Standby power supply charging and discharging circuit and security device

Abstract

The utility model relates to a standby power supply charging and discharging circuit and a security device, and the standby power supply charging and discharging circuit comprises a diode D1, a switching element M1, a switching element Q1, a voltage dividing branch circuit, and a control unit. The anode of the diode D1 is electrically connected with a first conductive end, and the cathode is electrically connected with a charging and discharging common end. The switch piece Q1 is provided with two through-flow ends, and one through-flow end is electrically connected to the control end of the switch piece M1. The voltage dividing branch has two opposite ends and a voltage dividing node between the two ends, and one end is electrically connected to the first conductive end. The control unit has a trigger end and a sampling end. When the voltage sampling value is larger than the sampling upper limit value, the control unit outputs a turn-off signal to the control end of the switching piece Q1, charging of the standby battery is stopped, and the standby battery is prevented from being damaged due to too high voltage. In a discharge state, the control unit compares a voltage sampling value with a sampling lower limit value. When the voltage sampling value is smaller than the sampling lower limit value, the control unit outputs a stop signal to the outside, and the standby battery is prevented from being damaged due to too low voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the security power supply technical field, in particular to a kind of standby power supply charging and discharging circuit and security device. BACKGROUND

[0002] Security device is mainly applied to security field, it can be for realizing perimeter security and alarm, or for processing the feedback signal of various sensing elements and judging whether alarm signal needs to be sent.

[0003] In general, security device is powered by mains ac power supply.For the situation of mains power failure, security device is generally equipped with standby battery.In the case of mains power failure, standby battery outputs power supply current to other power modules in security device.

[0004] However, in the conventional security device, the related circuit of standby battery can only control the on-off of charging and discharging loop, but when the voltage of standby battery is abnormal, it cannot provide timely protection for standby battery. Utility model content

[0005] Therefore, the utility model provides a kind of standby power supply charging and discharging circuit and security device that can solve or at least alleviate the above technical problems.

[0006] The utility model provides a kind of standby power supply charging and discharging circuit, comprising:

[0007] Diode D1, anode is electrically connected with the first conductive end, cathode is electrically connected with the charging and discharging public end;

[0008] Switch piece M1, one through-flow end is electrically connected to the charging and discharging public end, and the other through-flow end is electrically connected to the first conductive end;

[0009] Switch piece Q1, one through-flow end is electrically connected to the control end of the switch piece M1, and the other through-flow end is used for grounding;

[0010] Voltage division branch, with opposite two ends and voltage division node between two ends, one end is electrically connected to the first conductive end, and the other end is used for grounding;And

[0011] Control unit, with trigger end and sampling end;The trigger end of the control unit is electrically connected to the control end of the switch piece Q1;The sampling end of the control unit is electrically connected to the voltage division node of the voltage division branch, and obtains voltage sampling value from the voltage division node;The control unit controls the state of the switch piece Q1 or exports stop signal according to the size of voltage sampling value.

[0012] The backup power supply charging and discharging circuit, in general, outputs the AC power to the charging and discharging common terminal after being processed. The first conductive terminal is used for electrically connecting the positive pole of the backup battery, and the second conductive terminal grounded is used for electrically connecting the negative pole of the backup battery. When the backup battery needs to be charged, the control unit outputs the on signal to the control terminal of the switch Q1, and the two current terminals of the switch Q1 are turned on. Then, the control terminal of the switch M1 obtains the trigger level, and the two current terminals of the switch M1 are turned on, so that the charging current can be transmitted from the charging and discharging common terminal to the positive pole of the backup battery. The voltage sampling value of the backup battery is fed back to the control unit through the voltage dividing branch connected between the positive pole of the backup battery and the ground. In the charging state, the control unit compares the voltage sampling value with the sampling upper limit value. When the voltage sampling value is greater than the sampling upper limit value, it is confirmed that the voltage of the backup battery is greater than the voltage upper limit value, and the control unit outputs the off signal to the control terminal of the switch Q1 to stop charging the backup battery, so as to avoid damage to the backup battery due to the overhigh voltage. When the backup battery needs to discharge externally, the positive pole of the backup battery outputs the power supply current to other electrical modules through the first conductive terminal and the diode D1. When the power of the backup battery decreases, the voltage between the positive pole and the negative pole of the backup battery decreases. In the discharging state, the control unit compares the voltage sampling value with the sampling lower limit value. When the voltage sampling value is less than the sampling lower limit value, the control unit outputs the stop signal to stop the operation of the unnecessary electrical modules, so as to avoid damage to the backup battery due to the overlow voltage.

