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EP-3661007-B1 - LOW VOLTAGE CHARGING CONTROL AND PROTECTION CIRCUIT FOR ELECTRONIC CIGARETTE AND METHOD OF CHARGING THE ELECTRONIC CIGARETTE USING THE CIRCUIT

EP3661007B1EP 3661007 B1EP3661007 B1EP 3661007B1EP-3661007-B1

Inventors

  • Huimin, TAN
  • Zhengzhan, PENG

Dates

Publication Date
20260506
Application Date
20191128

Claims (14)

  1. A charging control and protection circuit for a battery of an electronic cigarette, comprising: an extended charging circuit (EC), configured to charge the battery of the electronic cigarette, when the battery is at a first voltage, through a first external power source, and to terminate charging of the battery when the battery is at a second voltage, wherein the first voltage is lower than the second voltage; a charging integrated circuit (IC), configured to charge the battery of the electronic cigarette in parallel with the extended charging circuit (EC), and to charge solely the battery of the electronic cigarette, when the battery is at a second voltage, through a second external power source; and a microcontroller (MCU), configured to control the extended charging circuit (EC), and the charging integrated circuit (IC), to alternately charge the battery of the electronic cigarette based on detected voltage of the battery.
  2. The charging control and protection circuit of claim 1, wherein the microcontroller (MCU), is configured to: record a number of charging after an over-discharging, calculate an accumulated total number of charging, and store the accumulated total number of charging; and disable charging of the battery by the extended charging circuit (EC), and the charging integrated circuit (IC), when the accumulated total number of charging after the over-discharging exceeds a predetermined number.
  3. The charging control and protection circuit of claim 1 or 2, wherein the extended charging circuit (EC), and the charging integrated circuit (IC), are independently and separately configured, with the extended charging circuit (EC), being disposed external to the charging integrated circuit (IC), and so called external extended charging circuit, wherein the external extended charging circuit includes: a first transistor (Q1) including a first base, a first collector, and a first emitter, wherein the first collector is connected with a first external power source through a first resistor (R1), the first base is connected with the first external power source through a second resistor (R2), the first emitter is connected with a first charging port of the battery, and a second charging port of the battery is connected with a ground; and a second transistor (Q2) including a second base, a second collector, and a second emitter, wherein the second collector is connected with the first base, the second collector is also connected with the ground through a voltage regulator tube, the second emitter is connected with the ground, the second emitter and the second base are connected through a third resistor (R3), and the second base is connected with the microcontroller (MCU),wherein a charging interface of the charging integrated circuit (IC), is connected with the first charging port of the battery, an input port of the charging integrated circuit (IC), is connected with a positive terminal of a second external power source, a negative terminal of the second external power source is connected with the ground, and the charging interface of the charging integrated circuit is connected with the ground through a third capacitor (C3), and wherein the positive terminal and the negative terminal of the second external power source are connected through a second capacitor (C2).
  4. The charging control and protection circuit of claim 1 or 2, wherein the extended charging circuit (EC), and the charging integrated circuit (IC), are integrally configured; and wherein except for the microcontroller (MCU), a circuit portion configured to charge the battery of the electronic cigarette, when the battery is at the first voltage is a portion of the extended charging circuit (EC), and a circuit portion configured to charge the battery of the electronic cigarette, when the battery is at the second voltage is a portion of the charging integrated circuit (IC).
  5. The charging control and protection circuit of claim 4, further comprising: a power source port configured to connect with an input port of the charging integrated circuit (IC), and connect with the microcontroller (MCU), through a voltage regulator module, wherein the microcontroller (MCU), is connected with an enabling pin of the charging integrated circuit (IC), and the enabling pin of the charging integrated circuit (IC), is connected with the ground through a pull-down resistor (RL); a first transistor (Q1') including a first base, a first collector, and a first emitter, wherein the first collector is connected with a first node (1), the first node (1) is connected with the power source port through a first resistor (R1'), the first node (1) and the first base are connected through a second resistor (R2'), the first emitter is connected with a second node (2), and the second node (2) is connected with an output port of the charging