first voltage detection unit, the first voltage detection unit includes a first resistor and a second resistor, and a ratio of the first resistor to the second resistor is greater than a ratio of the fourth resistor to the fifth resistor.

Optionally, the second switch unit includes a third switch tube, a fourth switch tube, a sixth resistor and a seventh resistor, the control end of the third switch tube is electrically connected to the voltage stabilizing module, the first end of the third switch tube is electrically connected to the second voltage detecting unit, the second end of the third switch tube is electrically connected to the control end of the fourth switch tube, the first end of the fourth switch tube is grounded, the second end of the fourth switch tube is electrically connected to one end of the sixth resistor, the other end of the sixth resistor is respectively connected to the state output end, one end of the seventh resistor and the first voltage selecting module, and the other end of the seventh resistor is electrically connected to the power input end.

Optionally, the third switching tube includes a PNP triode, the fourth switching tube includes an NPN triode, a base of the third switching tube is electrically connected to the voltage stabilizing module, an emitter of the third switching tube is electrically connected to the second voltage detecting unit, a collector of the third switching tube is electrically connected to the base of the fourth switching tube, the emitter of the fourth switching tube is grounded, and the collector of the fourth switching tube is electrically connected to one end of the sixth resistor.

Optionally, the voltage band-pass unit further includes an eighth resistor, one end of the eighth resistor is electrically connected to the power input terminal, and the other end of the eighth resistor is electrically connected to the voltage stabilizing module.

Optionally, the voltage stabilizing module includes a voltage stabilizing diode, an anode of the voltage stabilizing diode is grounded, and a cathode of the voltage stabilizing diode is electrically connected to the first voltage selecting module and the second voltage selecting module respectively.

On the other hand, the embodiment of the present application further provides a power supply circuit, where the power supply circuit includes a switch and the voltage band-pass device, the switch is electrically connected to the state output end of the voltage band-pass device, the switch is electrically connected to the power supply input end, and the switch is further used for connecting a load; wherein the content of the first and second substances,

the switch is used for being switched off when receiving the first signal and being switched on when receiving the second signal.

Optionally, the switch includes an MOS transistor, and a gate of the MOS transistor is electrically connected to the state output terminal of the voltage band-pass filter.

Optionally, the power circuit further includes a detection module, and the detection module is electrically connected to the switch to detect whether the power circuit is working normally.

Optionally, the detection module includes a ninth resistor and an LED, one end of the ninth resistor connected in series with the LED is electrically connected to the switch, and the other end of the ninth resistor is grounded.

Compared with the prior art, the method has the following beneficial effects:

the application provides a voltage band-pass device and a power circuit, wherein the voltage band-pass device comprises a power input end, a first voltage selection module, a second voltage selection module, a voltage stabilization module and a state output end, wherein the first voltage selection module is electrically connected with the second voltage selection module; the first voltage selection module is used for conducting when the voltage of the power input end is larger than a first voltage value, the second voltage selection module is used for conducting when the voltage of the power input end is larger than a second voltage value, and the first voltage value is larger than the second voltage value; the state output end is used for outputting a first signal when the first voltage selection module and the second voltage selection module are both switched on or switched off; the state output end is also used for outputting a second signal when the first voltage selection module is switched off and the second voltage selection module is switched on. On the one hand, the band-pass filter provided by the application can detect whether overvoltage or undervoltage occurs to the input voltage only through the circuit, so that the cost is lower. On the other hand, because the voltage stabilizing module is convenient to replace, the voltage value of overvoltage and undervoltage can be flexibly set in a mode of replacing the voltage stabilizing module, and the use is more flexible.

In order to make the aforementioned objects, features and advantages of the present application comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and it will be apparent to those skilled in the art that other related drawings can be obtained from the drawings without inventive effort.

Fig. 1 is a block diagram of a voltage bandpass device according to an embodiment of the present disclosure.

Fig. 2 is a schematic circuit diagram of a voltage bandpass device according to an embodiment of the present application.

Fig. 3 is a circuit schematic diagram of a power supply circuit according to an embodiment of the present disclosure.

