Voltage bandpass device and power supply circuit

Abstract

This application provides a voltage bandpass converter and power supply circuit, relating to the field of voltage detection technology. A first voltage selection module and a second voltage selection module are electrically connected, each electrically connected to a power input terminal, a status output terminal, and a voltage regulator module, respectively. The first voltage selection module is activated when the voltage at the power input terminal is greater than a first voltage value, and the second voltage selection module is activated when the voltage at the power input terminal is greater than a second voltage value, wherein the first voltage value is greater than the second voltage value. The status output terminal outputs a first signal when both the first and second voltage selection modules are activated or both are deactivated; the status output terminal also outputs a second signal when the first voltage selection module is deactivated and the second voltage selection module is activated. The voltage bandpass converter and power supply circuit provided in this application have the advantages of low cost and greater flexibility in use.

Description

Technical Field

[0001] This application relates to the field of voltage detection technology, and more specifically, to a voltage bandpass converter and power supply circuit. Background Technology

[0002] In recent years, electronic voltage products have become increasingly common, and voltage instability has been a persistent issue in power supply design, requiring circuits to handle overvoltage or undervoltage conditions. When the input voltage exceeds the maximum voltage that the electronic product can withstand, it can cause the product to burn out; conversely, when the voltage falls below the minimum operating voltage, the circuit may experience unpredictable states. Therefore, it is necessary to detect and protect against input voltage fluctuations.

[0003] Currently, TVS diodes are an important protection method, but they have limitations. When an overvoltage input persists, the TVS diode will burn out irreversibly, and the effects of undervoltage cannot be avoided. Alternatively, an MCU can be used for voltage detection to achieve input voltage monitoring and protection, but this method is costly and lacks flexibility.

[0004] In summary, existing technologies for detecting and protecting input voltage are costly and inflexible. Summary of the Invention

[0005] The purpose of this application is to provide a voltage bandpass converter and power supply to solve the problems of high cost and inflexibility in the prior art when detecting and protecting input voltage.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0007] On one hand, embodiments of this application provide a voltage bandpass device, which includes a power input terminal, a first voltage selection module, a second voltage selection module, a voltage regulator module, and a status output terminal. The first voltage selection module is electrically connected to the second voltage selection module, and both the first and second voltage selection modules are electrically connected to the power input terminal, the status output terminal, and the voltage regulator module, respectively.

[0008] The first voltage selection module is turned on when the voltage at the power input terminal is greater than a first voltage value, and the second voltage selection module is turned on when the voltage at the power input terminal is greater than a second voltage value, wherein the first voltage value is greater than the second voltage value.

[0009] The status output terminal is used to output a first signal when both the first voltage selection module and the second voltage selection module are turned on or both are turned off.

[0010] The status output terminal is also used to output a second signal when the first voltage selection module is turned off and the second voltage selection module is turned on.

[0011] Optionally, the first voltage selection module includes a first voltage detection unit and a first switching unit. The first voltage detection unit is electrically connected to the power input terminal and the first switching unit, respectively. The first switching unit is also electrically connected to the power input terminal, the voltage regulator module, and the status output terminal.

[0012] The first voltage detection unit is used to detect the voltage at the power input terminal;

[0013] The first switching unit is used to turn on when the voltage at the power input terminal is greater than the first voltage value.

[0014] Optionally, the first voltage detection unit includes a first resistor and a second resistor. One end of the first resistor and the second resistor connected in series is electrically connected to the power input terminal, and the other end is grounded. The first switch unit is connected between the first resistor and the second resistor.

[0015] Optionally, the first switching unit includes a first switching transistor, a second switching transistor, and a third resistor. The first end of the first switching transistor is connected to the voltage regulator module, the control end of the first switching transistor is electrically connected to the first voltage detection unit, the second end of the first switching transistor is electrically connected to one end of the third resistor and the control end of the second switching transistor, the first end of the second switching transistor and the other end of the third resistor are both electrically connected to the status output terminal, and the second end of the second switching transistor is electrically connected to the power input terminal.

