Patent Publication Number: US-2023161367-A1

Title: Power on/off circuit and electronic vaporization device

Description:
CROSS-REFERENCE TO PRIOR APPLICATION 
     Priority is claimed to Chinese Patent Application No. 202122873157.3, filed on Nov. 19, 2021, the entire disclosure of which is hereby incorporated by reference herein. 
     FIELD 
     This application relates to the field of switch circuits, and in particular, to a power on/off circuit and an electronic vaporization device. 
     BACKGROUND 
     A battery-powered product is usually provided with a power on/off circuit to shut down during an idle period to reduce power consumption while improving battery life time. 
     A type of power on/off circuit using a sensor as a starting element is popular on the market. When a user performs a power-on operation, a sensor outputs a power-on signal to make a circuit conductive, so as to achieve the purpose of power-on. 
     However, when the sensor is not reset for some reason and a power-off operation is subsequently performed, the sensor continuously outputs the power-on signal. As a result, the power on/off circuit cannot be disconnected, the circuit continuously supplies power, the standby current is large, and the battery usage time is reduced. 
     SUMMARY 
     In an embodiment, the present invention provides a power on/off circuit, comprising: a sensor configured to generate a corresponding first control signal based on a user operation; a first switch element, a first end of the first switch element being connected to a voltage input end, a second end of the first switch element being connected to a voltage output end, the voltage input end being connected to a power supply voltage; and a capacitor connected between a third end of the first switch element and the sensor, the capacitor being configured to control an on-off of the first switch element based on the first control signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Subject matter of the present disclosure will be described in even greater detail below based on the exemplary figures. All features described and/or illustrated herein can be used alone or combined in different combinations. The features and advantages of various embodiments will become apparent by reading the following detailed description with reference to the attached drawings, which illustrate the following: 
         FIG.  1    is a circuit diagram of a power on/off circuit according to a first embodiment of this application; 
         FIG.  2    is a characteristic diagram of a Hall sensor according to this application; 
         FIG.  3    is a circuit diagram of a power on/off circuit according to a second embodiment of this application; 
         FIG.  4    is a circuit diagram of a power on/off circuit according to a third embodiment of this application; 
         FIG.  5    is a timing diagram of a first control signal, a voltage of a third end of a first switch element, and an output voltage of a voltage output end according to a comparative example of this application; 
         FIG.  6    is a timing diagram of a first control signal, a voltage of a third end of a first switch element, and an output voltage of a voltage output end according to this application; 
         FIG.  7    is a circuit diagram of a power on/off circuit according to a fourth embodiment of this application; 
         FIG.  8    is a schematic structural diagram of an electronic vaporization device according to an embodiment of this application; and 
         FIG.  9    is a schematic structural diagram of an electronic vaporization device according to another embodiment of this application. 
     
    
    
     DETAILED DESCRIPTION 
     In an embodiment, the present invention provides a power on/off circuit, which can prevent the power on/off circuit from being continuously conductive and failing to shut down when a sensor is not reset. 
     In an embodiment, the present invention provides a power on/off circuit, including a sensor, a first switch element, and a capacitor. The sensor generates a corresponding first control signal based on a user operation; a first end of the first switch element is connected to a voltage input end, a second end of the first switch element is connected to a voltage output end, where the voltage input end is connected to a power supply voltage; and the capacitor is connected between a third end of the first switch element and the sensor, and controls whether the first switch element is conductive based on the first control signal. 
     The first control signal is switched to a logic low level when the sensor is triggered based on a power-on operation of the user; and the first control signal is switched to a logic high level when the sensor is reset. 
     The power on/off circuit further includes a control chip, the control chip including a signal output port, the signal output port being connected to a third end of the first switch element and configured to issue a second control signal to control whether the first switch element is conductive. 
     The power on/off circuit further includes a control chip and a second switch element, the control chip including a signal output port, a first end of the second switch element being connected to a ground voltage, a second end of the second switch element being connected to a third end of the first switch element, where a third end of the second switch element is connected to the signal output port to receive a second control signal issued by the control chip; and the control chip issues the second control signal to control the on-off of the second switch element. 
     The power on/off circuit further includes a first resistor, a first end of the first resistor is connected to the voltage input end, and a second end of the first resistor is connected to a third end of the first switch element and an end of the capacitor at the same time. 
     The power on/off circuit further includes a first diode, a cathode of the first diode is connected to the voltage input end, and an anode of the first diode is connected to a first end of the capacitor. 
