CN113358915A - Voltage signal detection circuit, power supply device and electric device - Google Patents

Abstract

The embodiment of the application relates to a voltage signal detection circuit, a power supply device and a power utilization device, wherein the circuit comprises a first switch unit and a pull-down resistor unit; the first end of the first switch unit is used for being connected with a first voltage signal input end, the second end of the first switch unit is electrically connected with the first end of the pull-down resistor unit, and the second end of the first switch unit is also used for being connected with the identification port. When the identification port is not connected with the first voltage signal, the pull-down resistance unit provides a voltage signal for the second end of the first switch unit, the first voltage signal input end provides a voltage signal for the first end of the first switch unit, the two voltage signals enable the first switch unit to be in a pass state, the first voltage signal input end provides a first level signal for the third end of the first switch unit, through the first level signal, the fact that the identification port is not connected with the first voltage signal can be judged, so that the accuracy of detecting whether the identification port of the power supply device is short-circuited with the voltage signal or not is improved, the circuit structure is simple, and the circuit cost is reduced.

Description

Voltage signal detection circuit, power supply device and electric device

Technical Field

The present application relates to the field of voltage detection, and in particular, to a voltage signal detection circuit, a power supply device, and an electric device.

Background

In the working process of many circuit systems, it is often necessary to identify whether a certain identification port of the circuit system is short-circuited with a certain voltage signal of the circuit system, and when it is identified that the identification port is short-circuited with the voltage signal, corresponding functional operations can be further executed. For example, in some cases of supplying power by using a battery, the battery outputs a positive power supply electrode to the outside, and the battery is further provided with an identification port for identifying whether the identification port is short-circuited to the positive power supply electrode, and when the identification port is short-circuited to the positive power supply electrode, the battery is discharged to supply power by using the battery.

The current voltage detection circuit for detecting whether the identification port is short-circuited to a certain voltage signal cannot accurately detect, is easy to identify by mistake, and has complex circuit and higher cost.

Disclosure of Invention

The embodiment of the application aims at providing a voltage signal detection circuit, a power supply device and an electric device, so that the accuracy of detecting whether a recognition port of the power supply device is short-circuited with a voltage signal is improved, and the circuit cost is reduced.

In order to solve the above technical problem, one technical solution adopted in the embodiments of the present application is:

in a first aspect, an embodiment of the present application provides a voltage signal detection circuit, which includes a first switch unit and a pull-down resistance unit. The first end of the first switch unit is used for being connected with a first voltage signal input end, the second end of the first switch unit is electrically connected with the first end of the pull-down resistor unit, the second end of the first switch unit is also used for being connected with an identification port, and the third end of the first switch unit is a signal output end of the first switch unit. The identification port is used for detecting whether the first voltage signal is connected or not, and the first switch unit is used for outputting a first level signal at the signal output end when a conduction condition is met.

In some embodiments, the voltage signal detection circuit further includes a second switching unit. The third end of the second switch unit is connected with the signal output end of the first switch unit, the first end of the second switch unit is electrically connected with the second voltage signal input end, the second end of the second switch unit is grounded, and the second switch unit is used for being switched on or switched off according to the signal output by the signal output end of the first switch unit. The first end of the second switch unit is a signal output end of the second switch unit.

In some embodiments, the voltage signal detection circuit further includes a voltage dividing unit, a first end of the voltage dividing unit is electrically connected to the signal output end of the first switch unit, a second end of the voltage dividing unit is grounded, a third end of the voltage dividing unit is connected to a third end of the second switch unit, and the voltage dividing unit is configured to divide a voltage connected to the first end of the voltage dividing unit, so as to output a voltage dividing signal at the third end of the voltage dividing unit.

In some embodiments, the first switching unit includes a first transistor, and the voltage dividing unit includes a first resistor and a second resistor. The base of the first triode is connected with the first end of the pull-down resistor unit, the base of the first triode is further used for being connected with the identification port, the emitting electrode of the first triode is used for being connected with the first voltage signal input end, the collecting electrode of the first triode is connected with one end of the first resistor, the other end of the first resistor is respectively connected with the third end of the second switch unit and one end of the second resistor, and the other end of the second resistor is grounded.

In some embodiments, the voltage signal detection circuit further comprises a first unidirectional conducting circuit. The first end of the first unidirectional conduction circuit is electrically connected with the first end of the first switch unit, and the second end of the first unidirectional conduction circuit is electrically connected with the first voltage signal input end.

In some embodiments, the voltage signal detection circuit further comprises a second unidirectional conducting circuit. The first end of the second unidirectional conduction circuit is electrically connected with the second end of the first switch unit and the first end of the pull-down resistor unit respectively, and the second end of the second unidirectional conduction circuit is used for being connected with the identification port.

