Detection circuit and power supply device

Abstract

The application discloses a detection circuit, which comprises a comparison unit, a reference unit, a detection unit and a first adjusting unit. The comparison unit comprises a first input end, a second input end and an output end. The reference unit is electrically connected with the first input end of the comparison unit and is used for generating a reference signal. The detection unit is electrically connected with the second input end of the comparison unit and is used for generating a detection signal. One end of the first adjusting unit is electrically connected with the output end of the comparison unit, and the other end is electrically connected with the reference unit or the detection unit. When the output signal of the output end of the comparison unit instantaneously jumps, the first adjusting unit adjusts the detection signal or the reference signal to increase the signal difference between the detection signal and the reference signal. The application further discloses a power supply device. The application can improve the stability of the circuit operation.

Description

Technical Field

[0001] This invention relates to the field of circuit technology, and in particular to a detection circuit and a power supply device. Background Technology

[0002] Power supply units typically include battery packs to provide electrical energy. To ensure the safe use of the power supply unit, it is usually necessary to monitor the voltage of the battery pack to prevent it from being under-voltage or to monitor its temperature to prevent it from overheating.

[0003] Existing detection circuits typically use comparators to compare the sampled signal with a reference signal. When the sampled signal is greater than or less than the reference signal, the comparator's output signal changes to detect battery temperature or voltage. However, due to zero drift, existing detection circuits cause the comparator's output signal to constantly change (i.e., jump continuously) when the sampled signal is in a critical state, i.e., when the sampled signal and the reference signal are close to or the same. This leads to instability in the detection circuit and may even damage electronic components. Summary of the Invention

[0004] This invention discloses a detection circuit and a power supply device, which can improve the stability of the detection circuit and thus improve the reliability of the power supply device.

[0005] In a first aspect, an embodiment of the present invention discloses a detection circuit, comprising:

[0006] The comparison unit includes a first input terminal, a second input terminal, and an output terminal;

[0007] A reference unit is electrically connected to the first input terminal of the comparison unit and is used to generate a reference signal.

[0008] The detection unit, electrically connected to the second input terminal of the comparison unit, is used to generate a detection signal; and

[0009] The first adjustment unit has one end electrically connected to the output terminal of the comparison unit, and the other end electrically connected to the reference unit or the detection unit;

[0010] When the output signal at the output terminal of the comparison unit changes instantaneously, the first adjustment unit adjusts the detection signal or the reference signal to increase the signal difference between the detection signal and the reference signal.

[0011] Secondly, the power supply device disclosed in the embodiments of the present invention includes:

[0012] A battery pack, comprising multiple battery modules; and

[0013] The detection circuit described in the first aspect is connected to the battery pack and is used to detect the voltage or temperature of the battery pack.

[0014] The detection circuit and power supply device of the present invention include a first adjustment unit. When the output signal at the output terminal of the comparison unit changes instantaneously, the first adjustment unit adjusts the reference signal or the detection signal to increase the signal difference between the detection signal and the reference signal. This ensures that the output signal at the output terminal of the comparison unit maintains the state after the change, preventing the output signal from constantly changing due to the detection signal and the reference signal being too close, thereby improving the stability of the detection circuit. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic block diagram of a power supply device according to an embodiment of the present invention.

[0017] Figure 2 for Figure 1 The schematic diagram of the first embodiment of the detection circuit in the diagram.

[0018] Figure 3 for Figure 1 The principle block diagram of the second embodiment of the detection circuit is shown.

[0019] Figure 4 for Figure 1 The principle block diagram of the third implementation of the detection circuit in the diagram.

[0020] Figure 5 for Figure 2 The circuit diagram of the detection circuit in the image.

[0021] Figure 6 for Figure 4 The circuit diagram of the detection circuit in the image. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] When an element is considered "connected" to another element, it can be directly connected to the other element or there may be an intervening element present. Unless otherwise defined, 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 invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0024] This application provides a power supply device and a detection circuit applied in the power supply device. The detection circuit is used to detect the voltage or temperature of the battery pack in the power supply device to prevent safety hazards caused by excessively high battery temperature or excessively low voltage. The detection circuit in the embodiments of this application can improve the stability of the detection circuit during operation. The embodiments of this application are described below with reference to the accompanying drawings.