     The power on/off circuit further includes a second diode, a cathode of the second diode is connected to a first end of the capacitor or a second end of the capacitor connected to the sensor, and an anode of the second diode is connected to a detection feedback port of the control chip to feed back a change in the first control signal to the control chip. 
     When a cathode of the second diode is connected to a first end of the capacitor, the power on/off circuit further includes a third diode, an anode of the third diode is connected to a third end of the first switch element, and a cathode of the third diode is connected to a first end of the capacitor. 
     The first switch element is a PMOS transistor, and the second switch element is an NMOS transistor. 
     To resolve the above technical problems, a second technical solution according to this application is to provide an electronic vaporization device, including the power on/off circuit according to any one of the above description. 
     The beneficial effect of this application is different from that in the prior art. The power on/off circuit and the electronic vaporization device according to this application include a sensor, a first switch element, and a capacitor. The sensor generates a corresponding first control signal based on a user operation; a first end of the first switch element is connected to a voltage input end, a second end of the first switch element is connected to a voltage output end, where the voltage input end is connected to a power supply voltage; and the capacitor is connected between a third end of the first switch element and the sensor, and controls whether the first switch element is conductive based on the first control signal. The power on/off circuit can prevent the power on/off circuit from being continuously conductive and failing to shut down when a sensor is not reset. 
     The technical solutions in the embodiments of this application are clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are merely some rather than all of the embodiments of this application. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the protection scope of this application. 
     The terms “first”, “second”, and “third” in this application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defining “first”, “second”, and “third” can explicitly or implicitly include at least one of the features. 
     “Embodiment” mentioned in the specification means that particular features, structures, or characteristics described with reference to the embodiment may be included in at least one embodiment of this application. The term appearing at different positions of the specification may not refer to the same embodiment or an independent or alternative embodiment that is mutually exclusive with another embodiment. A person skilled in the art explicitly or implicitly understands that the embodiments described in the specification may be combined with other embodiments. 
     Referring to  FIG.  1   ,  FIG.  1    is a circuit diagram of a power on/off circuit according to a first embodiment of this application. A power on/off circuit  1  includes a voltage input end VI, a voltage output end V 2 , a sensor  21 , a first switch element Q 1 , a first capacitor C 1 , and a second capacitor C 2 . Specifically, an input side of the sensor  21  is connected to the voltage input end V 1  and a first end of the first capacitor C 1 , a ground side of the sensor  21  is connected to a second end of the first capacitor C 1  and a ground voltage, an output side of the sensor  21  is connected to a second end of the second capacitor C 2 , a first end of the second capacitor C 2  is connected to a third end of the first switch element Q 1 , a first end of the first switch element Q 1  is connected to the voltage input end V 1 , and a second end of the first switch element Q 1  is connected to the voltage output end V 2 . The voltage input end V 1  is connected to a power supply voltage and is configured to provide a voltage VIN, the third end of the first switch element Q 1  is a control end, the output side of the sensor  21  generates a corresponding first control signal SW 1  based on a user operation, and the second capacitor C 2  controls the on-off of the first switch element Q 1  based on the first control signal SW 1 . 
     Specifically, a user operates the sensor  21  to provide the first control signal SW 1  to conduct the first switch element Q 1  through the second capacitor C 2 , so as to turn on a battery-powered product. The voltage input end V 1  supplies power to a load through the first switch element Q 1  and the voltage output end V 2 . In this embodiment, by arranging the second capacitor C 2  between the first switch element Q 1  and the sensor  21 , that the sensor  21  directly outputs a control signal for the first switch element Q 1  is converted into that the sensor  21  outputs a control signal for the first switch element Q 1  through the second capacitor C 2 , which implements the isolation of the sensor  21  from the first switch element Q 1 , so that the power on/off circuit  1  can be prevented from being continuously conductive and failing to shut down when the sensor  21  is not reset. 
     In an implementation, the sensor  21  is a Hall sensor and configured to provide the first control signal SW 1 . Referring to  FIG.  2   ,  FIG.  2    is a characteristic diagram of a Hall sensor according to this application. When the user operates a magnetic element to approach the Hall sensor and the strength of a magnetic field where the Hall sensor is located is greater than a certain value (BOPS), the Hall sensor provides a logic low level to conduct the first switch element Q 1 ; when the user operates the magnetic element away from the Hall sensor or the magnetic element is self-reset, and the strength of the magnetic field where the Hall sensor is located is less than a certain value (BRPS), the Hall sensor provides a logic high level. If there is no second capacitor C 2  in the circuit, when the magnetic element is not reset due to improper operations by the user or other reasons, the Hall sensor continuously outputs a logic low level. As a result, the power on/off circuit continuously supplies power, the standby current is large, and the battery usage time is reduced. In this implementation, by arranging the second capacitor C 2  between the first switch element Q 1  and the sensor  21 , that the sensor  21  directly outputs a control signal for the first switch element Q 1  is converted into that the sensor  21  outputs a control signal for the first switch element Q 1  through the second capacitor C 2 , which implements the isolation of the sensor  21  from the first switch element Q 1 , so that the power-off of the circuit can be implemented when the sensor  21  is not reset and the second capacitor C 2  outputs a logic high level. 
