Power supply control circuit and electric appliance

Abstract

This invention relates to the field of power electronics technology and discloses a power supply control circuit and electrical equipment. The circuit includes: a first switching circuit, a voltage divider circuit, a second switching circuit, and a comparator circuit. The voltage input terminal of the voltage divider circuit is connected to a rechargeable power supply. The first terminal of the first switching circuit is connected to the rechargeable power supply, the second terminal is connected to the power supply interface of the object being supplied, and the control terminal is connected to the voltage output terminal of the voltage divider circuit. The first terminal of the second switching circuit is connected to the rechargeable power supply, the second terminal is connected to the voltage output terminal of the voltage divider circuit, the first control terminal receives the standby control signal of the object being supplied, and the second control terminal is connected to the output terminal of the comparator circuit. The first input terminal of the comparator circuit is connected to the rechargeable power supply, and the second input terminal is connected to the power supply interface of the object being supplied. Power supply control between the rechargeable power supply and the object being supplied is achieved through a hardware circuit signal self-drive method, eliminating the need for external control signals and controllers, thus reducing production costs.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, specifically to power supply control circuits and electrical equipment. Background Technology

[0002] Currently, portable electronic devices are becoming increasingly common, such as portable electric fans. Due to the overall size limitations of these portable electronic devices, the size and capacity of their built-in batteries are generally not very large. In this case, it is necessary to consider not only the operating time that the battery can maintain when the device is working normally, but also the battery life in standby mode. This is to avoid the need for frequent charging when the user is not using the device, as well as the problem of the battery being damaged due to over-discharge when the user is not charging the device.

[0003] To extend battery standby time, two common techniques are employed: increasing battery capacity to extend battery life, and adding a switch to cut off battery power when the device is not in use, reducing battery output and minimizing power loss. Both of these approaches increase battery capacity but also increase size, hindering overall device assembly and failing to meet the design requirements for portability and miniaturization. While adding a switch can cut off battery power when the device is not in use and extend standby time, ensuring the battery charges normally while disconnecting power presents a new technical challenge.

[0004] In related technologies, the battery's power-off operation and normal charging are controlled by adding external control signals through software processing using the main control chip. This requires modifications to the product's existing controller circuitry, increasing production costs. Summary of the Invention

[0005] In view of this, the present invention provides a power supply control circuit and electrical equipment to solve the problem that the switching control between power outage resumption and normal charging of electrical equipment in related technologies requires external control signals from the main control chip, resulting in high production costs.

[0006] In a first aspect, the present invention provides a power supply control circuit, comprising: a first switching circuit, a voltage divider circuit, a second switching circuit, and a comparator circuit;

[0007] The voltage input terminal of the voltage divider circuit is connected to a rechargeable power supply.

[0008] The first terminal of the first switching circuit is connected to the rechargeable power supply, the second terminal is connected to the power supply interface of the power supply object, and the control terminal is connected to the voltage output terminal of the voltage divider circuit. When the first terminal and the second terminal of the first switching circuit are turned on, there is a conduction voltage drop.

[0009] The first terminal of the second switching circuit is connected to the rechargeable power supply, the second terminal is connected to the voltage output terminal of the voltage divider circuit, the first control terminal receives the standby control signal of the power supply object, and the second control terminal is connected to the output terminal of the comparator circuit.

[0010] The first input terminal of the comparator circuit is connected to the rechargeable power supply, and the second input terminal is connected to the power supply interface of the power supply object. When the power supply interface of the power supply object is connected to an external charging voltage, the comparator circuit outputs a drive signal. The charging voltage of the rechargeable power supply is greater than the supply voltage of the rechargeable power supply.

[0011] The second switching circuit is turned on when it receives the standby control signal and the comparison circuit does not output a drive signal, and turned off when it does not receive the standby control signal or the comparison circuit outputs a drive signal.

