Electronic circuit and electronic cigarette for measuring load resistance

Abstract

The present application provides an electronic circuit for measuring load resistance, including: a power module, a resistor R6, a MOS switch, a load heating wire, and a control module, wherein the control module has a first connection end and a second connection end. The two ends of the resistor R6 are respectively connected to the power module and the MOS switch, and the MOS switch is connected to the first connection end, and the first connection end is used to output a high level to control the MOS switch to close. The second connection end is connected to the load heating wire, which is used to detect the voltage across the two ends of the load heating wire, and the resistor R6 is connected in series with the load heating wire. This design not only simplifies the circuit structure, but also allows the size of the control board to be reduced, thereby meeting the compactness requirements of modern electronic cigarette product design. In addition, due to the reduction in the number of components, the manufacturing cost is also reduced accordingly, which improves the market competitiveness of the product.

Description

Technical Field

[0001] The present application relates to the field of electronic cigarettes, and in particular to an electronic circuit for measuring load resistance and an electronic cigarette. Background Art

[0002] With the rapid development of the e-cigarette industry, the demand for personalized and functional products is growing. Among many functions, real-time monitoring and adjustment of the resistance of the heating wire (load) of the e-cigarette is crucial to ensure product performance and user experience. The heating wire of the e-cigarette is one of its core components and is responsible for the heating element that produces smoke. Since different users may use heating wires with different resistance values, and the resistance of the same heating wire will also change at different temperatures, accurate measurement and control of the resistance of the heating wire is of great significance to ensure the stable operation of the e-cigarette and optimize the user experience.

[0003] In traditional solutions, the circuit design for measuring the resistance of electronic cigarette loads often uses multiple electronic components, including P-type metal oxide semiconductor field effect transistors (P MOS), N-type metal oxide semiconductor field effect transistors (NMOS) and resistors. These solutions measure the current flowing through the load heating wire and the voltage difference between the two ends by establishing complex circuits, and then calculate the resistance. However, this traditional method usually requires more components, resulting in a large control board, increased costs, and lack of flexibility in product design.

[0004] Therefore, it is necessary to develop a circuit design that can accurately measure the load resistance and reduce the number of components and costs. Utility Model Content

[0005] In view of this, it is necessary to provide a circuit design that can accurately measure the load resistance and reduce the number of components and costs to solve the above problems.

[0006] The embodiment of the present application provides an electronic circuit for measuring load resistance, comprising: a power module, a resistor R6, a MOS switch, a load heating wire, and a control module, wherein the control module has a first connection terminal and a second connection terminal;

[0007] Two ends of the resistor R6 are connected to the power module and the MOS switch respectively, the MOS switch is connected to the first connection end, and the first connection end is used to output a high level to control the MOS switch to be closed;

[0008] The second connection end is connected to the load heating wire for detecting the voltage across the load heating wire, and the resistor R6 is connected in series with the load heating wire.

[0009] In at least one embodiment of the present application, the MOS switch has a first pin, a second pin and a third pin, the first pin is connected to the first connection end, the second pin is connected to the load heating wire, and the third pin is connected to the power module.

[0010] In at least one embodiment of the present application, the MOS switch further includes a body diode, a positive terminal of the body diode is connected to the second pin, and a negative terminal of the body diode is connected to the third pin.

[0011] In at least one embodiment of the present application, the electronic circuit for measuring the load resistance further includes a resistor R8, one end of the resistor R8 is connected between the first connection end and the first pin, and the other end is grounded.

[0012] In at least one embodiment of the present application, the electronic circuit for measuring the load resistance further includes a resistor R7, one end of the resistor R7 is connected between the load heating wire and the second pin, and the other end is connected to the second connection end.

[0013] In at least one embodiment of the present application, the electronic circuit for measuring the load resistance further includes a resistor R9, one end of the resistor R9 is grounded, and the other end is connected to the second connection end.

[0014] In at least one embodiment of the present application, the power module has a BAT voltage, and the BAT voltage is obtained by measuring the internal working voltage of the control module, or by an external sampling circuit.