     Referring to  FIG.  3   ,  FIG.  3    is a circuit diagram of a power on/off circuit according to a second embodiment of this application. Different from the power on/off circuit  1 , a power on/off circuit  2  in this embodiment further includes a control chip  22 . The control chip  22  includes a signal output port P 1 . The signal output port P 1  is connected to the third end of the first switch element Q 1 , and is configured to issue a second control signal SW 2  to control the on-off of the first switch element Q 1 . In this embodiment, the user operates the sensor  21  to provide the first control signal SW 1  to conduct the first switch element Q 1 , so that the battery-powered product is turned on. Even if the sensor  21  is reset and no longer provides the first control signal SW 1 , the signal output port P 1  of the control chip  22  in the battery-powered product can, as required, output the second control signal SW 2  through a second switch element Q 2  to control the first switch element Q 1  to be continuously conductive or shut-off. For example, after the battery-powered product is turned on, the control chip  22  is powered on, and the control chip  22  outputs a logic high level to continuously conduct the first switch element Q 1  as required, so as to supply power to the load through the voltage output end V 2 . Upon completion of the power supply, the control chip  22  may also output a logic low level to shut off the first switch element Q 1  as required. 
     Referring to  FIG.  4   ,  FIG.  4    is a circuit diagram of a power on/off circuit according to a third embodiment of this application. Different from the power on/off circuit  2 , a power on/off circuit  3  in this embodiment further includes a first resistor R 1 , a first diode D 1 , a second diode D 2 , the second switch element Q 2 , and a detection feedback port P 2  of the control chip  22 . The voltage input end V 1  is connected to a first end of the first resistor R 1  and a cathode of the first diode D 1 , and the first end of the second capacitor C 2  is connected to a second end of the first resistor R 1  and an anode of the first diode D 1 . A first end of the second switch element Q 2  is connected to the ground voltage, a second end of the second switch element Q 2  is connected to the third end of the first switch element Q 1 , where a third end of the second switch element Q 2  is a control end, and the third end of the second switch element Q 2  is connected to the signal output port. An anode of the second diode D 2  is connected to the detection feedback port P 2  of the control chip  22 , and a cathode of the second diode D 2  is connected between the second capacitor C 2  and the sensor  21 . When the first switch element Q 1  is conductive, the battery-powered product is turned on, and the voltage input end V 1  charges the second capacitor C 2  through the first resistor R 1 , so that the second capacitor C 2  is gradually converted from inputting a logic low level to outputting a logic high level, so as to avoid the continuous conduction of the first switch element Q 1  when the sensor  21  is not reset. And the third end of the second switch element Q 2  receives the second control signal SW 2  issued by the control chip  22 , and controls whether the second switch element Q 2  is conductive based on the second control signal SW 2 , thereby determining whether to conduct the first switch element Q 1  by the ground voltage. The second diode D 2  is connected between the second capacitor C 2  and the sensor  21  to feed back a change in the first control signal SW 1  to the control chip  22 . Specifically, in this embodiment, when the user does not perform a power-on operation or the magnetic element is away from the Hall sensor, the sensor  21  outputs a logic high level. Since the first resistor R 1  raises a voltage of the first switch element Q 1 , the first switch element Q 1  is not conductive, the circuit remains a power-off state, and there is no voltage at two ends of the second capacitor C 2 . When the user performs the power-on operation or the magnetic element is close to the Hall sensor, the sensor  21  outputs a logic low level, since the voltages of the two ends of the second capacitor C 2  cannot generate a sudden change, the two ends of the second capacitor C 2  both output a low voltage, the voltage of the first switch element Q 1  is lowered, the first switch element Q 1  is conducted, the battery-powered product is turned on, and the control chip  22  is powered on to execute a control program, so that the first switch element Q 1  is maintained continuously conductive when the battery-powered product needs to remain a power-on state and the control chip  22  outputs a logic high level; and the first switch element Q 1  is disconnected after the power supply of the battery-powered product is completed or when the load is not powered through the voltage output end V 2  within a certain time threshold, and when the control chip  22  outputs a logic low level. 
