CN118201148A - Heating circuit, heating method and heating device - Google Patents

Abstract

The invention discloses a heating circuit, which comprises: one end of the first controllable switch is connected with a power supply of the heating circuit: one end of the oscillating circuit is connected with the other end of the first controllable switch, and the other end of the oscillating circuit is grounded; the oscillating circuit comprises a first branch and a second branch which are connected in parallel, the first branch comprises a first capacitor, the second branch comprises an inductance coil and a second capacitor which are connected in series, and the inductance coil can generate induction current in the heating element when being electrified. The heating circuit provided by the invention avoids the problem of high-temperature heating caused by short circuit of the power supply to the ground when the controllable switch is fully conducted. The invention also provides a heating method and a heating device.

Description

Heating circuit, heating method and heating device

Technical Field

The present invention relates to the field of novel tobacco, and in particular to a heating circuit, a heating method and a heating device.

Background technique

Traditional tobacco is harmful to the health of users. As a substitute for traditional tobacco, new aerosol generating devices have been developing rapidly in recent years. Common aerosol generating devices can be roughly divided into electronic cigarettes, heated cigarettes and other categories according to the form of aerosol generating materials. Liquid materials are used to generate aerosols in electronic cigarettes, while solid materials are used to generate aerosols in heated cigarettes, that is, solid aerosol-forming matrices, such as tobacco flakes, tobacco particles, tobacco shreds, reconstituted tobacco, etc.

The heating methods of existing aerosol generating devices mainly include resistance heating and electromagnetic heating. The principle of the aerosol generating device using resistance heating is to use the Joule effect of electric current to convert electrical energy into thermal energy. The heat energy is generated by the heating element and transmitted to the heated object through radiation, convection and conduction. The principle of the aerosol generating device using electromagnetic heating is to use high-frequency alternating voltage to act on the electromagnetic heating coil wound around the surface of the heated object to generate a magnetic field. The magnetic field acts on the surface of the object to be heated to generate eddy currents inside, so that the heated object generates heat.

Among them, common electromagnetic drive methods include single-tube drive, half-bridge drive, full-bridge drive, and E-type amplifier drive. Half-bridge drive uses the upper and lower bridge arms to control separately. The upper and lower bridge arms are turned on in time to control the flow direction of the current in the coil, so as to achieve the alternation of the electric field in the coil, form a stable changing magnetic field, and make the receptors in the magnetic field heat up the smoke. In the existing half-bridge drive circuit, the upper and lower bridge arms are connected to the power supply and the ground respectively. When the system fails, the upper and lower bridge arms may be turned on at the same time, causing a short circuit between the power supply and the ground, which in turn causes the risk of high temperature.

Summary of the invention

The purpose of the present invention is to solve the problem that in the existing half-bridge drive circuit, when the upper and lower bridge arms are turned on at the same time, the power supply is short-circuited to the ground, thereby causing the risk of high temperature heating.

In a first aspect, the heating circuit provided by the present invention avoids the problem of high temperature heating caused by a short circuit of the power supply to the ground when all controllable switches are turned on.

To solve the above technical problems, an embodiment of the present invention discloses a heating circuit, comprising: a first controllable switch, one end of which is connected to a power supply of the heating circuit; an oscillation circuit, one end of which is connected to the other end of the first controllable switch, and the other end of the oscillation circuit is grounded; wherein the oscillation circuit comprises a first branch and a second branch connected in parallel, the first branch comprises a first capacitor, and the second branch comprises an inductor coil and a second capacitor connected in series, and the inductor coil can generate an induced current in the heating element when energized.

By adopting the above technical scheme, the heating circuit provided by the present invention is provided with a first capacitor and a second capacitor on the loop between the power supply and the ground, and the first capacitor and the second capacitor are connected in parallel. The capacitors have the characteristics of blocking direct current and passing alternating current. Therefore, even if the controllable switches are turned on at the same time, the heating circuit will not be short-circuited, and the high temperature problem caused by it will not occur.

