Patent Description:
For an atomization device, the core element is a heating element, a core technology is to control the temperature of the heating element, and a key of temperature control is to measure the temperature of the heating element. Moreover, the heating element is usually a heating resistor, and the heating resistor is powered to generate heat, so that the atomized substrate is heated, and the atomized substrate is heated to generate aerial fog or aerosol. In a current heating circuit, a sampling resistor is usually connected to a heating loop circuit in series to detect the resistance value of a heating resistor, and then the voltage drop on the sampling resistor is amplified by an operational amplifier and then collected and calculated by a MCU (Microcontroller Unit), wherein the MCU obtains current through the formula I = U<NUM>/R<NUM>, Where U<NUM> is the voltage drop across the sampling resistor, R<NUM> is the resistance of the sampling resistor, and I is the current. Because the voltage of the MCU is usually obtained through the LDO (Low Dropout Regulator) after voltage reduction, the voltage that the MCU can collect is lower than the voltage of the heating power supply (battery), so the voltage on the heating resistor also needs to be divided by the sampling resistor and then collected by the MCU. The resistance of the heating resistor is then calculated by formula R<NUM> = U<NUM>/I, where U<NUM> is the voltage drop across the heating resistor and R<NUM> is the resistance of the heating resistor. In this way, because the sampling resistor is connected in series with the heating loop circuit, the sampling resistance value must be very small (mΩ level) to avoid affecting the heating efficiency. Because the voltage drop on the sampling resistor is very small, an operational amplifier needs to be added to amplify the voltage drop of the sampling resistor. Because that sampling resistor is very small, the precision of the resistance value cannot be very high, in addition, the error of the operational amplifier is also caused, so that the error of the sampled current is relatively large, in addition, the precision error of the sampling resistor causes that the collect voltage on the heating resistor also has an error, therefore, the resistance error of the heating resistor calculated by formula R<NUM>=U<NUM>/I is relatively large, and the cost is relatively high due to the fact that an operational amplify needs to be added.

Publication <CIT> is considered to be relevant to the present application.

The technical problem to be solved by the invention is that the prior art has the defects of large error and high cost. The problem underlying the present application is solved by a heating circuit for an atomization device having the features of claim <NUM>, an atomization device having the features of claim <NUM>, a heating method for an atomization device having the features of claim <NUM> and a readable storage medium having the features of claim <NUM>.

The invention adopts the technical scheme that a heating circuit of the atomization device comprises a heating resistor, an MCU and a sampling resistor, wherein the resistance value of the sampling resistor is greater than the resistance value of the heating resistor;.

the MCU controls a battery power supply to only supply power to the heating resistor in a first time period of a PWM (Pulse Width Modulation) period, so that the heating resistor works normally;.

the MCU controls the battery power supply to supply power to the sampling resistor and the heating resistor which are connected in series in a second time period of a PWM period, and respectively collects a voltage of the heating resistor and a voltage of the sampling resistor, and calculates the resistance value of the heating resistor according to the resistance value of the sampling resistor and the collected voltages.

The invention also comprises: a first driving unit, a second driving unit, and,.

According to the invention, the first driving unit comprises a PMOS (Positive Channel Metal Oxide Semiconductor,) transistor, a switching device, a third resistor and a fourth resistor. A first IO port of the MCU is respectively connected with a control end of the switching device and a first end of the fourth resistor, a first end of the switching device and a second end of the fourth resistor are respectively electrical grounding, and a second end of the switching device is respectively connected with a gate of the PMOS transistor and a first end of the third resistor; a source electrode of the PMOS transistor and a second end of the third resistor are respectively connected with a battery power supply, a drain electrode of the PMOS transistor is connected with a first end of the heating resistor, and a second end of the heating resistor is electrical grounding.

In an alternative embodiment, the second driving unit comprises a first transistor, a base electrode of the first transistor is connected with a second IO port of the MCU, a collector electrode of the first transistor is connected with a battery power supply, and an emitter electrode of the first transistor is respectively connected with a first end of the sampling resistor and a third IO port of the MCU; a second end of the sampling resistor is respectively connected with the first end of the heating resistor and a fourth IO port of the MCU.