[0016] Optionally, the first switching transistor includes an NPN transistor, the second switching transistor includes a PNP transistor, the emitter of the first switching transistor is connected to the voltage regulator module, the base of the first switching transistor is electrically connected to the first voltage detection unit, the collector of the first switching transistor is electrically connected to one end of the third resistor and the base of the second switching transistor, the emitter of the second switching transistor and the other end of the third resistor are both electrically connected to the status output terminal, and the collector of the second switching transistor is electrically connected to the power input terminal.

[0017] Optionally, the second voltage selection module includes a second voltage detection unit and a second switching unit. The second voltage detection unit is electrically connected to the power input terminal and the second switching unit, respectively. The second switching unit is also electrically connected to the power input terminal, the voltage regulator module, and the status output terminal.

[0018] The second voltage detection unit is used to detect the voltage at the power input terminal;

[0019] The second switching unit is used to turn on when the voltage at the power input terminal is greater than the second voltage value.

[0020] Optionally, the second voltage detection unit includes a fourth resistor and a fifth resistor. One end of the fourth resistor and the fifth resistor connected in series is electrically connected to the power input terminal, and the other end is grounded. The second switching unit is connected between the first resistor and the second resistor.

[0021] Optionally, the first voltage selection module includes a first voltage detection unit, which includes a first resistor and a second resistor, wherein the ratio of the first resistor to the second resistor is greater than the ratio of the fourth resistor to the fifth resistor.

[0022] Optionally, the second switching unit includes a third switching transistor, a fourth switching transistor, a sixth resistor, and a seventh resistor. The control terminal of the third switching transistor is electrically connected to the voltage regulator module. The first terminal of the third switching transistor is electrically connected to the second voltage detection unit. The second terminal of the third switching transistor is electrically connected to the control terminal of the fourth switching transistor. The first terminal of the fourth switching transistor is grounded. The second terminal of the fourth switching transistor is electrically connected to one end of the sixth resistor. The other end of the sixth resistor is electrically connected to the status output terminal, one end of the seventh resistor, and the first voltage selection module. The other end of the seventh resistor is electrically connected to the power input terminal.

[0023] Optionally, the third switching transistor includes a PNP transistor, the fourth switching transistor includes an NPN transistor, the base of the third switching transistor is electrically connected to the voltage regulator module, the emitter of the third switching transistor is electrically connected to the second voltage detection unit, the collector of the third switching transistor is electrically connected to the base of the fourth switching transistor, the emitter of the fourth switching transistor is grounded, and the collector of the fourth switching transistor is electrically connected to one end of the sixth resistor.

[0024] Optionally, the voltage bandpass converter further includes an eighth resistor, one end of which is electrically connected to the power input terminal, and the other end of which is electrically connected to the voltage regulator module.

[0025] Optionally, the voltage regulator module includes a Zener diode, the anode of which is grounded, and the cathode of which is electrically connected to the first voltage selection module and the second voltage selection module, respectively.

[0026] On the other hand, this application embodiment also provides a power supply circuit, the power supply circuit including a switch and the aforementioned voltage bandpass converter, the switch being electrically connected to the state output terminal of the voltage bandpass converter, the switch being electrically connected to the power input terminal, and the switch being further used to connect a load; wherein,

[0027] The switch is used to open when a first signal is received and to open when a second signal is received.

[0028] Optionally, the switch includes a MOS transistor, the gate of which is electrically connected to the state output terminal of the voltage bandpass.

[0029] Optionally, the power supply circuit further includes a detection module, which is electrically connected to the switch to detect whether the power supply circuit is working properly.

[0030] Optionally, the detection module includes a ninth resistor and an LED, with one end of the ninth resistor and the LED connected in series to the switch and the other end grounded.