In some embodiments, the first unidirectional conducting circuit comprises a first diode and a second diode. The anode of the first diode is electrically connected with the first voltage signal input end, the cathode of the first diode is connected with the anode of the second diode, and the cathode of the second diode is electrically connected with the first end of the first switch unit.

In some embodiments, the second unidirectional conducting circuit comprises a third diode. And the cathode of the third diode is respectively connected with the second end of the first switch unit and the first end of the pull-down resistor unit, and the anode of the third diode is used for connecting the identification port.

In some embodiments, the second switching unit includes a second transistor. The base electrode of the second triode is connected with the third end of the voltage division unit, the collector electrode of the second triode is connected with the second voltage signal input end, and the emitting electrode of the second triode is grounded.

In some embodiments, the voltage signal detection circuit further comprises a filtering circuit. The first end of the filter circuit is electrically connected with the second voltage signal input end and the first end of the second switch unit respectively, the second end of the filter circuit is grounded, the third end of the filter circuit is the output end of the filter circuit, and the filter circuit is used for filtering a second voltage signal input by the second voltage signal input end.

In some embodiments, the filter circuit includes a third resistor and a capacitor. One end of the third resistor is connected with the second voltage signal input end and the first end of the second switch unit respectively, the other end of the third resistor is connected with one end of the capacitor, and the other end of the capacitor is grounded.

In some embodiments, the pull-down resistance unit includes a fourth resistor, one end of the fourth resistor is connected to the second end of the first switch unit, and the other end of the fourth resistor is grounded.

In some embodiments, the voltage signal detection circuit further includes a controller connected to the second voltage signal input terminal and the first terminal of the second switching unit, respectively.

In a second aspect, an embodiment of the present application provides a power supply apparatus, including: in the voltage signal detection circuit, the power supply device is configured to provide the first voltage signal, and the power supply device is further provided with the identification port.

In a third aspect, an embodiment of the present application provides an electric device, which includes a load and the above power supply device, where the power supply device is configured to supply power to the load.

In some embodiments, the powered device comprises at least one of a drone or an electric vehicle or a power tool.

One or more embodiments in the present application include the following advantageous effects: different from the prior art, the voltage signal detection circuit comprises a first switch unit and a pull-down resistor unit, wherein a first end of the first switch unit is used for being connected with a first voltage signal input end, a second end of the first switch unit is electrically connected with a first end of the pull-down resistor unit, and a third end of the first switch circuit is a signal output end of the first switch circuit. When a certain identification port needs to be detected whether to be connected with a first voltage signal, the second end of the first switch unit can be connected with the identification port, when the identification port is not connected with the first voltage signal, the pull-down resistor unit provides a voltage signal for the second end of the first switch unit, the first voltage signal input end provides a voltage signal for the first end of the first switch unit, the two voltage signals enable the first switch unit to be in a pass state, the first voltage signal input end provides a first level signal for the third end of the first switch unit, and the first voltage signal which is not connected with the identification port can be judged through the first level signal, so that the accuracy of detecting whether the identification port of the power supply device is short-circuited with the voltage signal is improved, the circuit structure is simple, and the circuit cost is reduced.

Drawings

Fig. 1 is a schematic structural diagram of one of power supply devices provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a voltage signal detection circuit according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a voltage signal detection circuit according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of one of the voltage signal detection circuits provided in the embodiments of the present application;

fig. 5 is a schematic circuit structure diagram of one of the voltage signal detection circuits according to the embodiments of the present application.

Detailed Description

To facilitate an understanding of the present application, the present application is described in more detail below with reference to the accompanying drawings and detailed description. It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

First, some power supply devices capable of implementing the voltage signal detection circuit described in the embodiments of the present application will be described.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a power supply device according to an embodiment of the present disclosure, in which the power supply device 100 provides a first voltage signal, and in the embodiment shown in fig. 1, the power supply device 100 provides the first voltage signal through an output port 101. The power supply device 100 is further provided with an identification port 102, and the identification port 102 is used for identifying whether the port is connected with the first voltage signal or not. The first voltage signal may be from a positive power supply terminal of the power supply apparatus 100, and in other embodiments, the first voltage signal may also be from a negative power supply terminal of the power supply apparatus 100.

In the embodiment shown in fig. 1, the voltage detection circuit 10 is integrated in the power supply device 100, and in other embodiments, the voltage detection circuit 10 may be provided separately from the power supply device 100. The first voltage signal is used for supplying power to the voltage detection circuit 10, and the voltage detection circuit 10 is further connected to the identification port 102, and is used for detecting whether the identification port 102 is connected to the first voltage signal.

