A battery pack sleep wake-up method and circuit

Abstract

The present invention discloses a battery pack sleep wake-up method and circuit, which relates to the field of battery technology and includes the following steps: when the power switch is switched from the off state to the on state, the wake-up circuit enters the first state and cuts off the starting current; utilizing the energy storage characteristics of the energy storage capacitor in the wake-up circuit to determine the load time under the switching of the energy storage capacitor's charge and discharge states; when charging is completed, the energy storage capacitor's charge state is transformed before and after energy storage is completed, controlling the wake-up circuit to switch from the first state to the second state; in the second state, the starting current is no longer cut off by the wake-up circuit and flows into the main control chip. The present invention utilizes the conduction characteristics of the capacitor in different charge and discharge states before and after energy storage is completed to achieve control of the on and off of the transistor, avoiding the startup failure problem caused by too low current in the initial startup of the power-saving power tool and achieving rapid startup.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery pack sleep and wake-up method and circuit. Background Art

[0002] Power tool controllers on the market are categorized into two main categories: those with zero power consumption during startup and those with power consumption during startup. Because zero-power tools significantly reduce unnecessary power loss, they appeal to a wider audience than power-consuming tools.

[0003] However, when using the battery pack's sleep function, the first startup may fail. This is because the accompanying battery pack enters a sleep state when not in use, and its starting current must meet the required startup current for a successful startup. However, the starting current of a zero-power power tool controller can be very low, so startup failure may occur during the first startup. Summary of the Invention

[0004] To solve the problem of zero-power power tools failing to start due to insufficient starting current, the present invention proposes a battery pack sleep wake-up method. In the on state, the starting current output by the battery pack passes through a wake-up circuit for load simulation before being output to the main control chip. The method specifically includes the following steps:

[0005] S1: When the power switch switches from the off state to the on state, the wake-up circuit enters the first state and cuts off the startup current;

[0006] S2: Using the energy storage characteristics of the energy storage capacitor in the wake-up circuit, the load time is determined when the energy storage capacitor switches between charging and discharging states. If the energy storage capacitor remains in the charging state, it is determined that the load time does not meet the standard and the process returns to step S2. If the energy storage capacitor stops charging, it is determined that the load time meets the standard and the process enters step S3.

[0007] S3: The energy storage capacitor is used to store energy, and the charging state of the front and rear energy storage capacitors is changed, thereby controlling the wake-up circuit to switch from the first state to the second state.

[0008] S4: In the second state, the startup current is no longer cut off by the wake-up circuit and flows into the main control chip.

[0009] Furthermore, the wake-up circuit includes:

[0010] A state switching transistor, which switches the wake-up circuit between the first state and the second state by switching the conduction state;

[0011] The energy storage capacitor is used to store electrical energy and terminates the charging state when the energy storage reaches the maximum energy storage capacity. At this time, the state switching transistor enters the second state.

[0012] Furthermore, one end of the energy storage capacitor is connected to the base direction of the state switching transistor, and the other end is connected to the ground direction.

[0013] Furthermore, the wake-up circuit also includes a current-limiting resistor for setting the resistance value according to the starting current requirement of the power tool.

[0014] Furthermore, when the power switch is switched from the on state to the off state, the method further includes the following steps:

[0015] S5: Utilize the discharge characteristics of the energy storage capacitor in the wake-up circuit to discharge the energy storage capacitor under the preset delay.

[0016] Furthermore, the delayed discharge time is regulated by adjusting the resistance of the delay resistor connected in series with the energy storage capacitor.

[0017] The present invention also proposes a battery pack sleep wake-up circuit, comprising:

[0018] The state switching transistor has an emitter connected to the wake-up current, a collector connected to the ground through a current limiting resistor, a base connected to the ground through a first delay resistor, an energy storage capacitor, and a second delay resistor in sequence, and an emitter and a base connected through an input resistor.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] (1) The battery pack sleep wake-up method and circuit described in the present invention fully utilize the conduction characteristics of the capacitor in different charge and discharge states before and after energy storage is completed, thereby realizing the control of the on-off of the transistor, cutting off the small current and quickly directing the required power supply current to the main control chip, thereby avoiding the startup failure problem caused by the low current in the initial startup of the power-saving power tool;

[0021] (2) By utilizing the energy storage characteristics of the capacitor, the load simulation is realized when the power is turned on, and the discharge is delayed when the power is turned off, thereby avoiding damage to the power tool itself caused by sudden power outages and achieving true zero-power startup. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A step diagram of a battery pack sleep and wake-up method;

[0023] Figure 2 Schematic diagram of current supply direction;

[0024] Figure 3 The following is a circuit diagram of a battery pack sleep and wake-up circuit. DETAILED DESCRIPTION

[0025] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0026] Example 1

[0027] To solve the problem of power tool failure caused by too small starting current, such as Figure 1 as well as Figure 2 As shown, the present invention proposes a battery pack sleep wake-up method. In the on state, the starting current output by the battery pack will pass through the wake-up circuit for load simulation before being output to the main control chip. The specific steps include:

[0028] S1: When the power switch switches from the off state to the on state, the wake-up circuit enters the first state and cuts off the startup current;

[0029] S2: Using the energy storage characteristics of the energy storage capacitor in the wake-up circuit, the load time is determined when the energy storage capacitor switches between charging and discharging states. If the energy storage capacitor remains in the charging state, it is determined that the load time does not meet the standard and the process returns to step S2. If the energy storage capacitor stops charging, it is determined that the load time meets the standard and the process enters step S3.