[0012] This invention achieves power supply and charging of the internal rechargeable power supply by setting a first switching circuit to power the internal rechargeable power supply when the power supply object is working normally. The standby control signal triggered when the power supply object is in standby mode controls the second switching circuit to conduct, thereby controlling the first switching circuit to turn off. This enables the rechargeable power supply to automatically power off in standby mode, extending its battery life and avoiding power waste. Simultaneously, when external power is connected to the power supply object, the drive comparator circuit outputs a drive signal to control the second switching circuit to turn off, thereby controlling the first switching circuit to return to the conducting state. This enables the external power supply to charge the rechargeable power supply in standby mode. After the external power supply is removed, the on-state voltage drop of the first switching circuit drives the comparator circuit to stop outputting the drive signal, thus restoring the rechargeable power supply to its automatic power-off state in standby mode. The power supply control circuit provided in this embodiment achieves power supply control between the rechargeable power supply and the power supply object through a hardware circuit signal self-drive method. It eliminates the need for additional external control signals and controllers, and does not require modification of existing controller circuits. Simply setting this power supply control circuit between the rechargeable power supply and the power supply object significantly reduces production costs.

[0013] In one optional embodiment, the first switching circuit includes: a controlled switch, which is a P-type field-effect transistor, wherein the source of the P-type field-effect transistor is connected to the rechargeable power supply, the drain is connected to the power supply interface of the power supply object, and the gate is connected to the voltage output terminal of the voltage divider circuit.

[0014] By utilizing the principle that the P-type field-effect transistor generates a voltage drop due to its own impedance when it is turned on, the comparator circuit is driven to work, realizing the automatic switching function between charging the rechargeable power supply in standby mode and continuing to use the power supply after power failure. Only one switching device, the P-type field-effect transistor, is needed, making the circuit structure simpler and further reducing production costs.

[0015] In one optional implementation, the second switching circuit includes: a first controlled switch and a second controlled switch;

[0016] The first terminal of the first controlled switch is connected to the rechargeable power supply, and the second terminal is connected to the first terminal of the second controlled switch. The control terminal receives the standby control signal of the power supply object. When the first controlled switch receives the standby control signal of the power supply object, it controls the first terminal and the second terminal of the first controlled switch to be connected.

[0017] The second terminal of the second controlled switch is connected to the voltage output terminal of the voltage divider circuit, and the control terminal is connected to the output terminal of the comparator circuit. The second controlled switch is turned off when it receives the drive signal output by the comparator circuit.

[0018] By using two controlled switches to jointly control the circuit's on / off state, one controlled switch is turned on when the power supply is in standby mode, and the other controlled switch is turned on when the power supply is supplied by an external power source. Thus, automatic switching control between standby power supply and automatic charging of the rechargeable power supply is achieved using only two controlled switches. The circuit structure is simple, further reducing production costs.

[0019] In one optional implementation, the first controlled switch is a mechanical switch, which is disposed on the power supply object and is triggered to turn on when the power supply object performs a standby action.

[0020] By utilizing the robust, durable, and low-cost characteristics of mechanical switches, the mechanical switches are automatically triggered to conduct when the powered object is in standby mode. In addition, the mechanical switches can be manually operated according to the actual needs of the product, so that the power supply can be manually cut off when the automatic standby control fails or according to the actual power supply endurance requirements, thus improving the flexibility of power supply cut-off control.

[0021] In one alternative implementation, the mechanical switch is a micro switch.

[0022] Due to their compact structure, ease of installation, reliable operation, and long service life, microswitches are advantageous for miniaturizing products and ensuring product stability when used as standby trigger switches.

[0023] In one alternative implementation, the second controlled switch is a PNP transistor.

[0024] By utilizing the characteristics of PNP transistors—small size, light weight, low power consumption, and low price—production costs can be reduced and circuit power consumption decreased.

[0025] In one optional embodiment, the second switching circuit further includes a first resistor, one end of which is connected to the control terminal of the second controlled switch, and the other end is grounded.

[0026] By setting a first resistor to filter the circuit, the second controlled switch is prevented from malfunctioning due to noise signals, thus ensuring the stability of the circuit control.