The power supply 100 may include various implementations such as a battery, charger, or other power system. The number of the identification ports 102 of the power supply device 100 may be 1 or more, and the number thereof depends on the functional operation to be implemented, and often one identification port 102 corresponds to one or more functional operations.

For example, the voltage detection circuit may be used for a function of discharging a power supply device (e.g., a battery) to supply power to a power-consuming device (e.g., an electric vehicle). The power supply device can provide a power supply positive pole for the electric device (can also provide a power supply negative pole for the electric device) through the output port 101, when the power supply device is not used for the electric device, the identification port is suspended, the power supply positive pole is not accessed, then the controller judges that the identification port is not accessed to the power supply positive pole, and then the power supply device can not be subjected to discharging operation.

When the power supply device is used for an electric device, the output port 101 and the identification port 102 are in short circuit, the identification port 102 is connected to the positive power supply electrode, the controller can detect that the identification port is connected to the positive power supply electrode, and the power supply device is discharged to supply power to the electric device. The above only illustrates one function implementation, and if other functions need to be implemented additionally, more identification ports may be provided on the power supply device.

The number of the voltage signal detection circuits 10 corresponds to the number of the identification ports, and each identification port is provided with one voltage signal detection circuit 10 for detecting whether the identification port is connected to the first voltage signal, for example, for detecting whether the identification port is connected to the power supply positive electrode of the power supply apparatus 100.

It should be noted that, the above application environment is only for exemplary illustration, and in practical applications, the voltage signal detection circuit 10 provided in the embodiment of the present application may be further extended to other suitable application environments, and is not limited to the application environment shown in fig. 1. Such as: the voltage signal detection circuit 10 is used for identifying whether a system port of the motor controller is short-circuited with the positive electrode signal or identifying whether a system port of the battery charging system is short-circuited with the positive electrode signal.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a voltage signal detection circuit according to an embodiment of the present disclosure. As shown in fig. 2, the voltage signal detection circuit 10 includes a first switching unit 11 and a pull-down resistance unit 12. A first terminal of the first switch unit 11 is electrically connected to the first voltage signal input terminal 200, a second terminal of the first switch unit 11 is electrically connected to a first terminal of the pull-down resistor unit 12, and a third terminal of the first switch unit 11 is a signal output terminal of the first switch unit 11.

When it is required to detect whether the identification port is connected to the first voltage signal, the second terminal of the first switch unit 11 is electrically connected to the identification port of the power supply device 100. If the second terminal of the first switch unit 11 is not connected to the first voltage signal, the second terminal of the first switch unit 11 is in a floating state. The pull-down resistor unit provides a voltage signal to the second terminal of the first switch unit, the first voltage signal input terminal provides a voltage signal to the first terminal of the first switch unit, the two voltage signals make the first switch unit 11 in a pass state, and the first voltage signal input terminal provides a first level signal to the third terminal of the first switch unit 11. Through the first level signal, the identification port can be judged not to be connected with the first voltage signal.

When the second terminal of the first switch unit 11 is connected to the first voltage signal, the first terminal and the second terminal of the first switch unit 11 are both connected to the first voltage signal, so that the first switch unit is turned off, and the third terminal of the first switch unit cannot output the first level signal.

That is, when the second end of the first switch unit 11 is not connected to the first voltage signal, the signal output end of the first switch unit outputs the first level signal, and the first level signal can determine that the identification port of the power supply device 100 is not connected to the first voltage signal, so that the voltage signal can be accurately detected, and the circuit structure is simple and the circuit cost is reduced.

In the embodiment shown in fig. 3, the controller 13 is connected to the third terminal of the first switching unit to detect the first level signal, and determine whether the power supply device 100 is connected to the first voltage signal according to the first level signal. In other embodiments, other processing modules with operation processing capability may be utilized to detect the first level signal.

In some embodiments, the controller 13 may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a single chip, an ARM (Acorn RISC machine) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination of these components.

In some embodiments, the first voltage signal input 200 is a dc power supply, and the voltage thereof can be set according to the requirement. The first voltage signal input terminal 200 may be a separately provided power supply, or may be directly provided by the positive power supply pole or the negative power supply pole of the power supply apparatus 100.