In the figure: 100-voltage bandpass filter; 110-a first voltage selection module; 120-a second voltage selection module; 130-a voltage stabilizing module; 140-power input; 150-a status output; 111-a first voltage detection unit; 112-a first switching unit; 121-a second voltage detection unit; 122-a second switching unit; 200-a power supply circuit; 210-a switch; 220-a detection module; r1-a first resistor; r2-a second resistor; r3-a third resistor; r4-a fourth resistor; r5-a fifth resistor; r6-sixth resistor; r7-seventh resistor; r8-an eighth resistor; r9-ninth resistor; q1-first switch tube; q2-a second switch tube; q3-a third switching tube; q4-a fourth switching tube; d1, a voltage stabilizing diode; D2-LED.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. 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 application.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined or explained in subsequent figures. Meanwhile, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not to be construed as indicating or implying relative importance.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

Some embodiments of the present application will be described in detail below with reference to the accompanying drawings. The embodiments and features of the embodiments described below can be combined with each other without conflict.

As described in the background, currently, in power supply design, overvoltage and undervoltage related detection and protection are required for input voltage. The TVS transistor is one of important protection means, but the TVS transistor has limitations, and when an input voltage is over-voltage, the TVS transistor is burned out and cannot be recovered, and the influence caused by the under-voltage cannot be avoided.

In addition, voltage is required to be stabilized within a certain range in many products, and the requirement on the voltage range is strict, namely overvoltage and undervoltage cannot occur. The product can be burnt out to the excessive pressure, and uncertain condition can appear in the voltage, need close the product in order to avoid causing the loss, or need carry out the warning instruction when needing high pressure or low pressure in some products, like the battery power consumption of charging, the battery electric quantity is too low too high and all needs the warning. And the ad that needs MCU in the current scheme detects the participation, MCU normally work circuit will lose the detection function when in case the product low pressure, MCU can be burnt out when in case the excessive pressure, and the circuit detects the function and also can lose. Also, the detection is performed by the MCU, which can only detect a fixed voltage and is therefore inflexible.

In view of this, the present application provides a voltage band-pass device, which detects whether an input voltage has an over-voltage or an under-voltage condition in a circuit manner.

The following is an exemplary description of the voltage bandpass provided by the present application:

as an optional implementation manner, please refer to fig. 1, the voltage band pass device includes a power input terminal, a first voltage selection module, a second voltage selection module, a voltage stabilization module, and a state output terminal, wherein the first voltage selection module is electrically connected to the second voltage selection module, and the first voltage selection module and the second voltage selection module are respectively electrically connected to the power input terminal, the state output terminal, and the voltage stabilization module.

The first voltage selection module is used for conducting when the voltage of the power input end is larger than a first voltage value, the second voltage selection module is used for conducting when the voltage of the power input end is larger than a second voltage value, and the first voltage value is larger than the second voltage value. The state output end is used for outputting a first signal when the first voltage selection module and the second voltage selection module are both switched on or switched off; the state output end is also used for outputting a second signal when the first voltage selection module is switched off and the second voltage selection module is switched on.

It can understand, through this mode of setting, can determine one high one low two voltage values through first voltage selection module and second voltage selection module, only when the voltage of power input end input is in between these two voltage values, the voltage band-pass ware just can export the second signal, otherwise all can export first signal, and then the realization detects the condition whether overvoltage or undervoltage appears power supply voltage.

On the basis, when the power supply input by the power supply input end is under-voltage, the first voltage selection module and the second voltage selection module are not conducted, and the state output end outputs a first signal; when the power of power input end input the overvoltage condition appears, first voltage selection module all switches on with second voltage selection module, and the first signal is also exported to the state output this moment, and the signal through state output is different, can determine whether the voltage of power input end input is in fixed voltage value interval.

For example, by setting parameters of related devices in the voltage band pass device, the first voltage value is 5V, the second voltage value is 10V, if the voltage value input by the power input end is 4V, an under-voltage condition occurs, at this time, the first voltage selection module and the second voltage selection module are both in a cut-off state, and the state output end outputs a first signal. If the voltage value input by the power input end is 7V, the power supply is normal power supply voltage, at the moment, the first voltage selection module is in a cut-off state, but the second voltage selection module is in a conducting state, and the state output end outputs a second signal. If the voltage value input by the power input end is 14V, an overvoltage condition occurs, the first voltage selection module and the second voltage selection module are both in a conducting state, and the state output end outputs a second signal. Of course, after the status output terminal of the voltage band pass device outputs different signals, the status output terminal may be connected to a subsequent circuit, such as a switch circuit, to determine whether to output the voltage at the power input terminal to the load, which is not limited herein.