[0031] Compared with the prior art, this application has the following advantages:

[0032] This application provides a voltage bandpass filter and power supply circuit. The voltage bandpass filter includes a power input terminal, a first voltage selection module, a second voltage selection module, a voltage regulator module, and a status output terminal. The first and second voltage selection modules are electrically connected, and each is electrically connected to the power input terminal, the status output terminal, and the voltage regulator module, respectively. The first voltage selection module is used to conduct when the voltage at the power input terminal is greater than a first voltage value, and the second voltage selection module is used to conduct when the voltage at the power input terminal is greater than a second voltage value, wherein the first voltage value is greater than the second voltage value. The status output terminal outputs a first signal when both the first and second voltage selection modules are on or off. The status output terminal also outputs a second signal when the first voltage selection module is off and the second voltage selection module is on. On one hand, the bandpass filter provided by this application can detect overvoltage or undervoltage of the input voltage using only a circuit, thus reducing its cost. On the other hand, since the voltage regulator module is easy to replace, the overvoltage and undervoltage voltage values ​​can be flexibly set by replacing the voltage regulator module, making it more flexible in use.

[0033] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of a voltage bandpass converter provided in an embodiment of this application.

[0036] Figure 2 This is a circuit diagram of a voltage bandpass converter provided in an embodiment of this application.

[0037] Figure 3 A circuit diagram of the power supply circuit provided in an embodiment of this application.

[0038] In the diagram: 100 - Voltage bandpass; 110 - First voltage selection module; 120 - Second voltage selection module; 130 - Voltage regulator module; 140 - Power input terminal; 150 - Status output terminal; 111 - First voltage detection unit; 112 - First switching unit; 121 - Second voltage detection unit; 122 - Second switching unit; 200 - Power supply circuit; 210 - Switch; 220 - Detection module; R1 - First resistor; R2 - Second resistor; R3 - Third resistor; R4 - Fourth resistor; R5 - Fifth resistor; R6 - Sixth resistor; R7 - Seventh resistor; R8 - Eighth resistor; R9 - Ninth resistor; Q1 - First switching transistor; Q2 - Second switching transistor; Q3 - Third switching transistor; Q4 - Fourth switching transistor; D1 - Zener diode; D2 - LED. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0040] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0041] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] It should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0043] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0044] As described in the background section, current power supply design requires overvoltage and undervoltage detection and protection of the input voltage. TVS diodes are an important protection method, but they have limitations. When an overvoltage persists, the TVS diode will burn out irreversibly, and the effects of undervoltage cannot be avoided.

[0045] Furthermore, many products require stable voltage within a specific range, with stringent requirements for both overvoltage and undervoltage. Overvoltage can damage the product, and unpredictable voltage conditions necessitate shutting down the product to prevent losses. Some products also require alarm indications for high or low voltage conditions, such as battery charging, where alarms are needed for excessively low or high battery levels. Current solutions rely on MCU AD detection; if the product experiences low voltage, the MCU malfunctions, and the circuit loses its detection function. Conversely, overvoltage can burn out the MCU, resulting in the loss of detection functionality. Moreover, MCU-based detection is limited to fixed voltages, making it inflexible.

[0046] In view of this, this application provides a voltage bandpass converter that detects whether there is overvoltage or undervoltage in the input voltage through a circuit.

[0047] The voltage bandpass converter provided in this application is illustrated below:

[0048] As an optional implementation, please refer to Figure 1 The voltage bandpass includes a power input terminal, a first voltage selection module, a second voltage selection module, a voltage regulator module, and a status output terminal. The first voltage selection module and the second voltage selection module are electrically connected, and the first voltage selection module and the second voltage selection module are respectively electrically connected to the power input terminal, the status output terminal, and the voltage regulator module.

[0049] The first voltage selection module is activated when the voltage at the power input terminal is greater than a first voltage value, and the second voltage selection module is activated when the voltage at the power input terminal is greater than a second voltage value, wherein the first voltage value is greater than the second voltage value. Furthermore, the status output terminal outputs a first signal when both the first and second voltage selection modules are activated or both are deactivated; the status output terminal also outputs a second signal when the first voltage selection module is deactivated and the second voltage selection module is activated.