[0025] Please see Figure 1 An embodiment of the present invention provides a power supply device 300. The power supply device 300 includes a battery pack 200 and a detection circuit 100. The detection circuit 100 is connected to the battery pack 200 to detect the state parameters of the battery pack 200. The state parameters include at least one of current, voltage, or temperature. In this embodiment, the power supply device 300 is an emergency start-up power supply. In other embodiments, the power supply device 300 may be other types of power sources (such as power tools), which are not limited here.

[0026] In one embodiment, the battery pack 200 may include one or more interconnected battery modules (not shown), wherein each battery module may include at least one battery cell (single cell), for example, the battery cell may be a lightweight, energy-saving and environmentally friendly lithium-ion cell. In a specific embodiment, the multiple battery modules may be combined in series and parallel to increase the output voltage and current of the battery pack 200.

[0027] It is understandable that the number of battery modules included in the battery pack 200 varies depending on the specific design. For example, if a higher output voltage is required from the battery pack 200, a larger number of battery modules can be connected in series. If a lower output voltage is required from the battery pack 200, a smaller number of battery modules can be connected in series. The specific number of battery modules is not limited here.

[0028] Please see Figure 2 In a first embodiment, the detection circuit 100 includes a comparison unit 10, a reference unit 20, a detection unit 30, and a first adjustment unit 40. The comparison unit 10 includes a first input terminal, a second input terminal, and an output terminal.

[0029] The reference unit 20 is electrically connected to the first input terminal of the comparison unit 10 and is used to generate a reference signal.

[0030] The detection unit 30 is electrically connected to the second input terminal of the comparison unit 10 and is used to generate a detection signal.

[0031] One end of the first adjustment unit 40 is electrically connected to the output terminal of the comparison unit 10, and the other end is electrically connected to the detection unit 30. When the output signal of the comparison unit 10 changes instantaneously, the first adjustment unit 40 adjusts the detection signal to increase the signal difference between the detection signal and the reference signal.

[0032] The instantaneous change of the output signal at the output terminal of the comparison unit 10 refers to the instant when the output signal at the output terminal of the comparison unit 10 changes from a high level to a low level, or the instant when the output signal at the output terminal of the comparison unit 10 changes from a low level to a high level.

[0033] Please see Figure 3 In the second embodiment, compared with the first embodiment ( Figure 2 Unlike the detection circuit 100 in the previous example, one end of the first adjustment unit 40 is electrically connected to the output terminal of the comparison unit 10, and the other end is electrically connected to the reference unit 20. When the output signal of the comparison unit 10 changes instantaneously, the first adjustment unit adjusts the reference signal to increase the signal difference between the detection signal and the reference signal.

[0034] In summary, combining the first and second embodiments, one end of the first adjustment unit 40 is electrically connected to the output terminal of the comparison unit 10, and the other end is electrically connected to the reference unit 20 or the detection unit 30. When the output signal of the comparison unit 10 changes instantaneously, the first adjustment unit 40 adjusts the reference signal or the detection signal to increase the signal difference between the detection signal and the reference signal.

[0035] The detection circuit 100 disclosed in this application includes a first adjustment unit 40. When the output signal of the output terminal of the comparison unit 10 changes instantaneously, the first adjustment unit 40 adjusts the reference signal or the detection signal to increase the signal difference between the detection signal and the reference signal. This ensures that the output signal of the output terminal of the comparison unit 10 maintains the state after the change, preventing the output signal from constantly changing due to the detection signal and the reference signal being too close. This improves the stability of the detection circuit.

[0036] The power supply device 300 provided in this embodiment of the invention, by employing the aforementioned detection circuit 100, can improve the stability of the circuit during the detection process, thereby improving the performance and quality of the power supply device 300.

[0037] Please see Figure 4 In the third embodiment, compared with the second embodiment ( Figure 3 The difference lies in that the detection circuit 100 further includes a control unit 50 and a second adjustment unit 60. The second adjustment unit 60 is electrically connected between the control unit 50 and the reference unit 20. The second adjustment unit 60 is used to adjust the reference signal to increase the signal difference between the detection signal and the reference signal.