Meanwhile, the pure circuit is adopted to realize the detection and protection of the input voltage, so the cost is greatly reduced. In addition, because the relevant electrical apparatus parameter change of each module is comparatively convenient, therefore it is more convenient when setting up the band-pass voltage value. For example, when the voltage stabilizing module of the first type is adopted, the band-pass voltage value is 5V to 10V, that is, when the power voltage input by the power input end is between 5V and 10V, the power can be output to the rear-stage load, and if the power voltage is less than 5V or greater than 10V, the power voltage cannot be output to the rear-stage load. If the voltage stabilizing module of another model is replaced, the band-pass voltage value can be changed to 6V-11V, and then the voltage stabilizing modules of different models can be selected according to the band-pass voltages of different requirements, so that the use is more flexible.

As an implementation manner, please refer to fig. 2, the first voltage selection module includes a first voltage detection unit and a first switch unit, the first voltage detection unit is electrically connected to the power input terminal and the first switch unit, and the first switch unit is further electrically connected to the power input terminal, the voltage stabilization module, and the status output terminal. The first voltage detection unit is used for detecting the voltage of the power supply input end, and the first switch unit is used for being conducted when the voltage of the power supply input end is larger than a first voltage value.

The voltage of the power input end is detected by setting the divider resistor, and the divided value determines whether the first switch unit is switched on or not.

As an implementation manner, the first switch unit includes a first switch tube, a second switch tube and a third resistor, a first end of the first switch tube is connected with the voltage stabilizing module, a control end of the first switch tube is electrically connected with the first voltage detection unit, a second end of the first switch tube is electrically connected with one end of the third resistor and a control end of the second switch tube, a first end of the second switch tube and the other end of the third resistor are electrically connected with the state output end, and a second end of the second switch tube is electrically connected with the power input end.

The first switch tube and the second switch tube are not limited in type, and may be a triode, an MOS tube, or the like, and may be of an N type or a P type. When the first switch tube is an NPN triode and the second switch tube is a PNP triode, an emitting electrode of the first switch tube is connected with the voltage stabilizing module, a base electrode of the first switch tube is electrically connected with the first voltage detection unit, a collecting electrode of the first switch tube is electrically connected with one end of the third resistor and a base electrode of the second switch tube respectively, the emitting electrode of the second switch tube and the other end of the third resistor are electrically connected with the state output end, and a collecting electrode of the second switch tube is electrically connected with the power supply input end.

In addition, the voltage stabilizing module provided by the application comprises a voltage stabilizing diode, the anode of the voltage stabilizing diode is grounded, and the cathode of the voltage stabilizing diode is electrically connected with the first voltage selection module and the second voltage selection module respectively. Specifically, the cathode of the zener diode is connected to the emitter of the first switching tube.

When the zener diode and triode effects are not considered, VR2= VCC _ IN × R2/(R1 + R2), where VCC _ IN represents the voltage value at the power supply input and VR2 represents the voltage value flowing to the second resistor. According to the characteristics of the voltage stabilizing diode, when the input value of the voltage VD1 is smaller than the stabilized value, the voltage VD1 increases along with the increase of the input VCC _ IN. And VR2 voltage is equal to UD1+ UQ1be (UQ 1be represents the voltage between base and emitter in the first switching tube, and UQ1be depends on the triode model).

As an implementation manner, the second voltage selection module includes a second voltage detection unit and a second switch unit, the second voltage detection unit is electrically connected to the power input terminal and the second switch unit, and the second switch unit is further electrically connected to the power input terminal, the voltage stabilization module, and the status output terminal; the second voltage detection unit is used for detecting the voltage of the power supply input end; the second switch unit is used for conducting when the voltage of the power supply input end is larger than a second voltage value.

The second switch unit comprises a third switch tube, a fourth switch tube, a sixth resistor and a seventh resistor, the control end of the third switch tube is electrically connected with the voltage stabilizing module, the first end of the third switch tube is electrically connected with the second voltage detection unit, the second end of the third switch tube is electrically connected with the control end of the fourth switch tube, the first end of the fourth switch tube is grounded, the second end of the fourth switch tube is electrically connected with one end of the sixth resistor, the other end of the sixth resistor is respectively electrically connected with the state output end, one end of the seventh resistor and the first voltage selection module, and the other end of the seventh resistor is electrically connected with the power input end.