In an alternative embodiment, the switching device comprises a NMOS (Negative Channel Metal Oxide Semiconductor) transistor, the gate of the NMOS transistor is connected to the first IO port of the MCU, and a source electrode of the NMOS transistor is electrical grounding, a drain electrode of the NMOS transistor is respectively connected with the gate of the PMOS transistor and a first end of the third resistor.

In an alternative embodiment, the switching device comprises a second transistor and a fifth resistor, wherein abase electrode of the second transistor is respectively connected with the first end of the fourth resistor and a first end of the fifth resistor, and a collector electrode of the second transistor is respectively connected with the gate of the PMOS transistor and the first end of the third resistor; an emitter electrode of the second transistor and the second end of the fourth resistor are electrical grounding respectively, and a second end of the fifth resistor is connected to the first IO port of the MCU.

The present invention also provides an atomization device including the heating circuit described above.

The present invention also provides a heating method of the atomization device, which is applied to an MCU and comprises the following steps:.

According to the invention, controlling the battery power supply to only supply power to the heating resistor comprises:
by control a first driving unit, the battery power supply only supplies power to the heating resistor.

According to the invention, controlling the battery power supply to supply power to the sampling resistor and the heating resistor which are connected in series comprises:
by controlling a second driving unit, the battery power supply supplies power to the sampling resistor and the heating resistor which are connected in series.

The present invention also provides a readable storage medium which stores a computer program, the computer program realizes the heating method described above when it is executed by the processor.

According to the technical scheme provided by the invention, in addition to a heating loop circuit, an additional detection loop circuit is added to a heating circuit of the atomization device, and an MCU realizes heating control by adopting a PWM driving mode, that is, the heating loop circuit and the detection loop circuit are controlled to work at different time periods, specifically, in a first time period of a PWM period, the MCU controls a battery power supply to only supply power to a heating resistor, in a second time period of the PWM period, the MCU controls the battery power supply to supply power to a sampling resistor and the heating resistor which are connected in series, that is, the MCU controls the detection loop circuit to work. In the heating circuit, because the sampling resistor only works when the resistance of the heating resistor is detected (in the second time period of the PWM period) and does not work at other times, the sampling resistor can select a resistor with a greater resistance, so that on one hand, because the accuracy of the sampling resistor with a greater resistance can be higher, the resistance detection accuracy of the heating resistor can be improved; on the other hand, because the voltage on the sampling resistor can be directly sampled through an MCU (with an ADC (Analog To Digital Converter) port), amplification by an operational amplifier is no longer needed, the accuracy of voltage sampling can be improved, and then the resistance detection accuracy of the heating resistor is improved. At the same time, since an operational amplifier is not required, the cost can be reduced.

In order to more clearly illustrate the embodiments of the present invention, the following will briefly introduce the drawings used in the description of the embodiments. Wherein in the drawings:.

In the following, the technical solutions of the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings of the embodiments of the present invention.

Aiming at the technical problems of low detection precision of the resistance value of the heating resistor and high cost in the existing heating circuit, the invention provides a heating circuit of an atomization device, which includes an MCU, a heating resistor and a sampling resistor, and the resistance value of the sampling resistor is greater than that of heating resistor, for example, the sampling resistor is a high-precision resistor with a resistance value of Ω (that is, a resistance value of at least <NUM>Ω). In addition, the MCU controls a battery power supply to only supply power to the heating resistor in a first time period of a PWM period, so that the heating resistor works normally; the MCU controls the battery power supply to supply power to the sampling resistor and the heating resistor which are connected in series in a second time period of the PWM period, and respectively collects the voltage of the heating resistor and the voltage of the sampling resistor in the second time period, and calculates the resistance value of the heating resistor according to the resistance value of the sampling resistor and the collected voltages. It should be understood that the PWM period is equal to the sum of the first time period and the second time period.