[0038] The control unit 50 is also electrically connected to the detection unit 30 to acquire the detection signal, and controls the second adjustment unit 60 to adjust the reference signal based on the acquired detection signal. This allows for dual adjustment of the reference signal, further improving the stability and reliability of the circuit.

[0039] In this embodiment, the control unit 50 may be a microcontroller. The control unit 50 may include multiple signal acquisition ports, communication ports, multiple control ports, etc.

[0040] In one implementation, the second adjustment unit 60 has a higher priority in adjusting the reference unit 20 than the first adjustment unit 40. For example, the second adjustment unit 60 can be software-adjusted, while the first adjustment unit 40 can be hardware-adjusted. When the detection signal acquired by the control unit 50 is greater than a first preset threshold, the second adjustment unit 60 is controlled to operate to adjust the reference signal. When either the control unit 50 or the second adjustment unit 60 malfunctions, the detection signal will continue to rise. When the detection signal is greater than the reference signal, the output signal at the output terminal of the comparison unit 10 will jump. At this time, the first adjustment unit 40 operates to adjust the reference signal, thereby increasing the signal difference between the detection signal and the reference signal, making the output signal of the comparison unit 10 stable, and thus improving the stability of the circuit operation. The reference signal is greater than the first preset threshold.

[0041] Please see Figure 5 In one embodiment, the comparison unit 10 includes a comparator U, the first input terminal is the inverting input terminal of the comparator U, the second input terminal is the non-inverting input terminal of the comparator U, and the output terminal is the output terminal of the comparator U.

[0042] The reference unit 20 includes a first voltage divider resistor R1 and a second voltage divider resistor R2. The first voltage divider resistor R1 and the second voltage divider resistor R2 are connected in series between the power supply VCC and ground. The inverting input of the comparator U is connected to the connection node N1 between the first voltage divider resistor R1 and the second voltage divider resistor R2. In this embodiment, the power supply VCC is provided by the battery pack 100 and obtained after voltage regulation.

[0043] The detection unit 30 includes a third voltage divider resistor R3 and a fourth voltage divider resistor R4. The third voltage divider resistor R3 and the fourth voltage divider resistor R4 are connected in series between the detected object VBAT and ground. The non-inverting input of the comparator U is connected to the connection node N2 between the third voltage divider resistor R3 and the fourth voltage divider resistor R4. In this embodiment, the detected object VBAT is a battery module, specifically the positive terminal of a battery module.

[0044] The first adjustment unit 40 includes a resistor R5, a first electronic switch Q1, and a second electronic switch Q2. The control terminal of the first electronic switch Q1 is connected to the output terminal of the comparator U, the first connection terminal of the first electronic switch Q1 is connected to the power supply VCC, the second connection terminal of the first electronic switch Q1 is connected to the control terminal of the second electronic switch Q2, the first connection terminal of the second electronic switch Q2 is grounded, and the second connection terminal of the second electronic switch Q2 is connected to the non-inverting input terminal of the comparator U through the resistor R5.

[0045] In one specific embodiment, the control terminal, first connection terminal, and second connection terminal of the first electronic switch Q1 correspond to the base, emitter, and collector of a PNP transistor, respectively. The control terminal, first connection terminal, and second connection terminal of the second electronic switch Q2 correspond to the gate, source, and drain of an N-type MOS (Metal Oxide Semiconductor) field-effect transistor, respectively. In this embodiment, the N-type MOS field-effect transistor is a MOS field-effect transistor with a parasitic diode.

[0046] In one embodiment, the first adjustment unit 40 further includes a first bias resistor R6, a second bias resistor R7, a third bias resistor R8, and a fourth bias resistor R9. The first end of the first bias resistor R6 is connected to the first connection terminal of the first electronic switch Q1, and the second end of the first bias resistor R6 is connected to the control terminal of the first electronic switch Q1. The control terminal of the first electronic switch Q1 is connected to the output terminal of the comparator U through the second bias resistor R7. The first end of the third bias resistor R8 is connected to the first connection terminal of the second electronic switch Q2, and the second end of the third bias resistor R8 is connected to the control terminal of the second electronic switch Q2. The control terminal of the second electronic switch Q2 is connected to the second connection terminal of the first electronic switch Q1 through the fourth bias resistor R9.

