Serial port screen one-key on-off circuit based on field effect transistor
By designing a one-button switch circuit for serial port screen based on field effect transistors and transistors, using simple components and touch switches to realize the power-on and shutdown functions, the complex and cost problems of the switch-on and shutdown circuit in the existing technology are solved, and the problem of the power-on and shutdown circuit in the existing technology is realized. The simplicity of the circuit, fast response speed and high reliability.
Patent Information
- Application Number
- CN202323499209.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-21
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2033-12-21
AI Technical Summary
The existing switch circuit has complex structure, requires software cooperation and is costly, making it difficult to achieve simple and pure hardware boot control.
Design a one-button switch circuit for serial port screen based on field effect tubes and transistors. Using simple components such as PMOS tubes, NPN transistors and resistors, the switching function is realized by controlling the conduction and turn-off of field effect tubes and transistors, and using light touch Switching and capacitor components to implement self-locking circuits.
It realizes the simplicity of the circuit, fast reaction speed, low cost, and improves the reliability and efficiency of the system, avoiding the problem of circuit failure caused by controller failure.
Smart Images
Figure CN222300297U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of on / off control of liquid crystal display screens, in particular to a one-button on / off circuit of a serial port screen based on a field effect tube. Background Art
[0002] The switch circuit is a mechanism used to control the on and off action of the voltage of the electronic system. When the switch is pressed, the power of the mainboard is turned on, and the circuit is in a continuously connected state; when the switch is pressed again, the mainboard is in a closed state, and no power is wasted or consumed. At present, the switch circuits on the market generally have complex circuit structures and require software coordination, and use dedicated PMU control, which has defects such as high cost. For example, the utility model patent with announcement number CN204009457U discloses a switch circuit based on PMU, including a switch circuit, a PMU and an MCU, the switch input pin of the PMU is connected to the output end of the switch circuit, the power pin of the PMU is connected to the power supply input end, the first power output end of the PMU is connected to the power input pin of the MCU, a GPIO pin of the PMU is connected to the first power output end through a first-class pull-up resistor, and the first power holding pin of the PMU is connected to the GPIO pin; the data communication interface of the PMU is connected to the data communication interface of the MCU. Utility Model Content
[0003] The utility model provides a serial port screen one-key on / off circuit based on a field effect tube with simple circuit and pure hardware startup.
[0004] The utility model solves the technical problem through the following technical solutions:
[0005] A one-button on / off circuit of a serial port screen based on a field effect tube, comprising an input power supply VCC-IN, a field effect tube Q1, a transistor Q2, a touch switch K1, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor R5;
[0006] Among them, the source of the field effect transistor Q1 is connected to the input power supply VCC-IN, the drain is connected to the output power supply VCC-OUT of the load, and the gate is connected to the collector of the transistor Q2; the two ends of the resistor R1 are respectively connected to the gate and the source of the field effect transistor Q1, the two ends of the resistor R5 are respectively connected to the gate of the PMOS tube Q1 and one end of the capacitor C1, and the two ends of the resistor R2 are respectively connected to the drain of the field effect transistor Q1 and one end of the resistor R4; the emitter of the transistor Q2 is grounded, the base of the transistor Q2 is connected to the resistor R4, and the collector of the transistor Q2 is connected to the gate of the field effect transistor Q1; one end of the touch switch K1 is connected to the capacitor C1, and the other end is connected to the resistor R3; the other end of the capacitor C1 is connected to GND; the other end of the resistor R3 is connected to GND.
[0007] Preferably, the transistor is an NPN transistor.
[0008] Preferably, the field effect transistor is a PMOS transistor.
[0009] The advantages and effects of the utility model are:
[0010] The utility model can realize the one-button power on and off function by using simple electronic components such as simple PMOS tubes, NPN transistors, resistors, etc., and has the advantages of simple circuit, pure hardware power on, fast response speed and low cost; in addition, the pure hardware circuit does not require a controller, and there will be no problem of the circuit not being able to work due to a controller failure. The reliability is high, and it is not limited by the controller, and the circuit is more efficient. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Figure 1 This is a circuit diagram of the utility model. DETAILED DESCRIPTION
[0012] The present invention is further described below in conjunction with embodiments, but the present invention is not limited to these embodiments.
[0013] like Figure 1 As shown, the utility model discloses a one-key on / off circuit of a serial port screen based on a field effect tube, including an input power supply VCC-IN, a field effect tube Q1, a transistor Q2, a touch switch K1, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor R5.
