CN217007453U - A kind of voltage rapid detection circuit and electronic equipment - Google Patents

Abstract

The embodiment of the utility model discloses a voltage rapid detection circuit and electronic equipment, comprising: the device comprises a conversion module, a low voltage detection circuit and a high voltage detection circuit; the low-voltage detection circuit and the high-voltage detection circuit are connected in parallel to form a parallel detection circuit; one end of the parallel detection circuit is a power supply connecting end, the other end of the parallel detection circuit is connected with the conversion module, and the other end of the conversion module is used as a feedback end and is connected with a target device; the parallel detection circuit is used for detecting whether the voltage of the connected power supply is within a preset numerical range, the conversion module is used for converting the voltage detection result of the parallel detection circuit into a level signal and feeding the level signal back to the target device, and the level signal is used for indicating the target device to execute corresponding operation. The voltage with large fluctuation of up and down is converted into stable level indication through a simple circuit, and a target device is protected.

Description

A kind of voltage rapid detection circuit and electronic equipment

technical field

The utility model relates to the field of circuit control, in particular to a voltage rapid detection circuit and electronic equipment.

Background technique

Most of the circuits for high and low voltage detection of the power supply of the car entertainment system in the existing market are given to the AD pin of the MCU through the analog voltage divided by the resistor, and the MCU judges the voltage value of the detection port after the internal AD conversion. The MCU scans this detection pin for a long time. When it detects that the voltage is lower than or higher than the rated voltage of the design specification for 3 to 5 times, the MCU shuts down the machine and puts the machine in a dormant state. Because the current AD detection requires the MCU to scan for a long time, it needs to occupy more MCU resources, which affects the speed of the MCU to process other tasks. In addition, multiple tests are needed to determine the power supply voltage state, and the speed is slow. When the power supply is disconnected or dropped instantaneously, it is easy for the MCU to not remember the state before the instantaneous disconnection or drop of the power supply. In addition, if the power supply voltage is too high and the voltage of the MCU detection port is greater than the maximum voltage that the detection port can withstand, there is a risk of damage to the MCU.

Utility model content

In view of this, the present application provides a voltage rapid detection circuit, comprising: a conversion module, a low voltage detection circuit and a high voltage detection circuit;

The low-voltage detection circuit and the high-voltage detection circuit are connected in parallel to form a parallel detection circuit; one end of the parallel detection circuit is a power supply connection end, and the other end is connected to the conversion module, and the other end of the conversion module is used as a feedback end for Connect with the target device;

The parallel detection circuit is used to detect whether the voltage of the connected power supply is within a preset value range, and the conversion module is used to convert the voltage detection result of the parallel detection circuit into a level signal and feed it back to the target device , the level signal is used to instruct the target device to perform a corresponding operation.

Further, the low voltage detection circuit includes a first Zener diode and a first resistor;

The anode of the first Zener diode is connected to one end of the first resistor, the cathode is connected to the conversion module, and the other end of the first resistor is connected to the power connection end.

Further, the high voltage detection circuit includes a second resistor, a third resistor, a second Zener diode and a first transistor;

The emitter of the first transistor is grounded, the collector is connected to the conversion module, and the base is connected to one end of the second resistor;

The anode of the second Zener diode is connected to the other end of the second resistor, and the cathode is connected to one end of the third resistor. The resistance of the second resistor is greater than that of the third resistor. The other end of the resistor is connected to the power connection end.

Further, the conversion module includes a second transistor, a third transistor, a fourth resistor and a fifth resistor;

The base of the second triode serves as the first end of the conversion module, and is connected to the parallel detection circuit, the emitter is grounded, and the collector is respectively connected to the base of the third triode and the One end of the fourth resistor is connected;

The emitter of the third triode is grounded, and the collector is connected to the voltage detection terminal of the target device;

The other end of the fourth resistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the emitter of the third triode;

The other end of the fourth resistor is also used for connecting with a working voltage, and the working voltage is used for supplying power to the second triode and the third triode.

Further, it also includes a capacitor, one end of the capacitor is connected to the voltage detection end of the target device, and the other end is grounded for low-pass filtering.

Further, the first triode, the second triode and the third triode are all NPN triodes.

Further, the high voltage detection circuit is further connected with a sixth resistor, one end of the sixth resistor is connected to the base of the first triode, and the other end is grounded.