[0013] In one of the embodiments, the resistor R2 is electrically connected between one of the current terminals of the switch M1 and the control terminal of the switch M1.

[0014] In one of the embodiments, the resistor R1 is electrically connected between one of the current terminals of the switch M1 and the charging and discharging common terminal.

[0015] In one of the embodiments, the diode D2 is electrically connected between one of the current terminals of the switch M1 and the cathode of the diode D2.

[0016] In one of the embodiments, the resistor R4 is electrically connected between the control terminal of the switch M1 and one of the current terminals of the switch Q1.

[0017] The utility model provides a kind of backup power supply charging and discharging circuit, comprising:

[0018] The diode D1 is electrically connected with the first conductive terminal at the anode, and the cathode is electrically connected with the charging and discharging common terminal.

[0019] The switch M1 has one current terminal electrically connected to the charging / discharging common terminal and another current terminal electrically connected to the first conducting terminal;

[0020] The switch Q1 has one current terminal electrically connected to the control terminal of the switch M1.

[0021] The voltage dividing branch has opposite two terminals and a voltage dividing node between the two terminals, and one terminal is electrically connected to the first conducting terminal.

[0022] The control unit has a trigger terminal and a sampling terminal; the trigger terminal of the control unit is electrically connected to the control terminal of the switch Q1; the sampling terminal of the control unit is electrically connected to the voltage dividing node of the voltage dividing branch, and a voltage sampling value is obtained from the voltage dividing node; the control unit controls the state of the switch Q1 or outputs a stop signal according to the size of the voltage sampling value.

[0023] The switch Q2 has one current terminal electrically connected to the other current terminal of the switch Q1 and another current terminal for grounding; the control terminal of the switch Q2 is electrically connected to the other terminal of the voltage dividing branch; the control terminal of the switch Q2 is electrically connected with the charging / discharging common terminal through the resistor R3; the control terminal of the switch Q2 is electrically connected with the ground through the resistor R9; and

[0024] The diode D3 has an anode electrically connected to the control terminal of the switch Q2 and a cathode electrically connected to the first conducting terminal.

[0025] In the case of reverse connection between the docking port and the backup battery, the positive electrode of the backup battery is electrically connected to the second conducting terminal and the negative electrode of the backup battery is electrically connected to the first conducting terminal. At this time, since the cathode of the diode D3 is electrically connected to the negative electrode of the backup battery, the potential of the control terminal of the switch Q2 is lower than the potential of the ground, so that the switch Q2 is turned off. When the control unit outputs a conduction signal to the control terminal of the switch Q1, the control terminal of the switch Q1 cannot obtain a bias voltage, so that the switch Q1 and the switch M1 will not be turned on. Therefore, in the case of reverse connection, the input voltage of the charging / discharging common terminal and the voltage of the backup battery can be prevented from being superimposed in the loop by the cooperation of the switch Q2 and the diode D3, so as to avoid the damage of the circuit elements in the backup power charging / discharging circuit due to the passage of a large current.

[0026] In one embodiment, the voltage dividing branch includes the resistor R7 and the resistor R8; the resistor R7 and the resistor R8 are connected in series between the first conducting terminal and the control terminal of the switch Q2; and the voltage dividing node between the resistor R7 and the resistor R8 is electrically connected to the sampling terminal of the control unit.

[0027] In one of the embodiments, a capacitor C1 is further included; one end of the capacitor C1 is electrically connected to a voltage division node between the resistor R7 and the resistor R8, and the other end is electrically connected to the control end of the switch Q2.

[0028] In one of the embodiments, a diode D4 is further included; the cathode of the diode D4 is electrically connected to the control end of the switch Q2; and the resistor R3 is electrically connected between the common charging and discharging end and the anode of the diode D4.

