A key switch circuit based on bistable circuit and printer

Abstract

The utility model discloses a kind of key switch machine circuit and printer based on bistable circuit, wherein, key switch machine circuit based on bistable circuit, including power supply conversion unit, self-locking circuit and button, bistable circuit;The enable end of power supply conversion unit is connected by self-locking circuit and button, bistable circuit;Power supply conversion unit is used to convert input power supply into working power supply, and its enable control end is used to control power output;Self-locking circuit is used to pull low the enable end of power supply conversion unit after button is pressed and maintain low level, realize the self-locking of power output;Bistable circuit is used to change output state when button is pressed again, cut off self-locking circuit, so that the enable end of power supply conversion unit restores high level, to close power output.The utility model discloses the key switch machine circuit based on bistable circuit of the utility model, using single self-resetting button can complete the opening and closing of power supply, and, circuit response is stable, operation logic is clear.

Description

Technical Field

[0001] This utility model relates to the field of printer switch circuit technology, and in particular to a button switch circuit and printer based on a bistable circuit. Background Technology

[0002] The printer system typically operates on a 3.3V power supply, which is converted from the input power supply via a power conversion unit. The power conversion unit has an / EN terminal and a +3.3V power output terminal. The / EN terminal is the enable control terminal for power on / off. When / EN is low, the +3.3V power supply is output. When / EN is floating or high, the +3.3V power supply stops outputting.

[0003] Currently, most control of the / EN terminal uses self-locking switches (such as toggle switches, rocker switches, etc.) to achieve self-locking switch control. However, self-locking switches (such as toggle switches, rocker switches, etc.) have the problem of large size. Due to limitations such as printer structure or requirements, it is necessary to use a small single button (self-reset) to control the +3.3V power supply. Existing control circuits are difficult to implement single button (self-reset) self-locking switch control of the +3.3V power supply. Utility Model Content

[0004] To solve the above-mentioned technical problems, this utility model provides a key-operated power switch circuit and printer based on a bistable circuit. The key-operated power switch circuit based on a bistable circuit includes a power conversion unit, a self-locking circuit, a key, and a bistable circuit. The enable terminal of the power conversion unit is connected to the button and bistable circuit through a self-locking circuit; The power conversion unit is used to convert the input power into the working power, and its enable control terminal is used to control the power output. The self-locking circuit is used to pull down the enable terminal of the power conversion unit and maintain it at a low level after the button is pressed, thereby achieving self-locking of the power output. The bistable circuit is used to change the output state when the button is pressed again, cut off the self-locking circuit, and restore the enable terminal of the power conversion unit to a high level to shut down the power output.

[0005] Preferably, the self-locking circuit includes MOSFET Q2, MOSFET Q3, resistor R8, resistor R13, resistor R12, capacitor C3, and resistor R9, wherein: The enable terminal of the power conversion unit is grounded through MOSFET Q2, capacitor C3, and resistor R9 respectively. The connection node between the enable terminal of the power conversion unit and MOSFET Q2 is connected to the button. MOSFET Q2 is connected to the power output terminal of the power conversion unit through resistor R8; the connection node between MOSFET Q2 and resistor R8 is grounded through MOSFET Q3 and resistor R12 respectively; MOSFET Q3 is connected to one end of resistor R13 and the bistable circuit; the other end of resistor R13 is grounded.

[0006] Preferably, the bistable circuit includes MOSFET Q1, transistor U2, transistor U3, diode D1, diode D2, resistors R1, R2, R3, R4, R5, R6, R7, R10, R11, capacitors C1, C2, and C4, wherein: The collector of transistor U2 is connected to the base of transistor U3 through resistor R10; the base of transistor U2 is connected to the collector of transistor U3 through resistor R11. The base capacitor C4 of transistor U2 is grounded, and the emitter of transistor U2 and the emitter of transistor U3 are both grounded; The collector of transistor U2 is connected to the power output terminal of the power conversion unit through resistor R2; the collector of transistor U3 is connected to the power output terminal of the power conversion unit through resistor R4. The collector of transistor U2 is connected to the resistor R2 in sequence through resistor R6 and capacitor C1, and then to the base of transistor U3; the collector of transistor U3 is connected to the resistor R4 in sequence through resistor R7 and capacitor C2, and then to the base of transistor U2. The connection point of resistor R6 and capacitor C1 is connected to the cathode of diode D1, and the connection point of resistor R7 and capacitor C2 is connected to the cathode of diode D2. The anodes of diodes D1 and D2 are both connected to the drain of MOSFET Q1 through resistor R1. The source of MOSFET Q1 is connected to the power output terminal of the power conversion unit. The gate of MOSFET Q1 is connected to the power output terminal of the power conversion unit through resistor R3, and is also connected to the button through resistor R5.