According to another specific embodiment of the present invention, the first branch further includes a second controllable switch connected in series with the first capacitor.

According to another specific embodiment of the present invention, the second branch further includes a second controllable switch connected in series with the inductor and the second capacitor.

In a second aspect, an embodiment of the present invention discloses a heating method, including a heating circuit as described above, the method comprising: controlling a first controllable switch to be turned on so that a power supply charges a first capacitor or a second capacitor; based on determining that the first capacitor or the second capacitor satisfies a first condition, controlling the first controllable switch to be turned off so that an oscillating current is generated in the oscillation circuit.

By adopting the above technical solution, a first capacitor and a second capacitor are connected in parallel between the power supply and the ground terminal, so as to realize the heating function of the heating circuit to heat the target object while preventing the power supply from being short-circuited to the ground and the risk of high temperature heating caused by it.

According to another specific embodiment of the present invention, the first condition includes: the voltage, current or power of the first capacitor or the second capacitor is greater than a preset threshold.

According to another specific embodiment of the present invention, the heating circuit is the heating circuit according to any one of claims 2 to 3; the step of controlling the first controllable switch to be turned on includes controlling the second controllable switch to be turned off;

After controlling the first controllable switch to be turned off, the method further comprises:

The second controllable switch is controlled to be turned on.

According to another specific embodiment of the present invention, when the heating temperature of the heating element exceeds a preset temperature, the second controllable switch is controlled to be disconnected or both the first controllable switch and the second controllable switch are controlled to be turned on.

According to another specific embodiment of the present invention, when the real-time power level of the first capacitor or the second capacitor is lower than a preset threshold, the first controllable switch is turned on to allow the power supply to charge the first capacitor or the second capacitor.

In a third aspect, the present invention provides a heating device, comprising: a heating circuit as described above; and a heating element, wherein the inductor in the heating circuit is used to generate an induced current in the heating element.

By adopting the above technical solution, the heating device can heat the heating element through the heating circuit using the electromagnetic heating principle. The heating circuit can avoid short circuit to reduce damage to the heating device caused by overheating, while satisfying the user's sensory experience and preventing accidents that may cause user injury.

In a fourth aspect, the present invention provides a heating device using the aforementioned heating method, comprising a heating element, wherein an inductor coil in the heating circuit is used to generate an induced current in the heating element.

By adopting the above technical solution, the heating device can use the above heating method to heat the heating element through the above heating circuit using the electromagnetic heating principle. The heating circuit can avoid short circuit to reduce the damage to the heating device caused by overheating, while satisfying the user's sensory experience and preventing accidents that may cause user injury.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 shows a circuit diagram of a heating circuit in a first embodiment of the present invention;

FIG2 shows a circuit diagram 1 of a heating circuit in a second embodiment of the present invention;

FIG3 shows a second circuit diagram of a heating circuit in a second embodiment of the present invention;

FIG4 shows a third circuit diagram of a heating circuit in a second embodiment of the present invention;

FIG5 shows a current waveform diagram 1 in one embodiment of the present invention;

FIG6 shows a second current waveform diagram in one embodiment of the present invention;

FIG7 shows a circuit diagram of a heating circuit in a third embodiment of the present invention;

FIG8 shows a flow chart 1 of a heating method in one embodiment of the present invention;

FIG. 9 shows a second flow chart of a heating method in one embodiment of the present invention.

Detailed ways

The following specific embodiments illustrate the implementation of the present invention, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this implementation. On the contrary, the purpose of introducing the invention in conjunction with the implementation is to cover other options or modifications that may extend based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

In the description of this embodiment, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this embodiment can be understood according to specific circumstances.

In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

1 , in the first embodiment of the present invention, a heating circuit 1 is provided, namely a classic electromagnetic half-bridge driving circuit. The heating circuit 1 comprises two parallel branches, namely an upper bridge branch and a lower bridge branch.