[0029] The utility model provides a kind of security device, including the standby power supply charging and discharging circuit of any one embodiment above. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is the structure schematic view of security device of an embodiment of the application.

[0031] Figure 2 It is the structure schematic view of security device of another embodiment of the application.

[0032] Significant: 100, security device;20, standby power supply charging and discharging circuit;V+, common charging and discharging end;21, control unit;30, standby battery. DETAILED DESCRIPTION

[0033] The technical solutions of the present application will be described clearly and completely below in conjunction with the drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0034] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mounting", "connected", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection, or mechanical connection, or electrical connection, or direct connection, or indirect connection through intermediate medium, or internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] The technical solutions provided by the embodiments of the present application will be described below with reference to the drawings.

[0037] In combination with Figure 1 As shown in the figure, the present application provides a security device 100. In general, the security device 100 is powered by commercial power. In the case of power failure, the operation of the security device 100 is powered by the backup battery 30.

[0038] Optionally, in combination with Figure 1 As shown in the figure, the security device 100 is internally provided with a backup battery 30. Optionally, the security device 100 is provided with a docking port for docking with an external backup battery 30.

[0039] In some embodiments, the security device 100 is a pulse electronic fence host. Understandably, in the pulse electronic fence system, the security device 100 is used to generate a high-voltage pulse signal and form a protective barrier through the front-end fence wire.

[0040] In some embodiments, the security device 100 is an alarm host. Understandably, the security device 100 is used to receive trigger signals from various front-end detectors, or the security device 100 is used to start the sound and light alarm to deter intruders. Exemplarily, the front-end detector is an infrared detector, a door magnet, a glass breaking sensor or a smoke detector.

[0041] In some embodiments, the security device 100 includes a backup power supply charging and discharging circuit 20. The backup power supply charging and discharging circuit 20 is used to control the on-off of the charging loop of the backup battery 30.

[0042] In some embodiments, the security device 100 further includes a detection module, which is used to monitor the working state of the electronic fence in real time and convert the physical intrusion behavior into an identifiable electrical signal to trigger the alarm and linkage response. The backup power supply charging and discharging circuit 20 is electrically connected to the detection module. Understandably, in the case of power failure, the backup power supply charging and discharging circuit 20 can supply power to the detection module.

[0043] In some embodiments, the security device 100 further comprises an alarm driving module for triggering the start or stop of the sound and light alarm terminal or linkage. The backup power charging and discharging circuit 20 is electrically connected to the detection module. Understandably, in the case of power failure, the backup power charging and discharging circuit 20 can supply power to the alarm driving module.

[0044] In some embodiments, the security device 100 further comprises an alarm driving module for triggering the start or stop of the sound and light alarm terminal or linkage. The backup power charging and discharging circuit 20 is electrically connected to the detection module. Understandably, in the case of power failure, the backup power charging and discharging circuit 20 can supply power to the alarm driving module. Figure 1 As shown, the backup power charging and discharging circuit 20 comprises a diode D1, a switch M1, a switch Q1, a voltage dividing branch and a control unit 21. The anode of the diode D1 is electrically connected to a first conducting end, and the cathode is electrically connected to a charging and discharging common end V+. The switch M1 has two current-carrying ends, one of which is electrically connected to the charging and discharging common end V+, and the other of which is electrically connected to the first conducting end. The switch Q1 has two current-carrying ends, one of which is electrically connected to the control end of the switch M1, and the other of which is used for grounding. The voltage dividing branch has two opposite ends and a voltage dividing node between the two ends, one end is electrically connected to the first conducting end, and the other end is used for grounding. The control unit 21 has a trigger end and a sampling end. The trigger end of the control unit 21 is electrically connected to the control end of the switch Q1. The sampling end of the control unit 21 is electrically connected to the voltage dividing node of the voltage dividing branch, and obtains a voltage sampling value from the voltage dividing node. The control unit 21 controls the state of the switch Q1 or outputs a stop signal according to the size of the voltage sampling value.

