CN218167936U - Constant-power control circuit and steam cleaning equipment with same - Google Patents

Abstract

The utility model relates to a constant power control circuit and steam cleaning equipment with the same. The circuit includes: a voltage detection circuit, electrically connected to the DC power supply of the steam cleaning device, and used to detect the output voltage of the power supply; a controller, electrically connected to the DC power supply and the voltage detection circuit, used to receive the output voltage of the power supply, and output according to the output voltage of the power supply The PWM drive signal; and the PWM drive circuit are electrically connected to the steam component, the DC power supply and the controller of the steam cleaning device, and are used to receive the PWM drive signal and control the steam component to run at constant power according to the PWM drive signal. The utility model detects the output voltage of the power supply, and the controller outputs the corresponding PWM driving signal to the PWM driving circuit according to the detected output voltage of the power supply, and the PWM driving circuit realizes the constant power control of the steam assembly according to the PWM driving signal, realizing continuous and stable steam Effect, improve equipment cleaning effect and user experience.

Description

Constant power control circuit and steam cleaning equipment with it

technical field

The utility model relates to the field of cleaning equipment, in particular to a constant power control circuit and steam cleaning equipment with the same.

Background technique

Steam is widely used in daily life due to its good cleaning and sterilization effects, and steam cleaning equipment has also entered people's lives. The current steam cleaning equipment mostly uses AC as the power supply of the equipment, and needs to be connected to the AC power supply through a power cord. However, when it is inconvenient to connect to the AC power supply (such as outdoors), the steam cleaning equipment cannot be used normally. Therefore, the application range of AC-powered steam cleaning equipment is easily limited, and it is necessary to develop DC-powered steam cleaning equipment.

For the steam cleaning equipment powered by DC, it needs to use a DC power source (such as a battery pack) to supply DC power to it. However, when the DC power supply is used to power the steam cleaning equipment, as the voltage of the DC power supply decreases, the power of the equipment will decrease accordingly, which cannot meet the demand for stable power of the steam cleaning equipment, and cannot guarantee the constant power operation of the equipment, which will easily lead to steam The effect is getting worse and worse, and the equipment cleaning effect and user experience need to be improved.

Utility model content

Therefore, the technical problem to be solved by the utility model is how to control the steam cleaning equipment with constant power when the DC power supply supplies power to the steam cleaning equipment, so as to ensure the constant power operation of the steam cleaning equipment, realize continuous and stable steam effect, and then ensure Equipment cleaning effect and user experience.

In order to solve the above technical problems, the utility model provides a constant power control circuit, which is used in the steam cleaning equipment, and is electrically connected with the DC power supply and the steam assembly of the steam cleaning equipment, and the steam assembly is electrically connected with the DC power supply connections, including:

A voltage detection circuit, electrically connected to the DC power supply, for detecting the output voltage of the power supply;

a controller, electrically connected to the DC power supply and the voltage detection circuit, for receiving the output voltage of the power supply, and outputting a PWM driving signal according to the output voltage of the power supply; and

A PWM driving circuit, electrically connected to the steam assembly, the DC power supply and the controller, for receiving the PWM driving signal, and controlling according to the PWM driving signal under the action of the output voltage of the power supply The steam assembly operates at constant power.

Optionally, the PWM drive circuit includes an NMOS transistor Q5;

The gate of the NMOS transistor Q5 is electrically connected to the controller, the drain of the NMOS transistor Q5 is electrically connected to the negative input terminal of the steam component, and the source of the NMOS transistor Q5 is connected to the DC power supply. The negative pole is electrically connected; the positive pole input end of the steam assembly is electrically connected to the positive pole of the DC power supply, and the common connection between the source of the NMOS transistor Q5 and the negative pole of the DC power supply is grounded;

The NMOS tube Q5 is used to generate a PWM duty ratio according to the PWM driving signal, and control the on-off of the steam component according to the PWM duty ratio, so that the effective voltage of the steam component is constant in each control cycle .

