An electric quantity display circuit

Abstract

This invention discloses a battery level display circuit. It solves the problems of conventional battery level display circuits failing to accurately display battery level and requiring multiple pins for integration into a chip, increasing cost and reducing practical value. The battery level display circuit includes a battery pack, a voltage-to-current conversion unit, and a battery level display unit. The voltage-to-current conversion unit includes several comparators corresponding to the battery level display stage, several trigger signal sub-circuits, and a reference sub-circuit providing different reference voltages for each comparator. The battery level display unit includes several display sub-circuits corresponding to the battery level display stage and a voltage divider sub-circuit providing different control voltages for each display sub-circuit. This invention can accurately and dynamically display battery level, and after integration into a chip, only one pin is needed, reducing the manufacturing cost of the integrated chip and improving its practical value.

Description

Technical Field

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

[0002] Lithium batteries need to display their battery level during daily use. Commonly used battery level display circuits include... Figure 1 As shown, a circuit consisting of several resistors, Zener diodes, and indicator lights connected in series is routed across the battery terminals. When the battery voltage rises, the Zener diode breaks down, and the indicator lights illuminate. By selecting an appropriate Zener diode value, different battery level display values ​​can be obtained. However, this circuit has drawbacks. The displayed battery level is limited by the Zener diode, making it difficult to accurately display the battery level, especially during charging when dynamic display, such as indicator light flashing, is required, which this circuit cannot achieve. Lithium batteries typically have protection chips in use. If the battery level display circuit were integrated into the chip, the aforementioned drawbacks would be resolved. However, this introduces another problem: multiple indicator lights require multiple pins for support. Pin resources are a primary consideration in integrated circuit design, as the number of pins directly affects the chip's cost and practical value. Summary of the Invention

[0003] This invention primarily addresses the problems of commonly used power display circuits failing to accurately display battery power, and the need for multiple pins to support such circuits when integrated into a chip, which increases cost and reduces practical value. It provides a new power display circuit.

[0004] The above-mentioned technical problems of the present invention are mainly solved by the following technical solution: a power display circuit, including a battery pack, a voltage-to-current conversion unit and a power display unit;

[0005] The voltage-to-current conversion unit includes several comparators corresponding to the power display stage, several trigger signal sub-circuits, and a reference sub-circuit that provides different reference voltages for each comparator.

[0006] The positive input of each comparator is connected to the positive terminal of the battery pack, and the inverting input of each comparator is connected to the corresponding voltage divider point of the reference sub-circuit.

[0007] Each trigger signal sub-circuit is connected in parallel. After the parallel connection, one end of the circuit is connected to the power supply, and the other end serves as the signal output terminal of the voltage-current conversion unit. Each trigger signal sub-circuit includes a first control switch that controls its operation. The output terminal of each comparator is connected to the control terminal of the corresponding first control switch.

[0008] The power display unit includes several display sub-circuits corresponding to the power display stage, and a voltage divider sub-circuit that provides different control voltages to each display sub-circuit.

[0009] Each display sub-circuit includes a second control switch that controls its operation. The second control switch is connected to the corresponding voltage dividing point of the voltage divider sub-circuit. The signal output terminal of the voltage-current conversion unit is connected to the input terminal of the voltage divider sub-circuit.

[0010] This invention detects the battery pack voltage during charging and outputs a control signal to the circuit display unit when a set charging stage is reached. This control signals the corresponding display sub-circuit to illuminate the indicator lights. Each time the battery pack reaches a charging stage, the corresponding indicator light illuminates, allowing for accurate display of the battery pack's charge level. The circuit design comprises a voltage-to-current conversion unit and a charge display unit. The voltage-to-current conversion unit controls the flashing of the circuit display unit via a single signal output terminal. This facilitates integration of the voltage-to-current conversion unit into an integrated chip. Since there is only one signal output terminal, only one pin is needed after integration, reducing the manufacturing cost of the integrated chip and increasing its usability.

