CN221669549U - Anode protection circuit - Google Patents

Abstract

The utility model relates to the technical field of circuits, and discloses an anode protection circuit; the circuit includes a switch circuit, a current detection circuit, and a voltage detection circuit; the switch circuit is connected to the negative pole of a digital battery port, the control end of a single-chip microcomputer is connected to the switch circuit, and the control end of the single-chip microcomputer controls the switch circuit to be turned on or off; the switch circuit is connected to the current detection circuit, and the current detection circuit is used to detect the current of the negative pole of the digital battery port; the voltage detection circuit is connected to the negative pole of the digital battery port, and the voltage detection circuit is used to detect the voltage of the negative pole of the digital battery port. The utility model can solve the problem that the battery protection effect of the traditional anode protection circuit is not good.

Description

Anode protection circuit

Technical Field

The utility model relates to the technical field of circuits, in particular to an anode protection circuit.

Background Art

Traditional anode protection is to add a switch tube and a thermistor to the battery anode. The protection chip monitors the battery voltage. When there is an overcharge or discharge state, it switches to an external power field effect tube to protect the battery. The functions of the protection chip include overcharge protection, overdischarge protection, and overcurrent/short circuit protection. The current battery protection circuit has a simple structure and poor protection effect, which may cause damage to the battery or even the entire product.

Utility Model Content

In view of this, the utility model provides an anode protection circuit to solve the problem that the dual ports of the battery cannot be charged and discharged at the same time, and the upper and lower limits of the battery charge and discharge are limited, and the function cannot be fully exerted.

The utility model provides an anode protection circuit, comprising:

A switch circuit, comprising a first switch tube, a second switch tube and a third switch tube; the first switch tube comprises a first control end, a first connection end and a second connection end; the second switch tube comprises a second control end, a third connection end and a fourth connection end; the third switch tube comprises a third control end, a fifth connection end and a sixth connection end; the first connection end of the first switch tube, the third connection end of the second switch tube and the fifth connection end of the third switch tube are sequentially connected to the negative electrode of the digital battery cell port; the first control end of the first switch tube, the second control end of the second switch tube and the third control end of the third switch tube are respectively connected to the control end of the single-chip microcomputer; the control end of the single-chip microcomputer is used to control the first switch tube, the second switch tube and the third switch tube to be turned on or off; the second connection end of the first switch tube, the fourth connection end of the second switch tube and the sixth connection end of the third switch tube are sequentially connected to the current sampling circuit;

The current sampling circuit includes a first resistor and a second resistor; the second resistor is connected in parallel with the first resistor; one end of the first resistor is connected to the second connection end, the fourth connection end and the sixth connection end, and the other end of the first resistor is grounded; the first detection port of the single chip microcomputer is used to connect one end of the first resistor;

The voltage sampling circuit includes a fourth switch tube and a fifth switch tube; the fourth switch tube includes a fourth control terminal, a seventh connection terminal and an eighth connection terminal; the fifth switch tube includes a fifth control terminal, a ninth connection terminal and a tenth connection terminal;

The eighth connection terminal of the fourth switch tube is connected to the negative electrode of the digital battery cell port; the fourth control terminal of the fourth switch tube is connected to the eighth connection terminal; the fourth control terminal is connected to the ninth connection terminal; the fifth control terminal is connected to the eighth connection terminal, the fourth control terminal is connected to the fifth control terminal, and the tenth connection terminal is grounded; the seventh connection terminal is connected to the second detection port of the single-chip microcomputer.