[0014] The source of the field effect transistor Q1 is connected to the input power supply VCC-IN, the drain is connected to the output power supply VCC-OUT of the load, and the gate is connected to the collector of the transistor Q2; the two ends of the resistor R1 are respectively connected to the gate and source of the PMOS transistor Q1, the two ends of the resistor R5 are respectively connected to the gate of the PMOS transistor Q1 and one end of the capacitor C1, and the two ends of the resistor R2 are respectively connected to the drain of the PMOS transistor Q1 and one end of the resistor R4; the emitter of the transistor Q2 is grounded, the base of the transistor Q2 is connected to the resistor R4, and the collector of the transistor Q2 is connected to the gate of the PMOS transistor Q1; one end of the touch switch K1 is connected to the capacitor C1, and the other end is connected to the resistor R3; one end of the capacitor C1 is connected to the second end of the touch switch K1, and the other end is connected to GND; one end of the resistor R3 is connected to the first end of the touch switch K1, and the other end is connected to GND.
[0015] Furthermore, the transistor is an NPN transistor, and the field effect transistor is a PMOS transistor.
[0016] In actual application, the switch is realized by controlling the conduction and cutoff of the field effect tube (Q1 PMOS). When the button K1 is pressed, the field effect tube (Q1 PMOS) is turned on, the 5V main power flows into the subsequent stage, and forms R2 and R3 bias to make the transistor Q2 continuously turned on, forming a self-locking. By controlling the conduction of the transistor Q2, the PMOS can be turned on all the time, and the power can be turned on.
[0017] Boot process:
[0018] In the initial state, VCC-IN charges capacitor C1 to +5V through resistors R1 and R5. Q1 and Q2 are both cut off, VCC cannot flow into the next stage, and the system is in the shutdown state. When switch K1 is closed, the voltage stored on capacitor C1 turns on transistor Q2 through resistor R4, and the conduction of transistor Q2 turns on field effect transistor Q1. The 5V main power flows into the next stage, and forms R2 and R3 bias to keep field effect transistor Q2 turned on, forming a self-locking state. Even if the button is released, the field effect transistor is still turned on, thereby realizing the power-on function.
[0019] Shutdown process:
[0020] When the switch K1 is pressed again, the 5V main power supply charges the capacitor C1 through the resistor R2 and the switch K1. The voltage at the left end of the switch K1 is instantly pulled down, causing the transistor Q2 and the field effect transistor Q1 to be turned off in turn. The VCC main power supply is cut off, and the power is turned off after the button is released.
[0021] The utility model discloses a one-key power on / off circuit of a serial port screen based on a field effect tube, which realizes the power on / off function through a switch K1, a capacitor C1, a field effect tube Q2, a transistor Q1, etc., thereby realizing the power on / off of the serial port screen, and the user can use the serial port screen conveniently and for a long time.
[0022] The above embodiments are only specific examples for further illustrating the purpose, technical scheme and beneficial effects of the utility model, and the utility model is not limited thereto. Any modification, equivalent replacement, improvement, etc. made within the scope of the disclosure of the utility model are included in the protection scope of the utility model.
Claims
1. A one-button power on / off circuit for a serial port screen based on a field effect tube, characterized in that: It includes an input power supply VCC-IN, a field effect transistor Q1, a transistor Q2, a touch switch K1, a resistor R1, a resistor R2, a resistor R3, a resistor R4 and a resistor R5; Among them, the source of the field effect transistor Q1 is connected to the input power supply VCC-IN, the drain is connected to the output power supply VCC-OUT of the load, and the gate is connected to the collector of the transistor Q2; the two ends of the resistor R1 are respectively connected to the gate and the source of the field effect transistor Q1, the two ends of the resistor R5 are respectively connected to the gate of the PMOS tube Q1 and one end of the capacitor C1, and the two ends of the resistor R2 are respectively connected to the drain of the field effect transistor Q1 and one end of the resistor R4; the emitter of the transistor Q2 is grounded, the base of the transistor Q2 is connected to the resistor R4, and the collector of the transistor Q2 is connected to the gate of the field effect transistor Q1; one end of the touch switch K1 is connected to the capacitor C1, and the other end is connected to the resistor R3; the other end of the capacitor C1 is connected to GND; the other end of the resistor R3 is connected to GND.
2. According to the field effect tube-based serial port screen one-key power on / off circuit of claim 1, it is characterized by: The transistor is an NPN transistor.
3. According to the field effect tube-based serial port screen one-key power on / off circuit of claim 2, it is characterized by: The field effect tube is a PMOS tube.