[0027] In one optional embodiment, the comparison circuit includes: a comparator, wherein the inverting input terminal of the comparator is connected to the rechargeable power supply, the non-inverting input terminal is connected to the power supply interface of the power supply object, and the output terminal is connected to the second control terminal of the second switching circuit.

[0028] Signal comparison can be achieved by setting up a comparator, which is low-cost, highly reliable, and beneficial for product cost control.

[0029] In one optional embodiment, the power supply control circuit further includes: a first terminal and a second terminal.

[0030] The power supply control circuit is connected to the rechargeable power source through the first terminal block;

[0031] The power supply control circuit is connected to the power supply interface of the object being powered through the second terminal.

[0032] The installation of wiring terminals facilitates the connection of the power supply control circuit with the rechargeable power source and the object being powered, thus simplifying installation and maintenance.

[0033] In one alternative implementation, the rechargeable power source is a battery.

[0034] Powering the target object with batteries reduces power supply costs.

[0035] In a second aspect, the present invention also provides an electrical device, comprising: a rechargeable power supply, a power supply object, and a power supply control circuit as provided in the first aspect and any alternative embodiment thereof.

[0036] The electrical equipment provided in this invention realizes power supply control between the rechargeable power supply and the electrical equipment through a hardware circuit signal self-drive method. It does not require the addition of external control signals and controllers, nor does it require modification of the existing controller circuit. It only needs to set the power supply control circuit between the rechargeable power supply and the electrical equipment, which greatly reduces production costs.

[0037] In one optional implementation, the electrical device is an electric fan, and the power supply is the electric fan motherboard.

[0038] By utilizing a power supply control circuit, the power supply between the fan power supply and the fan motherboard is controlled, which extends the power supply life of the fan and enables automatic switching between power outage recovery and charging, reducing the production cost of the fan and improving the user experience.

[0039] In one optional embodiment, the electric fan is a foldable electric fan. When the first controlled switch in the second switching circuit is a micro switch, the micro switch is located at the folding part of the foldable electric fan, and the micro switch is triggered to conduct when the folding part is folded.

[0040] By utilizing the fact that the electric fan is in a non-working state when folded, it can adapt to the unfolding and folding states of the entire machine's folding structure, automatically triggering the micro switch to close and open without any additional operation, thus further enhancing the user experience. Attached Figure Description

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is a schematic diagram of the conventional control circuit structure between the battery and the motherboard in the existing technology;

[0043] Figure 2 This is a schematic diagram of the power supply control circuit according to an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the structure of an electrical device according to an embodiment of the present invention. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0046] Currently, portable electronic devices are becoming increasingly common, such as portable electric fans. Due to the overall size limitations of these portable electronic devices, the size and capacity of their built-in batteries are generally not very large. In this case, it is necessary to consider not only the operating time that the battery can maintain when the device is working normally, but also the battery life in standby mode. This is to avoid the need for frequent charging when the user is not using the device, as well as the problem of the battery being damaged due to over-discharge when the user is not charging the device.

[0047] To extend battery standby time, two methods are typically used in related technologies:

[0048] First, increase battery capacity to extend battery life;

[0049] Secondly, a switch is added to cut off battery power when the equipment is not in use, reducing battery output and thus reducing losses.

[0050] Both of these solutions increase battery capacity but also increase size, which is detrimental to overall device assembly and fails to meet the design requirements for portability and miniaturization. While adding a switch can cut off battery power when the device is not in use, extending battery standby time, ensuring normal battery charging while cutting off power presents a new technical challenge.

[0051] For example, such as Figure 1 As shown, a control switch KEY1 is installed between the battery terminal CN3 and the motherboard terminal CN4. After the motherboard goes into standby mode, the power supply from the battery to the motherboard is cut off. When the control switch KEY1 is turned off, although the battery life can be extended and the battery wear can be reduced, the battery cannot be charged at this time.