The switch circuit in the utility model is controlled by the control end of the single-chip microcomputer; the first switch tube, the second switch tube and the third switch tube are connected to the control end. When the battery is overcharged or over-discharged during operation, the control end controls the first switch tube, the second switch tube and the third switch tube to be turned off to protect the battery and the circuit. The current sampling circuit in the utility model includes a first resistor and a second resistor. The first resistor and the second resistor are sampling resistors. The voltage passes through the sampling resistor to form an electrical signal and is transmitted to the first detection port of the single-chip microcomputer. The first detection port of the single-chip microcomputer is used to detect the current. The voltage sampling circuit in the utility model includes a fourth switch tube and a fifth switch tube; the negative input voltage sampling circuit of the digital battery port, the fourth switch tube and the fifth switch tube are turned on at the same time, the second detection port of the single-chip microcomputer is connected to the fourth switch tube, and the second detection port of the single-chip microcomputer is used to detect the voltage. Therefore, the anode protection circuit provided by the utility model can turn off the first switch tube, the second switch tube and the third switch tube when the voltage or current is abnormal, so as to achieve the purpose of battery protection. Compared with the conventional scheme, the anode protection circuit provided by the utility model has a better protection effect on the battery through the related circuits for synchronous detection of current and voltage.

In an optional implementation, the current sampling circuit includes a third resistor; one end of the third resistor is connected to one end of the first resistor, and the other end of the third resistor is connected to the first detection port.

The third resistor in the utility model is used for voltage division and current limiting to ensure the normal operation of the current sampling circuit.

In an optional implementation, the current sampling circuit further includes a capacitor;

One end of the capacitor is connected to one end of the third resistor, and the other end of the capacitor is grounded.

The capacitor in the utility model plays an overvoltage protection and overcurrent protection role on the current sampling circuit through the current storage role.

In an optional implementation, the voltage sampling circuit includes a fourth resistor;

One end of the fourth resistor is connected to the eighth connection end, and the other end of the fourth resistor is connected to the fourth control end.

The fourth resistor in the utility model plays a role of voltage division, limiting the current while ensuring the normal operation of the fourth switch tube and the fifth switch tube.

In an optional implementation, the voltage sampling circuit further includes a fifth resistor;

One end of the fifth resistor is connected to the fifth control end, and the other end of the fifth resistor is connected to the tenth connection end.

The fifth resistor in the utility model provides a bias voltage for the fifth switch tube; the fifth resistor also plays an anti-static role, under which the fifth resistor is equivalent to a discharge resistor, avoiding damage to the fifth control terminal and the tenth connection terminal of the fifth switch tube.

In an optional implementation, the voltage sampling circuit further includes a diode; the diode includes a positive electrode and a negative electrode;

The anode of the diode is connected to the cathode of the digital battery port, and the cathode of the diode is connected to the eighth connection terminal.

The diode in the utility model is a voltage stabilizing diode, and the characteristics of the voltage stabilizing diode are utilized to ensure the input voltage stability of the voltage sampling circuit.

In an optional implementation, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the fifth switch tube are all field effect tubes.

In an optional implementation, the positive electrode of the battery is connected to the positive electrode of the digital battery port; the negative electrode of the battery is the ground connected to the first resistor.

In an optional implementation, the first control end, the second control end and the third control end are connected to the negative electrode of the digital battery port through a plurality of cables.

In the utility model, a plurality of cables are designed to be connected with the first control end, the second control end and the third control end, so as to play an overcurrent protection role and ensure the normal operation of the first switch tube, the second switch tube and the third switch tube.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of the structure of a conventional anode protection circuit;

FIG2 is a schematic diagram of the structure of an anode protection circuit of the present utility model;

FIG3 is a schematic diagram of the structure of the control circuit and the current sampling circuit in the utility model;

FIG. 4 is a schematic diagram of the structure of a voltage sampling circuit in the present invention.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

As shown in Figure 1, it is a schematic diagram of the structure of the traditional anode protection circuit. The traditional anode protection is to add switch tubes MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET, metal-oxide-semiconductor field-effect transistor) M1 and M2 and RX (such as NTC, Negative Temperature Coefficient, thermistor) to the battery anode, and monitor the battery voltage through the protection IC (Integrated Circuit) chip. When there is an overcharge and discharge state, it will switch to an external power MOSFET to protect the battery. The functions of the protection IC include overcharge protection, over-discharge protection and over-current/short circuit protection.

The utility model adds two independent anode protection circuits on the basis of the anode protection circuit to meet the charging and discharging requirements of the dual ports, and achieves the balance of simultaneous charging and discharging through IC control.