[0030] S3: The energy storage capacitor is used to store energy, and the charging state of the front and rear energy storage capacitors is changed, thereby controlling the wake-up circuit to switch from the first state to the second state.

[0031] S4: In the second state, the startup current is no longer cut off by the wake-up circuit and flows into the main control chip;

[0032] S5: When the power switch is switched from the on state to the off state, the energy storage capacitor in the wake-up circuit is discharged with a preset delay by utilizing the discharge characteristics of the energy storage capacitor.

[0033] Typically, the starting current of a battery pack changes from low to high after startup. This process can prevent a power tool from starting properly before the starting current reaches the rated operating current. Therefore, the present invention simulates the load during the rising phase of the supply current by increasing the load. This method cuts off the supply current from flowing to the main control chip if the starting current falls below the specified level, and restores power to the main control chip when the starting current exceeds the rated current.

[0034] For this reason, Figure 3 As shown, the present invention also designs a circuit for a battery pack sleep wake-up method based on the idea, including:

[0035] The state switching transistor Q80 has its emitter connected to the wake-up current VB+, its collector is grounded through the current limiting resistor R80, its base is grounded through the first delay resistor R82, the energy storage capacitor C80 and the second delay resistor R83 in sequence, and its emitter and base are connected through the input resistor R81.

[0036] Among them, the resistance value of the current limiting resistor R80 is set according to the starting current requirement of the power tool.

[0037] This wake-up circuit primarily utilizes the electrical characteristics of the state-switching transistor Q80 and the energy storage capacitor C80. When the power switch of the power tool switches from the off state to the on state, the voltage on the base of the state-switching transistor Q80 begins to rise, so the state-switching transistor Q80 remains on, and the supply current is connected to ground through the current-limiting resistor R80.

[0038] Furthermore, during the charging process of the energy storage capacitor C80, the energy storage capacitor C80 is equivalent to a load. When the state switching transistor Q80 is in the on state, the energy storage capacitor C80 acts as the load end under low supply current, but due to the energy storage characteristics of the energy storage capacitor C80, this part of the electrical energy is not actually consumed. Among them, the energy storage time is determined by the energy storage capacitor C80, the first delay resistor R82 and the second delay resistor R83, that is, T = RC, and considering the actual supply current requirements, this time is generally in the millisecond level.

[0039] When the energy storage capacitor C80 has finished storing energy, the base voltage of the state switching transistor Q80 changes, and its conduction state also changes accordingly, entering the off state. Therefore, at this time, the energy storage capacitor C80 is in a short circuit state because it has stopped charging, and the state switching transistor Q80 is in the off state. Then, the supply current with a current value that has reached the standard will flow directly to the main control chip, thereby achieving a truly zero-power start of the power tool.

[0040] When the power switch is switched from the on state to the off state, the energy storage capacitor C80 plays the role of delayed discharge to avoid damage to the power tool and internal circuits due to large potential changes after the power switch is disconnected. Similarly, the delayed discharge time is also determined by the first delay resistor R82 and the second delay resistor R83.

[0041] The battery pack sleep and wake-up method and circuit described in the present invention fully utilize the conduction characteristics of the capacitor in different charge and discharge states before and after energy storage is completed, thereby realizing the control of the on and off of the transistor, cutting off the small current and quickly directing the power supply current that meets the requirements to the main control chip, thereby avoiding the startup failure problem caused by too small current in the initial startup of the power-saving power tool.

[0042] By utilizing the energy storage characteristics of capacitors, load simulation can be achieved when power is turned on, and discharge can be delayed when the circuit is powered off, thus avoiding damage to the power tool itself caused by sudden power outages and achieving true zero-power startup.

[0043] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0044] In addition, in the present invention, descriptions such as "first," "second," and "one" are for descriptive purposes only and should not be understood to indicate or imply their relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0045] In the present invention, unless otherwise specified or limited, the terms "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can mean fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will be able to understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0046] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A battery pack sleep wake-up circuit, characterized in that: When the power switch of the power tool switches from the off state to the on state, the startup current output by the battery pack will first pass through the wake-up circuit to simulate the load before flowing into the main control chip; The wake-up circuit includes a state switching transistor and an energy storage capacitor, wherein the emitter of the state switching transistor is connected to the wake-up current, that is, the start-up current, the collector is grounded through a current-limiting resistor, the base is grounded through a first delay resistor, an energy storage capacitor, and a second delay resistor in sequence, and the emitter and base are connected through an input resistor; The state switching transistor switches the wake-up circuit between the first state and the second state by switching between the on state and the off state; When the power switch is switched from the off state to the on state, the starting current output by the battery pack after startup changes from low to high. The power tool cannot start normally before the starting current reaches the rated working current. At this time, the state switching transistor is in the on state, and the wake-up circuit enters the first state. The starting current is grounded through the state switching transistor and the current limiting resistor, thereby cutting off the starting current flowing into the main control chip. At the same time, the energy storage capacitor starts to charge and acts as the load end of the starting current. The energy storage characteristics of the energy storage capacitor are used to realize the load simulation. The energy storage time is determined by the energy storage capacitor, the first delay resistor and the second delay resistor. When the energy storage capacitor reaches the maximum energy storage capacity, the charging state ends, that is, the energy storage is completed, the state switching transistor enters the off state from the on state, and the wake-up circuit enters the second state. The starting current that is already greater than the rated working current directly flows into the main control chip, thereby starting the power tool.

2. The wake-up circuit according to claim 1, wherein: The current limiting resistor is used to set the resistance value according to the starting current requirement of the power tool.

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