[0052] To address the above problems, embodiments of the present invention provide a power supply control circuit, such as... Figure 2 As shown, the power supply control circuit includes: a first switching circuit 101, a voltage divider circuit 102, a second switching circuit 103, and a comparator circuit 104;

[0053] The voltage input terminal of the voltage divider circuit 102 is connected to a rechargeable power supply;

[0054] The first terminal of the first switching circuit 101 is connected to the rechargeable power supply, the second terminal is connected to the power supply interface of the power supply object, and the control terminal is connected to the voltage output terminal of the voltage divider circuit 102. When the first terminal and the second terminal of the first switching circuit 101 are turned on, there is a conduction voltage drop.

[0055] The first terminal of the second switching circuit 103 is connected to the rechargeable power supply, the second terminal is connected to the voltage output terminal of the voltage divider circuit 102, the first control terminal receives the standby control signal of the power supply object, and the second control terminal is connected to the output terminal of the comparator circuit 104.

[0056] The first input terminal of the comparator circuit 104 is connected to the rechargeable power supply, and the second input terminal is connected to the power supply interface of the object being powered. When the power supply interface of the object being powered is connected to an external charging voltage, the comparator circuit 104 outputs a drive signal, and the charging voltage of the rechargeable power supply is greater than the supply voltage of the rechargeable power supply.

[0057] The second switching circuit 103 is turned on when it receives a standby control signal and the comparator circuit 104 does not output a drive signal, and is turned off when it does not receive a standby control signal or the comparator circuit 104 outputs a drive signal.

[0058] For example, the rechargeable power source is a battery. Powering the target object with a battery results in lower power supply costs. The target object is the motherboard of an electrical appliance; for example, if the electrical appliance is an electric fan, the target object is the electric fan motherboard.

[0059] This invention achieves power supply and charging of the internal rechargeable power supply by setting a first switching circuit to power the internal rechargeable power supply when the power supply object is working normally. The standby control signal triggered when the power supply object is in standby mode controls the second switching circuit to conduct, thereby controlling the first switching circuit to turn off. This enables the rechargeable power supply to automatically power off in standby mode, extending its battery life and avoiding power waste. Simultaneously, when external power is connected to the power supply object, the drive comparator circuit outputs a drive signal to control the second switching circuit to turn off, thereby controlling the first switching circuit to return to the conducting state. This enables the external power supply to charge the rechargeable power supply in standby mode. After the external power supply is removed, the on-state voltage drop of the first switching circuit drives the comparator circuit to stop outputting the drive signal, thus restoring the rechargeable power supply to its automatic power-off state in standby mode. The power supply control circuit provided in this embodiment achieves power supply control between the rechargeable power supply and the power supply object through a hardware circuit signal self-drive method. It eliminates the need for additional external control signals and controllers, and does not require modification of existing controller circuits. Simply setting this power supply control circuit between the rechargeable power supply and the power supply object significantly reduces production costs.

[0060] In some alternative implementations, the first switching circuit includes: a controlled switch, such as... Figure 2 As shown, the controlled switch is a P-type field-effect transistor U1. The source of the P-type field-effect transistor U1 is connected to the rechargeable power supply, the drain is connected to the power supply interface of the object being powered, and the gate is connected to the voltage output terminal of the voltage divider circuit 102.

[0061] By utilizing the voltage drop generated by the impedance of a P-type field-effect transistor (FET) when it is turned on, a comparator circuit is driven to achieve automatic switching between charging the rechargeable power supply in standby mode and resuming operation after power failure. This simplifies the circuit structure by using only a single switching device, the P-type FET, further reducing production costs. Furthermore, since the power supply control circuit is mainly used in the power supply path and typically involves large currents, the FET provides better control and a simpler circuit structure.

[0062] It should be noted that in practical applications, the above-mentioned controlled switch can also be composed of switches with conduction voltage drop, such as IGBT devices, and their peripheral circuits. The specific controllable switch model selection and peripheral circuit design can be flexibly set according to actual needs, as long as the power supply control of the rechargeable power supply and the powered object can be realized. This invention is not limited to this.

[0063] In some alternative implementations, such as Figure 2 As shown, the voltage divider circuit 102 is composed of a second resistor R1 and a third resistor R3. One end of the second resistor R1 is connected to the rechargeable power supply, and the other end is connected to one end of the third resistor R3 and the control terminal of the first switching circuit 101. The other end of the third resistor R3 is grounded.