[0015] In at least one embodiment of the present application, the resistance of the resistor R6 is 20Ω, and the resistance of the MOS switch is negligible.

[0016] In at least one embodiment of the present application, a stabilized high-level output terminal is provided between the second pin and the load heating wire, and the stabilized high-level output terminal is connected to the ground.

[0017] In at least one embodiment of the present application, an electronic cigarette includes a housing, a circuit board arranged in the housing, and any one of the electronic circuits described above.

[0018] The electronic circuit for measuring the load resistance provided above adopts a single MOS switch and a small amount of resistors, outputs a high level through the first connection terminal of the control module to close the MOS switch, connects the resistor R6, the power module and the load heating wire in series, and the current flows through the resistor R6 and the MOS switch to the load heating wire. The current value of the resistor R6 is equal to the current value of the load heating wire, and the second connection terminal is connected in parallel with the load heating wire. The voltage value of the second connection terminal is equal to the voltage value of the load heating wire. The voltage of the load heating wire is obtained by sampling the voltage of the second connection terminal. The voltage difference between the two ends of the resistor R6 can be calculated by obtaining the voltage of the power module, thereby calculating the current value of the resistor R6, and then knowing the resistance value of the load heating wire. This design not only simplifies the circuit structure, but also allows the size of the control board to be reduced, thereby meeting the compactness requirements of modern electronic cigarette product design. In addition, due to the reduction in the number of components, the manufacturing cost is also reduced accordingly, which improves the market competitiveness of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the structure of an electronic circuit for measuring load resistance in one embodiment of the present application.

[0020] Figure 2 Schematic diagram of the structure of a MOS switch in an embodiment of the present application.

[0021] Main component symbols

[0022] 100. electronic circuit; 10. power module; 20. MOS switch; 21. first pin; 22. second pin; 23. third pin; 24. body diode; 30. load heating wire; 40. control module; IO1. first connection terminal; IO2. second connection terminal; 50. high-level output terminal after voltage stabilization. DETAILED DESCRIPTION

[0023] The embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0024] It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a central component at the same time. When a component is considered to be "located on" another component, it may be directly located on the other component or there may be a central component at the same time. The terms "top", "bottom", "upper", "lower", "left", "right", "front", "back", and similar expressions used herein are for illustrative purposes only.

[0025] The embodiment of the present application provides an electronic circuit for measuring load resistance, comprising: a power module, a resistor R6, a MOS switch, a load heating wire, and a control module, wherein the control module has a first connection terminal and a second connection terminal;

[0026] Two ends of the resistor R6 are connected to the power module and the MOS switch respectively, the MOS switch is connected to the first connection end, and the first connection end is used to output a high level to control the MOS switch to be closed;

[0027] The second connection end is connected to the load heating wire for detecting the voltage across the load heating wire, and the resistor R6 is connected in series with the load heating wire.

[0028] The electronic circuit for measuring the load resistance provided above adopts a single MOS switch and a small amount of resistors, and outputs a high level through the first connection terminal of the control module to close the MOS switch, connects the resistor R6, the power module and the load heating wire in series, and the current flows through the resistor R6, the MOS switch to the load heating wire. The current value of the resistor R6 is equal to the current value of the load heating wire, and the second connection terminal is connected in parallel with the load heating wire. The voltage value of the second connection terminal is equal to the voltage value of the load heating wire. The voltage of the load heating wire is obtained by sampling the voltage of the second connection terminal. The voltage difference between the two ends of the resistor R6 can be calculated by obtaining the voltage of the power module, thereby calculating the current value of the resistor R6, and then knowing the resistance value of the load heating wire. This design not only simplifies the circuit structure, but also allows the size of the control board to be reduced, thereby meeting the compactness requirements of modern electronic cigarette product design. In addition, due to the reduction in the number of components, the manufacturing cost is also reduced accordingly, which improves the market competitiveness of the product.