The upper bridge branch includes an upper arm electronic switch IGBT1 (insulated gate bipolar transistor, in English, Insulated Gate Bipolar Transistor, abbreviated as IGBT), a first capacitor C1, and an inductor L connected in series. The lower bridge branch includes a lower arm electronic switch IGBT2, a second capacitor C2, and an inductor L connected in series. In the heating circuit 1, the power supply of the heating circuit 1 is respectively connected to the upper arm electronic switch IGBT1 and the first capacitor C1 of the upper bridge branch; the ground terminal of the heating circuit 1 is respectively connected to the lower arm electronic switch IGBT2 and the second capacitor C2.

Among them, the first capacitor C1 and the second capacitor C2 are non-polar capacitors; L is an inductor coil; the upper arm electronic switch and the lower arm electronic switch can use IGBT, MOS or Darlington tube; VCC is the power supply of the heating circuit 1, and the power supply provides the power supply voltage for the heating circuit 1; GND is the ground of the heating circuit, or the reference plane, that is, the grounding terminal.

Referring to FIG1 , the working principle of the heating circuit 1 is:

When the upper arm electronic switch IGBT1 is turned on, the lower arm electronic switch IGBT2 is turned off, and the current starts from the power supply VCC, flows through the upper arm electronic switch IGBT1, the inductor coil L, and the second capacitor C2, and then is grounded. That is, the current flowing through the inductor coil L is from left to right. Since the inductor coil L has the characteristic of maintaining current, the current in the inductor coil L will gradually increase until it reaches the peak value. Keeping the upper arm electronic switch IGBT1 in the on state, the voltage across the second capacitor C2 gradually increases during the charging process, so that the voltage difference across the inductor coil L gradually decreases. Since the inductor coil L has the characteristic of maintaining current, the inductor coil L continues to output current, and gradually decreases from the peak value. Then, the upper arm electronic switch IGBT1 is turned off.

When the lower arm electronic switch IGBT2 is turned on, the upper arm electronic switch IGBT1 is turned off, and the current starts from the power supply VCC, flows through the first capacitor C1, the inductor L, and the lower arm electronic switch IGBT2 and then grounded. The current direction of the inductor L is from right to left. Since the inductor L has the characteristic of maintaining current, the current in the inductor L will gradually increase until it reaches the peak value. Keep the lower arm electronic switch IGBT2 in the on state. Since the inductor L has the characteristic of maintaining current, the inductor L continuously outputs current. Since the second capacitor C2 discharges to the ground GND through the inductor L and the lower bridge arm switch IGBT2, as the energy storage of the second capacitor C2 decreases, the current flowing through the inductor L gradually decreases from the peak value until the energy in the inductor L is discharged. By controlling the heating circuit 1 to be in different working states by turning on and off the upper arm electronic switch IGBT1 and the lower arm electronic switch IGBT2, the electric field of the inductor L is alternating, and a changing magnetic field is generated to heat the heating element located in the magnetic field.

In this embodiment, in the heating circuit 1, if the upper arm electronic switch IGBT1 and the lower arm electronic switch IGBT2 are turned on at the same time, the power supply VCC will be short-circuited to the ground terminal GND. That is, since the resistance of the upper arm electronic switch IGBT1 and the lower arm electronic switch IGBT2 is small and the current is too large, a large amount of heat is generated on the upper arm electronic switch IGBT1 and the lower arm electronic switch IGBT2, resulting in high temperatures of the upper arm electronic switch IGBT1 and the lower arm electronic switch IGBT2, causing serious system risks and potential safety hazards.