According to the invention, in addition to a heating loop circuit, a detection loop circuit is additionally arranged in the heating circuit, and the MCU adopts a PWM driving mode to realize heating control, that is, to control the heating loop circuit and the detection loop circuit to work in different time periods. Specifically, in a first time period of a PWM period, the MCU controls the battery power supply to only supply power to the heating resistor, that is, to control the heating loop circuit to work; in a second period of the PWM period, the MCU controls the battery power supply to supply power to the sampling resistor and the heating resistor which are connected in series, that is, the MCU controls the detection loop circuit to work. In the heating circuit of the invention, because the sampling resistor only works when the resistance of the heating resistor is detected (in the second time period of the PWM period) and does not work at other times, the sampling resistor can be a resistor with a greater resistance, so that, on one hand, the accuracy of the sampling resistor with a greater resistance can be higher, therefore, the resistance value detection accuracy of the heating resistor can be improved; on the other hand, because the voltage on the sampling resistor can be directly sampled by the MCU (with an ADC port) and does not need to be amplified by an operational amplifier, the accuracy of voltage sampling can be improved, and then the resistance value detection accuracy of the heating resistor is higher; and meanwhile, because the operational amplifier is not needed, the cost can be reduced.

Further, according to the invention, the heating circuit of the present invention further comprises a first driving unit and a second driving unit, and the MCU controls the first driving unit through a corresponding IO port to enable the battery power supply to only supply power to the heating resistor in the first time period of the PWM period; the MCU controls the second driving unit through a corresponding IO port to enable the battery power supply to supply power to the sampling resistor and the heating resistor which are connected in series in a second time period of the PWM period, and respectively collects the voltage of the heating resistor and the voltage of the sampling resistor through one or more corresponding IO ports, and calculating the resistance value of the heating resistor according to the resistance value of the sampling resistor and the collected voltages.

<FIG> is a circuit diagram of a heating circuit of an atomization device according to a first embodiment of the present invention, in which the heating circuit of the embodiment comprises an MCU U1 (That is, microcontroller U1), a heating resistor R2, a sampling resistor R1, a first driving unit and a second driving unit, and the resistance value of the sampling resistor R1 is greater than the resistance value of the heating resistor R2.

The first driving unit comprises a PMOS transistor Q1, an NMOS transistor Q3, a third resistor R3 and a fourth resistor R4, wherein a first IO port (PMOS) of the MCU U1 is respectively connected with the gate of the NMOS transistor Q3 and a first end of the fourth resistor R4, and a source electrode of the NMOS transistor Q3 and a second end of the fourth resistor R4 are respectively electrical grounding. A drain electrode of the NMOS transistor Q3 is respectively connected with a gate of the PMOS transistor Q1 and a first end of the third resistor R3, a source electrode of the PMOS transistor Q1 and a second end of the third resistor R3 are respectively connected with a battery power supply (BAT), a drain electrode of the PMOS transistor Q1 is connected with a first end of a heating resistor R2, and a second end of a heating resistor R2 is electrical grounding.

The second driving unit comprises a first transistor Q2, and, a base electrode of the first transistor Q2 is connected with a second IO port (ISEN) of the MCU U1, a collector electrode of the first transistor Q2 is connected with the battery power supply (BAT), and an emitter electrode of the second transistor Q2 is respectively connected with a first end of the sampling resistor R1 and a third IO port (IS1) of the MCU U1; a second end of the sampling resistor R1 is respectively connected to the first end of the heating resistor R2 and a fourth IO port (IS2) of the MCU U1. It should be understood that the third IO port (IS1) and the fourth IO port IS2 of the MCU U1 are AD ports.

The working principle of the heating circuit is described as follows:.