Further, the present application also provides an electronic device, including a power supply arranged in sequence, a voltage rapid detection circuit and a microcontroller as described in any one of the above embodiments;

The microcontroller is used to detect the voltage condition of the power supply through the voltage fast detection circuit.

Further, the microcontroller is further configured to control the device to a working state when the voltage rapid detection circuit outputs a high-level signal;

The microcontroller is further configured to switch the device to a sleep state when the voltage fast detection circuit outputs a low level signal.

Further, the electronic device is an in-vehicle entertainment device.

The embodiment of the utility model discloses a voltage rapid detection circuit and electronic equipment, comprising: a conversion module, a low voltage detection circuit and a high voltage detection circuit; the low voltage detection circuit and the high voltage detection circuit are connected in parallel to form a parallel detection circuit; One end of the parallel detection circuit is a power supply connection end, and the other end is connected to the conversion module, and the other end of the conversion module is used as a feedback end for connecting with the target device; the parallel detection circuit is used to detect the connected power supply. Whether the voltage is within a preset value range, the conversion module is used to convert the voltage detection result of the parallel detection circuit into a level signal and feed it back to the target device, where the level signal is used to indicate the target device. Take the appropriate action. A simple circuit converts the voltage with large fluctuation up and down into a stable level indication, which protects the target device and reduces the scanning operation of the power supply voltage.

Description of drawings

In order to illustrate the technical solutions of the present invention more clearly, the accompanying drawings required in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore do not It should be regarded as a limitation on the protection scope of the present invention. In the various figures, similar components are numbered similarly.

FIG. 1 shows a schematic structural diagram of a voltage rapid detection circuit according to an embodiment of the present application;

FIG. 2 shows a circuit diagram of a rapid voltage detection circuit according to an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. .

The components of the embodiments of the invention generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Accordingly, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely representative of selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present invention.

Hereinafter, the terms "comprising", "having" and their cognates, which may be used in various embodiments of the present invention, are only intended to denote particular features, numbers, steps, operations, elements, components, or combinations of the foregoing. , and should not be construed as first excluding the presence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing or adding one or more features, numbers, steps, operations, elements, Possibility of components or combinations of the foregoing.

Furthermore, the terms "first", "second", "third", etc. are only used to differentiate the description and should not be construed as indicating or implying relative importance.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which various embodiments of this invention belong. The terms (such as those defined in commonly used dictionaries) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized or overly formal meaning, Unless clearly defined in the various embodiments of the present invention.

Next, the technical solutions of the present application are explained with specific embodiments.

As shown in FIG. 1 , it is a schematic structural diagram of a voltage rapid detection circuit according to an embodiment of the present application.

The voltage rapid detection circuit of this embodiment includes a low voltage detection circuit 100 , a high voltage detection circuit 200 and a conversion module 300 .

The low voltage detection circuit 100 and the high voltage detection circuit 200 are connected in parallel. One end of the parallel detection circuit formed by the two is connected to the conversion module 300, the other end is used to connect to the power supply, and the other end of the conversion module 300 is used to connect to the target device, such as microcontroller.

The low-voltage detection circuit 100 and the high-voltage detection circuit 200 in FIG. 1 can detect the voltage connected to the right side through the configuration of their own circuits, and feed back the detection status to the conversion module 300, and the conversion module 300 converts the parallel detection circuit The voltage detection result is converted into a level signal and fed back to the target device, where the level signal is used to instruct the target device to perform a corresponding operation.

The target device is a microcontroller (MCU), and the microcontroller controls whether the corresponding system of the device where it is located is in a working or dormant state through the difference of high and low level signals obtained by feedback.

The specific details of each circuit structure can be understood with reference to the circuit diagram shown in FIG. 2 .

The conversion module 300 of the embodiment of the present application includes a second transistor Q2, a third transistor Q3, a fourth resistor R4 and a fifth resistor R5;

The base of the second triode Q2 is used as the first end of the conversion module, and is connected to the parallel detection circuit, the emitter is grounded, and the collector is respectively connected to the base and the third triode Q3. One end of the fourth resistor R4 is connected, and the fourth resistor R4 is used as a pull-up resistor for the base of Q3 and is connected to a working voltage, and the working voltage is used to supply power to the second transistor and the third transistor , in this embodiment, the working voltage can be selected as 3.3v; the emitter of the third transistor Q3 is grounded, and the collector is connected to the MCU; the other end of the fourth resistor R4 is connected to the fifth resistor R5 One end of the fifth resistor R5 is connected to the emitter of the third triode transistor.

