On-off circuit based on single self-reset switch

Abstract

The invention discloses a startup and shutdown circuit based on a single self-reset switch, which belongs to the field of startup and shutdown circuits and comprises a battery module, a self-reset switch, a P-MOS (P-Metal Oxide Semiconductor) power-on circuit, a switching power supply circuit and an MCU (Microprogrammed Control Unit), the battery module is electrically connected with the input end of the switching power supply circuit, the power supply output end of the switching power supply circuit is electrically connected with the input end of the MCU, the control output end of the MCU is electrically connected with the input end of the P-MOS power-on circuit, the monitoring output end of the MCU is connected with the input end of the self-reset switch, and the output end of the self-reset switch is connected with the P-MOS power-on circuit. And the control power supply output end of the P-MOS power-on circuit is electrically connected with the battery module. The system is flexible and simple to use, can monitor long-time non-operation, can realize intelligent shutdown, greatly prolongs the service time, can realize startup and shutdown only by using a self-reset switch, and can realize autonomous intelligent shutdown; the device has the characteristics of simplicity, space saving, cost saving and energy saving.

Description

Technical Field

[0001] The present invention relates to the field of power-on and power-off circuits, and specifically to a power-on and power-off circuit based on a single self-resetting switch. Background Art

[0002] At present, the development trend of handheld devices such as electronic thermometers and handheld blood pressure monitors is towards miniaturization and simplicity, and there are also various requirements for the buttons controlling power-on and power-off. Existing buttons are generally self-locking buttons. The main function of a self-locking button is to be able to maintain its state after being pressed until it is operated again to change its state. Specifically, after a self-locking button is pressed, even if the finger is released, the button still remains in the current state, usually closing or opening the circuit, until it is pressed again to return to the initial state.

[0003] Although traditional self-locking buttons can achieve the power-on and power-off functions, they have disadvantages such as poor feel and the inability to automatically power off due to no operation for a long time, resulting in power consumption of dry batteries or lithium batteries for power supply. Summary of the Invention

[0004] Regarding the above problems existing in the prior art, the purpose of the present invention is to provide a power-on and power-off circuit based on a single self-resetting switch to solve the problems proposed in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A power-on and power-off circuit based on a single self-resetting switch includes a battery module, a self-resetting switch, a P-MOS power-on circuit, a switching power supply circuit, and an MCU; the input ends of the battery module and the switching power supply circuit are electrically connected, the power supply output end of the switching power supply circuit and the input end of the MCU are electrically connected, the control output end of the MCU and the input end of the P-MOS power-on circuit are electrically connected, the monitoring output end of the MCU and the input end of the self-resetting switch are connected, the output end of the self-resetting switch and the P-MOS power-on circuit are connected, and the control power supply output end of the P-MOS power-on circuit and the battery module are electrically connected.

[0007] As a further solution of the present invention: the battery membrane is a dry battery or a lithium battery.

[0008] As a further solution of the present invention: the P-MOS power-on circuit includes a P-MOS transistor Q1; the source electrode of the P-MOS transistor Q1 is connected to the positive power supply terminal in the battery module; the source electrode of the P-MOS transistor Q1 is simultaneously connected to one end of a resistor R45, and the other end of the resistor R45 is connected to the gate of the P-MOS transistor Q1; the gate of the P-MOS transistor Q1 is simultaneously connected to one end of a capacitor C37 and one end of a resistor R46, and the other end of the capacitor C37 is grounded;

[0009] The other end of resistor R46 is connected to the collector of triode N2, and the emitter of triode N2 is grounded;

[0010] The gate of P-MOS transistor Q1 is connected to the positive electrode of diode D1, the negative electrode of diode D1 is connected to one end of resistor R56, and the other end of resistor R56 is connected to one end of switch K1 in the self-resetting switch; the other end of switch K1 is grounded.

[0011] As a further solution of the present invention: the model of the P-MOS transistor Q1 is Si3407DVT1-GE3.

[0012] As a further solution of the present invention: one end of switch K1 in the self-resetting switch is connected to one end of resistor R47, the other end of resistor R47 is connected to the negative electrode of diode D2, and the positive electrode of diode D2 is connected to the +3.3V power supply;

[0013] As a further solution of the present invention: a capacitor C36 is connected in parallel at both ends of switch K1 in the self-resetting switch.