[0011] In this design, the reference sub-circuit has multiple voltage divider points, providing different reference voltages. The inverting input of each comparator is connected to the corresponding voltage divider point to obtain the corresponding reference voltage. By comparing this voltage with the battery charging voltage, the comparator controls the corresponding trigger signal sub-circuit to conduct, forming a control signal that is sent to the power display unit. The power display unit includes several display sub-circuits corresponding to different power display stages, as well as a voltage divider sub-circuit. The voltage divider sub-circuit has multiple voltage divider points, providing control voltage to the corresponding second control switches. After passing through the voltage divider sub-circuit, the control signal controls the on / off state of each second control switch. Whenever the battery pack reaches a certain charging stage, the corresponding second control switch is turned on by the control signal, and the corresponding display sub-circuit operates, i.e., the corresponding indicator light illuminates.

[0012] As a preferred embodiment, the comparator includes a corresponding number of comparators BG1…BGn according to the set power display stage.

[0013] As a preferred embodiment, the reference sub-circuit includes a reference voltage source E0 and resistors RE1…REn corresponding to the power display level. The resistors RE1…REn are connected in series, and the circuit after series connection is connected across the reference voltage source E0. The negative terminal of the reference voltage source E0 is connected to the negative terminal of the battery pack, and the inverting input terminal of the comparator BGk is connected to the end of the resistor REk connected to the positive terminal of the reference voltage source E0, where k=1…n.

[0014] In this scheme, the reference sub-circuit provides a reference voltage for each comparator. Resistors RE1...REn are connected in series, and the two ends of the series circuit are respectively connected to the two ends of the reference voltage source. The endpoints of each resistor form a voltage divider. Resistors RE1 and REn serve as the two ends of the series circuit. One end of resistor RE1 is connected to the positive terminal of the reference voltage source, and the other end of resistor RE1 is connected to one end of resistor RE2. One end of resistor REn is connected to the negative terminal of the reference voltage source, and the other end of resistor REn is connected to one end of resistor REn-1. The end of resistor REk connected to the positive terminal of the reference voltage source E0 is either directly connected to the positive terminal of the reference voltage source E0 or connected to the positive terminal of the reference voltage source E0 through a series resistor.

[0015] In a preferred embodiment, the trigger signal sub-circuit includes a MOSFET Qk and a resistor RHk, where k = 1…n. The first control switch is the MOSFET Qk. One end of the resistor RHk is connected to the power supply, and the other end of the resistor RHk is connected to the source of the MOSFET Qk. The drain of the MOSFET Qk is connected to the signal output terminal of the voltage-to-current conversion unit, and the gate of the MOSFET Qk is connected to the output terminal of the comparator BGk. In this embodiment, the MOSFET acts as the first control switch, controlling the on / off state of the trigger signal sub-circuit. When the battery pack reaches a certain charging stage, the corresponding comparator sends a signal to the corresponding first control switch, causing the corresponding trigger signal sub-circuit to conduct and sending a control signal to the power display unit.

[0016] In a preferred embodiment, the trigger signal sub-circuit includes a MOSFET Qk and a constant current source IDk, where k = 1…n. The first control switch is the MOSFET Qk. The positive terminal of the constant current source IDk is connected to the power supply, the negative terminal of the constant current source IDk is connected to the source of the MOSFET Qk, the drain of the MOSFET Qk is connected to the signal output terminal of the voltage-to-current conversion unit, and the gate of the MOSFET Qk is connected to the output terminal of the comparator BGk. In this embodiment, the voltage is connected to the MOSFET after passing through the constant current source to provide a constant current. The MOSFET acts as the first control switch, controlling the on / off state of the trigger signal sub-circuit. When the battery pack is charged to a certain stage, the corresponding comparator sends a signal to the corresponding first control switch, causing the corresponding trigger signal sub-circuit to conduct and sending a control signal to the power display unit.