[0064] It should be noted that in practical applications, other circuit structures can be selected for the voltage divider circuit, as long as they can achieve the function of voltage divider output. This invention is not limited to these.

[0065] In some alternative implementations, the second switching circuit 103 includes: a first controlled switch and a second controlled switch;

[0066] The first terminal of the first controlled switch is connected to the rechargeable power supply, and the second terminal is connected to the first terminal of the second controlled switch. The control terminal receives the standby control signal of the power supply object. When the first controlled switch receives the standby control signal of the power supply object, it controls the first terminal and the second terminal of the first controlled switch to be connected.

[0067] The second terminal of the second controlled switch is connected to the voltage output terminal of the voltage divider circuit 102, and the control terminal is connected to the output terminal of the comparator circuit 104. The second controlled switch is turned off when it receives the drive signal output by the comparator circuit.

[0068] By using two controlled switches to jointly control the circuit's on / off state, one controlled switch is turned on when the power supply is in standby mode, and the other controlled switch is turned on when the power supply is supplied by an external power source. Thus, automatic switching control between standby power supply and automatic charging of the rechargeable power supply is achieved using only two controlled switches. The circuit structure is simple, further reducing production costs.

[0069] In some alternative implementations, the first controlled switch is a mechanical switch, which is disposed on the power supply object and is triggered to conduct when the power supply object performs a standby action.

[0070] By utilizing the robust, durable, and low-cost characteristics of mechanical switches, the mechanical switches are automatically triggered to conduct when the powered object is in standby mode. In addition, the mechanical switches can be manually operated according to the actual needs of the product, so that the power supply can be manually cut off when the automatic standby control fails or according to the actual power supply endurance requirements, thus improving the flexibility of power supply cut-off control.

[0071] For example, such as Figure 2 As shown, the mechanical switch is a micro switch K1.

[0072] Because of its compact structure, ease of installation, reliable operation, and long service life, the micro switch K1 is suitable for use as a standby trigger switch, which facilitates product miniaturization and ensures product stability.

[0073] It should be noted that the selection of micro switch K1 as a mechanical switch is only for illustrative purposes. Depending on the different usage scenarios, appropriate switch types can be selected. For example, when using micro switch K1, it can adapt to the unfolded and folded state of the whole machine's folding structure, automatically triggering the micro switch to close and open without any additional operation. If the whole machine does not have a folding structure, a toggle switch can also be used to achieve conduction and disconnection through manual operation. Since the user does not need to remember the switch state when using micro switch K1 (or a switch of the same type), and it only switches automatically according to the state of the whole machine, the actual user experience is better.

[0074] Furthermore, in practical applications, the aforementioned first controlled switch can also be an electronic switch, such as a transistor or a MOSFET. Taking a transistor as an example, by connecting the base of the transistor to the power supply controller, the controller sends a high-level signal to the base of the transistor to control the transistor to conduct when it detects that the power supply is in standby mode. This achieves automatic standby control of turning on the second switch circuit and turning off the first switch circuit to disconnect the power supply connection between the battery and the motherboard. This invention is not limited to this.

[0075] In some alternative implementations, such as Figure 2 As shown, the second controlled switch is a PNP transistor Q1.

[0076] By utilizing the characteristics of PNP transistors—small size, light weight, low power consumption, and low price—production costs can be reduced and circuit power consumption decreased.

[0077] It should be noted that in practical applications, the second controlled switch can also be a P-type field-effect transistor, IGBT, or other switching devices. The circuit connection method and working principle are the same, but in practical applications, cost and the suitability of the MOSFET drive voltage need to be considered. Specific settings can be flexibly configured according to the actual application scenario and circuit performance requirements; this invention is not limited thereto.

[0078] In some alternative implementations, such as Figure 2 As shown, the second switch circuit 103 further includes a first resistor R2, one end of which is connected to the control terminal of the second controlled switch, and the other end is grounded.