[0045] The backup power charging / discharging circuit 20 of this application, under normal circumstances, outputs AC power from the mains to the charging / discharging common terminal V+ after rectification. A first conductive terminal is used to electrically connect to the positive terminal of the backup battery 30, and a grounded second conductive terminal is used to electrically connect to the negative terminal of the backup battery 30. When charging of the backup battery 30 is required, the control unit 21 outputs a conduction signal to the control terminal of switch Q1, causing conduction between the two current-carrying terminals of switch Q1. Subsequently, the control terminal of switch M1 receives a trigger level, causing conduction between the two current-carrying terminals of switch M1, allowing the charging / discharging common terminal V+ to transfer charging current to the positive terminal of the backup battery 30. A voltage divider branch is electrically connected between the positive terminal of the backup battery 30 and ground, and feeds back the voltage sample value of the backup battery 30 to the control unit 21 through the voltage divider node. During charging, the control unit 21 compares the voltage sample value with the upper limit of the sample value. When the voltage sample value exceeds the upper limit, it is confirmed that the voltage of the backup battery 30 is greater than the upper limit. The control unit 21 outputs a shutdown signal to the control terminal of the switch Q1 to stop charging the backup battery 30 and prevent damage to the backup battery 30 due to overvoltage. When the backup battery 30 needs to discharge, its positive terminal supplies power to other electrical modules through the first conductive terminal and diode D1. When the power of the backup battery 30 decreases, the voltage between its positive and negative terminals drops. During discharge, the control unit 21 compares the voltage sample value with the lower limit. When the voltage sample value is less than the lower limit, the control unit 21 outputs a stop signal to stop the operation of unnecessary electrical modules and prevent damage to the backup battery 30 due to low voltage.

[0046] Understandably, the detection module and alarm drive module of the security device 100, as well as other electrical modules, are electrically connected to the charging and discharging common terminal V+ to obtain power supply current from the charging and discharging common terminal V+ in the event of a mains power outage. Optionally, the first conductive terminal and the second conductive terminal form a docking port.

[0047] In some implementations, combined Figure 1 As shown, the backup power charging and discharging circuit 20 also includes a resistor R2. Resistor R2 is electrically connected between one current-carrying terminal of switch M1 and the control terminal of switch M1. Understandably, since the other current-carrying terminal of switch Q1 is grounded, when switch Q1 is turned on, switch Q1 transmits a low-level signal to the control terminal of switch M1. At this time, due to the potential difference between the two ends of resistor R2, one current-carrying terminal of switch M1 and the control terminal receive a bias voltage, causing switch M1 to conduct. When switch Q1 is turned off, the potential of one current-carrying terminal of switch M1 is transmitted to the control terminal of switch M1 through resistor R2, making the potential of one current-carrying terminal of switch M1 equal to that of the control terminal, thereby turning off switch M1.

[0048] Exemplarily, the switch M1 is a P-channel enhancement-mode MOS transistor.

[0049] In some other embodiments, the switch M1 can also be a relay.

[0050] It is understandable that, in combination with Figure 1 As shown, the backup power charge-discharge circuit 20 further comprises a resistor R5. The resistor R5 is electrically connected between the control unit 21 and the control terminal of the switch Q1, so as to limit the upper limit of the current between the control unit 21 and the switch Q1.

[0051] Exemplarily, the control unit 21 is in the form of an MCU.

[0052] In some embodiments, in combination with Figure 1 As shown, the backup power charge-discharge circuit 20 further comprises a resistor R1. The resistor R1 is electrically connected between one current passing terminal of the switch M1 and the charge-discharge common terminal V+. It is understandable that, in the charging state, the resistor R1 is in series with the switch M1 between the charge-discharge common terminal V+ and the positive electrode of the backup battery 30. Since there can be a large potential difference between the charge-discharge common terminal V+ and the positive electrode of the backup battery 30, by arranging the resistor R1, the potential difference can be applied to the resistor R1, and the resistor R1 limits the current size between the charge-discharge common terminal V+ and the positive electrode of the backup battery 30, avoiding damage to the switch M1 due to passing too large current.

