CN217824767U - Atomization sheet control circuit with current feedback - Google Patents

Abstract

The utility model discloses a take current feedback's atomizing piece control circuit relates to atomizing piece control technology field, and control circuit includes: the device comprises a controller, an NMOS (N-channel metal oxide semiconductor) tube and a current feedback circuit; the controller and the current feedback circuit are both connected with an NMOS (N-channel metal oxide semiconductor) tube, and the NMOS tube is connected with the atomizing sheet; when a PWM signal generated by the controller is received, the NMOS tube is switched on to drive the atomizing sheet to start working; the current feedback circuit collects the current flowing through the atomizing sheet and sends the current to the controller; the controller is also used for stopping generating the PWM signal according to the condition that when the current is larger than the preset current, the NMOS tube is cut off, and therefore the atomization piece stops working. The utility model discloses set up current feedback circuit, avoided the electric current too big through the atomizing piece to avoid atomizing piece high temperature and damaged.

Description

A atomizer control circuit with current feedback

technical field

The utility model relates to the technical field of atomizing sheet control, in particular to an atomizing sheet control circuit with current feedback.

Background technique

The atomizing sheet is a piezoelectric ceramic component used for atomization and humidification, and its physical model is an emission piezoelectric ceramic transducer. According to the needs of energy output, the two electrodes of the atomizer are generally designed to be one large and one small. The large side is generally called the large silver surface, also known as the surface electrode, and the small side is generally called the small silver surface, also known as the driving electrode or point electrode. At the same time, in order to facilitate the connection with the peripheral drive circuit, lead wires should be welded on the two electrodes.

The interaction between the micro-shock wave caused by cavitation under the liquid surface and the limited-amplitude surface tension wave caused by ultrasonic vibration, when the amplitude reaches a certain value, the liquid droplets fly out from the wave crest to form fog. According to this principle, the substrate can be sprayed quickly and evenly.

The existing atomizing sheet control circuit does not have a current detection function. When there is no liquid on the atomizing sheet, the equivalent resistance of the atomizing sheet will decrease, resulting in an increase in the current passing through the atomizing sheet, causing the atomizing sheet to be damaged due to excessive temperature.

Utility model content

The purpose of the utility model is to provide a control circuit for the atomizing sheet with current feedback, which avoids damage to the atomizing sheet due to excessive temperature.

In order to achieve the above object, the utility model provides the following scheme:

An atomizing sheet control circuit with current feedback, comprising: a controller, an NMOS tube, and a current feedback circuit; both the controller and the current feedback circuit are connected to the NMOS tube, and the NMOS tube is connected to the atomizing sheet, The current feedback circuit is connected to the controller;

The controller is used to generate a PWM signal according to an external signal;

The NMOS tube is used to turn on when receiving the PWM signal, and drive the atomizing sheet to start working;

The current feedback circuit is used to collect the current flowing through the atomizing sheet, and send the current to the controller;

The controller is also used to stop generating the PWM signal when the current is greater than a preset current, and cut off the NMOS tube, so that the atomizing sheet stops working.

Optionally, the current feedback circuit includes: a current collecting resistor and a current limiting resistor; one end of the current collecting resistor is connected to the source of the NMOS transistor, and the other end of the current collecting resistor is grounded; the current limiting resistor One end of the resistor is connected to one end of the current collecting resistor, and the other end of the current limiting resistor is connected to the controller;

The current collection resistor is used to collect the current flowing through the atomized sheet;

and current limiting resistors are used to send the current to the controller.

Optionally, the control circuit further includes: a pulse coupling circuit; one end of the pulse coupling circuit is connected to the controller, and the other end of the pulse coupling circuit is connected to the NMOS transistor;

The pulse coupling circuit is used for coupling the PWM signal.

Optionally, the control circuit further includes: a voltage amplifying circuit; the first end of the voltage amplifying circuit is connected to the atomizing sheet, the second end of the voltage amplifying circuit is connected to the drain of the NMOS transistor and the The atomizing sheet is connected, and the third end of the voltage amplification circuit is connected to the power supply;

The voltage amplifying circuit is used to boost the voltage of the power supply to a pulse voltage of 100V to drive the atomizing sheet to start working when the NMOS transistor is turned on.

Optionally, the pulse coupling circuit includes: a first capacitor and a first resistor; one end of the first capacitor is connected to the controller, and the other end of the first capacitor is connected to one end of the first resistor ; The other end of the first resistor is connected to the gate of the NMOS transistor, and the other end of the first resistor is grounded.

Optionally, the voltage amplifying circuit is a triangular inductor.

Optionally, the control circuit further includes: a serial port; the serial port is respectively connected to the controller and external equipment;

The serial port is used to send the external signal sent by the external device to the controller.

Optionally, the control circuit further includes: a second capacitor; one end of the second capacitor is connected to the controller and the power supply, the other end of the second capacitor is connected to the controller, and the second capacitor is connected to the controller. The other end of the capacitor is grounded;

The second capacitor is used for filtering for the controller.

Optionally, the controller is a STC15W401AS single-chip microcomputer;

The P3.0 pin and the P3.1 pin of the STC15W401AS single-chip microcomputer are used to receive the external signal, the P3.6 pin of the STC15W401AS single-chip microcomputer is connected with one end of the pulse coupling circuit, and the P1 of the STC15W401AS single-chip microcomputer .0 pin is connected to the current feedback circuit.