As shown in FIG2 , the utility model provides an anode protection circuit, comprising:

As shown in FIG3 , the switch circuit includes a first switch tube Q1, a second switch tube Q2 and a third switch tube Q3; the first switch tube Q1 includes a first control end, a first connection end and a second connection end; the second switch tube Q2 includes a second control end, a third connection end and a fourth connection end; the third switch tube Q3 includes a third control end, a fifth connection end and a sixth connection end; the first connection end of the first switch tube Q1, the third connection end of the second switch tube Q2 and the fifth connection end of the third switch tube Q3 are sequentially connected to the negative electrode of the digital battery port; the negative electrode of the digital battery port Used to supply power to the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3; the first control end of the first switch tube Q1, the second control end of the second switch tube Q2 and the third control end of the third switch tube Q3 are connected to the control end G1 of the single-chip computer U1 in sequence; the control end G1 of the single-chip computer U1 is used to control the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 to turn on or off; the second connection end of the first switch tube Q1, the fourth connection end of the second switch tube Q2 and the sixth connection end of the third switch tube Q3 are connected to the current sampling circuit in sequence.

The switch circuit in the utility model is controlled by the control terminal G1 of the single-chip microcomputer U1. The single-chip microcomputer U1 automatically identifies the negative voltage and current state of the digital battery port, turns on a high level to turn on the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3, or turns on a low level to turn off the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3; the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 are connected to the control terminal. When the battery is overcharged or over-discharged during operation, the control terminal controls the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 to be turned off to protect the battery and the circuit.

As shown in FIG3 , the current sampling circuit includes a first resistor R1 and a second resistor R2; one end of the first resistor R1 is connected to the second connection end, the fourth connection end and the sixth connection end, and the other end of the first resistor R1 is grounded; the first detection port A1 of the microcontroller U1 is used to connect one end of the first resistor R1.

The current sampling circuit in the present invention includes a first resistor R1 and a second resistor R2. The first resistor R1 and the second resistor R2 are sampling resistors. The voltage passes through the sampling resistors to form an electrical signal that is transmitted to the first detection port A1 of the microcontroller U1. The first detection port A1 of the microcontroller U1 is used to detect current.

As shown in FIG4 , the voltage sampling circuit includes a fourth switch tube Q4 and a fifth switch tube Q5 ; the fourth switch tube Q4 includes a fourth control terminal, a seventh connection terminal and an eighth connection terminal; the fifth switch tube Q5 includes a fifth control terminal, a ninth connection terminal and a tenth connection terminal.

The eighth connection terminal of the fourth switch tube Q4 is connected to the negative electrode of the digital battery port; the fourth control terminal of the fourth switch tube Q4 is connected to the eighth connection terminal; the fourth control terminal is connected to the ninth connection terminal; the fifth control terminal is connected to the eighth connection terminal, the fourth control terminal and the fifth control terminal are connected, and the tenth connection terminal is grounded; the seventh connection terminal is connected to the second detection port A2 of the single-chip computer U1.

The voltage sampling circuit in the utility model includes a fourth switch tube Q4 and a fifth switch tube Q5; the negative input voltage sampling circuit of the digital battery port, the fourth switch tube Q4 and the fifth switch tube Q5 are turned on and work at the same time, the second detection port A2 of the single-chip microcomputer U1 is connected to the fourth switch tube Q4, and the second detection port A2 of the single-chip microcomputer U1 is used to detect voltage.

In this embodiment, the current sampling circuit includes a third resistor R3; one end of the third resistor R3 is connected to one end of the first resistor R1, and the other end of the third resistor R3 is connected to the first detection port A1.

The third resistor R3 in the utility model is used for voltage division and current limiting to ensure the normal operation of the current sampling circuit.

In this embodiment, the current sampling circuit further includes a capacitor C1; one end of the capacitor C1 is connected to one end of the third resistor R3, and the other end of the capacitor C1 is grounded.

The capacitor C1 in the utility model plays an overvoltage protection and overcurrent protection role on the current sampling circuit through the current storage role.