[0053] It is understandable that, when the backup battery 30 needs to discharge externally, if the output current of the positive electrode of the backup battery 30 is transmitted from the switch M1 and the resistor R1 to the charge-discharge common terminal V+, the resistor R1 can cause the potential of the charge-discharge common terminal V+ to have a large drop relative to the potential of the positive electrode of the backup battery 30, or cause the potential of the charge-discharge common terminal V+ to be unstable, and can also cause a part of the electric energy to be consumed in the resistor R1. In addition, when the output current passes through the switch M1 and the resistor R1, the current can exceed the current carrying range of the parasitic diode of the switch M1, causing damage to the switch M1.

[0054] In some embodiments, in combination with Figure 1As shown, the backup power supply charging and discharging circuit 20 further comprises a diode D2. The anode of the diode D2 is electrically connected to the charging and discharging common terminal V+. The resistor R1 is electrically connected between one of the current passing terminals of the switch M1 and the cathode of the diode D2, so as to inhibit the output current of the backup battery 30 from the positive electrode to pass from the switch M1 and the resistor R1 to the charging and discharging common terminal V+, and to allow the output current to pass through the diode D1 only. The potential of the charging and discharging common terminal V+ is closer to the potential of the positive electrode of the backup battery 30, and the potential of the charging and discharging common terminal V+ is not affected by the size of the output current. At the same time, after the diode D2 is provided, the power consumption caused by the output current passing through the resistor R1 is avoided, and the switch M1 is not damaged by the large current carried by the parasitic diode.

[0055] Exemplarily, the backup battery 30 is a direct current 12V lead-acid battery with a capacity of 4.5AH.

[0056] In some embodiments, in combination with Figure 1 As shown, the backup power supply charging and discharging circuit 20 further comprises a resistor R4. The resistor R4 is electrically connected between the control terminal of the switch M1 and one of the current passing terminals of the switch Q1. Understandably, when the city alternating current is output to the charging and discharging common terminal V+ after being rectified, the resistor R2 and the resistor R4 form a series cooperation to play a voltage dividing role, so that the voltage difference between the two ends of the resistor R2 can adapt to the bearing range between one of the current passing terminals and the control terminal of the switch M1, and the switch M1 is not damaged.

[0057] In some embodiments, in combination with Figure 2As shown, the backup power supply charge-discharge circuit 20 comprises a diode D1, a switch M1, a switch Q1, a voltage dividing branch, a control unit 21, a switch Q2 and a diode D3. The anode of the diode D1 is electrically connected to a first conducting terminal, and the cathode is electrically connected to a charge-discharge common terminal V+. The switch M1 has two conducting terminals, one of which is electrically connected to the charge-discharge common terminal V+, and the other of which is electrically connected to the first conducting terminal. The switch Q1 has two conducting terminals, one of which is electrically connected to the control terminal of the switch M1. The voltage dividing branch has two opposite ends and a voltage dividing node between the two ends, and one end is electrically connected to the first conducting terminal. The control unit 21 has a trigger terminal and a sampling terminal. The trigger terminal of the control unit 21 is electrically connected to the control terminal of the switch Q1. The sampling terminal of the control unit 21 is electrically connected to the voltage dividing node of the voltage dividing branch, and the control unit 21 obtains a voltage sampling value from the voltage dividing node. The control unit 21 controls the state of the switch Q1 or outputs a stop signal according to the size of the voltage sampling value. The switch Q2 has two conducting terminals, one of which is electrically connected to the other conducting terminal of the switch Q1, and the other of which is used for grounding. The control terminal of the switch Q2 is electrically connected to the other end of the voltage dividing branch, and the control terminal of the switch Q2 is electrically connected to the charge-discharge common terminal V+ through a resistor R3. The control terminal of the switch Q2 is electrically connected to the ground through a resistor R9. The anode of the diode D3 is electrically connected to the control terminal of the switch Q2, and the cathode is electrically connected to the first conducting terminal.