[0017] As a preferred embodiment, the voltage divider circuit includes resistors RF1…RFn corresponding to the power display stage. Resistors RF1…RFn are connected in series. One end of the series circuit serves as the input terminal of the power display circuit and is connected to the signal output terminal of the voltage-to-current conversion circuit. The other end of the series circuit is grounded. In this embodiment, the number of resistors in the voltage divider circuit is set according to the power display stage. The resistors are connected in series, and their endpoints form the voltage divider points. Specifically, resistors RF1…RFn are connected in series to form a series circuit, where resistors RF1 and RFn are the resistors at both ends of the series circuit. One end of resistor RF1 is connected to the signal output terminal of the voltage-to-current conversion circuit, and the other end of resistor RF1 is connected to one end of resistor RF2. One end of resistor RFn is grounded, and the other end of resistor RFn is connected to resistor RFn-1.

[0018] As a preferred embodiment, the display sub-circuit includes a resistor RLk, a light-emitting diode (LEDk), and a MOSFET Gk, where k = 1…n. The second control switch is the MOSFET Gk. One end of the resistor RLk is connected to the power supply, and the other end is connected to the positive terminal of the LEDk. The negative terminal of the LEDk is connected to the drain of the MOSFET Gk, the source of the MOSFET Gk is grounded, and the gate of the MOSFET Gk is connected to the end of the resistor RFk connected to the input terminal of the display circuit. The number of display sub-circuits in this embodiment corresponds to the display stages. When charging reaches a certain stage, the MOSFET Gk in the corresponding stage detects that the gate voltage has reached the conduction requirement, and the MOSFET Gk conducts, thus activating the display sub-circuit and causing the LED to flash. The end of the resistor RFk connected to the input terminal of the display circuit can be directly connected to the input terminal or connected to the input terminal of the display circuit through a series resistor.

[0019] As a preferred embodiment, the current display unit further includes an oscillator H, which is connected to the signal output terminal of the voltage-to-current conversion unit. In this embodiment, the trigger signal sub-circuits are connected in parallel and then connected to the signal output terminal via the oscillator. The signal output terminal is connected to the power display unit, and the indicator light on the display unit can flash due to the action of the oscillator, enabling dynamic display of the power level during battery charging.

[0020] As a preferred embodiment, the display sub-circuit further includes an oscillator Hk, where k = 1…n. One end of the oscillator Hk is connected to the drain terminal of the MOSFET Qk, and the other end of the oscillator Hk is connected to the signal output terminal of the voltage-to-current conversion unit. In this embodiment, an oscillator is connected to each trigger signal sub-circuit. After the trigger signal sub-circuit is turned on, the signal is transmitted to the signal output terminal via the oscillator. The signal output terminal is connected to the power display unit. Through the action of the oscillator, the indicator light on the display unit can flash, enabling dynamic display of the power level during battery charging.

[0021] As a preferred embodiment, the voltage-to-current conversion circuit is integrated within an integrated chip, and its signal output terminal forms a single pin on the integrated chip. In this solution, the voltage-to-current conversion circuit is integrated within the integrated chip, requiring only one pin for signal output, thus reducing costs.

[0022] Therefore, the advantages of the present invention are:

[0023] 1. A comparator is used to compare and detect the voltage of the battery during charging. When the set voltage is reached, the corresponding indicator light is controlled to light up, so as to accurately display the battery level.

[0024] 2. The indicator light of the oscillator can flash, so that the circuit can dynamically display the charging status of the battery pack.

[0025] 3. The voltage-to-current conversion circuit has only one signal output terminal. After being integrated into the chip, it only needs to be supported by one pin, which reduces the manufacturing cost of the integrated chip and improves its practical value. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a circuit structure commonly used in existing power display circuits;

[0027] Figure 2 This is a schematic diagram of a circuit structure according to the present invention;

[0028] Figure 3 This is a schematic diagram of the second circuit structure of the present invention.

