CN209821692U

CN209821692U - Circuit of electron cigarette that can realize constant power output

Info

Publication number: CN209821692U
Application number: CN201920846851.6U
Authority: CN
Inventors: 方建平; 郭晋亮; 张鑫
Original assignee: XI'AN TUOER MICROELECTRONICS CO Ltd
Current assignee: Shenzhen Tuoer Microelectronics Co., Ltd
Priority date: 2019-06-06
Filing date: 2019-06-06
Publication date: 2019-12-20
Anticipated expiration: 2029-06-06

Abstract

The utility model provides a can realize circuit of constant power output's electron cigarette and implementation method thereof, the input signal of current sampling module and voltage sampling module is respectively for current and voltage from load impedance department sampling, the sampling result of current sampling module and voltage sampling module exports to the AD converter, the output of AD converter links to each other with two inputs of digital multiplier, the output of power setting circuit equals the constant power of demand, PWM produces the output of circuit and is connected to a PMOS switch, the PMOS switch is arranged in the direct current path of battery BAT to output OUT. The circuit of the invention provides a constant power output, the smoke quantity of the constant power electronic cigarette is more uniform, the constant power electronic cigarette has better user taste, and the constant power output is relatively more stable and energy-saving, and the use of the electronic cigarette is not influenced by overhigh temperature of the electronic cigarette body, so the constant power output type electronic cigarette has more advantages.

Description

Circuit of electron cigarette that can realize constant power output

Technical Field

The invention relates to the field of circuits, in particular to a circuit of an electronic cigarette.

Background

The electronic cigarette is used as electronic equipment for simulating cigarettes, and the taste and the smoke of real cigarettes are simulated, so that the traditional cigarettes are replaced, the expenditure of consumers is saved, and the harm of second-hand cigarettes to bodies is reduced. Most of electronic cigarettes are composed of a switch control module, an atomizer, a lithium battery and the like, and most of the electronic cigarettes are constant-voltage output electronic cigarettes in the market at present. The constant voltage output type electronic cigarette chip is mostly realized by sampling the voltage of an output load, so that a PWM circuit is arranged to generate a signal with a corresponding duty ratio to drive a switch, as shown in fig. 1. When the battery voltage is V_BATThe output voltage on the load impedance is V_OUTThen, then

V_oUT＝V_BATDuty

Duty is the Duty cycle of the PWM generated signal. Generally, the load voltage is sampled, the sampled voltage is converted into a digital signal, the digital signal is compared with the required constant output voltage in a PWM (pulse-width modulation) generating circuit, and the duty ratio of the generated signal is determined according to the comparison result, so that when the output voltage on the load changes, the duty ratio of the signal generated by the PWM circuit can be directly changed, and the PMOS switch is subjected to feedback control to keep the average output voltage constant, namely, the function of constant voltage output is realized.

The voltage and the power of the electronic cigarette directly influence the size and the taste of the smoke, and the smoke quantity can change along with the voltage when the current and the load resistance are not changed.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides the circuit of the electronic cigarette capable of realizing constant power output and the realization method thereof.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a circuit of an electronic cigarette capable of realizing constant power output comprises a sampling module, an analog-to-digital converter, a digital multiplier, a PWM generating circuit and a power setting circuit; the sampling modules are respectively a current sampling module and a voltage sampling module, input signals of the current sampling module and the voltage sampling module are respectively current and voltage sampled from a load impedance, and sampling results of the current sampling module and the voltage sampling module are output to respective next-stage AD converters AD1 and AD 2; the outputs of the two AD converters are connected with two input ends of the digital multiplier and used as two input signals of the digital multiplier; the PWM circuit has two input ends, one of which is connected with the output end of the digital multiplier, the other input end is connected with the output end of the power setting circuit, the output of the power setting circuit is equal to the required constant power, the output end of the PWM generating circuit is connected to a PMOS switch, and the PMOS switch is arranged in a direct current path from the battery BAT to the output OUT.

The current sampling module and the voltage sampling module respectively sample output current and voltage on a load, current and voltage sampling results respectively pass through independent AD converters AD1 and AD2 to obtain corresponding digital signals, and the two converted digital signals are respectively the output current and the output voltage; because the output current and voltage sampling result is converted into a corresponding digital signal, the two paths of digital signals can be sent to a digital multiplier to be multiplied to obtain output power, namely the output power obtained by monitoring the load; comparing the monitored output power with the constant power provided by the power setting circuit in a comparator of the PWM generating circuit, and finally outputting a pulse signal related to the monitored output power and the constant power after passing through the PWM generating circuit, wherein the duty ratio of the pulse signal is determined by the ratio of the actual monitored power to the set constant power; the pulse signal output by the PWM generating circuit returns to the PMOS switch, and the PWM generating circuit forms a direct current path from a power supply to a load through control, so that the purpose of enabling the output power of the load to be constant is achieved.

The electronic cigarette with the constant power has the advantages that the constant power output is provided, the smoke quantity of the electronic cigarette with the constant power is more uniform, the electronic cigarette with the constant power has better user taste, the constant power output is relatively more stable and energy-saving, and the situation that the use is influenced due to overhigh temperature of the electronic cigarette body is avoided, so that the electronic cigarette with the constant power output has more advantages.

Drawings

Fig. 1 is a schematic connection diagram of an output power control circuit of a conventional electronic cigarette.

Fig. 2 is a connection diagram of the electronic cigarette output power control circuit according to the present invention.

Detailed Description

The invention is further illustrated with reference to the following figures and examples.

According to the invention, a PWM generating circuit is arranged in the chip, the monitored output power and the constant preset power are integrated, and a novel constant-power electronic cigarette circuit for controlling the constant output power on the electronic cigarette load through PWM output pulses is designed.