To this end, with reference to FIGS. 2 to 4 , in a second embodiment of the present invention, a heating circuit 2 is provided. The heating circuit 2 includes a controllable switch. In some possible embodiments provided by the present invention, the controllable switch is any one of a unipolar switch, an IGBT, a MOS tube (Metal-Oxide-Semiconductor Field-Effect Transistor, abbreviated as MOSFET, referred to as MOS tube for short), and a Darlington tube. FIG. 2 shows a heating circuit 21 in which the controllable switch is an IGBT. FIG. 3 shows a heating circuit 22 in which the controllable switch is a unipolar switch. FIG. 4 shows a heating circuit 23 in which the controllable switch is a MOS tube.

Referring to FIG2 , the heating circuit 21 includes a first controllable switch IGBT1 and an oscillating circuit. One end of the first controllable switch IGBT1 is connected to the power supply VCC of the heating circuit 21. One end of the oscillating circuit is connected to the other end of the first controllable switch IGBT1, and the other end of the oscillating circuit is grounded GND. The oscillating circuit includes a first branch and a second branch connected in parallel, the first branch includes a first capacitor C1, and the second branch includes an inductor L and a second capacitor C2 connected in series, and the inductor L can generate an induced current in the heating element when powered on.

By adopting the above technical solution, a first capacitor C1 and a second capacitor C2 are provided between the power supply VCC and the ground terminal GND, and the first capacitor C1 and the second capacitor C2 are arranged in parallel, so as to realize the heating function of the heating circuit 21 to heat the target object while preventing the power supply VCC from being short-circuited to the ground GND and preventing the risk of high temperature heating caused by it.

In the heating circuit 21, the first capacitor C1 and the second capacitor C2 are non-polar capacitors; L is an inductor; the upper arm electronic switch and the lower arm electronic switch can be made of IGBT, MOS or Darlington tube; VCC is the power supply of the heating circuit 1, and the power supply provides the power supply voltage for the heating circuit 1; GND is the ground terminal, and CTL is the signal input terminal, which is interconnected with the micro control unit MCU and is used to receive the control signal of the micro control unit MCU to turn on or off the first controllable switch or the second controllable switch.

In the heating circuit 21, the first controllable switch IGBT1 is controlled to be turned on so that the power supply VCC charges the first capacitor C1; the first controllable switch IGBT1 is controlled to be turned off so that the first branch and the second branch form an oscillation loop, and current is passed through the inductor L to heat the target object provided with the heating element.

In some other possible embodiments provided by the present invention, the second branch further includes a second controllable switch IGBT2 connected in series with the inductor L1 and the second capacitor C2. That is, the second branch further includes a second controllable switch IGBT2, and the second capacitor C2 is grounded through the second controllable switch IGBT2.

Referring to FIG. 2 , the working principle of the heating circuit 21 is:

The first controllable switch IGBT1 is turned on, and the second controllable switch IGBT2 is turned off. The voltage at point A is equal to the voltage of the power supply VCC. The current starts from the power supply VCC, flows through the first controllable switch IGBT1 and the first capacitor C1, and reaches the ground terminal GND. In this process, the power supply VCC charges the first capacitor C1, so that the voltage at the A terminal of the first capacitor C1 to the ground GND is equal to the voltage of the power supply VCC. (Here, it is assumed that the first controllable switch IGBT1 and the second controllable switch IGBT2 are both ideal switches with no internal resistance).

The first controllable switch IGBT1 is disconnected, the second controllable switch IGBT2 is turned on, and the voltage at point C is equal to the voltage at the ground terminal GND. The first capacitor C1, the inductor L1, the second capacitor C2, and the second controllable switch IGBT2 form a loop. Since the first capacitor C1 stores electricity and the second capacitor C2 does not store electricity, the voltage at point A is higher than that at point B. The first capacitor C1 will charge the second capacitor C2 through the inductor L1. At this time, the current direction is the first capacitor C1, the inductor L1, the second capacitor C2, the second controllable switch IGBT2, and the ground terminal GND. Since the inductor L1 is an inductive element and has the characteristic of hindering current changes, the current will gradually increase. When the voltages at points A and B are equal, the current on the inductor L1 reaches the maximum value. Due to the current-maintaining characteristic of the inductor, the first capacitor C1 will continue to charge the second capacitor C2, the charging current will gradually decrease, and the voltage at point B will gradually increase. When the current on the inductor L1 is zero, the charging of the second capacitor C2 is cut off.