[0050] Understandably, this setting allows the first voltage selection module and the second voltage selection module to determine two voltage values, one high and one low. The voltage bandpass converter will only output the second signal when the voltage input at the power input terminal is between these two voltage values; otherwise, it will output the first signal, thereby enabling the detection of whether the power supply voltage is over-voltage or under-voltage.

[0051] Based on this, when the power input terminal experiences undervoltage, neither the first voltage selection module nor the second voltage selection module will conduct, and the status output terminal will output the first signal. When the power input terminal experiences overvoltage, both the first voltage selection module and the second voltage selection module will conduct, and the status output terminal will also output the first signal. By observing the different signals output by the status output terminal, it can be determined whether the voltage input to the power input terminal is within a fixed voltage value range.

[0052] For example, by setting the parameters of relevant components in the voltage bandpass converter, such that the first voltage value is 5V and the second voltage value is 10V, if the voltage input at the power input terminal is 4V, an undervoltage condition occurs. In this case, both the first and second voltage selection modules are in the off state, and the status output terminal outputs the first signal. If the voltage input at the power input terminal is 7V, it is a normal power supply voltage. In this case, the first voltage selection module is in the off state, but both the first and second voltage selection modules are in the on state, and the status output terminal outputs the second signal. If the voltage input at the power input terminal is 14V, an overvoltage condition occurs. In this case, both the first and second voltage selection modules are in the on state, and the status output terminal outputs the second signal. Of course, after the status output terminal of the voltage bandpass converter outputs different signals, the status output terminal can be connected to subsequent circuits, such as a switching circuit, to determine whether to output the voltage from the power input terminal to the load; this is not limited here.

[0053] Meanwhile, since this application uses pure circuitry to detect and protect the input voltage, its cost is greatly reduced. Furthermore, because the electrical parameters of each module are relatively easy to change, setting the pass-through voltage value is more convenient. For example, when using the first type of voltage regulator module, the pass-through voltage is 5V to 10V. That is, when the power input voltage is between 5V and 10V, the power can be output to the downstream load; if it is less than 5V or greater than 10V, it will not be output to the downstream load. However, if a different type of voltage regulator module is used, the pass-through voltage value may change to 6V to 11V. Therefore, different types of voltage regulator modules can be selected according to different pass-through voltage requirements, making the application more flexible.

[0054] As one implementation method, please refer to Figure 2 The first voltage selection module includes a first voltage detection unit and a first switching unit. The first voltage detection unit is electrically connected to the power input terminal and the first switching unit, respectively. The first switching unit is also electrically connected to the power input terminal, the voltage regulator module, and the status output terminal. Specifically, the first voltage detection unit is used to detect the voltage at the power input terminal, and the first switching unit is used to turn on when the voltage at the power input terminal is greater than a first voltage value.

[0055] Optionally, the first voltage detection unit includes a first resistor and a second resistor. One end of the first resistor and the second resistor connected in series is electrically connected to the power input terminal, and the other end is grounded. The first switching unit is connected between the first resistor and the second resistor.

[0056] By setting voltage divider resistors, the voltage at the power input terminal can be detected, and the value after voltage division determines whether the first switching unit is turned on.

[0057] In one implementation, the first switching unit includes a first switching transistor, a second switching transistor, and a third resistor. The first end of the first switching transistor is connected to the voltage regulator module, the control end of the first switching transistor is electrically connected to the first voltage detection unit, the second end of the first switching transistor is electrically connected to one end of the third resistor and the control end of the second switching transistor, the first end of the second switching transistor and the other end of the third resistor are both electrically connected to the status output terminal, and the second end of the second switching transistor is electrically connected to the power input terminal.