[0079] By setting the first resistor R2 to filter the circuit, the second controlled switch is prevented from malfunctioning due to noise signals, thus ensuring the stability of the circuit control.

[0080] In some alternative implementations, such as Figure 2 As shown, the comparator circuit 104 includes: a comparator U2-A, the inverting input terminal of the comparator U2-A is connected to a rechargeable power supply, the non-inverting input terminal is connected to the power supply interface of the power supply object, and the output terminal is connected to the second control terminal of the second switching circuit 103.

[0081] The signal comparison function is achieved by setting up comparator U2-A, which is low-cost, highly reliable, and beneficial to product cost control.

[0082] It should be noted that the above-mentioned comparison circuit 104 can also be implemented using a digital processing chip with voltage comparison function, such as an MCU, and the present invention is not limited thereto.

[0083] In some alternative implementations, such as Figure 2 As shown, the power supply control circuit also includes: a first terminal CN1 and a second terminal CN2.

[0084] The power supply control circuit is connected to the rechargeable power source via the first terminal CN1;

[0085] The power supply control circuit is connected to the power supply interface of the object being powered through the second terminal CN2.

[0086] The installation of wiring terminals facilitates the connection of the power supply control circuit with the rechargeable power source and the object being powered, thus simplifying installation and maintenance.

[0087] The working principle and process of the power supply control circuit provided in the embodiments of the present invention will be explained in detail below with reference to specific application examples.

[0088] For example Figure 2Taking the power supply control circuit shown as an example, CN1 is connected to a rechargeable power source, which is a battery, and CN2 is connected to the power supply object, which is the mainboard of the electric fan. In the original technical solution, the battery is directly connected to the mainboard, and the battery cannot be disconnected. The battery continues to degrade, and the battery life is shortened. If a switch is added between the two, the battery charging function cannot be realized after the switch is opened. In this embodiment of the invention, a micro switch K1 is added. When the user is not using the device (e.g., when it is stored or in standby mode), the micro switch K1 is touched by changing the state of the whole device (e.g., when it is stored or folded), causing the state of the micro switch K1 to change. In this solution, a normally open switch is used. When the whole device is stored, K1 is closed and conducting.

[0089] The battery and the motherboard are connected by a field-effect transistor U1. R1 and R3 are the driving resistors of U1. This embodiment of the invention takes a single battery as an example (battery voltage 3-4.2V). The motherboard outputs 5V to charge the battery.

[0090] VIN represents the input signal to the motherboard, i.e., the external power supply signal, and VB represents the battery voltage. When there is no VIN input, the circuit is powered by the battery. The field-effect transistor U1 is connected to the motherboard via a voltage divider through resistors R1 and R3, satisfying the transistor's conduction condition. U1 conducts, and the battery voltage powers the motherboard through U1. When the device is in its stored state, microswitch K1 is triggered and closed. The emitter of PNP transistor Q1 is connected to the battery. Since the base of Q1 is connected to GND through resistor R2, the low-level conduction condition of the PNP transistor is met, and Q1 conducts. At this time, the VEC voltage of the transistor is 0. K1 and Q1 are connected in series, and then in parallel with resistor R1. After K1 and Q1 conduct in series, the voltage drop across this branch is 0. The voltage drop across the parallel resistor R1 is also 0, and the potentials at the gate (G) and source (S) of the field-effect transistor are equal, failing to meet the transistor's conduction condition. U1 is then turned off, and the battery is disconnected from the motherboard. In this case, the battery is not connected to any load, resulting in no power consumption and extended standby time. It should be noted that after Q1 is turned on, Q1 itself is a switching device and its loss can be ignored. The power consumption of resistor R2 can be minimized by selecting an appropriate resistance value. Although there is a slight power consumption here, it can be ignored compared with the load power consumption before U1 is turned off.