Referring to fig. 4, fig. 4 is a schematic circuit structure diagram of a voltage signal detection circuit according to an embodiment of the present disclosure, where the voltage signal detection circuit further includes a voltage dividing unit 14, a first end of the voltage dividing unit 14 is electrically connected to a third end of the first switch unit 11, a second end of the voltage dividing unit 14 is grounded, and a third end of the voltage dividing unit 14 is electrically connected to the controller 13. When the second terminal of the first switch unit 11 is not connected to the first voltage signal, the first switch unit 11 is in a conducting state, the signal output terminal of the first switch unit 11 outputs a first level signal, and when the voltage dividing unit 14 is connected to the first level signal, the voltage dividing unit 14 divides the first level signal, and transmits the divided voltage signal to the controller 13 through the third terminal, and the controller 13 processes and analyzes the divided voltage signal.

Referring to fig. 4, in some embodiments, the voltage signal detecting circuit 10 further includes a first unidirectional conducting circuit 15 and a second unidirectional conducting circuit 16. The first end of the first unidirectional conducting circuit 15 is electrically connected to the first end of the first switch unit 11, the second end of the first unidirectional conducting circuit 15 is electrically connected to the first voltage signal input end 200, the first end of the second unidirectional conducting circuit 16 is electrically connected to the second end of the first switch unit 11 and the first end of the pull-down resistor unit 12, and the second end of the second unidirectional conducting circuit 16 is used for connecting the identification port 102.

The second unidirectional conducting circuit 16 is used for performing short-circuit protection on the first unidirectional conducting circuit 15 and the first switch unit 11 to ground, and preventing the second terminal of the first switch unit 11 from being burnt out due to being connected to ground or a low-level signal. The first voltage signal input end 200 generates a voltage drop on the first unidirectional conducting circuit 15, and then acts on the first end of the first switch unit 11, if the second end of the second unidirectional conducting circuit 16 is connected to the first voltage signal, the first voltage signal generates a voltage drop on the second unidirectional conducting circuit 16, and then acts on the second end of the first switch unit 11, the voltage drop generated on the first unidirectional conducting circuit 15 is greater than or equal to the voltage drop generated on the second unidirectional conducting circuit 16, so that the voltage of the first end of the first switch unit 11 is less than or equal to the voltage of the second end of the first switch unit 11, and thus the first switch unit 11 is ensured to be reliably disconnected, and therefore, the first unidirectional conducting circuit 15 is used for ensuring that the first switch unit 11 can be reliably disconnected when the second end of the second unidirectional conducting circuit 16 is connected to the first voltage signal.

In other embodiments, the voltage detection circuit 10 may also include only the first unidirectional conducting circuit 15, but not the second unidirectional conducting circuit 16, and the voltage at the first end of the first switch unit 11 may also be smaller than or equal to the voltage at the second end of the first switch unit 11, so as to ensure that the first switch unit 11 is reliably turned off.

In some embodiments, the voltage signal detecting circuit 10 further includes a second switch unit 17, a third terminal of the second switch unit 17 is connected to a third terminal of the voltage dividing unit 14, a first terminal of the second switch unit 17 is electrically connected to the second voltage signal input terminal 300 and the controller 13, respectively, a second terminal of the second switch unit 17 is grounded, and the second switch unit 17 is configured to be turned on or off based on a signal output by the signal output terminal of the first switch unit 11. The first end of the second switch unit 17 is a signal output end, the second end of the second switch unit 17 is a driving end, and the third end of the second switch unit 17 is a signal input end.

When the second end of the first switch unit 11 is not connected to the first voltage signal, the second end of the first switch unit 11 is in a floating state, the voltage of the first end of the first switch unit 11 is greater than the voltage of the second end of the first switch unit 11, and the first switch unit 11 is in a conducting state, then the signal output end of the first switch unit 11 outputs the first level signal (the first level signal may be a high level signal), the second switch unit 17 is conducting, then the first end and the second end of the second switch unit 17 are connected, and the controller 13 receives a low level signal. When the second terminal of the first switch unit 11 is connected to the first voltage signal, the voltage of the first terminal of the first switch unit 11 is less than or equal to the voltage of the second terminal of the first switch unit 11, the first switch unit 11 is in a cut-off state, and the third terminal of the second switch unit 17 is also in a cut-off state because no input voltage is present, so that the controller obtains a high level signal through the second voltage signal input terminal 300. Accordingly, the controller 13 may determine whether the identification port is connected to the first voltage signal according to the acquired high level signal or low level signal.

In some embodiments, the first switch unit 11 or the second switch unit 17 may include a transistor, a MOS transistor, a contactor, a relay, an electronic switch, a time delay switch, a photoelectric switch, a tact switch, a proximity switch, a double control switch, and the like.