[0029] Some embodiments of the present application are described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0030] See also Figure 1-Figure 2 The embodiment of the present application provides an electronic circuit 100 for measuring load resistance, including: a power module 10, a resistor R6, a MOS switch 20, a load heating wire 30, and a control module 40, wherein the control module 40 has a first connection terminal IO1 and a second connection terminal IO2.

[0031] The two ends of the resistor R6 are respectively connected to the power module 10 and the MOS switch 20, the MOS switch 20 is connected to the first connection end IO1, and the first connection end IO1 is used to output a high level to control the MOS switch 20 to be closed; the second connection end IO2 is connected to the load heating wire 30, and is used to detect the voltage across the two ends of the load heating wire 30, and the resistor R6 is connected in series with the load heating wire 30.

[0032] In a specific embodiment, the resistance of the resistor R6 is 20Ω, and the resistance of the MOS switch is negligible.

[0033] Specifically, the power module 10 provides current and voltage for use by components in the circuit. Resistor R6 is a resistor with a resistance of 20Ω, and its function is to limit the current flowing through the circuit. MOS switch 20 is an N MOS type switch, which is responsible for controlling the on and off of the load heating wire 30. By controlling the on and off state of the MOS switch 20, the flow of current can be controlled. The load heating wire 30 is a heating element, usually used as a heater, and heat is generated by passing current through the heating wire to achieve the purpose of heating. The control module 40 is the internal control core of the electronic cigarette. The first connection terminal IO1 and the second connection terminal IO2 are two output ports in the control module 40, which are responsible for outputting control signals and detecting and processing voltage information.

[0034] Furthermore, when the first connection terminal IO1 of the control module 40 outputs a high level, the MOS switch 20 is closed and turned on, the resistor R6, the power module 10 and the load heating wire 30 are connected in series, and then the current flows to the load heating wire 30 through the resistor R6, and the load heating wire 30 generates heat.

[0035] When the MOS switch 20 is closed and turned on, the resistor R6 is connected in series with the power module 10 and the load heating wire 30, and the internal resistance of the MOS switch 20 is 0. At this time, the voltage difference U across the resistor R6 is R6 The voltage value of the power module minus the voltage value of the load heating wire, that is, U R6 =U BAT -U 负载。 By formula:

[0036]

[0037] The current value of the resistor R6 is obtained. The current value passing through the resistor R6, the MOS switch 20 and the load heating wire 30 is equal, that is, I R6 =I 负载 At the same time, the second connection terminal IO2 is connected in parallel with the load heating wire 30, and the voltage in the parallel circuit is equal, that is, U 负载 =U IO2 , the voltage value of the load heating wire 30 is obtained by sampling the voltage of the second connection terminal IO2. When the resistance value of the load heating wire 30 needs to be obtained, the formula is:

[0038]

[0039] Among them, U 负载 =U IO2 , I R6 =I 负载, the resistance value of the load heating wire 30 can be obtained by calculation.

[0040] The electronic circuit 100 combines control and measurement functions and is suitable for application scenarios where the temperature or resistance value of a load needs to be accurately controlled.

[0041] In a specific embodiment, the MOS switch 20 has a first pin 21, a second pin 22 and a third pin 23, the first pin 21 is connected to the first connection terminal IO1, the second pin 22 is connected to the load heating wire 30, and the third pin 23 is connected to the power module 10.

[0042] Specifically, the MOS switch 20 is an N MOS type switch. The three pins on the MOS switch 20 are: the first pin 21 is the gate, which is the key pin for controlling the MOS tube switch. By changing the voltage on this pin, the MOS tube is controlled to be turned on and off, thereby controlling whether the current can flow from the third pin 23 to the second pin 22; the second pin 22 is the source, which is the pin into which the current flows; the third pin 23 is the drain, which is the pin from which the current flows. When the gate of the MOS switch 20, i.e., the first pin 21, has a voltage higher than its threshold voltage, the switch is closed. This usually requires that the gate voltage be increased above the source voltage and there is a certain voltage difference, such as 5 to 10V. When the MOS switch 20 is turned on, if the drain has a higher potential relative to the source, then the current will flow from the drain to the source. When the control signal is applied to the gate, i.e., the first pin 21, the MOS switch 20 is turned on, allowing the current to flow from the drain, i.e., the third pin 23, to the source, i.e., the second pin 22; when the control signal is removed, the MOS switch 20 is closed, preventing the current from flowing.