In this embodiment, the voltage sampling circuit includes a fourth resistor R4; one end of the fourth resistor R4 is connected to the eighth connection end, and the other end of the fourth resistor R4 is connected to the fourth control end.

The fourth resistor R4 in the present invention plays a role of voltage division, limiting the current while ensuring the normal operation of the fourth switch tube Q4 and the fifth switch tube Q5.

In this embodiment, the voltage sampling circuit further includes a fifth resistor R5; one end of the fifth resistor R5 is connected to the fifth control end, and the other end of the fifth resistor R5 is connected to the tenth connection end.

The fifth resistor R5 in the present invention provides a bias voltage for the fifth switch tube Q5; the fifth resistor R5 also plays an anti-static role. Under this role, the fifth resistor R5 is equivalent to a discharge resistor, which prevents the MOSFET switch tube from malfunctioning and further causing static current to break through the fifth control terminal and the tenth connection terminal of the fifth switch tube Q5 in this embodiment.

The digital cell port in this embodiment is the P terminal of the digital cell; the common anode protection circuit in this embodiment is connected to the negative electrode of the P terminal of the digital cell; the positive electrode BAT+ of the battery is connected to the positive electrode of the P terminal of the digital cell; when the battery is working normally, the single chip microcomputer U1 turns on the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 through the control terminal G1, the negative electrode of the P terminal is turned on to the current detection circuit, and the negative electrode BAT- of the battery is connected to the negative electrode of the P terminal of the digital cell, so that the battery is in a conducting state, and the battery starts to discharge. At this moment, the first detection port A1 collects the battery current through the sampling resistor and monitors the battery current at any time; the voltage detection circuit is also connected to the negative electrode of the P terminal of the digital cell, and the fourth switch tube Q4 and the fifth switch tube Q5 are turned on at the same time through the voltage division of the diode D1 and the fourth resistor R4. At this time, the second detection port A2 is connected to the seventh connection terminal to receive the voltage of the negative electrode of the P terminal of the digital cell port, and the second detection port A2 monitors the negative electrode of the P terminal of the digital cell port and the battery voltage at any time. When over-discharge occurs during the battery discharge process, the first detection port A1 and the second detection port A2 of the single-chip microcomputer U1 detect abnormal voltage or current. At this time, the single-chip microcomputer U1 turns off the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3 through the control terminal G1 to protect the battery and the circuit. The single-chip microcomputer involved in the utility model is a single-chip microcomputer with a control terminal G1, a first detection port A1 and a second detection port A2. The control terminal G1 can be a control pin on the single-chip microcomputer, and the first detection port A1 and the second detection port A2 can specifically be two GPIO (General Purpose Input/Output) pins on the single-chip microcomputer. This embodiment does not specifically limit the model of the single-chip microcomputer. The model of the single-chip microcomputer can be, for example, an ATmega128 series single-chip microcomputer, an STM32 series single-chip microcomputer, a PIC18F46K40 series single-chip microcomputer, etc.

In this embodiment, the voltage sampling circuit further includes a diode D1; the diode D1 includes an anode and a cathode; the anode of the diode D1 is connected to the cathode of the digital cell port, and the cathode of the diode D1 is connected to the eighth connection terminal.

The diode D1 in the utility model is a voltage stabilizing diode, and the characteristics of the voltage stabilizing diode are utilized to ensure the input voltage stability of the voltage sampling circuit.

In this embodiment, the first switch tube Q1 , the second switch tube Q2 , the third switch tube Q3 , the fourth switch tube Q4 and the fifth switch tube Q5 are all field effect tubes.

Specifically, the first control end of the first switch tube Q1 is the gate, the first connection end is the drain, and the second connection end is the source; the second control end of the second switch tube Q2 is the gate, the third connection end is the drain, and the fourth connection end is the source; the third control end of the third switch tube Q3 is the gate, the fifth connection end is the drain, and the sixth connection end is the source; the fourth control end of the fourth switch tube Q4 is the gate, the seventh connection end is the drain, and the eighth connection end is the source; the fifth control end of the fifth switch tube Q5 is the gate, the ninth connection end is the drain, and the tenth connection end is the source.