In some embodiments, the voltage signal detecting circuit 10 further includes a filter circuit 18, a first terminal of the filter circuit 18 is electrically connected to the second voltage signal input terminal and the first terminal of the second switch unit 17, respectively, a second terminal of the filter circuit 18 is grounded, a third terminal of the filter circuit 18 is electrically connected to the controller 13, and the filter circuit 18 is configured to filter a signal at the second voltage signal input terminal. When the second switch unit 17 is turned on, the second voltage signal input terminal, the second switch unit 17 and the ground form a closed loop, the first terminal of the filter circuit 18 is equivalent to ground, and the filter circuit 18 sends a low level signal to the controller 13 through the third terminal thereof. When the second switch unit 17 is turned off, the signal at the second voltage signal input terminal is filtered by the filter circuit 18 and then transmitted to the controller 13, and the controller 13 receives the high level signal. Therefore, the controller 13 determines whether the second terminal of the first switching unit 11 is connected to the first voltage signal according to the received level signal.

Referring to fig. 5, fig. 5 is a schematic circuit structure diagram of a voltage signal detection circuit according to an embodiment of the present disclosure, in which an anode of a power supply device 100 provides a first voltage signal, an anode of the first voltage signal is P +, and a cathode of the first voltage signal is P-. The first switch unit 11 includes a first triode Q1, the voltage dividing unit 14 includes a first resistor R1 and a second resistor R2, the base of the first triode Q1 is connected with the first end of the pull-down resistor unit 12, the emitter of the first triode Q1 is connected with P +, the collector of the first triode Q1 is connected with one end of a first resistor R1, the other end of the first resistor R1 is connected with one ends of the second switch unit 17 and the second resistor R2, and the other end of the second resistor R2 is grounded.

In the embodiment of the present application, the first transistor Q1 is a PNP transistor or a PMOS transistor, and the PNP transistor is taken as an example in the figure, and the voltage of the first voltage signal input end 200 is a positive voltage provided by the power supply. The first resistor R1 and the second resistor R2 are voltage dividing resistors, and are configured to divide the voltage output by the first transistor Q1.

The first unidirectional circuit 15 includes a first diode D1 and a second diode D2, an anode of the first diode D1 is electrically connected to the anode P + of the first voltage signal input terminal 200, a cathode of the first diode D1 is connected to an anode of the second diode D2, a cathode of the second diode D2 is electrically connected to the first end of the first switch unit 11, and specifically, a cathode of the second diode D2 is connected to an emitter of the first transistor Q1.

The second unidirectional conducting circuit 16 includes a third diode D3, a cathode of the third diode D3 is respectively connected to the second terminal of the first switch unit 11 and the first terminal of the pull-down resistor unit 12, specifically, a cathode of the third diode D3 is connected to a base of the first transistor Q1, and an anode of the third diode D3 is connected to the identification port ON. In the embodiment of the present application, the first diode D1, the second diode D2, and the third diode D3 may be the same type and have the same specification, which may be schottky diodes, fast recovery diodes, and common switching diodes.

The second switching unit 17 includes a second transistor Q2, a base of the second transistor Q2 is connected to a third end of the voltage dividing unit 14, a collector of the second transistor Q2 is connected to the second voltage signal input terminal VCC and the controller 13, respectively, and an emitter of the second transistor Q2 is grounded. Specifically, the base of the second transistor Q2 is connected to the node between the first resistor R1 and the second resistor R2. In the embodiment of the present application, the second transistor Q2 may be an NPN transistor or an NMOS transistor, and the NPN transistor is taken as an example in the figure.

The filter circuit 18 includes a third resistor R3 and a capacitor C1, one end of the third resistor R3 is connected to the second voltage signal input terminal and the first end of the second switch unit 17, specifically, one end of the third resistor R3 is connected to the second voltage signal input terminal VCC and the collector of the second transistor Q2, the other end of the third resistor R3 is connected to one end of the capacitor C1 and the ON _ IN signal terminal of the controller chip MCU, and the other end of the capacitor C1 is grounded.

The pull-down resistor unit 12 includes a fourth resistor R4, one end of the fourth resistor R4 is connected to the second end of the first switch unit 11, specifically, one end of the fourth resistor R4 is connected to the base of the first transistor Q1, and the other end of the fourth resistor R4 is grounded. The fourth resistor R4 is used to connect one terminal to ground to fix the other terminal (i.e., the base of the first transistor Q1) at a low level.

In some embodiments, the voltage signal detection circuit 10 further includes a fifth resistor R5, one end of the fifth resistor R5 is connected to the second voltage signal input terminal, and the other end of the fifth resistor R5 is connected to one end of the third resistor R3 and the collector of the second transistor Q2, respectively. The fifth resistor R5 is a pull-up resistor. The fifth resistor R5 is used to connect one end with the second voltage signal input terminal (high voltage signal) to fix the other end (i.e., the ON _ IN terminal of the controller) at a high level.