[0043] Further, the first pin 21 is connected to the first connection terminal IO1 of the control module 40, and is used to receive a signal from the control module 40, so as to control the on / off state of the MOS switch 20. The second pin 22 is connected to the load heating wire 30, and is used to turn on or off the current of the load heating wire 30, and by connecting to the load heating wire 30, the current is controlled, so as to control the heating of the load heating wire 30. The third pin 23 is connected to the power module 10, and obtains power supply from the power module 10 to ensure the normal operation of the MOS switch 20.

[0044] To sum up, when the control circuit is powered normally, the control module 40 controls the first connection terminal IO1 to output a high-level signal. When the first pin 21 of the MOS switch 20 receives the high-level signal, the MOS switch 20 is turned on. After being turned on, the third pin 23 is connected to the power module 10 to obtain power supply, and the second pin 22 is connected to the load heating wire 30. Current flows through the load heating wire 30 to generate heat.

[0045] In a specific embodiment, the MOS switch 20 further includes a body diode 24 , wherein the positive terminal of the body diode 24 is connected to the second pin 22 , and the negative terminal of the body diode 24 is connected to the third pin 23 .

[0046] Specifically, the MOS switch 20 is an N MOS type switch, which is used to control the switch of the current. When the MOS switch 20 is turned on, the body diode 24 can provide a reverse conduction path to protect the MOS switch 20 from being broken down by the reverse voltage. When the control module 40 sends a high level signal to the control end of the MOS switch 20, the MOS switch 20 is turned on, and the current can flow from the source (the second pin 22) to the drain (the third pin 23), and the load heating wire 30 is energized and starts to heat. At the same time, when the load heating wire 30 is powered off, the current will flow in the reverse direction. At this time, the body diode 24 will work, providing a reverse conduction path to prevent the MOS switch 20 from being broken down by the reverse voltage and protect the MOS switch 20.

[0047] In a specific embodiment, the electronic circuit 100 for measuring load resistance further includes a resistor R8, one end of the resistor R8 is connected between the first connection terminal IO1 and the first pin 21, and the other end of the resistor R8 is grounded.

[0048] Specifically, the resistor R8 is used to limit the current and protect other components. One end of the resistor R8 is connected between the first connection terminal IO1 of the control module 40 and the first pin 21 of the MOS switch 20, and the other end is grounded to form a series resistor network. When the control module 40 sends a high level signal to the connection point of the MOS switch 20, a part of the current will flow to the ground through the resistor R8, limiting the current size of the control signal.

[0049] In a specific embodiment, the electronic circuit 100 for measuring the load resistance value further includes a resistor R7, one end of which is connected between the load heating wire 30 and the second pin 22, and the other end is connected to the second connection terminal IO2. The electronic circuit 100 for measuring the load resistance value further includes a resistor R9, one end of which is grounded, and the other end is connected to the second connection terminal IO2.

[0050] Specifically, the resistor R7 is a fixed resistor. The resistor R9 plays the role of limiting the current and providing a circuit reference point in the circuit. One end of the resistor R7 is connected to the second connection terminal IO2 of the control module 40, limiting the current from the MOS switch 20 to the second connection terminal IO2, and protecting the second connection terminal IO2 port from damage by excessive current. The second connection terminal IO2 of the control module 40 is connected in series between the resistor R7 and the resistor R9, and the resistor R9 limits the current from the second connection terminal IO2 to the ground, providing a stable reference ground potential, and protecting the second connection terminal IO2 port from damage by excessive current. The resistor R7 and the resistor R9 form an RC low-pass filter together with the parasitic capacitance between the source of the MOS switch 20 and the second connection terminal IO2. This filter can slow down the transmission speed of the source voltage change, thereby reducing the noise received by the second connection terminal IO2.