When the voltage of the general car entertainment system is lower than 7.8V, the power supply voltage is insufficient and cannot work normally, and when the voltage is higher than 17.2V, there is a danger of damaging the electronic components.

Therefore, for the conversion module 300, when the power supply voltage is lower than 7.8V or higher than 17.2V, as long as the voltage at the point C does not meet the conduction condition of the second diode Q2, the point D in the conversion module 300 will be due to R4 gets a high level, so that the third transistor Q3 is turned on, so the voltage at point E is pulled down to 0, so the conversion module 300 will output a low level to the MCU, and the MCU will control the car entertainment system when it detects a low level. Enter sleep state.

When the power supply voltage is between 7.8V and 17.2V, the voltage at point C satisfies the conduction condition of the second diode Q2. When the second diode is turned on, the voltage at point D is caused by the second diode Q2. The diode Q2 is grounded, so it is pulled down to 0, so the third transistor Q3 is not turned on, so the voltage at point E gets a high level because the fifth resistor R5 is pulled up, so the conversion module 300 will output a high level level to the MCU, the MCU detects a high level to keep the in-vehicle entertainment system active.

The low voltage detection circuit 100 of the present application includes a first Zener diode Z1 and a first resistor R1, which are connected in series. The anode of the first Zener diode Z1 is connected to one end of the first resistor R1, and the cathode is connected to the conversion module. , the other end of the first resistor R1 is connected to the power supply end.

The low-voltage detection circuit 100 is used to ensure that the voltage passing through the circuit is higher than a certain value, so it is necessary to make the voltage passing through the low-voltage detection circuit 100 greater than 7.8V. The diode Q2 is turned on. When it is less than 7.8V, Q2 is not turned on. As shown in Figure 2, all diodes are NPN type. Therefore, according to the conduction principle, as long as the C point at low voltage is in the The low voltage state is sufficient. Therefore, the voltage can be divided by setting the reverse voltage of the first Zener diode Z1 and the resistance value of the first resistor R1, so that the voltage at point C is too small when the voltage is less than 7.8V.

For example, a first Zener diode Z1 with a reverse voltage of 6.7V can be set, and the resistance value of the first resistor R1 can be set to one thousand ohms, so that the first resistor R1 can divide the voltage of about 0.3V to 0.4V, and use The turn-on voltage of the second diode Q2 is 1V, so that when the voltage of the power supply drops below 7.8V, the voltage at point C is not enough to maintain the conduction state of Q2. It can be known from the working principle that when the power supply voltage is lower than 7.8V, the conversion module 300 will output a low level to the MCU.

The high voltage detection circuit 200 includes a second resistor R2, a third resistor R3, a second Zener diode and a Z2 first transistor Q1;

The emitter of the first transistor Q1 is grounded, the collector is connected to the conversion module, and the base is connected to the second resistor R2; the second resistor R2, the third resistor R3 and the second Zener diode Z2 is connected in series; the anode of the second Zener diode Z2 is connected to the second resistor R2, the cathode is connected to the third resistor R3, and the third resistor R3 is connected to the power connection terminal. The resistance value of the second resistor R2 is greater than that of the third resistor R3, so as to ensure that the above-mentioned second Zener diode can be broken down when the voltage is large enough, and the second resistor R2 can also be used as a protection resistor to protect the first Transistor Q1.

The high voltage detection circuit 200 is used to pull down the voltage at point C when the voltage is too large, so that Q2 is in a non-conducting state, but under normal working voltage, the voltage at point C should be kept normal, so as long as 17.2 Keeping the voltage at point B before V is not enough to make the first transistor Q1 turn on. When it is higher than 17.2V, the first transistor Q1 is turned on, so that point C can be pulled down to ground.

Specifically, a second Zener diode Z2 with a reverse voltage of 16V can be set, the second resistor R2 can be 4,700 ohms, the third resistor R3 can be 1,000 ohms, and the turn-on voltage of Q1 can be 0.7V Therefore, when the power supply voltage is 17.2V, R2 and R3 can be combined with the second Zener diode Z2 to divide the voltage of 16.5V, so that when the power supply voltage is between 7.8 and 17.2V, the first transistor will not be caused. Q1 is turned on, and when the power supply voltage exceeds 17.2V, the voltage at point B will exceed the turn-on voltage of Q1, so that Q1 is turned on, and then point C is grounded, so that the voltage at point C can change when it exceeds 17.2V. The voltage is low, so that the second diode Q2 is non-conductive, which meets the working requirements of the conversion module 300 .