[0058] Specifically, before the backup battery 30 starts charging, the city alternating current flows to direct current after being arranged, and the direct current voltage is output between the charge-discharge common terminal V+ and the ground. The resistor R3 and the resistor R9 form a series cooperation to divide the voltage of the direct current, and apply a bias voltage to the control terminal of the switch Q2 to make the switch Q2 conductive. In the case of correct docking between the docking port and the backup battery 30, when the control unit 21 outputs a conductive signal to the control terminal of the switch Q1, the two conducting terminals of the switch Q1 are conductive. The control terminal of the switch M1 is grounded through the switch Q1 and the switch Q2, so that the two conducting terminals of the switch M1 are conductive, and the charge-discharge common terminal V+ can transmit the charging current to the positive electrode of the backup battery 30. The voltage dividing branch and the resistor R9 are connected in series between the positive electrode of the backup battery 30 and the ground, and the voltage dividing node of the voltage dividing branch feeds back the voltage sampling value of the backup battery 30 to the control unit 21.

[0059] In the case of reverse connection between the docking port and the backup battery 30, the positive pole of the backup battery 30 is electrically connected to the second conductive terminal, and the negative pole of the backup battery 30 is electrically connected to the first conductive terminal. At this time, since the cathode of the diode D3 is electrically connected to the negative pole of the backup battery 30, the potential of the control terminal of the switch Q2 is lower than the potential of the ground, so that the switch Q2 is turned off. When the control unit 21 outputs a conduction signal to the control terminal of the switch Q1, the control terminal of the switch Q1 cannot obtain a bias voltage, so that the switch Q1 and the switch M1 will not be turned on. Therefore, in the case of reverse connection, under the cooperation of the switch Q2 and the diode D3, the input voltage of the charge-discharge common terminal V+ and the voltage of the backup battery 30 can be prevented from being superimposed in the loop, so as to avoid that the circuit elements in the backup power supply charge-discharge circuit 20 are damaged by passing through a large current.

[0060] In some embodiments, in combination with Figure 2 As shown, the voltage dividing branch includes the resistor R7 and the resistor R8.

[0061] Optionally, the resistor R7 and the resistor R8 are connected in series between the first conductive terminal and the control terminal of the switch Q2. The voltage dividing node between the resistor R7 and the resistor R8 is electrically connected to the sampling terminal of the control unit 21.

[0062] Optionally, the resistor R7 and the resistor R8 are connected in series between the first conductive terminal and the ground.

[0063] Understandably, one or both of the resistor R7 and the resistor R8 can be understood as an equivalent resistance after two or more resistor elements are connected in series.

[0064] In some embodiments, in combination with Figure 2 As shown, the backup power supply charge-discharge circuit 20 further includes a capacitor C1. One end of the capacitor C1 is electrically connected to the voltage dividing node between the resistor R7 and the resistor R8, and the other end is electrically connected to the control terminal of the switch Q2. Understandably, one end of the capacitor C1 is electrically connected to the voltage dividing node, so as to stabilize the voltage sampling value and reduce the fluctuation amplitude of the voltage sampling value, thereby avoiding that the control unit 21 incorrectly outputs an off signal due to the fluctuation of the voltage sampling value.

[0065] Understandably, in the case of reverse connection between the docking port and the backup battery 30, the voltage of the backup battery 30 can be applied between the control terminal and the other current terminal of the switch Q2, and the potential of the other current terminal of the switch Q2 is higher than the potential of the control terminal of the switch Q2. Therefore, the control terminal and the other current terminal of the switch Q2 can be reversely broken down, so that the backup battery 30 can output a large reverse current from the other current terminal to the control terminal of the switch Q2, thereby causing damage to the switch Q2.

[0066] In some embodiments, in combination with Figure 2As shown, the backup power source charging and discharging circuit 20 further comprises a diode D4. The cathode of the diode D4 is electrically connected to the control end of the switching element Q2. The resistor R3 is electrically connected between the charging and discharging common terminal V+ and the anode of the diode D4. Understandably, the diode D4 is difficult to be reversely broken down, and under the limitation of the diode D4, the backup battery 30 is prevented from releasing current through the switching element Q2 and the diode D3 in the reverse connection state, and the switching element Q2 is prevented from being damaged.