[0091] When the battery needs charging (i.e., after the external adapter is plugged in), the motherboard's VIN output voltage first connects to the battery through the body diode of the field-effect transistor. However, due to limitations in the body diode's parameters, the current is generally small, requiring U1 to be turned on simultaneously to provide a larger current for charging the battery. U2-A is a comparator (pins 4 and 8 are power supply pins). Pin 2 of the comparator is connected to the battery as a reference voltage, pin 3 is connected to VIN, and pin 1 is the comparator output. When the voltage at pin 3 is greater than the reference voltage (battery voltage), the comparator outputs a high level; otherwise, it outputs a low level. After VIN is input, although the voltage is pulled down by the battery voltage, the voltage drop caused by the impedance of the field-effect transistor itself results in VIN > VB, satisfying the comparator's condition. The comparator outputs a high level at pin 1. Since transistor Q1 is driven by a low level, the driving condition is not met at this time, and transistor Q1 is turned off. Resistors R1 and R3 return to their voltage divider state, satisfying the field-effect transistor's turn-on condition. Therefore, U1 conducts, and the motherboard connects to the battery through U1, allowing the battery to be charged.

[0092] When the adapter is unplugged, due to the forward voltage drop of U1, the voltage at point VIN is slightly lower than the voltage at point VB. At this time, the condition for the comparator to output a high level (VIN > VB) is not met, so the comparator has no output. The comparator output changes from high to low, at which point transistor Q1 meets the conduction condition. Because Q1 is conducting, the voltage drop across the parallel resistor R1 becomes 0, which does not meet the conduction condition of U1, thus U1 is disconnected. This fulfills the product's requirement of disconnecting the load during standby and allowing charging after plugging in the adapter.

[0093] The aforementioned power supply control circuit utilizes the on-resistance of a field-effect transistor (FET) to create a forward voltage drop at its drain and source terminals. This voltage difference before and after the on-resistance is used to drive a comparator, which outputs a drive signal to control the circuit's on / off state. Thus, without adding external control signals or a new main control MCU, a self-driven power supply control circuit with internal circuit signals is added between the battery and the motherboard. This reduces production costs and improves product performance without altering the existing controller circuitry.

[0094] According to embodiments of the present invention, an electrical device is provided, such as... Figure 3 As shown, the electrical device includes: a rechargeable power supply 201, a power supply object 202, and a power supply control circuit 203 provided in another embodiment of the present invention.

[0095] The electrical equipment provided in this invention realizes power supply control between the rechargeable power supply and the electrical equipment through a hardware circuit signal self-drive method. It does not require the addition of external control signals and controllers, nor does it require modification of the existing controller circuit. It only needs to set the power supply control circuit between the rechargeable power supply and the electrical equipment, which greatly reduces production costs.

[0096] Specifically, the electrical device is an electric fan, the power supply object 202 is the electric fan mainboard, and the rechargeable power supply 201 is a battery. For the specific structure and working principle of the power supply control circuit 203, please refer to the relevant description in the above-described power supply control circuit embodiment, which will not be repeated here.

[0097] By utilizing a power supply control circuit, the power supply between the fan power supply and the fan motherboard is controlled, which extends the power supply life of the fan and enables automatic switching between power outage recovery and charging, reducing the production cost of the fan and improving the user experience.

[0098] In some alternative implementations, the electric fan is a foldable electric fan. When the first controlled switch in the second switching circuit is a micro switch, the micro switch is located at the folding part of the foldable electric fan and is triggered to conduct when the folding part is folded.

[0099] By utilizing the fact that the electric fan is in a non-working state when folded, it can adapt to the unfolding and folding states of the entire machine's folding structure, automatically triggering the micro switch to close and open without any additional operation, thus further enhancing the user experience.