Optionally, the PWM drive circuit further includes a switch control subcircuit;

The controller is electrically connected to the base of the NMOS transistor Q5 through the switch control subcircuit, and the switch control subcircuit is also electrically connected to both the steam assembly and the DC power supply;

The switch control subcircuit is configured to control the on-off of the NMOS transistor Q5 according to the PWM driving signal, and transmit the PWM driving signal to the NMOS transistor Q5 when the NMOS transistor Q5 is turned on. .

Optionally, the switch control subcircuit includes a first triode Q1, a first resistor R1 and a second resistor R2;

The base of the first transistor Q1 is electrically connected to the controller, and the collector of the first transistor Q1 is electrically connected to the first end of the second resistor R2 through the first resistor R1 , the second terminal of the second resistor R2 is connected to the common connection terminal between the positive input terminal of the steam component and the positive terminal of the DC power supply, and the emitter of the first triode Q1 is grounded; The NMOS transistor Q5 is connected to the common connection terminal between the first terminal of the first resistor R1 and the first terminal of the second resistor R2.

Optionally, the PWM drive circuit also includes a MOS transistor drive boost sub-circuit;

The controller is electrically connected to the base of the NMOS transistor Q5 through the switch control sub-circuit and the MOS tube drive boost sub-circuit in turn, and the MOS tube drive boost sub-circuit is also connected to the steam component and the The DC power supply is electrically connected;

The MOS transistor drive boost sub-circuit is used to increase the driving voltage of the NMOS transistor Q5.

Optionally, the MOS transistor drive improvement sub-circuit includes a second triode Q2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5;

The base of the second triode Q2 is connected to the switch control sub-circuit, the collector of the second triode Q2 is grounded through the third resistor R3 and the fourth resistor R4 sequentially, and the first The emitter of the triode Q2 is connected to the common connection between the positive input terminal of the steam assembly and the positive terminal of the DC power supply; the first terminal of the fifth resistor R5 is connected to the third resistor On the common connection terminal between R3 and the fourth resistor R4, the second terminal of the fifth resistor R5 is electrically connected to the NMOS transistor Q5.

Optionally, the PWM drive circuit also includes a MOS tube push-pull sub-circuit;

The controller is electrically connected to the base of the NMOS transistor Q5 through the switch control subcircuit, the MOS transistor drive boost subcircuit and the MOS transistor push-pull subcircuit in turn, and the MOS transistor push-pull subcircuit It is also electrically connected to both the steam assembly and the DC power supply;

The MOS transistor push-pull sub-circuit is used to improve the fast on-off capability of the NMOS transistor Q5.

Optionally, the MOS transistor push-pull sub-circuit includes a third transistor Q3, a fourth transistor Q4 and a sixth resistor R6;

Both the base of the third triode Q3 and the base of the fourth triode Q4 are electrically connected to the MOS tube driving improvement sub-circuit, and the collector of the third triode Q3 is connected to the On the common connection between the positive input end of the steam assembly and the positive electrode of the DC power supply, the collector of the fourth triode Q4 is grounded, the emitter of the third triode Q3 is connected to the first The emitters of the four transistors Q4 are electrically connected; the first end of the sixth resistor R6 is connected to the common common between the emitters of the third transistor Q3 and the emitters of the fourth transistor Q4 On the connecting end, the second end of the sixth resistor R6 is electrically connected to the NMOS transistor Q5.

Optionally, the voltage detection circuit includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a capacitor C;

The first end of the seventh resistor R7 is electrically connected to the positive pole of the DC power supply, the second end of the seventh resistor R7 is grounded through the eighth resistor R8, and the first end of the ninth resistor R9 is connected to On the common connection end between the second end of the seventh resistor R7 and the eighth resistor R8, the second end of the ninth resistor R9 is electrically connected to the controller, and the second end of the capacitor C One end is connected to the common connection end between the second end of the ninth resistor R9 and the controller, and the second end of the capacitor C is grounded.