[0007] Preferably, the button is connected to the self-locking circuit and the bistable circuit via a bidirectional diode U1.

[0008] This utility model also provides a printer that uses a bistable circuit-based button power on / off circuit as described above.

[0009] The push-button power switch circuit based on a bistable circuit provided in this embodiment of the invention achieves the following technical effects through the synergistic effect of the power conversion unit, the self-locking circuit, the button, and the bistable circuit: The power can be turned on and off using a single self-reset button, overcoming the problems of large size and space occupation of traditional self-locking switches (such as toggle switches and rocker switches), and is especially suitable for compact devices such as printers. The self-locking circuit maintains the power output state after the button is pressed, avoiding the need to continuously press the button and improving the user experience. By utilizing a bistable circuit to cut off the self-locking mechanism upon the second button press, reliable power shutdown is achieved. The circuit response is stable and the operation logic is clear. Attached Figure Description

[0010] Figure 1 A circuit diagram of a push-button power switch circuit based on a bistable circuit provided for an embodiment of this utility model; Among them: 11, power conversion unit; 12, self-locking circuit; 13, button; 14, bistable circuit. Detailed Implementation

[0011] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model is further described below in conjunction with specific embodiments. However, the following embodiments are merely preferred embodiments of this utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of this utility model. Unless otherwise specified, the experimental methods in the following embodiments are conventional methods. Unless otherwise specified, the materials and reagents used in the following embodiments can be obtained commercially.

[0012] In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0013] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0014] like Figure 1As shown, this utility model provides a button power switch circuit and printer based on a bistable circuit. The button power switch circuit based on a bistable circuit includes a power conversion unit 11, a self-locking circuit 12, a button 13, and a bistable circuit 14. The enable terminal of the power conversion unit 11 is connected to the button 13 and the bistable circuit 14 through the self-locking circuit 12; the power conversion unit 11 is used to convert the input power into the working power, and its enable control terminal is used to control the power output; the power conversion unit 11 has an enable terminal ( / EN pin), a +3.3V power output terminal, and a VCC-IN power input terminal. The power conversion unit 11 can adopt the existing power conversion circuit structure, which will not be described in detail here. The self-locking circuit 12 is used to pull down the enable terminal of the power conversion unit 11 and maintain it at a low level after the button 13 is pressed, so as to realize the self-locking of the power output. The bistable circuit 14 is used to change the output state when the button 13 is pressed again, cut off the self-locking circuit, and restore the enable terminal of the power conversion unit 11 to a high level to turn off the power output.

[0015] In specific implementation, the self-locking circuit 12 includes MOSFET Q2, MOSFET Q3, resistor R8, resistor R13, resistor R12, capacitor C3, and resistor R9, wherein: The enable terminal of the power conversion unit 11 is grounded through MOSFET Q2, capacitor C3 and resistor R9 respectively. The connection node between the enable terminal of the power conversion unit 11 and MOSFET Q2 is connected to the button 13 through bidirectional diode U1. MOSFET Q2 is connected to the power output terminal of power conversion unit 11 through resistor R8; the connection node between MOSFET Q2 and resistor R8 is grounded through MOSFET Q3 and resistor R12 respectively; MOSFET Q3 is connected to one end of resistor R13 and bistable circuit 14; the other end of resistor R13 is grounded. The self-locking circuit 12 provided in this embodiment has a simple circuit structure, low cost, and is easy to implement and integrate; it ensures stable recognition of button actions and prevents false triggering by utilizing the delay characteristics of MOSFETs and capacitors; and it reliably pulls down and maintains the power enable terminal by utilizing the voltage divider of resistors and the switching characteristics of MOSFETs, ensuring the reliability of the self-locking function.