[0100] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A power supply control circuit, characterized by comprising: include: The circuit consists of a first switching circuit, a voltage divider circuit, a second switching circuit, and a comparator circuit. The voltage input terminal of the voltage divider circuit is connected to a rechargeable power supply. The first terminal of the first switching circuit is connected to the rechargeable power supply, the second terminal is connected to the power supply interface of the power supply object, and the control terminal is connected to the voltage output terminal of the voltage divider circuit. When the first terminal and the second terminal of the first switching circuit are turned on, there is a conduction voltage drop. The first terminal of the second switching circuit is connected to the rechargeable power supply, the second terminal is connected to the voltage output terminal of the voltage divider circuit, the first control terminal receives the standby control signal of the power supply object, and the second control terminal is connected to the output terminal of the comparator circuit. The first input terminal of the comparator circuit is connected to the rechargeable power supply, and the second input terminal is connected to the power supply interface of the power supply object. When the power supply interface of the power supply object is connected to an external charging voltage, the comparator circuit outputs a drive signal. The charging voltage of the rechargeable power supply is greater than the supply voltage of the rechargeable power supply. The second switching circuit is turned on when it receives the standby control signal and the comparison circuit does not output a drive signal, and turned off when it does not receive the standby control signal or the comparison circuit outputs a drive signal.

2. The power supply control circuit of claim 1, wherein, The first switching circuit includes: a controlled switch, which is a P-type field-effect transistor. The source of the P-type field-effect transistor is connected to the rechargeable power supply, the drain is connected to the power supply interface of the power supply object, and the gate is connected to the voltage output terminal of the voltage divider circuit.

3. The power supply control circuit of claim 1, wherein, The second switching circuit includes: a first controlled switch and a second controlled switch; The first terminal of the first controlled switch is connected to the rechargeable power supply, and the second terminal is connected to the first terminal of the second controlled switch. The control terminal receives the standby control signal of the power supply object. When the first controlled switch receives the standby control signal of the power supply object, it controls the first terminal and the second terminal of the first controlled switch to be connected. The second terminal of the second controlled switch is connected to the voltage output terminal of the voltage divider circuit, and the control terminal is connected to the output terminal of the comparator circuit. The second controlled switch is turned off when it receives the drive signal output by the comparator circuit.

4. The power supply control circuit of claim 3, wherein, The first controlled switch is a mechanical switch, which is disposed on the power supply object and is triggered to turn on when the power supply object performs a standby action.

5. The power supply control circuit of claim 4, wherein, The mechanical switch is a micro switch.

6. The power supply control circuit according to claim 3, characterized in that, The second controlled switch is a PNP transistor.

7. The power supply control circuit according to claim 3, characterized in that, The second switching circuit further includes a first resistor, one end of which is connected to the control terminal of the second controlled switch, and the other end is grounded.

8. The power supply control circuit according to claim 1, characterized in that, The comparison circuit includes: a comparator, the inverting input terminal of which is connected to the rechargeable power supply, the non-inverting input terminal of which is connected to the power supply interface of the power supply object, and the output terminal of which is connected to the second control terminal of the second switching circuit.

9. The power supply control circuit according to any one of claims 1-8, characterized in that, Also includes: First terminal and second terminal The power supply control circuit is connected to the rechargeable power source through the first terminal block; The power supply control circuit is connected to the power supply interface of the object being powered through the second terminal.

10. The power supply control circuit according to any one of claims 1-8, characterized in that, The rechargeable power source is a battery.

11. An electrical appliance, characterized in that, include: A rechargeable power supply, a power supply object, and a power supply control circuit as described in any one of claims 1-10.

12. The electrical equipment according to claim 11, characterized in that, The electrical device is an electric fan, and the power supply is the electric fan motherboard.

13. The electrical equipment according to claim 12, characterized in that, The second switching circuit includes: a first controlled switch and a second controlled switch; a first terminal of the first controlled switch is connected to the rechargeable power supply, and a second terminal is connected to the first terminal of the second controlled switch; a control terminal receives a standby control signal from the power supply object; when the first controlled switch receives the standby control signal from the power supply object, it controls the first and second terminals of the first controlled switch to be turned on; a second terminal of the second controlled switch is connected to the voltage output terminal of the voltage divider circuit, and a control terminal is connected to the output terminal of the comparator circuit; the second controlled switch is turned off when it receives a drive signal output by the comparator circuit; the electric fan is a foldable electric fan; when the first controlled switch in the second switching circuit is a micro switch, the micro switch is located at the folding part of the foldable electric fan, and the micro switch is triggered to conduct when the folding part is folded.

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