[0058] This application does not limit the types of the first and second switching transistors; they can be transistors or MOSFETs, and can be N-type or P-type. When the first switching transistor is an NPN transistor and the second switching transistor is a PNP transistor, the emitter of the first switching transistor is connected to the voltage regulator module, the base of the first switching transistor is electrically connected to the first voltage detection unit, the collector of the first switching transistor is electrically connected to one end of the third resistor and the base of the second switching transistor, the emitter of the second switching transistor and the other end of the third resistor are both electrically connected to the status output terminal, and the collector of the second switching transistor is electrically connected to the power input terminal.

[0059] Furthermore, the voltage regulator module provided in this application includes a Zener diode, the anode of which is grounded, and the cathode of which is electrically connected to a first voltage selection module and a second voltage selection module, respectively. Specifically, the cathode of the Zener diode is connected to the emitter of a first switching transistor.

[0060] When the effects of the Zener diode and transistor are not considered, VR2 = VCC_IN * R2 / (R1 + R2), where VCC_IN represents the voltage at the power input terminal, and VR2 represents the voltage flowing to the second resistor. According to the characteristics of the Zener diode, when the input value is less than the regulated voltage, VD1 increases as the input VCC_IN increases. The VR2 voltage is equal to UD1 + UQ1be (UQ1be represents the voltage between the base and emitter of the first switching transistor, and UQ1be is determined by the transistor model).

[0061] In one implementation, the second voltage selection module includes a second voltage detection unit and a second switching unit. The second voltage detection unit is electrically connected to the power input terminal and the second switching unit, respectively. The second switching unit is also electrically connected to the power input terminal, the voltage regulator module, and the status output terminal. The second voltage detection unit is used to detect the voltage at the power input terminal. The second switching unit is used to turn on when the voltage at the power input terminal is greater than a second voltage value.

[0062] Optionally, the second voltage detection unit includes a fourth resistor and a fifth resistor. One end of the fourth resistor and the fifth resistor connected in series is electrically connected to the power input terminal, and the other end is grounded. The second switching unit is connected between the first resistor and the second resistor.

[0063] The second switching unit includes a third switching transistor, a fourth switching transistor, a sixth resistor, and a seventh resistor. The control terminal of the third switching transistor is electrically connected to the voltage regulator module. The first terminal of the third switching transistor is electrically connected to the second voltage detection unit. The second terminal of the third switching transistor is electrically connected to the control terminal of the fourth switching transistor. The first terminal of the fourth switching transistor is grounded. The second terminal of the fourth switching transistor is electrically connected to one end of the sixth resistor. The other end of the sixth resistor is electrically connected to the status output terminal, one end of the seventh resistor, and the first voltage selection module. The other end of the seventh resistor is electrically connected to the power input terminal.

[0064] Similarly, when the third switch is a PNP transistor and the fourth switch is an NPN transistor, the base of the third switch is electrically connected to the voltage regulator module, the emitter of the third switch is electrically connected to the second voltage detection unit, the collector of the third switch is electrically connected to the base of the fourth switch, the emitter of the fourth switch is grounded, and the collector of the fourth switch is electrically connected to one end of the sixth resistor.

[0065] Similar to the voltage divider principle of the first voltage selection module, when the influence of the Zener diode and transistor is not considered, VR5 = VCC_IN * R5 / (R4 + R5), and the voltage values ​​of VR2 and VR3 are both equal to UD1 + UQ1be. 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, VR2 = VCC_IN * R2 / (R1 + R2) must be less than VR5 = VCC_IN * R5 / (R4 + R5). Since VR2 and VR3 are only related to the ratio of the resistor string and the voltage at the power input terminal, the ratio of the first resistor to the second resistor provided in this application is greater than the ratio of the fourth resistor to the fifth resistor. Through this setting method, it can be ensured that the voltage bandpass can form a certain voltage range, so that the circuit will only conduct when the power input terminal can be input with a voltage within this voltage range, preventing overvoltage and undervoltage situations.