[0029] 1-Voltage-to-current conversion unit; 2-Power display unit; 3-Trigger signal sub-circuit; 4-Reference sub-circuit; 5-Display sub-circuit; 6-Voltage divider sub-circuit; 7-Comparator. Detailed Implementation

[0030] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0031] Example 1:

[0032] This embodiment provides a power display circuit, such as... Figure 2As shown, the system includes a battery pack B, a voltage-to-current conversion unit 1, and a power display unit 2. The battery pack consists of several batteries B1…Bn connected in series. During charging, the positive terminal of the battery pack is connected to the power supply, and the negative terminal is grounded. The voltage-to-current conversion unit 1 includes several comparators 7 corresponding to the power display stage, several trigger signal sub-circuits 3, and a reference sub-circuit 4 providing different reference voltages for each comparator. The positive input terminal of each comparator is connected to the positive terminal of the battery pack B, and the inverting input terminal of each comparator is connected to the corresponding voltage divider point on the reference sub-circuit. The trigger signal sub-circuits are connected in parallel, with one end connected to the power supply and the other end connected to one end of an oscillator. The other end of the oscillator serves as the signal output terminal of the voltage-to-current conversion unit. Each trigger signal sub-circuit includes a first control switch that controls its operation, and the output terminal of each comparator is connected to the control terminal of the corresponding first control switch. The power display unit 2 includes several display sub-circuits 5 corresponding to the power display stage, and a voltage divider sub-circuit 6 providing different control voltages to each display sub-circuit. Each display sub-circuit includes a second control switch that controls its operation. The second control switch is connected to the corresponding voltage divider point on the voltage divider sub-circuit. The signal output terminal of the voltage-to-current conversion unit is connected to the input terminal of the voltage divider sub-circuit. Furthermore, the voltage-to-current conversion unit is integrated into an integrated chip. The voltage-to-current conversion unit uses a single signal output terminal, requiring only one pin for support after integration, connected to the power display unit.

[0033] The specific structure of the circuit display circuit is explained below. The circuit display circuit divides the battery charging level into n stages for display. The voltage-current conversion unit has n comparators 7, and each comparator has n trigger signal sub-circuits 3. The power display unit has n display sub-circuits.

[0034] like Figure 2 As shown, the comparator includes comparators BG1…BGn, and each comparator has a positive input terminal, an inverting input terminal, and an output terminal.

[0035] The reference sub-circuit includes a reference voltage source E0 and resistors RE1…REn corresponding to the power level display. Resistors RE1…REn are connected in series, and the series circuit is connected across the reference voltage source E0. Specifically, resistors RE1 and REn are the resistances across the series circuit. One end of resistor RE1 serves as the input terminal of the series circuit, connected to the positive terminal of the reference voltage source, and one end of resistor REn serves as the output terminal of the series circuit, connected to the negative terminal of the reference voltage source. The negative terminal of the reference voltage source E0 is connected to the negative terminal of the battery pack. The inverting input terminal of the comparator BGk is connected to the end of resistor REk connected to the positive terminal of the reference voltage source E0, where k=1…n. Figure 2As shown, the inverting input of comparator BG1 is connected at the connection point between resistors RE1 and RE2. The connection structure of the inverting input of other comparators is similar, also connected between the corresponding two resistors. The inverting input of comparator BGn is connected at the connection point between resistor REn and the positive terminal of the reference voltage source E0.

[0036] The trigger signal sub-circuit includes a MOSFET Qk and a resistor RHk, where k = 1…n, and the first control switch is the MOSFET Qk. One end of the resistor RHk is connected to the power supply, and the other end of the resistor RHk is connected to the source of the MOSFET Qk. The drain of the MOSFET Qk is connected to one end of an oscillator, and the other end of the oscillator is connected to the signal output terminal of the voltage-to-current conversion unit. The gate of the MOSFET Qk is connected to the output terminal of the comparator BGk. Alternatively, the resistor RHk in the trigger signal sub-circuit can be replaced by a constant current source IDn.