In addition, the utility model also proposes a steam cleaning device, including:

Equipment body;

A DC power supply is provided on the device body;

a steam component, arranged on the device body, electrically connected to the DC power supply; and

The aforementioned constant power control circuit is electrically connected to both the DC power supply and the steam assembly of the steam cleaning device, and is used to control the steam assembly to operate at constant power under the power supplied by the DC power supply.

The technical scheme provided by the utility model has the following advantages:

The constant power control circuit provided by the utility model and the steam cleaning equipment provided with it can detect the power output voltage output by the DC power supply for the steam cleaning equipment through the voltage detection circuit, and feed back the output voltage of the power supply to the controller. According to the output voltage of the power supply, a corresponding PWM driving signal can be output to the PWM driving circuit, and the PWM driving circuit can maintain a constant power of the steam component in the steam cleaning device according to the corresponding PWM driving signal, and realize constant power control. Power operation to achieve continuous and stable steam effect, improve equipment cleaning effect and user experience.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the present invention. For example, those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Fig. 1 is a structural diagram of a constant power control circuit in Embodiment 1 of the present utility model;

Fig. 2 is the specific design diagram of the voltage detection circuit in the first embodiment of the utility model;

3 is a structural diagram of a PWM drive circuit in Embodiment 1 of the present invention;

Figure 4-1 is a schematic diagram of the waveform of the output voltage of the power supply changing with time in Embodiment 1 of the utility model;

Figure 4-2 is a schematic diagram of the waveform of the PWM square wave level signal changing with time in Embodiment 1 of the utility model;

5 is a structural diagram of another PWM drive circuit in Embodiment 1 of the present invention;

6 is a specific design diagram of another PWM driving circuit in Embodiment 1 of the present invention;

Fig. 7 is a structural diagram of a steam cleaning device in Embodiment 2 of the present invention.

detailed description

The technical solutions of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are part of the embodiments of the utility model, but not all of them. Hereinafter, the utility model will be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

It should be noted that the terms "first" and "second" in the specification and claims of the present utility model and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific order or sequence .

In the present utility model, in the case of no contrary description, the used orientation words such as "upper, lower, top, bottom" are usually for the direction shown in the drawings, or for the vertical position of the component itself. , vertically or in the direction of gravity; similarly, for ease of understanding and description, "inner and outer" refer to the inner and outer relative to the outline of each component itself, but the above-mentioned orientation words are not used to limit the utility model.

In the traditional technology, when the DC power supply is used to power the steam cleaning equipment, as the voltage of the DC power supply decreases, the steam cleaning equipment will decrease accordingly, resulting in poorer steam effect, poor cleaning effect of the equipment and poor user experience . In order to solve the above technical problems, the utility model proposes a constant power control circuit and a steam cleaning device with it.

The constant power control circuit and the steam cleaning equipment provided by the utility model can be applied to any steam cleaning products powered by direct current, such as steam cleaning equipment such as steam sweepers. In the following embodiments, the utility model is described by taking the application of the steam sweeper as an example.

Embodiment one

As shown in Figure 1, this embodiment provides a constant power control circuit, which is used in steam cleaning equipment, and is electrically connected to both the DC power supply and the steam assembly of the steam cleaning equipment, and the steam assembly is electrically connected to the DC power supply. The circuit includes:

A voltage detection circuit, electrically connected to the DC power supply, for detecting the output voltage of the power supply;

a controller, electrically connected to the DC power supply and the voltage detection circuit, for receiving the output voltage of the power supply, and outputting a PWM driving signal according to the output voltage of the power supply; and

The PWM drive circuit is electrically connected with the steam component, the DC power supply and the controller, and is used to receive the PWM drive signal, and under the action of the output voltage of the power supply, control the steam component to run at a constant power according to the PWM drive signal.