[0016] In specific implementation, the bistable circuit 14 includes MOSFET Q1, transistor U2, transistor U3, diode D1, diode D2, resistors R1, R2, R3, R4, R5, R6, R7, R10, R11, capacitors C1, C2, and C4, wherein: The collector of transistor U2 is connected to the base of transistor U3 through resistor R10; the base of transistor U2 is connected to the collector of transistor U3 through resistor R11. The base capacitor C4 of transistor U2 is grounded, and the emitter of transistor U2 and the emitter of transistor U3 are both grounded; The collector of transistor U2 is connected to the power output terminal of power conversion unit 11 through resistor R2; the collector of transistor U3 is connected to the power output terminal of power conversion unit 11 through resistor R4. The collector of transistor U2 is connected to the resistor R2 in sequence through resistor R6 and capacitor C1, and then to the base of transistor U3; the collector of transistor U3 is connected to the resistor R4 in sequence through resistor R7 and capacitor C2, and then to the base of transistor U2. The connection point of resistor R6 and capacitor C1 is connected to the cathode of diode D1, and the connection point of resistor R7 and capacitor C2 is connected to the cathode of diode D2. The anodes of diodes D1 and D2 are both connected to the drain of MOSFET Q1 via resistor R1. The source of MOSFET Q1 is connected to the power output terminal of power conversion unit 11, and the gate of MOSFET Q1 is connected to the power output terminal of power conversion unit 11 via resistor R3, and is also connected to button 13 via resistor R5 and bidirectional diode U1. MOSFET Q1 acts as a switch; when the button is pressed, MOSFET Q1 conducts, and power is input to the circuit through MOSFET Q1. Diodes D1 and D2 act as isolation devices, isolating the mutual influence of the downstream circuits of diodes D1 and D2. The bidirectional diode also acts as an isolation device, isolating the mutual influence of the self-locking circuit 12 and the bistable circuit 14. The bistable circuit 14 provided in this embodiment has good state retention characteristics through a complex combination of transistors, MOSFETs, diodes, resistors and capacitors, ensuring that the output state can be accurately switched every time a button is pressed. Furthermore, through RC delay and diode logic control, it achieves debouncing and stable response to the button signal, avoiding misoperation caused by button bounce.

[0017] In the circuit structure described above, MOSFET Q1 is a PMOS transistor, and the type that can be used includes, but is not limited to, NP3401; MOSFETs Q2 and Q3 are NMOS transistors, and the type that can be used includes, but is not limited to, NP3400; transistors U2 and U3 can be of types including, but not limited to, MMBT3904. The model parameters of the other components can be selected according to actual needs and parameter design, and will not be elaborated here.

[0018] like Figure 1 As shown, POWER1 is a single button. When the button 13 is pressed, the / EN pin of the power conversion unit 11 is pulled to a low level by the button 13 through the bidirectional diode U1. After the +3.3V output is passed through the resistor R8, the MOSFET Q2 is turned on to keep the / EN pin at a low level, thus achieving hardware self-locking. At this time, the button 13 is released, and the +3.3V is maintained in normal output, completing the power-on process.

[0019] When button 13 is pressed again, as Figure 1 As shown in the diagram, the bistable circuit on the right side of the circuit connects to GND via resistor R5 and bidirectional diode U1. At this time, the bistable output changes from low to high, turning on MOSFET Q3 and pulling the gate of MOSFET Q2 low. MOSFET Q2 then turns off, losing its latching function. When button 13 is released, the +3.3V output stops, completing the power-off process. Pressing button 13 again repeats the above process.