[0037] The voltage divider circuit includes resistors RF1…RFn corresponding to the power display stage. Resistors RF1…RFn are connected in series, with the point between any two resistors forming the voltage divider point. One end of the series circuit serves as the input terminal of the circuit display circuit and is connected to the signal output terminal of the voltage-to-current conversion circuit. The other end of the series circuit is grounded. Specifically, resistors RF1 and RFn are the two ends of the series circuit; one end of resistor RF1 forms the input terminal of the series circuit, and one end of resistor RFn forms the ground.

[0038] The display sub-circuit includes a resistor RLk, an LEDk, and a MOSFET Gk, where k = 1…n. The second control switch is the MOSFET Gk. One end of the resistor RLk is connected to the power supply, and the other end is connected to the positive terminal of the LEDk. The negative terminal of the LEDk is connected to the drain of the MOSFET Gk. The source of the MOSFET Gk is grounded, and the gate of the MOSFET Gk is connected to the end of the resistor RFk that is connected to the input terminal of the display circuit. Specifically, as shown below… Figure 2 As shown, the gate of MOSFET G1 is connected to the connection point between resistor RF1 and the input terminal of the current display unit, the gate of MOSFET G2 is connected to the connection point between resistor RF1 and resistor RF2 (not shown in the figure), and the connection structure follows the same pattern, with the gate of MOSFET Gn connected to the connection point between resistor RFn-1 and resistor RFn.

[0039] When the battery pack is charging, the positive terminal voltage rises. When the voltage at the positive input terminal of comparator BG1 reaches the reverse input terminal voltage, comparator BG1 outputs a high level to MOSFET Q1, turning on MOSFET Q1. This activates the signal trigger sub-circuit, and the control signal output from the signal trigger sub-circuit passes through an oscillator and enters the power display unit. Within the display unit, it passes through a voltage divider circuit to the gate of MOSFET Gn. When the gate voltage of MOSFET G1 reaches the turn-on voltage, MOSFET G1 turns on, activating its display sub-circuit, and LED1 flashes, dynamically displaying the current battery level. As the positive terminal voltage continues to rise, and the voltage at the positive input terminal of comparator BG2 reaches the reverse input voltage, the same steps are repeated until LED2 flashes. This process continues, with each LEDn flashing sequentially during charging, dynamically displaying the battery level.

[0040] Example 2:

[0041] This embodiment provides a second type of power display circuit, such as... Figure 3 As shown, the difference from Embodiment 1 is that the original oscillator H is removed from the voltage-to-current conversion unit. The trigger signal sub-circuit includes a MOSFET Qk, a constant current source IDk, and an oscillator Hk, where k=1…n. The positive terminal of the constant current source IDk is connected to the power supply, and the negative terminal of the constant current source IDk is connected to the source of the MOSFET Qk. The drain of the MOSFET Qk is connected to the input terminal of the oscillator H, and the output terminal of the oscillator Hk is connected to the signal output terminal of the voltage-to-current conversion unit. The gate of the MOSFET Qk is connected to the output terminal of the comparator BGk. Alternatively, the constant current source IDk can be a resistor. Thus, an oscillator is added to each trigger signal sub-circuit. When the trigger signal sub-circuit is turned on, the control signal is directly adjusted and output to the signal output terminal of the voltage-to-current conversion unit through its oscillator. Similarly, the trigger signal sub-circuits are connected in parallel to the signal output terminal of the voltage-to-current conversion unit, resulting in only one signal output terminal. The other structures in Embodiment 2 are the same as in Embodiment 1.