The high voltage detection circuit 200 is further connected with a sixth resistor connected to ground, and the sixth resistor is connected with the base of the first transistor.

Further, the present application also provides an electronic device, which includes a power supply arranged in sequence, a voltage rapid detection circuit as described in any one of the above embodiments, and a microcontroller. The microcontroller is used to detect the voltage condition of the power supply through the voltage fast detection circuit. Further, when the voltage rapid detection circuit outputs a high level, the microcontroller controls the device to a working state; when the voltage rapid detection circuit outputs a low level, the microcontroller switches the device to a sleep state.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may also be implemented in other manners.

In addition, each functional module or unit in each embodiment of the present invention can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part.

The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Replacement should be covered within the protection scope of the present invention.

Claims (10)

1. A voltage rapid detection circuit, characterized in that, comprising: a conversion module, a low voltage detection circuit and a high voltage detection circuit; The low-voltage detection circuit and the high-voltage detection circuit are connected in parallel to form a parallel detection circuit; one end of the parallel detection circuit is a power supply connection end, and the other end is connected to the conversion module, and the other end of the conversion module is used as a feedback end for Connect with the target device; The parallel detection circuit is used to detect whether the voltage of the connected power supply is within a preset value range, and the conversion module is used to convert the voltage detection result of the parallel detection circuit into a level signal and feed it back to the target device , the level signal is used to instruct the target device to perform a corresponding operation. 2. The fast voltage detection circuit according to claim 1, wherein the low voltage detection circuit comprises a first Zener diode and a first resistor; The anode of the first Zener diode is connected to one end of the first resistor, the cathode is connected to the conversion module, and the other end of the first resistor is connected to the power connection end. 3. The fast voltage detection circuit according to claim 1, wherein the high voltage detection circuit comprises a second resistor, a third resistor, a second Zener diode and a first transistor; The emitter of the first transistor is grounded, the collector is connected to the conversion module, and the base is connected to one end of the second resistor; The anode of the second Zener diode is connected to the other end of the second resistor, and the cathode is connected to one end of the third resistor. The resistance of the second resistor is greater than that of the third resistor. The other end of the resistor is connected to the power connection end. 4. The voltage rapid detection circuit according to claim 3, wherein the conversion module comprises a second triode, a third triode, a fourth resistor and a fifth resistor; The base of the second triode serves as the first end of the conversion module, and is connected to the parallel detection circuit, the emitter is grounded, and the collector is respectively connected to the base of the third triode and the One end of the fourth resistor is connected; The emitter of the third triode is grounded, and the collector is connected to the voltage detection terminal of the target device; The other end of the fourth resistor is connected to one end of the fifth resistor, and the other end of the fifth resistor is connected to the emitter of the third triode; The other end of the fourth resistor is also used for connecting with a working voltage, and the working voltage is used for supplying power to the second triode and the third triode. 5 . The rapid voltage detection circuit according to claim 1 , further comprising a capacitor, one end of the capacitor is connected to the voltage detection end of the target device, and the other end is grounded for low-pass filtering. 6 . 6 . The rapid voltage detection circuit according to claim 4 , wherein the first triode, the second triode and the third triode are all NPN triodes. 7 . 7 . The fast voltage detection circuit according to claim 3 , wherein the high voltage detection circuit is further connected with a sixth resistor, and one end of the sixth resistor is connected to the base of the first transistor. 8 . , and the other end is grounded. 8. An electronic device, characterized in that it comprises a power supply, a voltage rapid detection circuit as claimed in any one of claims 1 to 7, and a microcontroller arranged in sequence; The microcontroller is used to detect the voltage condition of the power supply through the voltage fast detection circuit. 9. The electronic device according to claim 8, wherein the microcontroller is further configured to control the device to a working state when the voltage rapid detection circuit outputs a high-level signal; The microcontroller is further configured to switch the device to a sleep state when the voltage fast detection circuit outputs a low level signal. 10. The electronic device according to claim 8 or 9, wherein the electronic device is an in-vehicle entertainment device.

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