[0020] The push-button power switch circuit based on a bistable circuit provided in this embodiment of the invention achieves a self-locking function at the electronic circuit level through the synergistic effect of a power conversion unit, a self-locking circuit, a button, and a bistable circuit. The circuit is composed of a self-locking circuit in the left half and a bistable circuit in the right half to realize a complete push-button power switch circuit, which has the following technical effects: The power can be turned on and off using a single self-reset button, overcoming the problems of large size and space occupation of traditional self-locking switches (such as toggle switches and rocker switches), and is especially suitable for compact devices such as printers. The self-locking circuit maintains the power output state after the button is pressed, avoiding the need to continuously press the button and improving the user experience. By utilizing a bistable circuit to cut off the self-locking mechanism upon the second button press, reliable power shutdown is achieved. The circuit response is stable and the operation logic is clear.

[0021] This utility model also provides a printer that uses a bistable circuit-based button power on / off circuit as described above.

[0022] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A push-button power switch circuit based on a bistable circuit, characterized in that, Includes a power conversion unit (11), a self-locking circuit (12), a button (13), and a bistable circuit (14), wherein: The enable terminal of the power conversion unit (11) is connected to the button (13) and the bistable circuit (14) through the self-locking circuit (12); The power conversion unit (11) is used to convert the input power into the working power, and its enable control terminal is used to control the power output. The self-locking circuit (12) is used to pull down the enable terminal of the power conversion unit (11) and maintain it at a low level after the button (13) is pressed, so as to realize the self-locking of the power output; The bistable circuit (14) is used to change the output state when the button (13) is pressed again, cut off the self-locking circuit, and restore the enable terminal of the power conversion unit (11) to a high level so as to turn off the power output.

2. The push-button power switch circuit based on a bistable circuit according to claim 1, characterized in that: The self-locking circuit (12) includes MOSFET Q2, MOSFET Q3, resistor R8, resistor R13, resistor R12, capacitor C3, and resistor R9, wherein: The enable terminal of the power conversion unit (11) is grounded through MOS transistor Q2, capacitor C3 and resistor R9 respectively. The connection between the enable terminal of the power conversion unit (11) and MOS transistor Q2 is connected to the button (13). MOSFET Q2 is connected to the power output terminal of power conversion unit (11) through resistor R8; the connection node between MOSFET Q2 and resistor R8 is grounded through MOSFET Q3 and resistor R12 respectively; MOSFET Q3 is connected to one end of resistor R13 and bistable circuit (14); the other end of resistor R13 is grounded.

3. The push-button power switch circuit based on a bistable circuit according to claim 2, characterized in that: The bistable circuit (14) includes MOSFET Q1, transistor U2, transistor U3, diode D1, diode D2, resistors R1, R2, R3, R4, R5, R6, R7, R10, R11, capacitors C1, C2, and C4, wherein: The collector of transistor U2 is connected to the base of transistor U3 through resistor R10; the base of transistor U2 is connected to the collector of transistor U3 through resistor R11. The base capacitor C4 of transistor U2 is grounded, and the emitter of transistor U2 and the emitter of transistor U3 are both grounded; The collector of transistor U2 is connected to the power output terminal of power conversion unit (11) through resistor R2; the collector of transistor U3 is connected to the power output terminal of power conversion unit (11) through resistor R4. The collector of transistor U2 is connected to the resistor R2 in sequence through resistor R6 and capacitor C1, and then to the base of transistor U3; the collector of transistor U3 is connected to the resistor R4 in sequence through resistor R7 and capacitor C2, and then to the base of transistor U2. The connection node of resistor R6 and capacitor C1 is connected to the cathode of diode D1, and the connection node of resistor R7 and capacitor C2 is connected to the cathode of diode D2. The anodes of diode D1 and diode D2 are both connected to the drain of MOSFET Q1 through resistor R1. The source of MOSFET Q1 is connected to the power output terminal of power conversion unit (11). The gate of MOSFET Q1 is connected to the power output terminal of power conversion unit (11) through resistor R3, and is connected to button (13) through resistor R5.

4. The push-button power switch circuit based on a bistable circuit according to any one of claims 1-3, characterized in that: The button (13) is connected to the self-locking circuit (12) and the bistable circuit (14) through a bidirectional diode U1.

5. A printer, characterized in that: The push-button power switch circuit based on a bistable circuit as described in any one of claims 1-4 is adopted.

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