[0042] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0043] Although this document frequently uses terms such as voltage-to-current conversion unit, power display unit, trigger signal sub-circuit, and reference sub-circuit, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. A power display circuit, characterized in that: The battery pack, the voltage-current conversion unit and the power display unit are included. The voltage-current conversion unit includes a plurality of comparators corresponding to the power display stages, a plurality of trigger signal sub-circuits, a reference sub-circuit providing different reference voltages for the comparators, The positive input terminals of the comparators are connected to the positive terminal of the battery pack respectively, and the negative input terminals of the comparators are connected to the corresponding voltage dividing points of the reference sub-circuit respectively, The trigger signal sub-circuits are connected in parallel, one end of the circuit after the connection is connected to the power supply, and the other end is used as the signal output end of the voltage-current conversion unit, each trigger signal sub-circuit includes a first control switch for controlling its operation and a resistor / constant current source, and the output terminals of the comparators are connected to the control terminals of the corresponding first control switches respectively. The power display unit includes a plurality of display sub-circuits corresponding to the power display stages, and a voltage dividing sub-circuit providing different control voltages for the display sub-circuits, Each display sub-circuit includes a second control switch for controlling its operation, each second control switch is connected to the corresponding voltage dividing point of the voltage dividing sub-circuit, and the signal output end of the voltage-current conversion unit is connected to the input terminal of the voltage dividing sub-circuit. The voltage dividing sub-circuit includes resistors RF1…RFn corresponding to the power display stages, the resistors RF1…RFn are connected in series, one end of the circuit after the connection is connected to the input terminal of the power display unit and the signal output end of the voltage-current conversion unit, and the other end of the circuit after the connection is grounded.

2. The electric quantity display circuit according to claim 1, characterized in that The comparators include a corresponding number of comparators BG1…BGn according to the set power display stages.

3. A charge display circuit according to claim 2, characterized in that The reference sub-circuit includes a reference voltage source E0 and resistors RE1…REn corresponding to the power display levels, the resistors RE1…REn are connected in series, the circuit after the connection is connected between the reference voltage source E0, the negative terminal of the reference voltage source E0 is connected to the negative terminal of the battery pack, and the negative input terminal of the comparator BGk is connected to one end of the resistor REk connected to the positive terminal of the reference voltage source E0, where k=1…n.

4. An electric quantity display circuit according to claim 2 or 3, characterized in that The trigger signal sub-circuit includes a MOS tube Qk and a resistor RHk, where k=1…n, the first control switch is the MOS tube Qk, one end of the resistor RHk is connected to the power supply, the other end of the resistor RHk is connected to the source of the MOS tube Qk, the drain of the MOS tube Qk is connected to the signal output end of the voltage-current conversion unit, and the gate of the MOS tube Qk is connected to the output terminal of the comparator BGk.

5. The electric quantity display circuit according to claim 2 or 3, characterized in that The trigger signal sub-circuit includes a MOS tube Qk and a constant current source IDk, where k=1…n, the first control switch is the MOS tube Qk, the positive terminal of the constant current source IDk is connected to the power supply, the negative terminal of the constant current source IDk is connected to the source of the MOS tube Qk, the drain of the MOS tube Qk is connected to the signal output end of the voltage-current conversion unit, and the gate of the MOS tube Qk is connected to the output terminal of the comparator BGk.

6. The electric quantity display circuit according to claim 1, characterized by The display sub-circuit comprises resistors RLk, light emitting diodes LEDk, MOS tubes Gk, wherein k=1…n, the second control switch is the MOS tube Gk, one end of the resistor RLk is connected to the power supply, the other end of the resistor RLk is connected to the positive electrode of the light emitting diode LEDk, the negative electrode of the light emitting diode LEDk is connected to the drain of the MOS tube Gk, the source of the MOS tube Gk is grounded, and the gate of the MOS tube Gk is connected to one end of the resistor RFk connected to the input end of the electric quantity display unit.

7. The electric quantity display circuit according to claim 4, characterized in that The electric quantity display unit further comprises an oscillator H connected to the signal output end of the voltage-current conversion unit.

8. The electric quantity display circuit according to claim 5, characterized in that The display sub-circuit further comprises oscillators Hk, wherein k=1…n, one end of the oscillator Hk is connected to the drain end of the MOS tube Qk, and the other end of the oscillator Hk is connected to the signal output end of the voltage-current conversion unit.

9. The electric quantity display circuit according to claim 1 or 2 or 3, characterized in that The voltage-current conversion circuit is integrated in an integrated chip, and the signal output end of the voltage-current conversion unit forms a pin of the integrated chip.

Images