Since the current of the inductor L1 is zero and the voltage of the second capacitor C2 is higher than the voltage of the first capacitor C1, the second capacitor C2 charges the first capacitor C1 through the inductor L1. At this time, the direction of the current flowing through the inductor L1 is opposite to the direction of the current flowing through the inductor L1 when the first capacitor C1 charges the second capacitor C2.

When the first controllable switch IGBT1 is turned off and the second controllable switch IGBT2 is turned on, the first capacitor C1 charges the second capacitor C2, and the second capacitor C2 charges the first capacitor C1 in a continuous and repeated cycle. Through the above process, an alternating current is formed on the inductor L1, and the alternating current in the inductor L1 forms an alternating magnetic field, which generates eddy currents on the surface of the heating element in the magnetic field, thereby generating heat, which is used to heat the target object.

In some possible embodiments provided by the present invention, as described above, the first controllable switch is any one of a unipolar switch, an IGBT, a MOS tube, and a Darlington tube, and the second controllable switch is any one of a unipolar switch, an IGBT, a MOS tube, and a Darlington tube.

In the heating circuit 21, even if the first controllable switch IGBT1 and the second controllable switch IGBT2 are turned on at the same time, the first capacitor C1 and the second capacitor C2 connected in parallel between the power supply VCC and the ground terminal GND can prevent the power supply VCC from being short-circuited to the ground GND and the risk of high temperature heating caused by this.

Referring to Fig. 3, the present invention provides a heating circuit 22, which is different from the heating circuit 21 only in that the first controllable switch and the second controllable switch are both single-pole switches. The heating principle of the heating circuit 22 is the same as that of the heating circuit 21, and will not be described in detail here.

Referring to FIG4 , the present invention provides a heating circuit 23, which is different from the heating circuit 22 and the heating circuit 21 only in that the first controllable switch and the second controllable switch are both MOS tubes. In the heating circuit 23, the source S of the first controllable switch Q1 is connected to the power supply, the gate G is connected to the signal input terminal, and the drain D is connected to one end of the oscillation circuit. The source S of the second controllable switch Q2 is grounded, the gate G is connected to the signal input terminal, and the drain D is connected to the second capacitor C2. The heating principle of the heating circuit 23 is the same as that of the heating circuit 21 and the heating circuit 22, and will not be repeated here.

Referring to FIG. 5 , it shows the current waveform at point B (as shown in FIG. 2 ) when the heating circuit 2 is working continuously, and the current waveform is approximately a sine wave.

Referring to Fig. 6, a single current oscillation waveform at point B (as shown in Fig. 2) when the heating circuit 2 is continuously working is shown, that is, the current waveform formed when the heating circuit 2 is charged only once, and its waveform is a damped oscillation shape, and its characteristic is that the oscillation waveform becomes smaller and smaller until it disappears over time.

7 , in the third embodiment of the present invention, the heating circuit 3 includes a first controllable switch Q1 and an oscillating circuit.

One end of the first controllable switch Q1 is connected to the power supply VCC of the heating circuit 3. One end of the oscillation circuit is connected to the other end of the first controllable switch Q1, and the other end of the oscillation circuit is grounded GND. The oscillation circuit includes a first branch and a second branch connected in parallel, the first branch includes a first capacitor C1 and a second controllable switch Q2 connected in series, and the first capacitor C1 is grounded GND through the second controllable switch Q2. The second branch includes an inductor L1 and a second capacitor C2 connected in series, and the inductor L1 can generate an induced current in the heating element when powered on.