integrated circuit (IC); a second transistor (Q2') including a second base, a second collector, and a second emitter, wherein the second collector is connected with the first base, the second base is connected with the microcontroller (MCU) through a third resistor (R3'), and the second emitter is connected with the ground; a third transistor (Q3') including a third base, a third collector, and a third emitter, wherein the third base is connected with a third node (3), the third node (3) is connected with the microcontroller through a fourth resistor, the third node (3) is also connected with the ground through a fifth resistor (R4'), the third collector is connected with the ground, the third emitter is connected with a fourth node (4), and the fourth node (4) is connected with the power source port through a sixth resistor (R6'); a fourth transistor (Q4') including a fourth base, a fourth collector, and a fourth emitter, the fourth base is connected with the fourth node (4), the fourth collector is connected with the second node (2), the fourth emitter is connected with a fifth node (5), the fifth node (5) is connected with a sixth node (6) through a seventh resistor (R7'), the sixth node (6) is connected with the microcontroller (MCU), and the sixth node (6) is connected with the ground through an eighth resistor (R8'); and a battery interface including a positive terminal connected with the fifth node (5), and a negative terminal connected with the ground.
  6. The charging control and protection circuit of claim 5, wherein the first transistor (Q1'), the second transistor (Q2'), and the fourth transistor (Q4') are all NPN types, and the third transistor (Q3') is a PNP type.
  7. An electronic cigarette, comprising: an atomizer; an E-liquid storage tank; a battery; and a control assembly, wherein the battery is connected with the control assembly, the control assembly is connected with the atomizer, and the E-liquid storage tank is configured to provide an E-liquid to the atomizer, wherein the control assembly includes the charging control and protection circuit according to any one of claims 1-6.
  8. A method for charging a battery of an electronic cigarette, comprising: controlling, by a microcontroller (MCU), an extended charging circuit (EC) to charge the battery, when the battery is at a first voltage , through a first external power source; controlling, by the microcontroller (MCU), a charging integrated circuit (IC) to charge the battery, in parallel with the extended charging circuit (EC), through a second external power source; and after the battery has been charged to a second voltage , controlling, by the microcontroller (MCU), the extended charging circuit (EC) to terminate charging of the battery through the first external power source, and controlling, by the microcontroller (MCU), the charging integrated circuit (IC) to charge the battery through the second external power source, wherein the first voltage is lower than the second voltage.
  9. The method of claim 8, further comprising: recording, by the microcontroller (MCU), a number of charging after an over-discharging; calculating, by the microcontroller (MCU), an accumulated total number of the charging after an over-discharging; storing, by the microcontroller (MCU), the accumulated total number of the charging after an over-discharging; and controlling, by the microcontroller (MCU), to terminate the charging by the extended charging circuit (EC) and by the charging integrated circuit (IC) after the accumulated total number of charging after an over-discharging has reached a predetermined number, preferably, said predetermined number is 10.
  10. The method of claim 8 or 9, further comprising: detecting, by the microcontroller (MCU), the voltage of the battery.
  11. The method of claim 10, further comprising: controlling, by the microcontroller (MCU), the extended charging circuit (EC) and the charging integrated circuit (IC) to alternately charge the battery based on the detected voltage of the battery.
  12. The method of any one of claims 8 to 10, wherein the method further comprises: when a voltage of the battery is below than a predetermined voltage, controlling, by the microcontroller, the extended charging circuit to charge the battery through the first external power source, and when the voltage of the battery reaches the predetermined voltage, controlling, by the microcontroller, the extended charging circuit to terminate charging of the battery by the extended charging circuit, and controlling, by the microcontroller, the charging integrated circuit to charge the battery through the second external power source.
  13. The method of claim 11, wherein controlling the extended charging circuit and the charging integrated circuit to alternately charge the battery based on the detected voltage of the battery comprises: controlling, by the microcontroller, the extended charging circuit to charge the battery when the detected voltage of the battery is lower than 2.5V; and controlling, by the microcontroller, the charging integrated circuit to charge the battery when the detected voltage of the battery is at least 3.3V.
  14. The method of claim 12, wherein the predetermined voltage is 3.6V or 3.3 V.