In some embodiments, the voltage signal detecting circuit 10 further includes a sixth resistor R6, one end of the sixth resistor R6 is connected to the anode of the first diode D1, and the other end of the sixth resistor R6 is connected to the base of the first transistor Q1, the cathode of the third diode D3, and one end of the fourth resistor R4, respectively. The sixth resistor R6 is used for dividing the voltage P +, and clamping the voltage difference between the base and the emitter of the first transistor Q1 within a reasonable range, so as to prevent the first transistor Q1 from being conducted by mistake.

Among the resistors, the first resistor R1 is a current-limiting resistor, the second resistor R2 and the sixth resistor R6 are bias resistors, the third resistor R3 is a filter resistor, the fourth resistor R4 is a pull-down resistor, and the fifth resistor R5 is a pull-up resistor.

Referring to fig. 5, in fig. 5, the battery is taken as an example, the positive electrode of the battery cell is B +, the negative electrode of the battery cell is B-, the positive electrode of the battery cell is P +/C +, the negative electrode of the battery cell is P-/C-, wherein the negative electrode of the battery cell B-is equivalent to a ground terminal, the identification port of the battery is an ON port, the voltage signal detection circuit is configured to detect whether the ON port has accessed the high voltage signal P +/C +, if the external switch SW1 simulates a connection state between the high voltage signal P +/C + and the identification port ON port, when the external switch SW1 is closed, the high voltage signal P + is short-connected to the ON port, when the external switch SW1 is open, the high voltage signal P + is not short-connected to the ON port, and the insulation resistance of the external switch SW1 is a resistance RL.

With reference to fig. 5, the operation principle of the voltage signal detection circuit can be described as follows:

when the ON port is IN a floating state, IN a power-up stage, the high voltage signal P + is grounded through the first diode D1, the second diode D2, the emitter of the first transistor Q1, the base of the first transistor Q1, and the fourth resistor R4, so that the BE junction of the first transistor Q1 is IN a forward bias state, and further the first transistor Q1 is turned ON, at this time, the high voltage signal P + is grounded through the first diode D1, the second diode D2, the emitter of the first transistor Q1, the collector of the first transistor Q1, the first resistor R1, and the second resistor R2, the first resistor R1 and the second resistor R2 divide the P + voltage, the divided signal is a high level signal, the high level signal acts ON the base of the second transistor Q2 to drive the second transistor Q2 to BE turned ON, the collector voltage of the second transistor Q2 is pulled down to GND, that is a low level, and at the same time, the ON _ level of the controller 13 recognizes the low level signal, and confirming that the ON port is not short-circuited with the high-voltage signal P +.

When the ON port is shorted to the high voltage signal P +, i.e., the external switch SW1 is closed, the base voltage of the first transistor Q1 is equal to the P + voltage minus the tube drop of the third diode D3, the emitter voltage of the first transistor Q1 is equal to the P + voltage minus the tube drops of the first diode D1 and the second diode D2, and meanwhile, the first transistor Q1, the second transistor Q2 and the third transistor Q3 are the same type of transistors with the same specification, so that the emitter voltage of the first transistor Q1 is necessarily smaller than the base voltage thereof, the first transistor Q1 is IN a cut-off state, the P + voltage cannot drive the second transistor Q2 through the divided voltage of the first resistor R1 and the second resistor R2, the second transistor Q2 is IN a cut-off state, and thus, the signal of the ON _ IN port of the controller 13 is pulled up to the second voltage signal input terminal by the fifth resistor R5, and the controller 13 can be interrupted by VCC while the ON _ IN port is detected as a high ON signal level, determining that the ON port is connected to P +, determining that the ON port has shorted the first voltage signal.

In practical use, attention needs to be paid to power consumption of the circuit, and appropriate resistance values of the first resistor R1, the second resistor R2 and the fourth resistor R4 need to be selected according to the magnitude of the input P + voltage. The leakage current characteristic of the transistor needs to be considered, the resistance value of the first resistor R1 is reasonably set to prevent the second triode Q2 from being conducted mistakenly due to overlarge leakage current, and the controller mistakenly identifies the interface state. Meanwhile, the proportional relation between the first resistor R1 and the second resistor R2 is considered, so that the second triode Q2 can be normally conducted when the P + is at the lowest voltage, the second triode Q2 needs to work in a saturation state, and the working state of the transistor is adjusted by adjusting the resistance values of the first resistor R1, the second resistor R2, the fourth resistor R4 and the fifth resistor R5. In order to prevent the first diode D1, the second diode D2 and the first transistor Q1 from being burned out when the ON port is shorted to ground, the third diode D3 with a proper reverse voltage withstanding value needs to be selected. In order to ensure the reliable operation of the circuit, the first diode D1, the second diode D2 and the third diode D3 should be the same type of diode, and in addition, in order to increase the robustness and reliability of the circuit, protective devices may be added as needed, such as a zener diode, a filter circuit, a transient voltage suppression diode, etc. at the ON port or the controller port.

