Charging state detection circuit suitable for lithium battery
By designing a low-cost lithium battery state of charge detection circuit using transistors, diodes and resistors, the problems of high power consumption and high cost in the prior art are solved, and low-power consumption and low-cost state of charge detection are achieved.
Patent Information
- Application Number
- CN202420972495.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-07
- Publication Date
- 2025-03-18
- Estimated Expiration
- 2034-05-07
AI Technical Summary
The existing lithium battery state-of-charge detection methods have problems of high power consumption and high cost, especially methods that require op amps to implement.
A charging state detection circuit suitable for lithium batteries is designed, and low-cost components such as transistors, diodes and resistors can be used to detect the charging state when the charging branch is turned off.
The charging state detection effect is achieved without power consumption when the charging state is not detected and with low power consumption when the charging state is detected.
Smart Images
Figure CN222636239U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of lithium battery charging detection, and particularly relates to a charging state detection circuit suitable for lithium batteries. Background Art
[0002] At present, with the development of lithium battery industry technology, lithium battery management system technology is developing faster and faster. There are two mainstream ways to detect the charging status of lithium batteries. One is to use a differential op amp to amplify the voltage on the current sampling resistor, and then use a comparator to compare the voltage with the reference voltage to detect the charging status; the other is to use the fact that the charging port voltage is greater than the battery voltage during charging, and use an op amp to compare the voltage of the battery charging port and the battery to detect the charging status.
[0003] However, method one requires opening the charging branch when detecting charging, which limits the usage scenario; method two requires an op amp to implement the circuit, which has the problem of power consumption and relatively high cost. Utility Model Content
[0004] The utility model provides a charging state detection circuit suitable for lithium batteries, which can realize charging state detection by using low-cost solutions such as triodes, diodes, resistors, etc. when the charging branch is closed.
[0005] The technical solution of the utility model is implemented as follows: a charging state detection circuit suitable for lithium batteries, including a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode terminal, a second diode, a third diode, a fourth diode, a first triode, a battery, a charger interface, a voltage detection unit and an electrode power supply, the electrode power supply is electrically connected to the first resistor and the second resistor, the second resistor is electrically connected to the second diode, the second diode is electrically connected to the third diode and the first triode, the first triode is electrically connected to the charger interface, the first resistor is electrically connected to the first diode, the first diode is electrically connected to the third resistor and the fourth diode, the third resistor is electrically connected to the third diode, the fourth diode is electrically connected to the fourth resistor and the battery, and the fourth resistor is electrically connected to the first triode. A complete circuit is formed to charge the battery.
[0006] The second resistor is electrically connected to the anode of the second diode, the cathode of the second diode is electrically connected to the cathode of the third diode and the first transistor, the first transistor is electrically connected to the charger interface, the first resistor is electrically connected to the anode of the first diode, the cathode of the first diode is electrically connected to the third resistor and the anode of the fourth diode, the third resistor is electrically connected to the anode of the third diode, and the anode of the fourth diode is electrically connected to the fourth resistor and the battery.
[0007] As an implementation method, the collector of the first transistor is electrically connected to the cathode of the second diode and the cathode of the third diode, the emitter of the first transistor is electrically connected to the charger interface, the base of the first transistor is electrically connected to the anode of the fourth diode and the battery, and the voltage detection unit is electrically connected between the first resistor and the first diode. The inspection and charging of the entire circuit are completed.
[0008] After adopting the above technical scheme, the beneficial effects of the utility model are: realizing the detection of the charging state, when the charging state is not detected, there is no power consumption, and when the charging state is detected, the power consumption is very small. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.
[0010] Figure 1 This is a lithium battery charging status detection circuit.
[0011] Figure 1 In the figure, R1 is the first resistor; R2 is the second resistor; R3 is the third resistor; R4 is the fourth resistor; D1 is the first diode; D2 is the second diode; D3 is the third diode; D4 is the fourth diode; Q1 is the first transistor; VCC is the electrode power supply; B is the battery; C is the charger interface; CHG STA is the voltage detection unit. DETAILED DESCRIPTION
[0012] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.
[0013] according to Figure 1As shown, a charging state detection circuit suitable for a lithium battery B includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first diode terminal, a second diode D2, a third diode D3, a fourth diode D4, a first transistor Q1, a battery B, a charger interface C, a voltage detection unit CHG STA and an electrode power supply VCC, wherein the electrode power supply VCC is electrically connected to the first resistor R1 and the second resistor R2, the second resistor R2 is electrically connected to the second diode D2, the second diode D2 is electrically connected to the third diode D3 and the first transistor Q1, the first transistor Q1 is electrically connected to the charger interface C, the first resistor R1 is electrically connected to the first diode D1, the first diode D1 is electrically connected to the third resistor R3 and the fourth diode D4, the third resistor R3 is electrically connected to the third diode D3, the fourth diode D4 is electrically connected to the fourth resistor R4 and the battery B, and the fourth resistor R4 is electrically connected to the first transistor Q1.