When the first controllable switch Q1 is turned on, the power source VCC charges the second capacitor C2 due to the direct current isolation characteristic of the inductor L1.

When the first controllable switch Q1 is turned off and the second controllable switch Q2 is turned on, the oscillating circuit (i.e., the first branch and the second branch) continuously repeats the aforementioned second capacitor C2 charging the first capacitor C1 and the first capacitor C1 charging the second capacitor C2. Through the above process, an alternating current is formed on the inductor L1, and the alternating current in the inductor L1 forms an alternating magnetic field, so that eddy currents are generated on the surface of the heating element located in the magnetic field, thereby generating heat for heating the target object. That is, the heating principle of the heating circuit 3 is the same as that of the heating circuit 2, and will not be repeated here.

When the first controllable switch Q1 and the second controllable switch Q2 are turned on at the same time, the first capacitor C1 and the second controllable switch Q2 are connected in series between the power supply VCC and the ground terminal GND, and the power supply VCC charges the first capacitor C1 to prevent the power supply VCC from being short-circuited to the ground GND and the risk of high temperature caused thereby.

In a second aspect, referring to FIG8 , the present invention provides a heating method for heating a circuit. The heating circuit is a heating circuit in any of the above embodiments. The heating method comprises:

S1: Control the first controllable switch IGBT1 to be turned on, so that the power supply VCC charges the first capacitor C1;

S2: Based on the determination that the first capacitor C1 satisfies the first condition, the first controllable switch IGBT1 is controlled to be turned off, so that an oscillating current is generated in the oscillating circuit. Current is passed through the inductor L1 to heat the heating element.

By adopting the above technical solution, a first capacitor C1 and a second capacitor C2 are provided in parallel between the power supply VCC and the ground terminal GND, so as to realize the heating function of the heating circuit 2 for heating the heating element while preventing the power supply VCC from being short-circuited to the ground GND and the risk of high temperature heating caused thereby.

For example, in some possible embodiments provided by the present invention, the first condition includes: the voltage of the first capacitor C1 is greater than a preset threshold value. That is, until the first capacitor C1 is fully charged, the first controllable switch IGBT1 is controlled to be disconnected. For another example, in some possible embodiments provided by the present invention, the first condition includes: the current of the first capacitor C1 is greater than a preset threshold value, and the first controllable switch IGBT1 is controlled to be disconnected. For another example, the first condition includes: the power of the first capacitor C1 is greater than a preset threshold value, and the first controllable switch IGBT1 is controlled to be disconnected.

In some other possible embodiments provided by the present invention, referring to Figures 2 to 5, the heating circuit is the heating circuit 2 described in the second embodiment and the heating circuit 3 described in the third embodiment. Referring to Figure 2, in S2: based on determining that the first capacitor C1 satisfies the first condition, after controlling the first controllable switch IGBT1 to be disconnected, the heating method further includes: controlling the second controllable switch IGBT2 to be turned on.

Specifically, referring to FIG. 9 and in combination with FIG. 2 , the heating method of the heating circuit 21 is:

S11: controlling the first controllable switch IGBT1 to be turned on and the second controllable switch IGBT2 to be turned off, so that the power supply VCC charges the first capacitor C1;

S12: Based on determining that the first capacitor C1 satisfies the first condition, the first controllable switch IGBT1 is controlled to be turned off and the second controllable switch IGBT2 is controlled to be turned on, so that an oscillating current is generated in the oscillation circuit, and the inductor L1 can generate an induced current in the heating element.

Exemplarily, as mentioned above, the first condition includes: the voltage of the first capacitor C1 is greater than a preset threshold, or the current of the first capacitor C1 is greater than a preset threshold, or the power of the first capacitor C1 is greater than a preset threshold. The present invention is not limited to this.