[0066] The working principle of the voltage bandpass converter provided in this application is illustrated below with an example:

[0067] If we assume that the regulated voltage of D1 is 3V, the input voltage of the power supply input terminal VCC_IN = 6V, R1 = 40K, R2 = 20K, R3 = 100K, R4 = 10K, R5 = 20K, R6 = 10K, R7 = 400K, R8 = 20K, and UQ1be = 1V.

[0068] UR2 = 6V * R2 / (R1 + R2) = 20 / 60 * 6 = 2V. VR2 is less than VD1 (3V), therefore Q1 is off, and Q2 is also off. VR5 = VCC_IN * R5 / (R4 + R5) = 20 / 30 * 6V = 4V = VD1 + 1, therefore Q3 is on, and Q4 is on. R4 and R7 form a voltage divider. R7 is much larger than R4, so the output is low, confirming that this is the normal operating state.

[0069] When the input is 5V, VR5 = 20 / 30 * 5 is approximately 3.33V, which is less than 3.7V. Therefore, Q3 is cut off, and the output is high. Similarly, when the input is 5V, Q1 and Q2 are also cut off, indicating an undervoltage state.

[0070] Similarly, when the input is 12V, UR2 = 16V * R2 / (R1 + R2) = 20 / 60 * 12 = 4V. At this time, Q1 is turned on, and the output VG voltage is VCC_IN, which indicates an overvoltage condition. When the input is VCC_IN 11V, 11 / 3 is less than 3.7, so Q1 and Q2 are turned off, which is the normal state.

[0071] As shown above, under the aforementioned parameter conditions, the selectable voltage range is approximately between 6V and 12V. Understandably, when it's necessary to adjust the selectable voltage range, the resistance values ​​of the first, second, fourth, or fifth resistors can be changed, thus altering the selectable voltage range. Alternatively, the voltage regulation value of the Zener diode can be changed, shifting the overall voltage range up or down. For example, if the selectable voltage range is 2V to 5V, increasing the Zener diode's voltage by 1V will change the selectable voltage range to 3V to 6V.

[0072] It's important to note that, on one hand, in the undervoltage state, Q1, Q2, Q3, and Q4 are all off. At this time, the voltage at the power input terminal is transmitted to the status output terminal through R7, resulting in a high-level output. On the other hand, when Q2 is off and Q4 is on, R7 and R6 form a voltage divider. Since R6 is much smaller than R7, the status output terminal outputs a voltage close to 0V, i.e., the output level. When both Q2 and Q4 are on, the voltage at the power input terminal flows to ground through the loop of Q2, R6, and Q4. Therefore, the voltage at the status output terminal equals the voltage at the power input terminal, resulting in a high-level output. Thus, when Q2 is on, R6 acts as a current-limiting resistor; when Q2 is off and Q4 is on, R6 acts as a voltage divider resistor, thereby achieving different functions in different scenarios.

[0073] It should also be noted that, in order to ensure that the Zener diode has a voltage value when undervoltage occurs, the voltage bandpass converter also 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 regulator module.

[0074] Based on the above implementation, this application also provides a power supply circuit. Please refer to [link / reference]. Figure 3 The power supply circuit includes a switch and the aforementioned voltage bandpass converter. The switch is electrically connected to the state output terminal of the voltage bandpass converter and to the power input terminal. The switch is also used to connect a load. The switch is used to disconnect when a first signal is received and to turn on when a second signal is received.

[0075] As one implementation method, such as Figure 3 As shown in Q5, the switch can be a MOSFET, and the gate of the MOSFET is electrically connected to the state output terminal of the voltage bandpass converter. This application uses a PMOS transistor. When the gate is low, the PMOS transistor is turned on, and the OUT port of this power supply circuit is used to connect the load. When the PMOS transistor is on, the power supply circuit can normally supply power to the downstream load. When the gate is high, the PMOS transistor is turned off, and the power supply circuit cannot supply power to the downstream load. Therefore, in the event of overvoltage or undervoltage, the power supply circuit will be unable to supply power to the load, thus protecting the load.