[0014] The second resistor R2 is electrically connected to the anode of the second diode D2, the cathode of the second diode D2 is electrically connected to the cathode of the third diode D3 and the first transistor Q1, the first transistor Q1 is electrically connected to the charger interface C, the first resistor R1 is electrically connected to the anode of the first diode D1, the cathode of the first diode D1 is electrically connected to the third resistor R3 and the anode of the fourth diode D4, the third resistor R3 is electrically connected to the anode of the third diode D3, the anode of the fourth diode D4 is electrically connected to the fourth resistor R4 and the battery B, forming a complete circuit, which can charge the battery B.
[0015] The collector of the first transistor Q1 is electrically connected to the cathode of the second diode D2 and the cathode of the third diode D3, the emitter of the first transistor Q1 is electrically connected to the charger interface C, the base of the first transistor Q1 is electrically connected to the anode of the fourth diode D4 and the battery B, and the voltage detection unit CHG STA is electrically connected between the first resistor R1 and the first diode D1. The inspection and charging of the entire circuit are completed.
[0016] Battery B is 0V, the charging branch is closed, and the terminal voltage is suspended when the charger is not plugged in. The first transistor Q1 is not turned on, the circuit does not form a loop, and the voltage measured by the voltage detection unit CHG STA is equal to the voltage of the electrode power supply VCC. When the charging branch is closed and the charger is plugged in, the voltage of the charger interface C is lower than the voltage of battery B. The voltage difference is the full charge voltage of the charger minus the voltage of battery B. In the corresponding figure, when the charger is plugged in, the voltage of battery B is greater than the voltage of the charger interface C. In addition to the battery B being fully charged, the voltage difference between battery B and charger interface C is generally greater than 0.7V. At this time, the charger interface C is turned on, the cathode voltage of the second diode D2 and the third diode D3 is the voltage of the charger interface C, the cathode voltage of the first diode D1 and the fourth diode D4 is about -0.7V, and the positive voltage of the first diode D1 is about 0V, that is, the voltage detected by the voltage detection unit CHG STA is 0V.
[0017] That is, the voltage measured by the voltage detection unit CHG STA can realize the judgment of the charging state. In the description of the present utility model, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In the description of the present utility model, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a mechanical connection or an electrical connection, or it can be the internal connection of two elements, it can be a direct connection, or it can be indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.
[0018] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A charging status detection circuit suitable for a lithium battery, characterized in that: It includes a first resistor, a second resistor, a third resistor, a fourth resistor, a first diode terminal, a second diode, a third diode, a fourth diode, a first triode, a battery, a charger interface, a voltage detection unit and an electrode power supply, the electrode power supply is electrically connected to the first resistor and the second resistor, the second resistor is electrically connected to the second diode, the second diode is electrically connected to the third diode and the first triode, the first triode is electrically connected to the charger interface, the first resistor is electrically connected to the first diode, the first diode is electrically connected to the third resistor and the fourth diode, the third resistor is electrically connected to the third diode, the fourth diode is electrically connected to the fourth resistor and the battery, and the fourth resistor is electrically connected to the first triode.
2. A charging status detection circuit suitable for a lithium battery according to claim 1, characterized in that: The second resistor is electrically connected to the anode of the second diode, the cathode of the second diode is electrically connected to the cathode of the third diode and the first transistor, the first transistor is electrically connected to the charger interface, the first resistor is electrically connected to the anode of the first diode, the cathode of the first diode is electrically connected to the third resistor and the anode of the fourth diode, the third resistor is electrically connected to the anode of the third diode, and the anode of the fourth diode is electrically connected to the fourth resistor and the battery.
3. A charging status detection circuit suitable for a lithium battery according to claim 1, characterized in that: The collector of the first transistor is electrically connected to the cathode of the second diode and the cathode of the third diode, the emitter of the first transistor is electrically connected to the charger interface, and the base of the first transistor is electrically connected to the anode of the fourth diode and the battery.
4. A charging status detection circuit suitable for a lithium battery according to claim 1, characterized in that: The voltage detection unit is electrically connected between the first resistor and the first diode.