The existing voltage signal detection circuit mainly drives an MOS tube or a triode to generate level inversion through partial voltage generated by a resistance voltage division circuit, and a controller identifies an inversion signal so as to judge whether a designated node (namely an identification port) has voltage access. The voltage dividing circuit is generally composed of two series resistors, one end of the voltage dividing circuit is connected with the identification port, the other end of the voltage dividing circuit is grounded, and a node between the two resistors is used as an output end of the voltage dividing circuit and is connected with the controller. In order to enable the identification port to be connected with the P + when the P + is low, the divider resistor needs to be large enough, and meanwhile, in order to reduce the power consumption of the circuit, the resistance values of the two series resistors need to be large, but detection errors are easily caused.

For example, when the insulation between the identification port and the P + output port of the battery is reduced due to water leakage or other reasons, even if the identification port and the output port are not really short-circuited, RL is still large, a voltage signal can be generated at the identification port, and the voltage dividing circuit can still output a large voltage dividing signal due to the large voltage dividing resistor, and at this time, the controller can detect the voltage dividing signal and mistakenly think that the identification port is connected with P +. Therefore, the insulation leakage resistance in the prior art is poor, false identification is easy to generate, if the probability of false identification is reduced, the resistance value of the divider resistor is reduced, the power consumption of the circuit is increased, and therefore the dual requirements of low power consumption and high identification precision cannot be met in the prior art.

In the technical solution of the embodiment of the present application, taking the embodiment shown in fig. 5 as an example, when the identification port is not connected to P +, the base of the first transistor Q1 is pulled to a low level due to the action of the pull-down resistor R4, the emitter of the first transistor Q1 is at a high level, the first transistor Q1 is in a conducting state, the second transistor Q2 is conducted due to the high level output by the first transistor Q1, and at this time, the controller detects a low level. When the insulation between the identification port and the P + output port of the battery is reduced due to water leakage or other reasons, RL is still large because the identification port and the output port are not really short-circuited, although the identification port can be connected with a voltage signal smaller than P +, the voltage of the base of the first triode is still smaller than the voltage of the emitter of the first triode, and the first triode Q1 is still in a conducting state.

Only when the identification port and the output port are really short-circuited, the insulation resistance RL is particularly small, the voltage dropped by the insulation resistance RL is particularly small, the voltage of the base electrode of the first triode Q1 can be larger than the voltage of the emitter electrode of the first triode Q1, the first triode Q1 is in a cut-off state, the second triode Q2 is cut off, the controller detects the high level of one end of the pull-up resistor R5, the level signal detected by the controller is inverted, and the controller detects that the identification port is connected with P +.

The voltage signal detection circuit 10 of the embodiment of the application has the advantages of strong insulation leakage resistance and high identification precision, and can not generate false identification when the insulation resistance RL is too large. Meanwhile, the voltage signal detection circuit 10 can reduce the power consumption of the circuit by adjusting the resistance values of the first resistor R1 and the second resistor R2, and therefore, the voltage signal detection circuit 10 can meet the dual requirements of low power consumption and identification accuracy.

To sum up, this voltage signal detection circuitry can accurate detection power supply unit's discernment port department with first voltage signal short circuit, and the discernment precision is high, and the consumption is lower.

The embodiment of the application also provides an electric device, which comprises a load and the electric device in any one of the above embodiments, wherein the electric device is an unmanned aerial vehicle, an electric vehicle or an electric tool.

It should be noted that the description of the present application and the accompanying drawings set forth preferred embodiments of the present application, however, the present application may be embodied in many different forms and is not limited to the embodiments described in the present application, which are not intended as additional limitations to the present application, but are provided for the purpose of providing a more thorough understanding of the present disclosure. Moreover, the above-mentioned technical features are combined with each other to form various embodiments which are not listed above, and all the embodiments are regarded as the scope described in the present specification; further, modifications and variations may occur to those skilled in the art in light of the foregoing description, and it is intended to cover all such modifications and variations as fall within the scope of the appended claims.