In a third aspect, the present invention provides a heating device (not shown in the figure), which includes a heating circuit 2 or a heating circuit 3 and a heating element as described above. Among them, the inductor L1 in the heating circuit 2 or the heating circuit 3 is used to generate an induced current in the heating element. With the above technical solution, the heating device can heat the heating element by using the electromagnetic heating principle through the heating circuit 2 or the heating circuit 3, and the heating circuit 2 or the heating circuit 3 can avoid short circuit to reduce the damage to the heating device caused by overheating, while satisfying the sensory experience of the user and preventing the occurrence of accidents of user injury.

In the present invention, the working process of the heating device is described by taking the heating circuit 21 of the second embodiment shown in FIG. 2 as an example:

The heating device comprises a heating circuit 21 and a micro control unit MCU. The micro control unit MCU is connected to the CTL1 and CTL2 signal receiving terminals of the heating circuit 21.

The heating device is turned on, and the program is set to make the microcontroller unit MCU send a signal to control the first controllable switch IGBT1 to be turned on. CTL1 receives the signal and turns on the first controllable switch IGBT1. In the heating circuit 21, the power supply VCC charges the first capacitor C1 until the first capacitor C1 is fully charged, and the microcontroller unit MCU controls the first controllable switch IGBT1 to be turned off through CTL1.

Next, the microcontroller unit MCU sends a signal to control the conduction of the second controllable switch IGBT2. Since the level in the first capacitor C1 is inconsistent with the level in the second capacitor C2, that is, the level in the first capacitor C1 is higher than the level in the second capacitor C2, the first capacitor C1 charges the second capacitor C2 through the inductor L1, and a changing current passes through the inductor L1. Since the inductor L1 is an inductive load, it has the characteristic of maintaining a constant current. In the process of charging the first capacitor C1 to the second capacitor C2, an overshoot will occur, that is, the level of the second capacitor C2 will be higher than the first capacitor C1. At this time, the second capacitor C2 charges the first capacitor C1 through the inductor L1, and so on, that is, an alternating current is generated on the inductor L1, and the heating element located in the magnetic field is heated by the principle of electromagnetic heating.

The heating device also includes a temperature measuring unit, which can measure the heating temperature of the heating element. When the heating temperature of the heating element exceeds a preset temperature, the microcontroller unit MCU controls the second controllable switch IGBT2 to disconnect and stop heating the heating element to cool the heating element.

Next, when the heating temperature of the heating element is lower than the preset temperature, the microcontroller unit MCU controls the first controllable switch IGBT1 to remain in the off state through CTL1, and controls the second controllable switch IGBT2 to be turned on through CTL2, that is, the oscillation circuit works to enable the heating circuit 21 to continue heating the heating element.

Alternatively, as mentioned above, the heating device further includes a temperature measuring unit, which can measure the heating temperature of the heating element. When the heating temperature of the heating element exceeds a preset temperature, the microcontroller unit MCU controls the first controllable switch IGBT1 to be turned on and the second controllable switch IGBT2 to be turned on, so as to cool the heating element. In this process, since the first capacitor C1 and the second capacitor C2 are connected in parallel in the loop between the power supply VCC and the ground terminal GND, the capacitors have the characteristics of blocking direct current and passing alternating current, so even if the first controllable switch IGBT1 and the second controllable switch IGBT2 are all turned on at the same time, there will be no high temperature risk caused by short circuit.

Next, when the heating temperature of the heating element is lower than the preset temperature, the microcontroller unit MCU controls the first controllable switch IGBT1 to be turned off through CTL1 and controls the second controllable switch IGBT2 to be turned on through CTL2, that is, the oscillation circuit works to enable the heating circuit 21 to continue heating the heating element.

In the above process, the heating device also includes a power monitoring unit for monitoring the real-time power of the first capacitor C1 and the second capacitor C2. When the real-time power of the first capacitor C1 is lower than a preset threshold, the microcontroller unit MCU controls the first controllable switch IGBT1 to turn on, so that the power supply VCC charges the first capacitor C1 until the first capacitor C1 is fully charged, and the microcontroller unit MCU controls the first controllable switch IGBT1 to turn off.