In this embodiment, the positive electrode BAT+ of the battery is connected to the positive electrode of the digital battery port; the negative electrode BAT- of the battery is the ground connected to the first resistor R1.

In this embodiment, the first control end, the second control end and the third control end are connected to the negative electrode of the digital battery port through a plurality of cables.

In the present invention, multiple cables are designed to be connected to the first control end, the second control end and the third control end, in order to provide overcurrent protection and ensure the normal operation of the first switch tube Q1, the second switch tube Q2 and the third switch tube Q3.

In the description of this specification, the description with reference to the terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims (9)

1. An anode protection circuit, characterized in that it comprises: A switch circuit, comprising a first switch tube, a second switch tube and a third switch tube; the first switch tube comprises a first control end, a first connection end and a second connection end; the second switch tube comprises a second control end, a third connection end and a fourth connection end; the third switch tube comprises a third control end, a fifth connection end and a sixth connection end; the first connection end of the first switch tube, the third connection end of the second switch tube and the fifth connection end of the third switch tube are sequentially connected to the negative electrode of the digital battery port; the first control end of the first switch tube, the second control end of the second switch tube and the third control end of the third switch tube are respectively connected to the control end of a single-chip microcomputer; the control end of the single-chip microcomputer is used to control the first switch tube, the second switch tube and the third switch tube to be turned on or off; the second connection end of the first switch tube, the fourth connection end of the second switch tube and the sixth connection end of the third switch tube are sequentially connected to a current sampling circuit; The current sampling circuit includes a first resistor and a second resistor; the second resistor is connected in parallel with the first resistor; one end of the first resistor is connected to the second connection end, the fourth connection end and the sixth connection end, and the other end of the first resistor is grounded; the first detection port of the single chip microcomputer is used to connect one end of the first resistor; A voltage sampling circuit, comprising a fourth switch tube and a fifth switch tube; the fourth switch tube comprises a fourth control terminal, a seventh connection terminal and an eighth connection terminal; the fifth switch tube comprises a fifth control terminal, a ninth connection terminal and a tenth connection terminal; The eighth connection terminal of the fourth switch tube is connected to the negative electrode of the digital battery cell port; the fourth control terminal of the fourth switch tube is connected to the eighth connection terminal; the fourth control terminal is connected to the ninth connection terminal; the fifth control terminal is connected to the eighth connection terminal, the fourth control terminal is connected to the fifth control terminal, and the tenth connection terminal is grounded; the seventh connection terminal is connected to the second detection port of the single-chip microcomputer. 2. The circuit according to claim 1, characterized in that The current sampling circuit also includes a third resistor; One end of the third resistor is connected to one end of the first resistor, and the other end of the third resistor is connected to the first detection port. 3. The circuit according to claim 2, characterized in that The current sampling circuit also includes a capacitor; One end of the capacitor is connected to one end of the third resistor, and the other end of the capacitor is grounded. 4. The circuit according to claim 3, characterized in that The voltage sampling circuit also includes a fourth resistor; One end of the fourth resistor is connected to the eighth connection end, and the other end of the fourth resistor is connected to the fourth control end. 5. The circuit according to claim 4, characterized in that The voltage sampling circuit also includes a fifth resistor; One end of the fifth resistor is connected to the fifth control end, and the other end of the fifth resistor is connected to the tenth connection end. 6. The circuit according to claim 5, characterized in that The voltage sampling circuit also includes a diode; the diode includes a positive electrode and a negative electrode; The anode of the diode is connected to the cathode of the digital cell port, and the cathode of the diode is connected to the eighth connection end. 7. The circuit according to claim 1, characterized in that The first switch tube, the second switch tube, the third switch tube, the fourth switch tube and the fifth switch tube are all field effect tubes. 8. The circuit according to claim 1, characterized in that The positive electrode of the battery is connected to the positive electrode of the digital battery port; the negative electrode of the battery is the ground connected to the first resistor. 9. The circuit according to claim 1, characterized in that The first control end, the second control end and the third control end are connected to the negative electrode of the digital battery port through a plurality of cables.