Claims (15)

1. A voltage signal detection circuit, comprising: a first switching unit and a pull-down resistance unit;

the first end of the first switch unit is used for being connected with a first voltage signal input end, the second end of the first switch unit is electrically connected with the first end of the pull-down resistor unit, the second end of the first switch unit is also used for being connected with an identification port, and the third end of the first switch unit is a signal output end of the first switch unit;

the identification port is used for detecting whether the first voltage signal is accessed, and the first switch unit is used for outputting a first level signal at the signal output end when a conduction condition is met.

2. The voltage signal detection circuit according to claim 1, further comprising: a second switching unit;

the third end of the second switch unit is connected with the signal output end of the first switch unit, the first end of the second switch unit is electrically connected with the second voltage signal input end, the second end of the second switch unit is grounded, the second switch unit is used for being switched on or switched off according to a signal output by the signal output end of the first switch unit, and the first end of the second switch unit is the signal output end of the second switch unit.

3. The voltage signal detection circuit according to claim 2, further comprising a voltage division unit;

the first end of the voltage division unit is electrically connected with the signal output end of the first switch unit, the second end of the voltage division unit is grounded, the third end of the voltage division unit is connected with the third end of the second switch unit, and the voltage division unit is used for dividing the voltage accessed by the first end of the voltage division unit so as to output a voltage division signal by the third end of the voltage division unit.

4. The voltage signal detection circuit of claim 3, wherein the first switching unit comprises a first triode, and the voltage division unit comprises a first resistor and a second resistor;

the base of the first triode is connected with the first end of the pull-down resistor unit, the base of the first triode is further used for being connected with the identification port, the emitting electrode of the first triode is used for being connected with the first voltage signal input end, the collecting electrode of the first triode is connected with one end of the first resistor, the other end of the first resistor is respectively connected with the third end of the second switch unit and one end of the second resistor, and the other end of the second resistor is grounded.

5. The voltage signal detection circuit of claim 1, further comprising a first unidirectional turn-on circuit;

the first end of the first unidirectional conduction circuit is electrically connected with the first end of the first switch unit, and the second end of the first unidirectional conduction circuit is electrically connected with the first voltage signal input end.

6. The voltage signal detecting circuit of claim 5, wherein the first unidirectional conducting circuit comprises a first diode and a second diode, an anode of the first diode is electrically connected to the first voltage signal input terminal, a cathode of the first diode is connected to an anode of the second diode, and a cathode of the second diode is electrically connected to the first terminal of the first switch unit.

7. The voltage signal detection circuit of claim 5, further comprising a second unidirectional conducting circuit;

the first end of the second unidirectional conduction circuit is electrically connected with the second end of the first switch unit and the first end of the pull-down resistor unit respectively, and the second end of the second unidirectional conduction circuit is used for being connected with the identification port.

8. The voltage signal detection circuit according to claim 7, wherein the second unidirectional conducting circuit comprises a third diode, a cathode of the third diode is connected to the second terminal of the first switch unit and the first terminal of the pull-down resistor unit, respectively, and an anode of the third diode is used for connecting the identification port.

9. The voltage signal detection circuit according to any one of claims 3 to 8, wherein the second switching unit includes a second transistor;

the base electrode of the second triode is connected with the third end of the voltage division unit, the collector electrode of the second triode is connected with the second voltage signal input end, and the emitting electrode of the second triode is grounded.

10. The voltage signal detection circuit according to claim 2, further comprising a filter circuit, wherein a first end of the filter circuit is electrically connected to the second voltage signal input terminal and the first end of the second switch unit, respectively, a second end of the filter circuit is grounded, a third end of the filter circuit is an output end of the filter circuit, and the filter circuit is configured to filter a signal input from the second voltage signal input terminal.

11. The voltage signal detection circuit according to claim 10, wherein the filter circuit includes a third resistor and a capacitor, one end of the third resistor is connected to the second voltage signal input terminal and the first end of the second switch unit, the other end of the third resistor is connected to one end of the capacitor, and the other end of the capacitor is grounded.

12. The voltage signal detection circuit according to any one of claims 1 to 8, wherein the pull-down resistance unit includes a fourth resistor, one end of the fourth resistor is connected to the second end of the first switch unit, and the other end of the fourth resistor is grounded.

13. The voltage signal detection circuit according to any one of claims 2 to 8, further comprising a controller connected to the second voltage signal input terminal and the first terminal of the second switching unit, respectively.

14. A power supply device, comprising: a voltage signal detection circuit according to any one of claims 1 to 13;

the power supply device is used for providing the first voltage signal, and the power supply device is further provided with the identification port.

15. An electrical device comprising a load and the power supply apparatus of claim 14, the power supply apparatus being configured to supply power to the load.

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