[0047] In this embodiment, the detection circuit 100 is used to detect the voltage of the battery module to provide undervoltage protection for the battery pack 100. The working principle of the detection circuit 100 in this embodiment is described below.

[0048] In this embodiment, the voltage (reference signal) at connection node N1 is set to 2.5V as an example. During the use of the battery pack 100, the battery module's charge gradually decreases. When the voltage (detection signal) at connection node N2 is greater than the voltage at connection node N1, the input voltage at the non-inverting input terminal of comparator U is greater than the input voltage at the inverting input terminal. At this time, the output terminal of comparator U outputs a high-level signal, causing the first electronic switch Q1 and the second electronic switch Q2 to be in the off state, meaning that the first adjustment unit 40 does not work at this time. When the voltage at connection node N2 is less than the voltage at connection node N1, the output terminal of comparator U outputs a low-level signal, causing the first electronic switch Q1 and the second electronic switch Q2 to be in the on state. This causes resistor R5 and the fourth voltage divider resistor R4 to be connected in parallel, pulling the voltage at connection node N2 even lower, thus increasing the signal difference between the detection signal and the reference signal, resulting in a continuous low-level signal output from the output terminal without any jumps.

[0049] It should be noted that when the output signal of comparator U becomes a low-level signal, the back-end control unit can control the battery pack 100 to stop discharging based on this signal, so as to protect the battery pack 100.

[0050] Please see Figure 6 In another embodiment, the structure of the comparison unit 10, the reference unit 20, and the detection unit 30 is... Figure 5 The detection circuit 100 is the same as that in this application embodiment. The difference is that the detection unit 30 is used to detect the temperature of the battery pack 200. The third voltage divider resistor R3 and the fourth voltage divider resistor R4 are connected in series between the power supply VCC and ground. The third voltage divider resistor R3 is a negative temperature coefficient (NTC) thermistor.

[0051] Furthermore, the structure and connection relationship of the first adjustment unit 40' in this embodiment are also similar to... Figure 5 The first adjustment unit 40 in the present application is also different. In this embodiment, the first adjustment unit 40' includes a first electronic switch Q3 and a resistor R10. The control terminal of the first electronic switch Q3 is connected to the output terminal of the comparator U, the first connection terminal of the first electronic switch Q3 is grounded, and the second connection terminal of the first electronic switch Q3 is connected to the connection node N1 through the resistor R10.

[0052] In one embodiment, the control terminal, the first connection terminal, and the second connection terminal of the first electronic switch Q3 correspond to the gate, source, and drain of the N-type MOS field-effect transistor, respectively. In this embodiment, the N-type MOS field-effect transistor also includes a parasitic diode.

[0053] In one specific embodiment, the first adjustment unit 40 further includes a first bias resistor R11. The control terminal of the first electronic switch Q3 is connected to the output terminal of the comparator U through the first bias resistor R11.

[0054] The second adjustment unit 60 includes a second electronic switch Q4. The control terminal of the second electronic switch Q4 is connected to the control unit 50, the first connection terminal of the second electronic switch Q4 is grounded, and the second connection terminal of the second electronic switch Q4 is connected to the connection node N1.

[0055] Furthermore, the second adjustment unit 60 also includes a diode D and a second bias resistor R12. The diode D is connected in series between the control unit 50 and the control terminal of the second electronic switch Q4. Specifically, the control terminal of the second electronic switch Q4 is connected to the anode of the diode D, and the cathode of the diode D is connected to the control unit 50. The control terminal of the second electronic switch Q4 is connected to the power supply VCC through the second bias resistor R12.

[0056] In one embodiment, the control terminal, first connection terminal, and second connection terminal of the second electronic switch Q4 correspond to the gate, source, and drain of an N-type MOS field-effect transistor, respectively. The N-type MOS field-effect transistor also includes a parasitic diode.

[0057] The following is about Figure 6 The working principle of the detection circuit 100 shown will be introduced.