Description

TECHNICAL FIELD The present disclosure relates to a low voltage charging control and protection circuit, and more specifically, to a low voltage charging control and protection circuit for an electronic cigarette, the electronic cigarette that includes the low voltage charging control and protection circuit, and a method of charging the electronic cigarette based on the low voltage charging control and protection circuit. BACKGROUND One type of electronic cigarette that is currently available in the market includes an atomizer, an electronic cigarette liquid ("E-liquid") storage tank, a battery, and a control assembly. The battery is electrically connected with the control assembly. The battery typically includes an electrical core, which may be directly charged and used repeatedly for multiple times. When the electronic cigarette is stored and not used for a long time, the electrical charge stored in the battery can be exhausted, and the electrical core can be overly discharged. Because the charging capacity of the integrated circuit ("IC") at 0 V is at about a 100 mA charging current, the electrical core cannot be charged or after charging for a long time (e.g., 3-5 hours) the electrical core may still not be fully charged. As a result, the battery cannot be charged normally, and the electronic cigarette cannot be used. In addition, the electronic cigarette may be thrown away because the electrical core cannot be awakened (i.e., charged), which can be a waste of resources, and can add a lot of pressure to the environment. Furthermore, in a normal use process of the electrical core of the battery, multiple times of repeated charging and discharging it typical. However, because the electrical core of the battery is in a low voltage state while being used, for protection of the electrical core of the battery, the electrical core of the battery may automatically shut down, no longer providing the electrical power. However, due to some human reasons, for example, the smoker needs to smoke at this moment, the user may forcefully start up the electrical core of the battery, causing the electrical core of the battery to continue discharging to provide electrical energy to the atomizer. The electrical core of the battery continuing to provide the electrical energy under the low voltage condition is an unsafe operation that is not a recommended use. In particular, after the electrical core of the battery has been overly discharged for multiple times, safety related issues (e.g., swelling, fluid leakage, etc.) may occur to the electrical core of the battery. If the electrical core is continuingly used, other safe issues may occur. Therefore, how to ensure the electrical energy is used to a maximum degree while enhancing the safety performance of the electrical core of the electrical battery, thereby reducing the waste of the product caused by an unintended operation has become an emerging issue to address. Document CN 105 304 962 is an example of prior art. This relates to an electronic cigarette and a charging method. The device includes an atomizer, charging port, battery, airflow sensing component, and charging component. When an external power supply is connected to the charging port, the battery is charged simultaneously by a first charging current provided via the airflow sensing component and a second charging current provided via the charging component. By combining these two charging currents, the total charging current is increased, thereby reducing the battery charging time. SUMMARY The objective of the present disclosure is to overcome the defects in the conventional technologies. A low voltage battery charging control and protection circuit for an electronic cigarette is provided. The circuit has features such as charging at a low voltage or even zero voltage, over-discharging proof, and improved safety performance. The present disclosure may be realized according to claim 1 and 8. Preferred embodiments are defined in the dependent claims. The technical solutions of the present disclosure realizes normal low voltage charging of the electrical core of the battery, and effectively ensures that the electrical core of the battery cannot continue to be charged and used after the electrical core has been overly discharged at a low voltage for a predetermined number of times, thereby ensuring that the electrical core is in a state in which the electrical core cannot be charged, to avoid the occurrence of an accident. BRIEF DESCRIPTION OF THE DRAWINGS To better explain the technical solutions of the present disclosure and of the conventional technologies, the accompany drawings that are referred to when describing the present disclosure or the conventional technologies will be briefly introduced. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure. A person having ordinary skills in the art can derive other drawings based on these drawings without creative la