Similarly, when the third switching tube is a PNP triode and the fourth switching tube is an NPN triode, the base of the third switching tube is electrically connected to the voltage stabilizing module, the emitter of the third switching tube is electrically connected to the second voltage detection unit, the collector of the third switching tube is electrically connected to the base of the fourth switching tube, the emitter of the fourth switching tube is grounded, and the collector of the fourth switching tube is electrically connected to one end of the sixth resistor.

Similar to the voltage division principle of the first voltage selection module, when the influences of the zener diode and the triode are not considered, VR5= VCC _ IN × R5/(R4 + R5), and the voltage values of VR2 and VR3 are both equal to UD1+ UQ1be, IN order to ensure that the first voltage value corresponding to the first voltage selection module is greater than the second voltage value corresponding to the second voltage selection module, it is required to satisfy that VR2= VCC _ IN × R2/(R1 + R2) is less than VR5= VCC _ IN × R5/(R4 + R5), and since VR2 and VR3 are only associated with the ratio of the resistor string and the voltage of the power input terminal, the ratio of the first resistor to the second resistor provided by the present application is greater than the ratio of the fourth resistor to the fifth resistor. Through this mode of setting up, can guarantee that voltage band-pass ware can form certain voltage interval for when power input end only can input the voltage in this voltage interval, the circuit just can switch on, prevents the circumstances of excessive pressure and undervoltage.

The working principle of the voltage band-pass device provided by the present application is illustrated as follows:

if the regulated voltage value of D1 is 3V, the input voltage VCC _ IN =6V, r1=40k, r2=20k, r3=100k, r4=10k, r5=20k, r6=10k, r7=400k, r8=20k, and uq1be = 11v at the power supply input terminal.

UR2=6V × R2/(R1 + R2) =20/60 × 6=2v, vr2 is less than VD 1V, so Q1 is off, when Q2 is off. And VR5= VCC _ IN R5/(R4 + R5) =20/30 × 6v =4v = vd1+1, so Q3 is on, Q4 is on at this time, and R4 and R7 divide voltage. R7 is far larger than R4, the output is low level, and the normal working state can be determined at the moment.

And when the input is 5V, VR5=20/30 × 5 is about 3.33V less than 3.7, q3 is off, and the output is high. Similarly, when the input is 5V, Q1 and Q2 are also in the off state, and it can be determined that the input is the under-voltage state.

Similarly, when the input is 12V, UR2=16v × R2/(R1 + R2) =20/60 × 12=4V, Q1 is turned on, the voltage of VG is VCC _ IN, and an overvoltage state can be determined. When the input is VCC _ IN 11V, 11/3 is less than 3.7, Q1 and Q2 are cut off, and the normal state is present.

From the above, the voltage range selected to pass is about 6V to 12V under the above parameters. It can be understood that when the voltage interval passing through the selection needs to be adjusted, the resistance values of the first resistor, the second resistor, or the fourth resistor and the fifth resistor can be changed, so that the change of the voltage interval passing through the selection is realized; of course, the voltage regulation value of the zener diode may be changed so that the entire voltage interval moves up and down. For example, when the voltage interval selected to pass is 2v to 5v, if the voltage regulator is increased by 1v, the voltage interval selected to pass is 3v to 6v.

On the other hand, when the voltage is in the undervoltage state, Q1, Q2, Q3, and Q4 are all turned off, and the voltage at the power input terminal is transmitted to the status output terminal through R7, so that the status output terminal outputs a high level; when Q2 is cut off and Q4 is conducted, R7 and R6 are connected in series for voltage division, and because R6 is far smaller than R7, the state output end outputs a voltage close to 0V, namely an output level; when Q2 is turned on and Q4 is turned on, the voltage at the power input end flows to the ground through the loop of Q2, R6 and Q4, so that the voltage at the status output end is equal to the voltage at the power input end and is at a high level. Therefore, when Q2 is turned on, R6 acts as a current limiting resistor; when Q2 is cut off and Q4 is turned on, R6 is used as a voltage dividing resistor, and further different functions are realized in different scenes.

It should be further noted that, in order to ensure that the voltage stabilizing diode has a voltage value when under-voltage, the voltage band-pass filter further includes an eighth resistor, one end of the eighth resistor is electrically connected to the power input terminal, and the other end of the eighth resistor is electrically connected to the voltage stabilizing module.