     In this embodiment, by arranging the second capacitor C 2  on a passage between the sensor  21  and the first switch element Q 1 , after the power-supplied product is turned on, the second capacitor C 2  completes charging through the voltage input end V 1  within a certain period of time, so that the third end of the first switch element Q 1  returns to a high level. Even if the sensor  21  continues to output a logic low level because there is no power-off operation of the user or the magnetic element is not reset, the control chip  22  can still independently perform control to output the second control signal SW 2  as a logic low level to shut off the first switch element Q 1  and cut off the current to turn off the battery-powered product. 
     In this embodiment, the anode of the first diode D 1  is connected to the first end of the second capacitor C 2 , and the cathode is connected to the voltage input end VI, to assist in discharging the first end of the second capacitor C 2  when the first control signal SW 1  is switched to a logic high level. As may be understood, in a case that there is no first diode D 1 , after the signal output port P 1  of the control chip  22  outputs a logic low level to cause the battery-powered product to automatically shut down, the second capacitor C 2  is fully charged, and the third end of the first switch element Q 1  returns to a high level. In this case, if the user operates the sensor  21  to perform a power-off operation or resets the magnetic element at this time, the sensor  21  is switched from outputting a logic low level to outputting a logic high level. Since the voltages of the two ends of the second capacitor C 2  cannot be abruptly changed, a voltage V of the third end of the first switch element Q 1  is instantly increased from the voltage VIN inputted by the voltage input end V 1  to 2VIN, and discharges slowly through the first resistor R 1 . If, in a process of slowly discharging by the first resistor R 1 , the user operates the battery-powered product to be turned on again, the sensor  21  outputs a logic low level, in this case, the voltage V of the third end of the first switch element Q 1  (VIN&lt;V&lt;2VIN) drops by a level of VIN, and the voltage may still be greater than a voltage at which the first switch element Q 1  is conductive. As a result, the first switch element Q 1  cannot be conducted. Or, in an extreme case, such as in a case that the sensor  21  outputs a logic low level, the control chip  22  independently controls the first switch element Q 1  to be disconnected, the user operates the sensor  21  to shut down and then rapidly performs a power-on action, the sensor  21  is quickly switched from outputting a logic high level to outputting a logic low level, and the voltage of the third end of the first switch element Q 1  is lowered from 2VIN to VIN. As a result, the battery-powered product cannot be turned on. In this embodiment, by arranging the first diode D 1 , when the user performs a power-off operation, the sensor  21  is switched from outputting a logic low level to outputting a logic high level, the existence of the first diode D 1  assists in discharging the first end of the second capacitor C 2 , the voltage of the third end of the first switch element Q 1  is maintained at a voltage close to the VIN value, the first diode D 1  has the functions of fast discharge and clamping voltage here, and the first switch element Q 1  still remains a power-off state. When the user quickly performs a power-on operation after a shutdown, causing the sensor  21  to be switched from outputting a logic high level to outputting a logic low level, the voltage of the third end of the first switch element Q 1  is quickly lowered, thereby implementing a rapid power-on. 
     Referring to  FIG.  5   ,  FIG.  5    is a timing diagram of a first control signal, a voltage of a third end of a first switch element, and an output voltage of a voltage output end according to a comparative example of this application. In  FIG.  5   , there is no first diode D 1  in the power on/off circuit  3 , the first switch element Q 1  is a PMOS transistor, when the battery-powered product shuts down to switch the first control signal SW 1  to a logic high level, a voltage of a gate of the first switch element Q 1  instantly rises to 2VIN, and is slowly discharged by the first resistor R 1  during the power-off, and then when the battery-powered product is turned on to switch the first control signal SW 1  to a logic low level, the dropped voltage of the gate of the first switch element Q 1  is still greater than the voltage at which the first switch element Q 1  is conductive. As a result, the battery-powered product cannot be turned on and there is no voltage output at the voltage output end V 2 . 