[0076] It should be noted that, in order to protect the MOSFET, a current-limiting resistor R10 is also connected to the gate of the MOSFET.

[0077] In addition, in order to detect whether the power supply circuit is outputting normally, the power supply circuit also includes a detection module, which is electrically connected to the switch to detect whether the power supply circuit is working properly.

[0078] In one implementation, the detection module includes a ninth resistor and an LED. One end of the resistor and LED connected in series is connected to the switch, and the other end is grounded. When the power supply circuit is normally supplying power to the downstream load, the LED lights up; when an overvoltage or undervoltage problem occurs, the LED turns off, thus indicating whether an overvoltage or undervoltage problem has occurred.

[0079] This application provides a voltage bandpass filter and power supply circuit. The voltage bandpass filter includes a power input terminal, a first voltage selection module, a second voltage selection module, a voltage regulator module, and a status output terminal. The first and second voltage selection modules are electrically connected, and each is electrically connected to the power input terminal, the status output terminal, and the voltage regulator module, respectively. The first voltage selection module is used to conduct when the voltage at the power input terminal is greater than a first voltage value, and the second voltage selection module is used to conduct when the voltage at the power input terminal is greater than a second voltage value, wherein the first voltage value is greater than the second voltage value. The status output terminal outputs a first signal when both the first and second voltage selection modules are on or off. The status output terminal also outputs a second signal when the first voltage selection module is off and the second voltage selection module is on. On one hand, the bandpass filter provided by this application can detect overvoltage or undervoltage of the input voltage using only a circuit, thus reducing its cost. On the other hand, since the voltage regulator module is easy to replace, the overvoltage and undervoltage voltage values ​​can be flexibly set by replacing the voltage regulator module, making it more flexible in use.

[0080] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

[0081] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A voltage bandpass converter, characterized in that, The voltage bandpass converter includes a power input terminal, a first voltage selection module, a second voltage selection module, a voltage regulator module, and a status output terminal. The first voltage selection module and the second voltage selection module are electrically connected, and both the first voltage selection module and the second voltage selection module are electrically connected to the power input terminal, the status output terminal, and the voltage regulator module, respectively. The first voltage selection module is turned on when the voltage at the power output terminal is greater than a first voltage value, and the second voltage selection module is turned on when the voltage at the power output terminal is greater than a second voltage value, wherein the first voltage value is greater than the second voltage value. The status output terminal is used to output a first signal when both the first voltage selection module and the second voltage selection module are turned on or both are turned off. The status output terminal is also used to output a second signal when the first voltage selection module is off and the second voltage selection module is on. The first voltage selection module includes a first voltage detection unit and a first switching unit. The first voltage detection unit is electrically connected to the power input terminal and the first switching unit, respectively. The first switching unit is also electrically connected to the power input terminal, the voltage regulator module, and the status output terminal. The first voltage detection unit is used to detect the voltage at the power supply output terminal; The first switching unit is used to turn on when the voltage at the power output terminal is greater than the first voltage value; The first switching unit includes a first switching transistor, a second switching transistor, and a third resistor. The first end of the first switching transistor is connected to the voltage regulator module. The control end of the first switching transistor is electrically connected to the first voltage detection unit. The second end of the first switching transistor is electrically connected to one end of the third resistor and the control end of the second switching transistor. The first end of the second switching transistor and the other end of the third resistor are both electrically connected to the status output terminal. The second end of the second switching transistor is electrically connected to the power input terminal.

2. The voltage bandpass converter as described in claim 1, characterized in that, The first voltage detection unit includes a first resistor and a second resistor. One end of the first resistor and the second resistor connected in series is electrically connected to the power input terminal, and the other end is grounded. The first switch unit is connected between the first resistor and the second resistor.