[0058] In this embodiment, the voltage (reference signal) at connection node N1 is set to 3.33V as an example. When the control unit 50 detects that the voltage at connection node N2 is less than a preset voltage (wherein the preset voltage is less than the reference voltage, such as 3V), the control unit 50 outputs a low-level signal, causing diode D to conduct. At this time, the second electronic switch Q4 is in the off state, and the output of comparator U outputs a low-level signal, which in turn causes the first electronic switch Q3 to also be in the off state. At this time, neither the first adjustment unit 40' nor the second adjustment unit 60 works, meaning the voltage at connection node N1 is unaffected. When the surface temperature of the battery pack 200 continues to rise, the resistance of the third voltage divider resistor R3 will decrease, causing the voltage at connection node N2 to rise. When the voltage at connection node N2 rises to a level greater than the preset voltage, the control unit 50 outputs a high-level signal, causing diode D to turn off. At this time, the second electronic switch Q4 conducts, which pulls the voltage at connection node N1 to ground (0V). At this time, the output of comparator U outputs a high-level signal. Because the reference signal is pulled to 0V, the signal difference between the detection signal and the reference signal is increased, causing the comparator U to continuously output a high-level signal without any transition.

[0059] When the control unit 50 or the second adjustment unit 60 malfunctions, the temperature of the battery pack 200 will continue to rise, which will cause the voltage at the connection node N2 to continue to rise. When the voltage at the connection node N2 rises to more than 3.33V, the output of the comparator U outputs a high-level signal, which turns on the first electronic switch Q3, and then makes the resistor R10 and the second voltage divider resistor R2 in parallel, which reduces the voltage at the connection node N1 (the reference signal decreases), thereby increasing the voltage difference between the detection signal and the reference signal, so that the comparator U continuously outputs a high-level signal without any jump.

[0060] It should be understood that the application of the detection circuit 100 in the power supply device 300 is merely an example, and the detection circuit 100 can also be applied to other electronic devices that need to detect temperature or battery voltage.

[0061] The above description is a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A detection circuit, characterized in that, include: The comparison unit includes a first input terminal, a second input terminal, and an output terminal; A reference unit is electrically connected to the first input terminal of the comparison unit and is used to generate a reference signal. The detection unit is electrically connected to the second input terminal of the comparison unit and is used to generate a detection signal; as well as The first adjustment unit has one end electrically connected to the output terminal of the comparison unit and the other end electrically connected to the reference unit; When the output signal at the output terminal of the comparison unit changes instantaneously, the first adjustment unit adjusts the reference signal to increase the signal difference between the detection signal and the reference signal. The detection circuit further includes a control unit and a second adjustment unit; the second adjustment unit is connected between the control unit and the reference reference unit, and is used to adjust the reference reference signal to increase the signal difference between the detection signal and the reference reference signal; the control unit is also electrically connected to the detection unit to acquire the detection signal, and controls the second adjustment unit to adjust the reference reference signal according to the acquired detection signal.

2. The detection circuit as described in claim 1, characterized in that, The output signal at the output terminal of the comparison unit maintains the state after the transition.

3. The detection circuit as described in claim 1, characterized in that, The first adjustment unit is electrically connected to the reference unit; when the output signal at the output terminal of the comparison unit changes instantaneously, the first adjustment unit adjusts the reference signal to increase the signal difference between the detection signal and the reference signal.

4. The detection circuit as described in claim 1, characterized in that, The second adjustment unit has a higher priority in adjusting the reference unit than the first adjustment unit.

5. The detection circuit as described in claim 3, characterized in that, The first adjustment unit includes a first electronic switch and a resistor; the control terminal of the first electronic switch is connected to the output terminal of the comparison unit, the first connection terminal of the first electronic switch is grounded, and the second connection terminal of the first electronic switch is connected to the reference unit through the resistor.

6. The detection circuit as described in claim 1, characterized in that, The second adjustment unit includes a second electronic switch; the control terminal of the second electronic switch is connected to the control unit, the first connection terminal of the second electronic switch is grounded, and the second connection terminal of the second electronic switch is connected to the reference unit.

7. The detection circuit according to any one of claims 1-6, characterized in that, The comparison unit includes a comparator; the first input terminal is the inverting input terminal of the comparator, and the second input terminal is the non-inverting input terminal of the comparator.

8. A power supply device, characterized in that, include: A battery pack, the battery pack comprising one or more battery modules; as well as The detection circuit according to any one of claims 1-7, wherein the detection circuit is connected to the battery pack and is used to detect the state parameters of the battery pack.

Images