The above-mentioned constant power control circuit in this embodiment detects the output voltage of the DC power supply output by the DC power supply for the steam cleaning equipment (such as a steam sweeper) through the voltage detection circuit, and feeds back the output voltage of the power supply to the controller. The controller can according to The output voltage of the power supply outputs a corresponding PWM driving signal to the PWM driving circuit, and the PWM driving circuit can maintain a constant power of the steam component in the steam cleaning device according to the corresponding PWM driving signal, and realize constant power control, through the constant power operation of the steam component , to achieve continuous and stable steam effect, improve equipment cleaning effect and user experience.

Specifically, the controller is specifically a single-chip microcomputer, and a suitable type of single-chip microcomputer can be selected according to the actual situation, for example, a GD32F series single-chip microcomputer is selected in this embodiment. The DC power supply is specifically a battery pack, and the steam component specifically includes a heating wire capable of heating the liquid in the steam cleaning device.

Preferably, as shown in FIG. 2, the voltage detection circuit includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a capacitor C;

The first end of the seventh resistor R7 is electrically connected to the positive pole of the DC power supply, the second end of the seventh resistor R7 is grounded through the eighth resistor R8, and the first end of the ninth resistor R9 is connected to the second end of the seventh resistor R7 and On the common connection between the eighth resistor R8, the second end of the ninth resistor R9 is electrically connected to the controller, and the first end of the capacitor C is connected to the common connection between the second end of the ninth resistor R9 and the controller terminal, and the second terminal of capacitor C is grounded.

In Figure 2, Vbat is the voltage of the battery pack, and Vbat_ref is the equivalent voltage delivered to the controller after the voltage of the battery pack is divided by the seventh resistor R7 and the eighth resistor R8, which is the DC power detected by the controller through the power detection circuit Power supply output voltage: According to the above circuit structure, the power supply voltage detection is realized, so that the controller can output the corresponding PWM driving signal according to the output power supply output voltage, and then control the power of the steam component to be constant through the PWM driving circuit.

Preferably, as shown in FIG. 3, the PWM driving circuit includes an NMOS transistor Q5;

The gate of the NMOS transistor Q5 is electrically connected to the controller, the drain of the NMOS transistor Q5 is electrically connected to the negative input terminal of the steam component, the source of the NMOS transistor Q5 is electrically connected to the negative pole of the DC power supply; the positive input terminal of the steam component is connected to the DC The positive pole of the power supply is electrically connected, and the common connection between the source of the NMOS transistor Q5 and the negative pole of the DC power supply is grounded;

The NMOS tube Q5 is used to generate a PWM duty ratio according to the PWM driving signal, and control the on-off of the steam component according to the PWM duty ratio, so that the effective voltage of the steam component is constant in each control cycle.

The NMOS tube Q5 generates a corresponding PWM duty ratio according to the PWM driving signal output by the controller, so as to control the on and off of the steam component in the steam cleaning device (ie, the steam component is turned on and off). Among them, the PWM driving signal is specifically a PWM square wave level signal, and the PWM duty cycle refers to the ratio of the high level time of the PWM square wave level signal to the period under pulse width modulation (PWM). . In this embodiment, the high level time of the PWM square wave level signal corresponds to the on time of the steam component, and the low level time of the PWM square wave level signal corresponds to the off time of the steam component.

For any control period, the product of the output voltage of the power supply and the PWM duty cycle is the effective voltage of the steam component in the control period; when the output voltage of the power supply is high, the controller outputs the corresponding PWM drive signal to control the NMOS tube Q5 generates a smaller PWM duty cycle, and controls the conduction time of the steam component in the above control cycle according to the smaller PWM duty cycle; when the output voltage of the power supply is low, the controller outputs the corresponding PWM drive signal, To control the PWM drive circuit to generate a larger PWM duty cycle, according to the larger PWM duty cycle to control the conduction time of the steam component in the above control cycle, as shown in Figure 4-1 and Figure 4-2; 4-1 is the waveform graph of the output voltage of the power supply changing with time. In Fig. 4-1, the abscissa is the time t, and the ordinate is the output voltage u ₁ of the power supply; Fig. 4-2 is the PWM square wave level signal changing with time In Fig. 4-2, the abscissa is the time t, the ordinate is the PWM square wave level signal u ₂ , and the high level time of the PWM square wave level signal (that is, the conduction time of the steam component ) is Ton, the time of the low level in the PWM square wave level signal (that is, the shut-off time of the steam assembly) is Toff, and in each control cycle, Ton+Toff=T is constant, where T is the control cycle . In any control period T, PWM duty ratio τ=Ton/T.