Based on the foregoing implementation manner, an embodiment of the present application further provides a power circuit, please refer to fig. 3, where the power circuit includes a switch and the voltage band-pass device, the switch is electrically connected to the state output terminal of the voltage band-pass device, the switch is electrically connected to the power input terminal, and the switch is further configured to connect to a load; the switch is used for being switched off when receiving the first signal and being switched on when receiving the second signal.

As an implementation manner, as shown by Q5 in fig. 3, the switch may be a MOS transistor, and a gate of the MOS transistor is electrically connected to the status output terminal of the voltage band pass device. Wherein, this application adopts the PMOS pipe, and when the grid was low level, the PMOS pipe switched on, and this power supply circuit's OUT port is used for connecting the load, and when the PMOS pipe switched on the back, power supply circuit can normally be the power supply of rear end load. When the grid is at a high level, the PMOS is cut off, and the power supply circuit cannot supply power to the rear-end load, so that when overvoltage and undervoltage conditions occur, the power supply circuit cannot supply power to the load, and the effect of protecting the load is further achieved.

In order to protect the MOS transistor, a current limiting resistor R10 is further connected to the gate of the MOS transistor.

In addition, in order to detect whether the power circuit normally outputs, the power circuit further comprises a detection module which is electrically connected with the switch so as to detect whether the power circuit normally works.

As an implementation mode, the detection module comprises a ninth resistor and an LED, wherein one end of the ninth resistor, which is connected with the LED in series, is electrically connected with the switch, and the other end of the ninth resistor is grounded. When the power circuit normally supplies power to the rear-end load, the LED is lightened; when the overvoltage or undervoltage problem appears, the LED and the like are extinguished so as to indicate whether the overvoltage or undervoltage problem appears.

The application provides a voltage band-pass device and a power circuit, wherein the voltage band-pass device comprises a power input end, a first voltage selection module, a second voltage selection module, a voltage stabilization module and a state output end, the first voltage selection module is electrically connected with the second voltage selection module, and the first voltage selection module and the second voltage selection module are respectively electrically connected with the power input end, the state output end and the voltage stabilization module; the first voltage selection module is used for conducting when the voltage of the power input end is larger than a first voltage value, the second voltage selection module is used for conducting when the voltage of the power input end is larger than a second voltage value, and the first voltage value is larger than the second voltage value; the state output end is used for outputting a first signal when the first voltage selection module and the second voltage selection module are both switched on or switched off; the state output end is also used for outputting a second signal when the first voltage selection module is turned off and the second voltage selection module is turned on. On the one hand, the band-pass filter provided by the application can detect whether overvoltage or undervoltage occurs to the input voltage only through the circuit, so that the cost is lower. On the other hand, because the voltage stabilizing module is convenient to replace, the voltage value of overvoltage and undervoltage can be flexibly set in a mode of replacing the voltage stabilizing module, and the use is more flexible.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

It will be evident to those skilled in the art that the present application is not limited to the details of the foregoing illustrative embodiments, and that the present application may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Claims

1. A voltage band-pass device is characterized by comprising a power input end, a first voltage selection module, a second voltage selection module, a voltage stabilization module and a state output end, wherein the first voltage selection module is electrically connected with the second voltage selection module; wherein, the first and the second end of the pipe are connected with each other,

the first voltage selection module is used for conducting when the voltage of the power supply input end is greater than a first voltage value, the second voltage selection module is used for conducting when the voltage of the power supply input end is greater than a second voltage value, and the first voltage value is greater than the second voltage value;

2. The voltage bandpass filter according to claim 1, wherein the first voltage selection module comprises a first voltage detection unit and a first switch unit, the first voltage detection unit is electrically connected to the power input terminal and the first switch unit respectively, and the first switch unit is further electrically connected to the power input terminal, the voltage stabilization module and the status output terminal; wherein the content of the first and second substances,

the first switch unit is used for being conducted when the voltage of the power supply input end is larger than the first voltage value.

3. The voltage bandpass filter according to claim 2, wherein the first voltage detection unit comprises a first resistor and a second resistor, one end of the first resistor connected in series with the second resistor is electrically connected to the power input terminal, the other end of the first resistor connected in series with the second resistor is grounded, and the first switch unit is connected between the first resistor and the second resistor.