[0014] As a further solution of the present invention: the switching power supply circuit includes chip U7, and pins 3 and 6 of chip U7 are simultaneously connected to the drain of P-MOS transistor Q1 in the P-MOS power-on circuit;

[0015] Pin 1 of chip U7 is connected to one end of inductor L2, and the other end of inductor L2 is connected to the drain of P-MOS transistor Q1 in the P-MOS power-on circuit;

[0016] Pin 3 of chip U7 is connected to one end of capacitor C24, and the other end of capacitor C24 is grounded;

[0017] Pin 5 of chip U7 is connected to one end of resistor R48, the other end of resistor R48 is connected to one end of resistor R49, the other end of resistor R49 is connected to pin 2 of chip U7, and the connection line between resistor R48 and resistor R49 is simultaneously connected to pin 4 of chip U7;

[0018] Pin 2 of chip U7 is grounded;

[0019] Pin 5 of chip U7 is connected to one end of capacitor C25, and the other end of capacitor C25 is grounded;

[0020] Pin 5 of chip U7 is connected to the +3.3V power supply.

[0021] As a further solution of the present invention: the chip U7 is a buck constant-current drive chip, and its model is AP2002.

[0022] As a further solution of the present invention: the MCU includes a chip IC1, and the pin 16 of the chip IC1 is connected to the base of the triode N2 in the P-MOS power-on circuit;

[0023] The pin 15 of the chip IC1 is connected to one end of the switch K1 in the self-resetting switch; the other end of the switch K1 is grounded;

[0024] The pin 8 of the chip IC1 is connected to one end of the capacitor C39, and the other end of the capacitor C39

[0025] The pin 7 of the chip IC1 is grounded;

[0026] The pin 9 of the chip IC1 is connected to the +3.3V power supply.

[0027] As a further solution of the present invention: the model of the chip IC1 is HC32Ll10C6PA.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The power-on and off circuit of the present invention using a single self-resetting switch is flexible and simple to use, and can monitor that it can be intelligently powered off after a long time without operation. The power consumption of dry batteries or lithium batteries is thus reduced, greatly extending the usage time. The purpose is to be applied to the power-on and off of handheld devices. Only one self-resetting switch is used to achieve power-on and off, which is flexible and simple to use, and can achieve autonomous intelligent power-off; it has the characteristics of simplicity, space and cost savings, and energy conservation. Description of the Drawings

[0030] Figure 1 It is a system block diagram of the power-on and off circuit based on a single self-resetting switch disclosed in the embodiment.

[0031] Figure 2 It is a schematic diagram of the P-MOS power-on circuit in the power-on and off circuit based on a single self-resetting switch disclosed in the embodiment.

[0032] Figure 3 It is a schematic diagram of the switching power supply circuit in the power-on and off circuit based on a single self-resetting switch disclosed in the embodiment.

[0033] Figure 4 It is a schematic diagram of the MCU in the power-on and off circuit based on a single self-resetting switch disclosed in the embodiment. Detailed Embodiments

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention; obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installed", "provided with", "connected", and "connected" should be understood in a broad sense; for example, it can be a fixed connection, a detachable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be directly connected, or it can be indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0036] Please refer to Figures 1-4 , a power-on and power-off circuit based on a single self-resetting switch, including a battery module, a self-resetting switch, a P-MOS power-on circuit, a switching power supply circuit, and an MCU;

[0037] The input end of the battery module is electrically connected to the input end of the switching power supply circuit, the power supply output end of the switching power supply circuit is electrically connected to the input end of the MCU, the control output end of the MCU is electrically connected to the input end of the P-MOS power-on circuit, the monitoring output end of the MCU is connected to the input end of the self-resetting switch, the output end of the self-resetting switch is connected to the P-MOS power-on circuit, and the control power supply output end of the P-MOS power-on circuit is electrically connected to the battery module.