Based on the controller and the above-mentioned PWM drive circuit, it can ensure that the product of the power output voltage of the steam component and the PWM duty cycle (that is, the effective voltage) in each control cycle is constant, because the current on the steam component is constant , so that the power on the steam assembly can also be kept constant, realizing the constant power operation of the steam assembly.

Preferably, as shown in FIG. 5, the PWM drive circuit further includes a switch control subcircuit;

The controller is electrically connected to the base of the NMOS tube Q5 through the switch control sub-circuit, and the switch control sub-circuit is also electrically connected to the steam component and the DC power supply;

The switch control sub-circuit is used to control the on-off of the NMOS transistor Q5 according to the PWM driving signal, and transmit the PWM driving signal to the NMOS transistor Q5 when the NMOS transistor Q5 is turned on.

Adding a switch control sub-circuit before the NMOS transistor Q5 can control the on and off of the NMOS transistor Q5, realize the switch control of the entire PWM drive circuit, and play a protective role in the PWM drive circuit.

Specifically, as shown in FIG. 6, the switch control subcircuit includes a first triode Q1, a first resistor R1 and a second resistor R2;

The base of the first transistor Q1 is electrically connected to the controller, the collector of the first transistor Q1 is electrically connected to the first end of the second resistor R2 through the first resistor R1, and the second end of the second resistor R2 is connected to On the common connection between the positive input terminal of the steam component and the positive terminal of the DC power supply, the emitter of the first triode Q1 is grounded; the NMOS transistor Q5 is connected between the first end of the first resistor R1 and the second resistor R2 on the common connection between them.

When the triode Q1 works in the saturation region, its emitter and collector are turned on, and the subsequent NMOS transistor Q5 is also turned on; when the triode Q1 works in the cut-off region, its emitter and collector are disconnected. , the NMOS transistor Q5 of the subsequent stage is also disconnected; the saturation and cut-off of the triode Q1 are used to realize the turn-on and turn-off of the NMOS transistor Q5, and then realize the switch control of the entire PWM drive circuit. In this embodiment, the first transistor Q1 is specifically an NPN transistor.

Preferably, as shown in Figure 5, the PWM drive circuit also includes a MOS tube drive boost sub-circuit;

The controller is electrically connected to the base of the NMOS transistor Q5 through the switch control sub-circuit and the MOS tube driving and improving sub-circuit in turn, and the MOS tube driving and improving sub-circuit is also electrically connected to the steam component and the DC power supply;

The MOS transistor driving boost sub-circuit is used to increase the driving voltage of the NMOS transistor Q5.

Adding a MOS transistor driving boost subcircuit between the switch control subcircuit and the NMOS transistor Q5 can increase the driving voltage of the NMOS transistor Q5 when the NMOS transistor Q5 is controlled to be turned on, thereby facilitating the improvement of the driving capability of the NMOS transistor Q5.

Specifically, as shown in FIG. 6 , the MOS transistor driving improvement sub-circuit includes a second triode Q2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5;

The base of the second triode Q2 and the switch control sub-circuit, the collector of the second triode Q2 is grounded through the third resistor R3 and the fourth resistor R4 in turn, and the emitter of the second triode Q2 is connected to the steam assembly On the common connection between the positive input end of the DC power supply and the positive pole of the DC power supply; the first end of the fifth resistor R5 is connected on the common connection end between the third resistor R3 and the fourth resistor R4, and the first end of the fifth resistor R5 The two terminals are electrically connected with the NMOS transistor Q5.