[0067] The above embodiments only describe the preferred embodiments of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by the ordinary engineering technicians in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A backup power supply charge-discharge circuit characterized by comprising: Comprising: a diode D1, having a first conductive end electrically connected to an anode and a common charging and discharging end electrically connected to a cathode; a switch M1, having one current passing end electrically connected to the common charging and discharging end and another current passing end electrically connected to the first conductive end; a switch Q1, having one current passing end electrically connected to a control end of the switch M1 and another current passing end for grounding; a voltage dividing branch, having opposite two ends and a voltage dividing node between the two ends, one end electrically connected to the first conductive end and the other end for grounding; and a control unit, having a triggering end and a sampling end, the triggering end of the control unit electrically connected to the control end of the switch Q1, the sampling end of the control unit electrically connected to the voltage dividing node of the voltage dividing branch and obtaining a voltage sampling value from the voltage dividing node, the control unit controlling a state of the switch Q1 or outputting a stop signal according to a size of the voltage sampling value.

2. The backup power supply charge-discharge circuit according to claim 1, wherein Further comprising a resistor R2, the resistor R2 electrically connected between one current passing end of the switch M1 and the control end of the switch M1.

3. The backup power supply charge-discharge circuit according to claim 1, wherein Further comprising a resistor R1, the resistor R1 electrically connected between one current passing end of the switch M1 and the common charging and discharging end.

4. The backup power supply charge-discharge circuit according to claim 3, wherein Further comprising a diode D2, the anode of the diode D2 electrically connected to the common charging and discharging end, the resistor R1 electrically connected between one current passing end of the switch M1 and the cathode of the diode D2.

5. The backup power supply charge-discharge circuit according to claim 1, wherein Further comprising a resistor R4, the resistor R4 electrically connected between the control end of the switch M1 and one current passing end of the switch Q1.

6. A backup power supply charge-discharge circuit characterized by comprising: Comprising: a diode D1, having a first conductive end electrically connected to an anode and a common charging and discharging end electrically connected to a cathode; a switch M1, having one current passing end electrically connected to the common charging and discharging end and another current passing end electrically connected to the first conductive end; a switch Q1, having one current passing end electrically connected to a control end of the switch M1; a voltage dividing branch, having opposite two ends and a voltage dividing node between the two ends, one end electrically connected to the first conductive end; a control unit, having a triggering end and a sampling end, the triggering end of the control unit electrically connected to the control end of the switch Q1, the sampling end of the control unit electrically connected to the voltage dividing node of the voltage dividing branch and obtaining a voltage sampling value from the voltage dividing node, the control unit controlling a state of the switch Q1 or outputting a stop signal according to a size of the voltage sampling value; a switch Q2, having one current passing end electrically connected to another current passing end of the switch Q1 and another current passing end for grounding, the control end of the switch Q2 electrically connected to the other end of the voltage dividing branch, the control end of the switch Q2 electrically connected with a resistor R3 between the control end and the common charging and discharging end, the control end of the switch Q2 electrically connected with a resistor R9 between the control end and the ground; and a diode D3, having an anode electrically connected to the control end of the switch Q2 and a cathode electrically connected to the first conductive end.

7. The backup power supply charge-discharge circuit according to claim 6, wherein The voltage dividing branch comprises a resistor R7 and a resistor R8; the resistor R7 and the resistor R8 are connected in series between the first conductive end and the control end of the switch Q2; and a voltage dividing node between the resistor R7 and the resistor R8 is electrically connected to a sampling end of the control unit.

8. The backup power supply charge-discharge circuit according to claim 7, wherein The voltage dividing branch further comprises a capacitor C1; one end of the capacitor C1 is electrically connected to the voltage dividing node between the resistor R7 and the resistor R8, and the other end is electrically connected to the control end of the switch Q2.

9. The backup power supply charge-discharge circuit according to claim 6, wherein The voltage dividing branch further comprises a diode D4; a cathode of the diode D4 is electrically connected to the control end of the switch Q2; and the resistor R3 is electrically connected between the common charging and discharging end and an anode of the diode D4.

10. A security device, characterised in that The backup power supply charging and discharging circuit comprises the backup power supply charging and discharging circuit according to any one of claims 1 to 9.

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