[0038] The self-resetting switch performs the power-on or power-off action by single-clicking;

[0039] For the P-MOS power-on circuit, when the self-resetting switch is single-clicked, the gate of the P-MOS transistor is pulled low, and the P-MOS transistor is thus turned on. The switching power supply gets power and outputs a +5V voltage. The MCU gets power and works. When it detects that the self-resetting switch is pressed, the MCU will output a signal to control the gate signal of the P-MOS transistor to be low to control the P-MOS transistor to continue to conduct, completing the power-on action;

[0040] After the switching power supply circuit gets power, it works and outputs a +5V voltage to the MCU;

[0041] The MCU is used to monitor the self-resetting button signal. When it detects that the self-resetting button is clicked for the first time, it will output a signal to control the gate signal of the P-MOS transistor to be low to achieve the power-on action; when it detects that the self-resetting button is clicked again, it will output a signal to control the gate signal of the P-MOS transistor to be high to achieve the power-off action.

[0042] The battery membrane mentioned above is a dry battery or a lithium battery, which can conveniently supply power to the entire circuit, enhance safety, and facilitate the use of the device. The dry battery or lithium battery is used to supply power to the switching power supply circuit of the handheld device.

[0043] As Figure 2 shown, the P-MOS power-on circuit includes a P-MOS transistor Q1. The source of the P-MOS transistor Q1 is connected to the positive power supply terminal in the battery module. The source of the P-MOS transistor Q1 is also connected to one end of a resistor R45, and the other end of the resistor R45 is connected to the gate of the P-MOS transistor Q1. The gate of the P-MOS transistor Q1 is also connected to one end of a capacitor C37 and one end of a resistor R46. The other end of the capacitor C37 is grounded.

[0044] The other end of the resistor R46 is connected to the collector of a triode N2, and the emitter of the triode N2 is grounded.

[0045] The gate of the P-MOS transistor Q1 is connected to the positive pole of a diode D1, the negative pole of the diode D1 is connected to one end of a resistor R56, and the other end of the resistor R56 is connected to one end of a switch K1 in the self-resetting switch. The other end of the switch K1 is grounded.

[0046] One end of the switch K1 in the self-resetting switch is connected to one end of a resistor R47, the other end of the resistor R47 is connected to the negative pole of a diode D2, and the positive pole of the diode D2 is connected to the +3.3V power supply.

[0047] A capacitor C36 is connected in parallel across both ends of the switch K1 in the self-resetting switch.

[0048] The model of the P-MOS transistor Q1 is Si3407DVT1-GE3.

[0049] In the P-MOS power-on circuit mentioned above, when the self-resetting switch K1 is clicked for the first time, K1 is shorted to GND, and the gate of the P-MOS transistor Q1 is thus pulled low, causing Q1 to conduct. The voltage of the dry battery or lithium battery is then supplied to the switching power supply circuit, and the switching power supply outputs +3.3V to the MCU. The MCU is powered on and monitors that the Vin_check signal changes from low level to high level after the self-resetting switch is clicked. The MCU thus believes that the power-on operation is being performed at this time, and the MCU outputs a high-level signal Vin_control. The N2 triode then conducts, and the gate of the P-MOS transistor Q1 is continuously pulled low to a low level. Thus, Q1 remains in a continuous conduction state, completing the power-on operation.

[0050] When the self-resetting switch K1 is clicked again, K1 is shorted to GND again. The monitored Vin_check signal of the MCU changes from high level to low level after the self-resetting switch is clicked. Therefore, the MCU thinks that the shutdown operation is being performed at this time. As a result, the MCU outputs a low-level signal Vin_control. Consequently, the N2 triode is turned off, and the gate of the P-MOS transistor Q1 is pulled up to the power supply voltage to a high level by R45. Then, the P-MOS transistor is turned off, and the switching power supply also stops working accordingly, thus completing the shutdown operation;

[0051] As Figure 3 shown, after the switching power supply circuit is powered on, it will output +3.3V required for the MCU to work

[0052] The switching power supply circuit includes a chip U7. The pins 3 and 6 of the chip U7 are simultaneously connected to the drain of the P-MOS transistor Q1 in the P-MOS power-on circuit;

[0053] The pin 1 of the chip U7 is connected to one end of the inductor L2, and the other end of the inductor L2 is connected to the drain of the P-MOS transistor Q1 in the P-MOS power-on circuit;