Using the second triode Q2, the third resistor R3 and the fourth R4, the driving voltage on the NMOS transistor Q5 is increased to the divided voltage of the DC power supply voltage on R3 and R4, and the driving voltage of the NMOS transistor Q5 is improved. .

Preferably, as shown in Figure 5, the PWM drive circuit also includes a MOS tube push-pull sub-circuit;

The controller is electrically connected to the base of the NMOS transistor Q5 through the switch control sub-circuit, the MOS tube driving boost sub-circuit and the MOS tube push-pull sub-circuit in turn, and the MOS tube push-pull sub-circuit is also electrically connected to the steam component and the DC power supply;

The MOS transistor push-pull sub-circuit is used to improve the fast on-off capability of the NMOS transistor Q5.

The MOS tube push-pull sub-circuit uses two power tubes with the same parameters (such as triode and MOS tube), which exist in the circuit in a push-pull manner, and each is responsible for the waveform amplification task of the positive and negative half cycles. When the circuit is working, the two power tubes each Only one of them is turned on at a time, so the switching speed can be increased. In this embodiment, a MOS tube push-pull sub-circuit is added between the MOS tube drive improvement sub-circuit and the NMOS tube Q5, which can strengthen the fast on-off capability of the NMOS tube Q5 based on the push-pull function of the MOS tube push-pull sub-circuit, thereby improving The switching performance of the NMOS tube is conducive to strengthening the accuracy of the NMOS tube Q5 to control the on and off of the steam component, reducing the delay, and helping to improve the accuracy of constant power control.

Specifically, as shown in FIG. 6, the MOS transistor push-pull subcircuit includes a third transistor Q3, a fourth transistor Q4, and a sixth resistor R6;

Both the base of the third triode Q3 and the base of the fourth triode Q4 are electrically connected to the MOS tube drive boost sub-circuit, and the collector of the third triode Q3 is connected to the positive input terminal of the steam assembly and the DC power supply The collector of the fourth triode Q4 is grounded, the emitter of the third triode Q3 is electrically connected to the emitter of the fourth triode Q4; the first of the sixth resistor R6 The second end of the sixth resistor R6 is electrically connected to the NMOS transistor Q5.

The third triode Q3 and the fourth triode Q4 are paired transistors in the MOS tube push-pull sub-circuit, and the third triode Q3 is an upper tube, which strengthens the fast conduction capability of the NMOS transistor Q5; the fourth triode The tube Q4 is a lower tube, which enhances the fast turn-off capability of the NMOS transistor Q5; through the MOS transistor push-pull sub-circuit with the above structure, the fast turn-off capability of the NMOS transistor Q5 is enhanced with a small conduction loss.

Embodiment two

As shown in Figure 7, this embodiment provides a steam cleaning device, which includes:

Equipment body;

DC power supply, located on the device body;

a steam assembly, located on the device body, electrically connected to a DC power supply; and

The constant power control circuit of Embodiment 1 is electrically connected to both the DC power supply and the steam component of the steam cleaning device, and is used to control the steam component to operate at constant power under the power supply of the DC power supply.

The steam cleaning device of this embodiment is based on a constant power control circuit, and the steam components therein can operate at constant power to achieve continuous and stable steam effects, effectively improving the cleaning effect of the device and user experience.

Specifically, as shown in Figure 7, the device body is also provided with a waterway and a steam pipeline corresponding to the steam component, the waterway is used to provide liquid for the steam component, and the steam pipeline is used to transmit the steam generated by the steam component to the steam cleaning device other components (such as cleaning components).

Preferably, as shown in Figure 7, the steam cleaning equipment also includes:

The water tank is located on the equipment body and communicates with the water path of the steam component for storing liquid;

The steam assembly is used to heat and vaporize the liquid in the water tank into steam at constant power; and

The cleaning component communicates with the steam pipeline in the steam component and is used for cleaning according to the steam generated in the steam component.