[0051] Further, when the control module 40 turns on the MOS switch 20, so that the load heating wire 30 works, the first connection terminal IO1 is set to a high level state. The high level signal is sent to the gate of the MOS switch 20, that is, the first pin 21, through the first connection terminal IO1, so that the MOS switch 20 is closed, and the current flows from the drain to the source, that is, the third pin 23 flows to the second pin 22. At this time, the second connection terminal IO2 provides a stable potential to the source of the MOS switch 20 through the resistor R7 to ensure that the channel is formed normally. The resistor R7 limits the current flowing to the second connection terminal IO2 and protects the second connection terminal IO2 from being damaged by excessive current. When the control module 40 turns off the MOS switch 20 and stops the operation of the load heating wire 30, the first connection terminal IO1 port will be set to a low level state. The low level signal will close the channel of the MOS switch 20, preventing the current from flowing from the drain to the source. At this time, the second connection terminal IO2 is still provided to the ground through the resistor R9. A stable potential.

[0052] In a specific embodiment, the power module 10 has a BAT voltage, and the BAT voltage is obtained by measuring the internal working voltage of the control module 40, or by an external sampling circuit.

[0053] Specifically, obtaining the BAT voltage usually requires sampling using an analog circuit, and then converting the sampling result into a digital signal through an analog-to-digital converter (ADC). The control module 40 can obtain the BAT voltage by reading the value of the ADC.

[0054] Furthermore, the BAT voltage is obtained by measuring the internal working voltage of the control module 40. The control module 40 usually has a stable working voltage, which is V REF or V DD, used as the reference voltage of ADC. Connect the input pin of ADC to the positive terminal of power module 10, and then set the reference voltage of ADC to the internal V REF or V DD Next, the control module 40 measures the battery voltage through the ADC and converts it into a corresponding digital value.

[0055] The actual voltage of the battery can be calculated by using the known ADC quantization value and the operating voltage. The formula is as follows

[0056]

[0057] Among them, V BAT is the BAT voltage, ADC BAT is the ADC value of the measured BAT voltage. REF is the ADC value of the ADC reference voltage, V REF is the operating voltage, from which the BAT voltage is derived.

[0058] Further, the BAT voltage is obtained through an external sampling circuit. The external circuit generally includes a resistor divider network and a filter. A low-pass filter is used to eliminate possible noise. The positive pole of the power module 10 is connected to a larger resistor, and the negative pole is connected to the ground. The ADC pin of the control module 40 is connected to the middle point of the resistor divider network. The control module 40 reads the voltage connected to the middle point of the resistor divider network through the ADC.

[0059] The BAT voltage can also be calculated using the known ADC quantization value and the voltage division ratio. The formula is similar to the method for the internal operating voltage mentioned above.

[0060]

[0061] Among them, V BAT is the BAT voltage, ADC BAT is the ADC value of the measured BAT voltage. REF is the ADC value of the ADC reference voltage, V REF is the internal operating voltage, from which the BAT voltage is derived.

[0062] In a specific embodiment, a stabilized high-level output terminal 50 is provided between the second pin 22 and the load heating wire 30 , and the stabilized high-level output terminal 50 is connected to the ground.

[0063] Specifically, the function of the high-level output terminal 50 after voltage stabilization is to provide a stable high-level signal to the load heating wire 30 to ensure its normal operation. The high-level output terminal 50 after voltage stabilization and the ground form a voltage output loop. When the power supply system starts to work, the high-level output terminal 50 after voltage stabilization will provide the power supply voltage to the load heating wire 30, so that the load heating wire 30 works. The current starts from the high-level output terminal 50 after voltage stabilization, flows to GND through the resistor R7 and the second connection terminal IO2 and the resistor R9, forming a closed loop.