A circuit capable of realizing constant power output of an electronic cigarette comprises a sampling module, an analog-to-digital converter, a digital multiplier, a PWM (pulse width modulation) generating circuit and a power setting circuit; the two sampling modules are respectively a current sampling module and a voltage sampling module, input signals of the current sampling module and the voltage sampling module are respectively current and voltage sampled from a load impedance, and sampling results of the current sampling module and the voltage sampling module are output to respective next-stage AD converters AD1 and AD 2; the outputs of the two AD converters are connected with two input ends of the digital multiplier and used as two input signals of the digital multiplier; the PWM circuit has two input ends, one of which is connected with the output end of the digital multiplier, the other input end is connected with the output end of the power setting circuit, the output of the power setting circuit is equal to the required constant power, the output end of the PWM generating circuit is connected to a PMOS switch, and the PMOS switch is arranged in a direct current path from the battery BAT to the output OUT.

The current sampling module and the voltage sampling module respectively sample output current and voltage on a load, current and voltage sampling results are respectively subjected to independent AD conversion to obtain corresponding digital signals, and the converted two digital signals respectively represent the output current and the output voltage; because the output current and voltage sampling result is converted into a corresponding digital signal, the two paths of digital signals can be sent to a digital multiplier to be multiplied to obtain output power, namely the output power obtained by monitoring the load; comparing the monitored output power with the constant power provided by the power setting circuit in a comparator of the PWM generating circuit, and finally outputting a pulse signal related to the monitored output power and the constant power after the processing of the PWM generating circuit, wherein the duty ratio of the pulse signal is determined by the ratio of the actual monitored power to the set power; the pulse signal output by the PWM generating circuit returns to the PMOS switch, and the PWM generating circuit controls whether a direct current path is formed between a power supply and a load or not, so that the purpose of enabling the output power of the load to be constant is achieved.

The PWM generating circuit compares the output power with the preset power to obtain a control pulse signal, and plays a role of a comparison core in the whole circuit.

The periphery of the circuit is provided with a battery power supply port, a pure resistance output load, a preset power input/output port and the like.

Through the connection mode of the modules and the working process of the whole circuit, the output power of the electronic cigarette chip load can be kept constant, and the expected target is achieved.

The specific working process of the invention is as follows:

as shown in fig. 2, only when M₁And when the direct current path from the power supply to the load exists, the current and the voltage on the load resistor are effective, otherwise, the direct current path is ineffective. The current sampling and voltage sampling module is used for instantaneous sampling, and monitoring and sampling are carried out when the current flowing through the load resistor and the output voltage on the load resistor are both effective to obtain corresponding current and voltage signals I_OUTAnd V_OUT. Thus, M₁The instantaneous power consumed on the output load when switched on is:

P_OUT＝V_OUTI_OUT

the analog-to-digital converter is respectively connected at the rear stage of the sampling circuit, the current-voltage analog signal obtained by sampling is converted into a digital signal, the current and voltage which cannot be calculated in the chip originally are converted into digital quantity which can be calculated through a digital logic structure, namely, the current and the voltage are converted through a digital multiplier to obtain the current-voltage analog signalMultiplying the obtained digital quantities to obtain a digital signal with a power dimension, defined as P_OUT. Meanwhile, due to the requirement of constant power, a power setting circuit is arranged in the chip, and a power signal is generated according to the required constant power and is defined as P_SETWhen the rated power of the chip is determined, P_SETI.e. a constant that is constant. Thus, there is a ratio:

beta and P_OUTThe signals are inversely proportional. Signal P output by digital multiplier_OUTAnd the signal P output by the power setting circuit_SETAs two input signals, the two signals are input to a core PWM generating circuit which can generate PWM according to different ratiosOutputting different square wave signals, wherein:

duty is the Duty ratio of the square wave signal, also equal to P_OUTInversely, K is a scaling factor greater than 0. Through the formula, the voltage and current signals monitored by the sampling circuit are changed when the output power of the load is changed, and P is found_OUTAnd the Duty changes accordingly, that is, the PWM generating circuit outputs a square wave signal with the Duty ratio changing along with the output power, and the square wave signal is used as a control signal and is input into the PMOS tube M₁Of the grid, control M₁That is, the dc path from the power source terminal BAT to the output terminal is controlled, so that the current and voltage at the output terminal will also be square wave signals with Duty ratio equal to Duty, and therefore the average power consumed by the load resistor is:

namely, the output power can be controlled to be equal to the constant power required by the chip output by the power setting circuit through the Duty ratio Duty, and the design requirement of the constant-power electronic cigarette is met.

Claims

1. The utility model provides a circuit of electron cigarette that can realize constant power output which characterized in that:

the circuit of the electronic cigarette capable of realizing constant power output comprises a sampling module, an analog-to-digital converter, a digital multiplier, a PWM (pulse-width modulation) generating circuit and a power setting circuit; the sampling modules are respectively a current sampling module and a voltage sampling module, input signals of the current sampling module and the voltage sampling module are respectively current and voltage sampled from a load impedance, and sampling results of the current sampling module and the voltage sampling module are output to respective next-stage AD converters AD1 and AD 2; the outputs of the two AD converters are connected with two input ends of the digital multiplier and used as two input signals of the digital multiplier; the PWM circuit has two input ends, one of which is connected with the output end of the digital multiplier, the other input end is connected with the output end of the power setting circuit, the output of the power setting circuit is equal to the required constant power, the output end of the PWM generating circuit is connected to a PMOS switch, and the PMOS switch is arranged in a direct current path from the battery BAT to the output OUT;