     Referring to  FIG.  6   ,  FIG.  6    is a timing diagram of a first control signal, a voltage of a third end of a first switch element, and an output voltage of a voltage output end according to this application. In  FIG.  6   , the first diode D 1  is arranged in the power on/off circuit  3 , when the battery-powered product shuts down to switch the first control signal SW 1  to a logic high level, after a voltage of a gate of the first switch element Q 1  instantly rises to 2VIN, the voltage of the gate of the first switch element Q 1  drops rapidly to VIN due to the role of the auxiliary discharge of the first diode D 1 , and then, when the battery-powered product turns on to switch the first control signal SW 1  to a logic low level, the voltage of the gate of the first switch element Q 1  falls to a voltage equal to or less than the voltage at which the first switch element Q 1  is conductive, the first switch element Q 1  is conducted, the battery-powered product is turned on, and the voltage output end V 2  outputs a voltage to supply power to the load. The second switch element Q 2  is an NMOS transistor, and during the time when the voltage output end V 2  outputs a high level, the control chip  22  may control the signal output port P 1  through the second switch element Q 2  to output a logic high level, so that the first switch element Q 1  is continuously conductive, to keep the power-on state; and according to an actual need, the control chip  22  may independently control the signal output port P 1  to output a logic low level through the second switch element Q 2  to shut off the first switch element Q 1 , so as to implement the shutdown. 
     In this embodiment, the cathode of the second diode D 2  is connected to the second end of the second capacitor C 2  connected to the sensor  21 , and the anode is connected to the detection feedback port P 2  of the control chip  22 , to detect the first control signal SW 1  outputted by the sensor  21 , and to feed back a change in the first control signal SW 1  to the control chip  22 . 
     Referring to  FIG.  7   ,  FIG.  7    is a circuit diagram of a power on/off circuit according to a fourth embodiment of this application. Different from the power on/off circuit  3 , in a power on/off circuit  4  according to this embodiment, the cathode of the second diode D 2  is connected to the first end of the second capacitor C 2 , the anode is connected to the detection feedback port P 2  of the control chip  22 , an anode of a third diode D 3  is connected to the third end of the first switch element Q 1 , and a cathode is connected to the first end of the second capacitor C 2 . 
     Specifically, since the second diode D 2  is connected to the first end of the second capacitor C 2 , a signal outputted from the detection feedback port P 2  of the control chip  22  is no longer a level signal, but a pulse signal, and since the second control signal SW 2  outputted from the signal output port P 1  lowers a voltage of the third end of the first switch element Q 1  after the battery-powered product is turned on, it is necessary to increase the third diode D 3  so that a change in the pulse signal can be detected before the battery-powered product is turned off. 
     Referring to  FIG.  8   , an electronic vaporization device includes a vaporizer  10  and a battery rod  20 . The vaporizer  10  stores a to-be-vaporized matrix. The battery rod  20  is electrically connected to the vaporizer  10  to supply power to the vaporizer  10  so that the vaporizer  10  heats and vaporizes the to-be-vaporized matrix. 
     In an implementation, referring to  FIG.  9   , the battery rod  20  includes a battery core  23  and a circuit board. The battery core  23  is configured to store electrical energy, the power on/off circuit according to any of the above embodiments is arranged on the circuit board, when the user performs the power-on operation, the first switch element Q 1  is conductive, and the battery core  23  provides a voltage to vaporize the to-be-vaporized matrix for the vaporizer  10  through the circuit board. 
     The foregoing descriptions are merely implementations of this application, and the protection scope of this application is not limited thereto. All equivalent structure or process changes made according to the content of this specification and accompanying drawings in this application or by directly or indirectly applying this application in other related technical fields shall fall within the protection scope of this application. 
     While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. It will be understood that changes and modifications may be made by those of ordinary skill within the scope of the following claims. In particular, the present invention covers further embodiments with any combination of features from different embodiments described above and below. Additionally, statements made herein characterizing the invention refer to an embodiment of the invention and not necessarily all embodiments. 
     The terms used in the claims should be construed to have the broadest reasonable interpretation consistent with the foregoing description. For example, the use of the article “a” or “the” in introducing an element should not be interpreted as being exclusive of a plurality of elements. Likewise, the recitation of “or” should be interpreted as being inclusive, such that the recitation of “A or B” is not exclusive of “A and B,” unless it is clear from the context or the foregoing description that only one of A and B is intended. Further, the recitation of “at least one of A, B and C” should be interpreted as one or more of a group of elements consisting of A, B and C, and should not be interpreted as requiring at least one of each of the listed elements A, B and C, regardless of whether A, B and C are related as categories or otherwise. Moreover, the recitation of “A, B and/or C” or “at least one of A, B or C” should be interpreted as including any singular entity from the listed elements, e.g., A, any subset from the listed elements, e.g., A and B, or the entire list of elements A, B and C.