[0054] The pin 3 of the chip U7 is connected to one end of the capacitor C24, and the other end of the capacitor C24 is grounded;

[0055] The pin 5 of the chip U7 is connected to one end of the resistor R48, the other end of the resistor R48 is connected to one end of the resistor R49, the other end of the resistor R49 is connected to the pin 2 of the chip U7, and the connection line between the resistor R48 and the resistor R49 is simultaneously connected to the pin 4 of the chip U7;

[0056] The pin 2 of the chip U7 is grounded;

[0057] The pin 5 of the chip U7 is connected to one end of the capacitor C25, and the other end of the capacitor C25 is grounded;

[0058] The pin 5 of the chip U7 is connected to the +3.3V power supply;

[0059] The chip U7 is a buck constant-current drive chip, and its model is AP2002. The input voltage range of the chip U7 is from 6V to 55V, suitable for a variety of power supply environments. The maximum output current of the chip U7 can reach 1.2A, meeting the requirements of the circuit.

[0060] As Figure 4 shown, the MCU includes a chip IC1. The pin 16 of the chip IC1 is connected to the base of the triode N2 in the P-MOS power-on circuit;

[0061] The pin 15 of the chip IC1 is connected to one end of the switch K1 in the self-resetting switch; the other end of the switch K1 is grounded;

[0062] Pin 8 of chip IC1 is connected to one end of capacitor C39, and the other end of capacitor C39

[0063] Pin 7 of chip IC1 is grounded;

[0064] Pin 9 of chip IC1 is connected to the +3.3V power supply;

[0065] The model of chip IC1 is HC32Ll10C6PA;

[0066] The described MCU is used to detect the Vin_check signal when the self-reset button is clicked and output the Vin_control signal to control the continuous conduction or cut-off of P-MOS transistor Q1. When it detects that the Vin_check signal changes from low level to high level, it is considered that the power-on operation is being performed at this time, so the Vin_control signal will be output as high level; when it detects that the Vin_check signal changes from high level to low level, it is considered that the power-off operation is being performed at this time, so the Vin_control signal will be output as low level.

[0067] The power-on and off circuit realizes the power-on and off functions through a single button, simplifies the circuit design, reduces the complexity of the circuit board, and makes the overall design more concise. Since the number of buttons is reduced, the production cost can be reduced, and the material cost and assembly cost can be reduced. Through the cooperation of software and hardware, more reliable power-on and off operations can be realized, and the failures caused by mechanical switch wear can be reduced. In the power-off state, the circuit does not form any loop and no current is generated, and the power-off power consumption is zero, which helps to save electric energy. Through software control, more complex power-on and off logics can be realized, such as short press to power on, long press to power off and other functions.

[0068] The power-on and off circuit of the present invention using a single self-reset switch is flexible and simple to use, and can monitor that it can be intelligently powered off when there is no operation for a long time. Therefore, the power consumption of dry batteries or lithium batteries is reduced, and the usage time is greatly extended. The purpose is to be applied to the power-on and off of handheld devices. Only a single self-reset switch is used to realize the power-on and off, which is flexible and simple to use, and can realize autonomous intelligent power-off.

[0069] The power-on and off circuit of a single self-reset switch is turned on when pressed and automatically resets and disconnects after being released, avoiding misoperations such as accidental power-off or restart caused by long-term pressing. It avoids the risk that the device cannot be powered off when the traditional self-locking switch gets stuck in the "on" state due to a fault, and is suitable for safety-critical scenarios such as emergency stop buttons. The self-reset switch only transmits instantaneous signals and does not directly connect or disconnect large currents, reducing the contact arc loss and having a longer lifespan. In battery-powered devices, the switch only wakes up the MCU to enter the working state, and the power module is controlled by the chip, optimizing the standby power consumption.

[0070] The power-on and power-off circuit of the present invention with a threshold based on a single self-resetting switch is characterized in that it does not require multiple buttons or self-locking buttons, and only relies on a single self-resetting switch to achieve the power-on or power-off operation of the device. The power-on and power-off circuit of the present invention uses only one self-resetting button to achieve power-on and power-off, and has the characteristics of simplicity, space and cost savings, and energy conservation.

[0071] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention, and any reference signs in the claims should not be regarded as limiting the claims involved.