Through the above-mentioned steam cleaning equipment, the excellent cleaning purpose can be achieved with continuous and stable steam effect.

Specifically, the steam cleaning equipment includes at least one of the following: a steam scrubber, a steam mop, and a steam cleaner.

The water tank, the steam component and the cleaning component in the steam cleaning device in this embodiment all adopt existing conventional structures or products, and the specific details will not be repeated here. At the same time, the constant power control circuit in this embodiment is the same as the constant power control circuit in Embodiment 1. For the unfinished details in this embodiment, please refer to Embodiment 1 and the specific descriptions in FIGS. 1 to 6. Let me repeat.

It should be noted that the utility model only solves the problem by improving the hardware circuit in the constant power control circuit. When the DC power supply is used to supply power to the steam cleaning equipment, as the voltage of the DC power supply decreases, the steam cleaning equipment will decrease accordingly. The problem that the steam effect is getting worse and worse, which only involves the improvement of the structure of each module circuit and the connection relationship of each electronic component in each module circuit, does not involve the improvement of computer programs, and each electronic component can be selected from the existing technology. product specification or model.

Apparently, the above-described embodiments are only some embodiments of the present utility model, rather than all embodiments. Based on the embodiments of the utility model, those skilled in the art can make other changes or changes in different forms without creative work, which should fall within the protection scope of the utility model.

Claims (10)

1. A constant power control circuit for use in a steam appliance, the constant power control circuit being electrically connected to both a DC power source and a steam assembly of the steam appliance, the steam assembly being electrically connected to the DC power source, comprising:

the voltage detection circuit is electrically connected with the direct current power supply and is used for detecting the output voltage of the power supply;

the controller is electrically connected with the direct current power supply and the voltage detection circuit and used for receiving the power supply output voltage and outputting a PWM (pulse width modulation) driving signal according to the power supply output voltage; and

and the PWM driving circuit is electrically connected with the steam assembly, the direct-current power supply and the controller and used for receiving the PWM driving signal and controlling the steam assembly to run at constant power according to the PWM driving signal under the action of the power supply output voltage.

2. The constant power control circuit according to claim 1, wherein the PWM driving circuit comprises an NMOS transistor Q5;

the grid electrode of the NMOS tube Q5 is electrically connected with the controller, the drain electrode of the NMOS tube Q5 is electrically connected with the negative electrode input end of the steam component, and the source electrode of the NMOS tube Q5 is electrically connected with the negative electrode of the direct-current power supply; the positive electrode input end of the steam component is electrically connected with the positive electrode of the direct current power supply, and the common connecting end between the source electrode of the NMOS tube Q5 and the negative electrode of the direct current power supply is grounded;

and the NMOS tube Q5 is used for generating a PWM duty ratio according to a PWM driving signal and controlling the on-off of the steam assembly according to the PWM duty ratio, so that the effective voltage of the steam assembly in each control period is constant.

3. The constant power control circuit according to claim 2, wherein the PWM driving circuit further comprises a switch control sub-circuit;

the controller is electrically connected with the base electrode of the NMOS tube Q5 through the switch control sub-circuit, and the switch control sub-circuit is also electrically connected with the steam assembly and the direct-current power supply;

the switch control sub-circuit is used for controlling the on-off of the NMOS tube Q5 according to the PWM driving signal and transmitting the PWM driving signal to the NMOS tube Q5 when the NMOS tube Q5 is switched on.

4. The constant power control circuit according to claim 3, wherein the switch control sub-circuit comprises a first transistor Q1, a first resistor R1 and a second resistor R2;

the base electrode of the first triode Q1 is electrically connected with the controller, the collector electrode of the first triode Q1 is electrically connected with the first end of the second resistor R2 through the first resistor R1, the second end of the second resistor R2 is connected with the common connecting end between the positive electrode input end of the steam component and the positive electrode of the direct-current power supply, and the emitting electrode of the first triode Q1 is grounded; the NMOS tube Q5 is connected to a common connection end between the first end of the first resistor R1 and the first end of the second resistor R2.