[0064] In a specific embodiment, an electronic cigarette includes a housing, a circuit board disposed in the housing, and an electronic circuit 100 for measuring load resistance.

[0065] Since the electronic circuit 100 for measuring load resistance has been described in detail above, it will not be described again here.

[0066] Thus, the electronic circuit 100 for measuring the load resistance provided above adopts a single MOS switch 20 and a small amount of resistors, and outputs a high level through the first connection terminal IO1 of the control module 40 to close the MOS switch 20, connects the resistor R6, the power module 10 and the load heating wire 30 in series, and the current flows through the resistor R6, the MOS switch 20 to the load heating wire 30. The current value of the resistor R6 is equal to the current value of the load heating wire 30, and the second connection terminal IO2 is connected in parallel with the load heating wire 30. The voltage value of the second connection terminal IO1 is equal to the voltage value of the load heating wire 30. The voltage of the load heating wire 30 is obtained by sampling the voltage of the second connection terminal IO2. The voltage difference between the two ends of the resistor R6 can be calculated by obtaining the voltage of the power module 10, thereby calculating the current value of the resistor R6, and then knowing the resistance value of the load heating wire 30. This design not only simplifies the circuit structure, but also allows the size of the control board to be reduced, thereby meeting the compactness requirements of modern electronic cigarette product design. In addition, due to the reduction in the number of components, the manufacturing cost is also reduced accordingly, which improves the market competitiveness of the product.

[0067] The above is only an implementation method of the present application. It should be pointed out that a person skilled in the art can make improvements without departing from the inventive concept of the present application, but these improvements are within the scope of protection of the present application.

Claims

1. An electronic circuit for measuring load resistance, characterized in that: include: A power module, a resistor R6, a MOS switch, a load heating wire, and a control module, wherein the control module has a first connection end and a second connection end; Two ends of the resistor R6 are connected to the power module and the MOS switch respectively, the MOS switch is connected to the first connection end, and the first connection end is used to output a high level to control the MOS switch to be closed; The second connection end is connected to the load heating wire for detecting the voltage across the load heating wire, and the resistor R6 is connected in series with the load heating wire.

2. The electronic circuit for measuring load resistance according to claim 1, characterized in that: The MOS switch has a first pin, a second pin and a third pin, the first pin is connected to the first connection end, the second pin is connected to the load heating wire, and the third pin is connected to the power module.

3. The electronic circuit for measuring load resistance according to claim 2, characterized in that: The MOS switch further includes a body diode, wherein an anode terminal of the body diode is connected to the second pin, and a cathode terminal of the body diode is connected to the third pin.

4. The electronic circuit for measuring load resistance according to claim 2, characterized in that: The electronic circuit for measuring the load resistance value further includes a resistor R8, one end of the resistor R8 is connected between the first connection end and the first pin, and the other end of the resistor R8 is grounded.

5. The electronic circuit for measuring load resistance according to claim 2, characterized in that: The electronic circuit for measuring the load resistance value further includes a resistor R7, one end of which is connected between the load heating wire and the second pin, and the other end of which is connected to the second connection end.

6. The electronic circuit for measuring load resistance according to claim 1, characterized in that: The electronic circuit for measuring the load resistance value further includes a resistor R9, one end of which is grounded, and the other end of which is connected to the second connection end.

7. The electronic circuit for measuring load resistance according to claim 1, characterized in that: The power supply module has a BAT voltage, and the BAT voltage is obtained by measuring the internal working voltage of the control module, or by an external sampling circuit.

8. The electronic circuit for measuring load resistance according to claim 1, characterized in that: The resistance of the resistor R6 is 20Ω.

9. The electronic circuit for measuring load resistance according to claim 2, characterized in that: A stabilized high-level output terminal is provided between the second pin and the load heating wire, and the stabilized high-level output terminal is connected to the ground.

10. An electronic cigarette, characterized in that: The invention comprises a housing, a circuit board arranged in the housing and the electronic circuit as claimed in any one of claims 1 to 9.

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