4. The voltage band-pass device according to claim 2, wherein the first switch unit comprises a first switch tube, a second switch tube and a third resistor, a first end of the first switch tube is connected to the voltage stabilizing module, a control end of the first switch tube is electrically connected to the first voltage detecting unit, a second end of the first switch tube is electrically connected to one end of the third resistor and a control end of the second switch tube, respectively, the first end of the second switch tube and the other end of the third resistor are electrically connected to the status output terminal, and the second end of the second switch tube is electrically connected to the power input terminal.

5. The voltage bandpass apparatus according to claim 4, wherein the first switch tube comprises an NPN transistor, the second switch tube comprises a PNP transistor, an emitter of the first switch tube is connected to the voltage regulation module, a base of the first switch tube is electrically connected to the first voltage detection unit, a collector of the first switch tube is electrically connected to one end of the third resistor and a base of the second switch tube, respectively, an emitter of the second switch tube and another end of the third resistor are electrically connected to the status output terminal, and a collector of the second switch tube is electrically connected to the power input terminal.

6. The voltage bandpass filter according to claim 1, wherein the second voltage selection module comprises a second voltage detection unit and a second switch unit, the second voltage detection unit is electrically connected to the power input terminal and the second switch unit respectively, and the second switch unit is further electrically connected to the power input terminal, the voltage stabilization module and the status output terminal; wherein, the first and the second end of the pipe are connected with each other,

7. The voltage band-pass filter according to claim 6, wherein the second voltage detection unit comprises a fourth resistor and a fifth resistor, one end of the fourth resistor connected in series with the fifth resistor is electrically connected to the power input terminal, the other end of the fourth resistor connected in series with the fifth resistor is grounded, and the second switch unit is connected between the fourth resistor and the fifth resistor.

8. The voltage bandpass filter according to claim 7 wherein the first voltage selection module comprises a first voltage detection unit comprising a first resistor and a second resistor, wherein a ratio of the first resistor to the second resistor is greater than a ratio of the fourth resistor to the fifth resistor.

9. The voltage band-pass device according to claim 7, wherein the second switch unit comprises a third switch tube, a fourth switch tube, a sixth resistor and a seventh resistor, a control terminal of the third switch tube is electrically connected to the voltage stabilizing module, a first terminal of the third switch tube is electrically connected to the second voltage detecting unit, a second terminal of the third switch tube is electrically connected to a control terminal of the fourth switch tube, a first terminal of the fourth switch tube is grounded, a second terminal of the fourth switch tube is electrically connected to one terminal of the sixth resistor, another terminal of the sixth resistor is electrically connected to the status output terminal, one terminal of the seventh resistor and the first voltage selecting module, respectively, and another terminal of the seventh resistor is electrically connected to the power input terminal.

10. The voltage band pass filter according to claim 9, wherein the third switching tube comprises a PNP triode, the fourth switching tube comprises an NPN triode, a base of the third switching tube is electrically connected to the voltage stabilizing module, an emitter of the third switching tube is electrically connected to the second voltage detecting unit, a collector of the third switching tube is electrically connected to a base of the fourth switching tube, an emitter of the fourth switching tube is grounded, and a collector of the fourth switching tube is electrically connected to one end of the sixth resistor.

11. The voltage bandpass apparatus according to claim 1, further comprising an eighth resistor, wherein one end of the eighth resistor is electrically connected to the power input terminal, and wherein the other end of the eighth resistor is electrically connected to the voltage stabilization module.

12. The voltage bandpass filter according to claim 1 wherein the voltage regulation module comprises a zener diode, an anode of the zener diode is grounded, and a cathode of the zener diode is electrically connected to the first voltage selection module and the second voltage selection module, respectively.

13. A power supply circuit comprising a switch and a voltage bandpass filter according to any one of claims 1 to 12, the switch being electrically connected to a status output of the voltage bandpass filter, the switch being electrically connected to a power supply input, the switch being further adapted to be connected to a load; wherein, the first and the second end of the pipe are connected with each other,

14. The power supply circuit of claim 13 wherein the switch comprises a MOS transistor having a gate electrically connected to the status output of the voltage bandpass.

15. The power circuit as claimed in claim 13, further comprising a detection module electrically connected to the switch to detect whether the power circuit is operating properly.

16. The power circuit as claimed in claim 15, wherein the detection module comprises a ninth resistor and an LED, wherein one end of the ninth resistor connected in series with the LED is electrically connected to the switch, and the other end is grounded.