When the heating device is not used, the microcontroller unit MCU controls the first controllable switch IGBT1 to be turned off through CTL1 and controls the second controllable switch IGBT2 to be turned off through CTL2, thereby turning off the heating circuit 21.

In a fourth aspect, the present invention provides a heating device (not shown in the figure) using the aforementioned heating method, comprising a heating element as described above, wherein the inductor coil L1 in the heating circuit is used to generate an induced current in the heating element for heating the target object.

By adopting the above technical scheme, the heating device using the aforementioned heating method can heat the heating element through the heating circuit 2 using the electromagnetic heating principle. The heating circuit 2 can avoid short circuit to reduce the damage to the heating device caused by overheating, while satisfying the user's sensory experience and preventing accidents that may cause user injury.

In some possible embodiments provided by the present invention, the heating device is an aerosol generating device. For example, the aerosol generating device is an electronic cigarette, and the electronic cigarette liquid is heated by the heating circuit 2 to satisfy the user's smoking experience; for another example, the aerosol generating device is a heat-not-burn smoking device, and the heated cigarette is heated by the heating circuit 2 to satisfy the user's smoking experience.

Although the present invention has been illustrated and described with reference to certain preferred embodiments of the present invention, it should be understood by those skilled in the art that the above contents are further detailed descriptions of the present invention in conjunction with specific embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. Those skilled in the art may make various changes in form and details, including making several simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims (10)

1. A heating circuit, comprising: A first controllable switch, one end of which is connected to a power supply of the heating circuit: an oscillating circuit, one end of the oscillating circuit being connected to the other end of the first controllable switch, and the other end of the oscillating circuit being grounded; The oscillation circuit includes a first branch and a second branch connected in parallel, the first branch includes a first capacitor, and the second branch includes an inductor coil and a second capacitor connected in series, and the inductor coil can generate an induced current in the heating element when powered on. 2 . The heating circuit according to claim 1 , wherein the first branch further comprises a second controllable switch connected in series with the first capacitor. 3. The heating circuit according to claim 1, characterized in that the second branch further includes a second controllable switch connected in series with the inductor and the second capacitor. 4. A heating method for a heating circuit, characterized in that the heating circuit is the heating circuit according to any one of claims 1 to 3, and the method comprises: Controlling the first controllable switch to be turned on so that the power supply charges the first capacitor or the second capacitor; Based on determining that the first capacitor or the second capacitor satisfies a first condition, the first controllable switch is controlled to be disconnected, so that an oscillating current is generated in the oscillation circuit. 5. The heating method according to claim 4, characterized in that the first condition includes: the voltage, current or power of the first capacitor or the second capacitor is greater than a preset threshold. 6. The heating method according to claim 4 or 5, characterized in that the heating circuit is the heating circuit according to any one of claims 2 to 3; the step of controlling the first controllable switch to be turned on includes controlling the second controllable switch to be turned off; After controlling the first controllable switch to be turned off, the method further comprises: The second controllable switch is controlled to be turned on. 7. The heating method according to claim 6, characterized in that when the heating temperature of the heating element exceeds a preset temperature, the second controllable switch is controlled to be disconnected or the first controllable switch and the second controllable switch are controlled to be turned on. 8. The heating method according to claim 6, characterized in that when the real-time charge of the first capacitor or the second capacitor is lower than a preset threshold, the first controllable switch is turned on to allow the power supply to charge the first capacitor or the second capacitor. 9. A heating device comprising: A heating circuit as claimed in any one of claims 1 to 3; and A heating element, wherein the inductor in the heating circuit is used to generate an induced current in the heating element. 10. A heating device using the heating method according to any one of claims 5 to 8, characterized in that it comprises the heating element, wherein the inductor in the heating circuit is used to generate an induced current in the heating element.