5. The constant-power control circuit according to claim 3, wherein the PWM driving circuit further comprises a MOS transistor driving boosting sub-circuit;

the controller is electrically connected with the base electrode of the NMOS tube Q5 through the switch control sub-circuit and the MOS tube driving improving sub-circuit in sequence, and the MOS tube driving improving sub-circuit is also electrically connected with the steam assembly and the direct-current power supply;

and the MOS tube driving and improving sub-circuit is used for improving the driving voltage of the NMOS tube Q5.

6. The constant power control circuit according to claim 5, wherein the MOS transistor driving boosting sub-circuit comprises a second transistor Q2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5;

the base electrode of the second triode Q2 is connected with the switch control sub-circuit, the collector electrode of the second triode Q2 is grounded sequentially through the third resistor R3 and the fourth resistor R4, and the emitter electrode of the second triode Q2 is connected to the common connecting end between the positive electrode input end of the steam component and the positive electrode of the direct-current power supply; the first end of the fifth resistor R5 is connected to the common connection end between the third resistor R3 and the fourth resistor R4, and the second end of the fifth resistor R5 is electrically connected with the NMOS transistor Q5.

7. The constant-power control circuit according to claim 5, wherein the PWM driving circuit further comprises a MOS transistor push-pull sub-circuit;

the controller is electrically connected with the base electrode of the NMOS tube Q5 through the switch control sub-circuit, the MOS tube drive improving sub-circuit and the MOS tube push-pull sub-circuit in sequence, and the MOS tube push-pull sub-circuit is also electrically connected with the steam assembly and the direct-current power supply;

and the MOS tube push-pull sub-circuit is used for improving the rapid on-off capacity of the NMOS tube Q5.

8. The constant-power control circuit according to claim 7, wherein the MOS transistor push-pull sub-circuit comprises a third transistor Q3, a fourth transistor Q4 and a sixth resistor R6;

the base electrode of the third triode Q3 and the base electrode of the fourth triode Q4 are electrically connected with the MOS tube driving boosting sub-circuit, the collector electrode of the third triode Q3 is connected with the common connecting end between the positive electrode input end of the steam component and the positive electrode of the direct-current power supply, the collector electrode of the fourth triode Q4 is grounded, and the emitter electrode of the third triode Q3 is electrically connected with the emitter electrode of the fourth triode Q4; a first end of the sixth resistor R6 is connected to a common connection end between the emitter of the third triode Q3 and the emitter of the fourth triode Q4, and a second end of the sixth resistor R6 is electrically connected to the NMOS transistor Q5.

9. The constant power control circuit according to any one of claims 1 to 8, wherein the voltage detection circuit comprises a seventh resistor R7, an eighth resistor R8, a ninth resistor R9 and a capacitor C;

the first end of the seventh resistor R7 is electrically connected with the positive pole of the direct-current power supply, the second end of the seventh resistor R7 is grounded through the eighth resistor R8, the first end of the ninth resistor R9 is connected with the common connection end between the second end of the seventh resistor R7 and the eighth resistor R8, the second end of the ninth resistor R9 is electrically connected with the controller, the first end of the capacitor C is connected with the common connection end between the second end of the ninth resistor R9 and the controller, and the second end of the capacitor C is grounded.

10. A steam cleaning device, comprising:

an apparatus body;

the direct current power supply is arranged on the equipment body;

the steam assembly is arranged on the equipment body and is electrically connected with the direct-current power supply; and

the constant power control circuit according to any one of claims 1 to 9, electrically connected to both a dc power source and a steam component of the steam cleaning device, for controlling the steam component to operate at a constant power under the power of the dc power source.

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