<FIG> is a circuit diagram of a second embodiment of the heating circuit of the atomization device of the present invention. Compared with the embodiment shown in <FIG>, the only difference of the heating circuit of this embodiment is that the switching device is replaced by a second transistor Q4 and a fifth resistor R5 instead of the NMOS transistor Q3. And a base electrode of the second transistor Q4 is respectively connected with the first end of the fourth resistor R4 and a first end of the fifth resistor R5, a collector electrode of the second transistor Q4 is respectively connected with the gate of PMOS transistor Q1 and the first end of the third resistor R3, and a emitter electrode the second transistor Q4 and the second end of fourth resistor R4 are respectively electrical grounding, a second end of the fifth resistor R5 is connected to the first IO port (PMOS) of the MCU U1. Other similar parts will not be described here.

The present invention also provides an atomization device including a heating circuit, and the structure of the heating circuit can be described with reference to the foregoing.

<FIG> is a flow chart of embodiment <NUM> of a heating method of an atomization device according to the present invention. The heating method of this embodiment is applied to an MCU, and specifically comprises the following steps:.

In this embodiment, in a PWM period, the heating control and resistance detection are performed on the heating resistor in different time periods, specifically, in a first time period of the PWM period, the MCU controls the battery power supply to only supply power to the heating resistor, that is, controls the heating resistor to work normally; in a second time period of the PWM period, the MCU controls the battery power supply to supply power to the sampling resistor and the heating resistor connected in series, that is, to detect the resistance value of the heating resistor. Because the sampling resistor only works when the resistance value of the heating resistor is detected (in the second time period of the PWM period), and does not work at other times, the sampling resistor can select a resistor with a greater resistance value, so that on one hand, because the accuracy of the sampling resistor with a greater resistance value can be higher, the resistance value detection accuracy of the heating resistor can be improved; on the other hand, because the voltage on the sampling resistor can be directly sampled by the MCU (with an ADC port) and does not need to be amplified by an operational amplifier, the accuracy of voltage sampling can be improved, and then the resistance value detection accuracy of the heating resistor is higher; and meanwhile, because the operational amplifier is not needed, the cost can be reduced.

Further, the MCU may control the first driving unit to enable the battery power supply to only supply power to the heating resistor. Accordingly, the MCU can control the second driving unit to enable the battery power supply to supply power to the sampling resistor and the heating resistor which are connected in series.

Claim 1:
A heating circuit of an atomization device, comprising a heating resistor (R2) and an MCU (U1), wherein the heating circuit further comprises a sampling resistor (R1), a first driving unit and a second driving unit, and the resistance value (R<NUM>) of the sampling resistor (R1) is greater than the resistance value (R<NUM>) of the heating resistor (R2), wherein
the MCU (U1) is configured to control the first driving unit through a corresponding IO port to enable a battery power supply to only supply power to the heating resistor (R2) in a first time period of a PWM period so as to enable the heating resistor (R2) to work;
the MCU (U1) is configured to control the second driving unit through a corresponding IO port to enable the battery power supply to supply power to the sampling resistor (R1) and the heating resistor (R2) which are connected in series in a second time period of the PWM period, and respectively to collect the voltage of the heating resistor (R2) and the voltage of the sampling resistor (R1) through one or more corresponding IO ports, and to calculate the resistance value (R<NUM>) of the heating resistor (R2) according to the resistance value (R<NUM>) of the sampling resistor (R1) and the collected voltages; wherein the heating circuit is characterized in that
the first driving unit comprises a PMOS transistor (Q1), a switching device (Q3, Q4), a third resistor (R3) and a fourth resistor (R4), wherein a first IO port of the MCU (U1) is respectively connected with a control end of the switching device (Q3, Q4) and a first end of the fourth resistor (R4); a first end of the switching device (Q3, Q4) and a second end of the fourth resistor (R4) are respectively electrical grounding, a second end of the switching device (Q3, Q4) is respectively connected with a gate of the PMOS transistor (Q1) and a first end of a third resistor (R3), a source electrode of the PMOS transistor (Q1) and a second end of the third resistor (R3) are respectively connected with a battery power supply, and a drain electrode of the PMOS transistor (Q1) is connected with a first end of the heating resistor (R2); a second end of the heating resistor (R2) is electrical grounding.