[0072] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A power on / off circuit based on a single self-resetting switch, characterized in that: It comprises a battery module, a self-reset switch, a P-MOS power-on circuit, a switching power supply circuit and an MCU; the battery module is electrically connected to the input end of the switching power supply circuit, the power supply output end of the switching power supply circuit is electrically connected to the input end of the MCU, the control output end of the MCU is electrically connected to the input end of the P-MOS power-on circuit, the monitoring output end of the MCU is connected to the input end of the self-reset switch, the output end of the self-reset switch is connected to the P-MOS power-on circuit, and the control power supply output end of the P-MOS power-on circuit is electrically connected to the battery module.

2. The on / off circuit based on a single self-resetting switch according to claim 1, characterized in that: The battery membrane is a dry cell or a lithium cell.

3. The on / off circuit based on a single self-resetting switch according to claim 2, characterized in that: The P-MOS power-on circuit includes a P-MOS tube Q1; the source of the P-MOS tube Q1 is connected to the positive power supply terminal in the battery module; the source of the P-MOS tube Q1 is connected to one end of the resistor R45, and the other end of the resistor R45 is connected to the gate of the P-MOS tube Q1; the gate of the P-MOS tube Q1 is connected to one end of the capacitor C37 and one end of the resistor R46, and the other end of the capacitor C37 is grounded; The other end of the resistor R46 is connected to the collector of the transistor N2, and the emitter of the transistor N2 is grounded; The gate of the MOS tube Q1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to one end of the resistor R56, the other end of the resistor R56 is connected to one end of the switch K1 in the self-resetting switch; the other end of the switch K1 is grounded.

4. The on / off circuit based on a single self-resetting switch according to claim 3, characterized in that: The model of the P-MOS tube Q1 is Si3407DVT1-GE3.

5. The on / off circuit based on a single self-resetting switch according to claim 4, characterized in that: One end of the switch K1 in the self-resetting switch is connected to one end of the resistor R47, the other end of the resistor R47 is connected to the cathode of the diode D2, and the anode of the diode D2 is connected to the +3.3V power supply.

6. The on / off circuit based on a single self-resetting switch according to claim 5, characterized in that: A capacitor C36 is connected in parallel between the two ends of the switch K1 in the self-resetting switch.

7. The on / off circuit based on a single self-resetting switch according to claim 6, characterized in that: The switching power supply circuit includes a chip U7, and pins 3 and 6 of the chip U7 are simultaneously connected to the drain of the P-MOS tube Q1 in the P-MOS power-on circuit; Pin 1 of chip U7 is connected to one end of inductor L2, and the other end of inductor L2 is connected to the drain of P-MOS tube Q1 in the P-MOS power-on circuit; Pin 3 of chip U7 is connected to one end of capacitor C24, and the other end of capacitor C24 is grounded; Pin 5 of chip U7 is connected to one end of resistor R48, the other end of resistor R48 is connected to one end of resistor R49, the other end of resistor R49 is connected to pin 2 of chip U7, and the connection line between resistor R48 and resistor R49 is also connected to pin 4 of chip U7; Pin 2 of chip U7 is grounded; Pin 5 of chip U7 is connected to one end of capacitor C25, and the other end of capacitor C25 is grounded; Pin 5 of chip U7 is connected to the +3.3V power supply.

8. The on / off circuit based on a single self-resetting switch according to claim 7, characterized in that: The chip U7 is a step-down constant current driver chip, and its model is AP2002.

9. The on / off circuit based on a single self-resetting switch according to claim 8, characterized in that: The MCU comprises a chip IC1, and a pin 16 of the chip IC1 is connected to the base of a transistor N2 in a P-MOS power-on circuit; Pin 15 of chip IC1 is connected to one end of switch K1 in the self-reset switch; the other end of switch K1 is grounded; Pin 8 of chip IC1 is connected to one end of capacitor C39, and the other end of capacitor C39 is connected to one end of capacitor C39. Pin 7 of chip IC1 is grounded; Pin 9 of chip IC1 is connected to +3.3V power supply.

10. The on / off circuit based on a single self-resetting switch according to claim 9, characterized in that: The model of the chip IC1 is HC32L110C6PA.

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