3. The voltage bandpass converter as described in claim 1, characterized in that, The first switching transistor includes an NPN transistor, and the second switching transistor includes a PNP transistor. The emitter of the first switching transistor is connected to the voltage regulator module, the base of the first switching transistor is electrically connected to the first voltage detection unit, the collector of the first switching transistor is electrically connected to one end of the third resistor and the base of the second switching transistor, the emitter of the second switching transistor and the other end of the third resistor are both electrically connected to the status output terminal, and the collector of the second switching transistor is electrically connected to the power input terminal.

4. The voltage bandpass converter as described in claim 1, characterized in that, The second voltage selection module includes a second voltage detection unit and a second switching unit. The second voltage detection unit is electrically connected to the power input terminal and the second switching unit, respectively. The second switching unit is also electrically connected to the power input terminal, the voltage regulator module, and the status output terminal. The second voltage detection unit is used to detect the voltage at the power supply output terminal; The second switching unit is used to turn on when the voltage at the power output terminal is greater than the second voltage value.

5. The voltage bandpass converter as described in claim 4, characterized in that, The second voltage detection unit includes a fourth resistor and a fifth resistor. One end of the fourth resistor and the fifth resistor connected in series is electrically connected to the power input terminal, and the other end is grounded. The second switch unit is connected between the fourth resistor and the fifth resistor.

6. The voltage bandpass converter as described in claim 5, characterized in that, The first voltage selection module includes a first voltage detection unit, which includes a first resistor and a second resistor. The ratio of the first resistor to the second resistor is greater than the ratio of the fourth resistor to the fifth resistor.

7. The voltage bandpass converter as described in claim 5, characterized in that, The second switching unit includes a third switching transistor, a fourth switching transistor, a sixth resistor, and a seventh resistor. The control terminal of the third switching transistor is electrically connected to the voltage regulator module. The first terminal of the third switching transistor is electrically connected to the second voltage detection unit. The second terminal of the third switching transistor is electrically connected to the control terminal of the fourth switching transistor. The first terminal of the fourth switching transistor is grounded. The second terminal of the fourth switching transistor is electrically connected to one end of the sixth resistor. The other end of the sixth resistor is electrically connected to the status output terminal, one end of the seventh resistor, and the first voltage selection module. The other end of the seventh resistor is electrically connected to the power input terminal.

8. The voltage bandpass converter as claimed in claim 7, characterized in that, The third switching transistor includes a PNP transistor, and the fourth switching transistor includes an NPN transistor. The base of the third switching transistor is electrically connected to the voltage regulator module, the emitter of the third switching transistor is electrically connected to the second voltage detection unit, the collector of the third switching transistor is electrically connected to the base of the fourth switching transistor, the emitter of the fourth switching transistor is grounded, and the collector of the fourth switching transistor is electrically connected to one end of the sixth resistor.

9. The voltage bandpass converter as claimed in claim 1, characterized in that, The voltage bandpass converter also includes an eighth resistor, one end of which is electrically connected to the power input terminal, and the other end of which is electrically connected to the voltage regulator module.

10. The voltage bandpass converter as claimed in claim 1, characterized in that, The voltage regulator module includes a Zener diode, the anode of which is grounded, and the cathode of which is electrically connected to the first voltage selection module and the second voltage selection module, respectively.

11. A power supply circuit, characterized in that, The power supply circuit includes a switch and a voltage bandpass converter as described in any one of claims 1 to 10, wherein the switch is electrically connected to the state output terminal of the voltage bandpass converter, the switch is electrically connected to the power input terminal, and the switch is also used to connect a load; wherein... The switch is used to open when a first signal is received and to open when a second signal is received.

12. The power supply circuit as described in claim 11, characterized in that, The switch includes a MOS transistor, the gate of which is electrically connected to the state output terminal of the voltage bandpass.

13. The power supply circuit as described in claim 11, characterized in that, The power supply circuit also includes a detection module, which is electrically connected to the switch to detect whether the power supply circuit is working properly.

14. The power supply circuit as described in claim 13, characterized in that, The detection module includes a ninth resistor and an LED. One end of the ninth resistor and the LED are connected in series and electrically connected to the switch, while the other end is grounded.

Images