According to the specific embodiment provided by the utility model, the utility model discloses the following technical effects:

The utility model discloses an atomizing sheet control circuit with current feedback, comprising: a controller, an NMOS tube and a current feedback circuit; both the controller and the current feedback circuit are connected with the NMOS tube, and the NMOS tube is connected with the atomizing sheet; When the PWM signal generated by the controller is received, the NMOS tube is turned on to drive the atomizer to start working; the current feedback circuit collects the current flowing through the atomizer and sends the current to the controller; the controller is also used to When the current is preset, the generation of PWM signal is stopped, and the NMOS tube is cut off, so that the atomizer stops working. The utility model is provided with a current feedback circuit to collect the current flowing through the atomizing sheet, so that the atomizing sheet starts or stops working, avoiding excessive current passing through the atomizing sheet, thereby avoiding damage to the atomizing sheet due to excessive temperature.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only the present invention. For some embodiments of the invention, those skilled in the art can also obtain other drawings according to these drawings without paying creative efforts.

Fig. 1 is the block diagram of the control circuit of atomizing sheet with current feedback provided by the embodiment of the present invention;

Fig. 2 is a structural diagram of an atomizing sheet control circuit with current feedback provided by an embodiment of the present invention.

Description of the drawings: 1-controller, 2-NMOS tube, 3-current feedback circuit, 4-atomizing sheet.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

The purpose of the utility model is to provide an atomizing sheet control circuit with current feedback, which aims at avoiding damage to the atomizing sheet due to excessive temperature, and can be applied in the technical field of atomizing sheet control.

In order to make the above purpose, features and advantages of the utility model more obvious and understandable, the utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a block diagram of the control circuit of the atomizing sheet 4 with current feedback provided by the embodiment of the present invention. As shown in Figure 1, the atomizer 4 control circuit with current feedback in this embodiment includes: a controller 1, an NMOS tube 2 and a current feedback circuit 3; both the controller 1 and the current feedback circuit 3 are connected to the NMOS tube 2 The NMOS tube 2 is connected with the atomizer 4, and the current feedback circuit 3 is connected with the controller 1.

The controller 1 is used for generating PWM signals according to external signals.

The NMOS tube 2 is used to turn on when receiving the PWM signal, and drive the atomizing sheet 4 to start working.

The current feedback circuit 3 is used to collect the current flowing through the atomizing sheet 4 and send the current to the controller 1 .

The controller 1 is also used to stop generating the PWM signal when the current is greater than the preset current, so that the NMOS tube 2 is turned off, so that the atomizing sheet 4 stops working.

Specifically, the model of the NMOS transistor 2 is PJM123NSA.

Fig. 2 is a structural diagram of an atomizing sheet control circuit with current feedback provided by an embodiment of the present invention. As shown in Figure 2, as an optional implementation, the current feedback circuit includes: a current collection resistor R3 and a current limiting resistor R2; one end of the current collection resistor R3 is connected to the source of the NMOS transistor Q1, and the current collection resistor R3 The other end is grounded; one end of the current limiting resistor R2 is connected to one end of the current collecting resistor R3, and the other end of the current limiting resistor R2 is connected to the controller.

The current collection resistor R3 is used to collect the current flowing through the atomizing sheet P1.

and current limiting resistor R2 to send current to the controller.

As an optional implementation manner, the control circuit further includes: a pulse coupling circuit; one end of the pulse coupling circuit is connected to the controller, and the other end of the pulse coupling circuit is connected to the NMOS transistor Q1.

A pulse coupling circuit is used to couple the PWM signal.

As an optional implementation, the control circuit also includes: a voltage amplifier circuit; the first end of the voltage amplifier circuit is connected to the atomizer P1, and the second end of the voltage amplifier circuit is connected to the drain of the NMOS transistor Q1 and the atomizer P1 is connected, and the third terminal of the voltage amplifying circuit is connected with the power supply.

The voltage amplifying circuit is used to boost the voltage of the power supply to 100V pulse voltage to drive the atomizer P1 to start working when the NMOS transistor Q1 is turned on.

As an optional implementation, the pulse coupling circuit includes: a first capacitor C1 and a first resistor R1; one end of the first capacitor C1 is connected to the controller, and the other end of the first capacitor C1 is connected to one end of the first resistor R1 ; The other end of the first resistor R1 is connected to the gate of the NMOS transistor Q1, and the other end of the first resistor R1 is grounded.

As an optional implementation manner, the voltage amplifying circuit is a triangular inductor L1.

As an optional implementation manner, the control circuit further includes: a serial port P2; the serial port P2 is respectively connected to the controller and external devices.

The serial port P2 is used to send the external signal sent by the external device to the controller.

As an optional implementation manner, the control circuit further includes: a second capacitor C2; one end of the second capacitor C2 is connected to the controller and the power supply, the other end of the second capacitor C2 is connected to the controller, and the other end of the second capacitor C2 One end is grounded.

The second capacitor C2 is used for filtering for the controller.

As an optional implementation, the controller is a STC15W401AS single-chip microcomputer U1.

The P3.0 pin and P3.1 pin of STC15W401AS single-chip microcomputer U1 are used to receive external signals, the P3.6 pin of STC15W401AS single-chip microcomputer U1 is connected to one end of the pulse coupling circuit, and the P1.0 pin of STC15W401AS single-chip microcomputer U1 is connected to the current feedback circuit connection.

Specifically, the workflow of the atomizer P1 control circuit with current feedback is:

The serial port P2 is connected to an external serial port device. After receiving the external serial port P2 information (external signal) through the serial port P2, the STC15W401AS microcontroller U1 generates a variable frequency (range 0-200KHz) PWM pulse signal. The pulse signal is coupled to the NMOS transistor Q1 (PJM123NSA) through the first capacitor C1 (100nf) (wherein, the role of the first capacitor C1 is to couple the PWM signal output by the controller. Capacitive coupling can make the pulse signal passing through the first resistor R1 (5kΩ) The current is quickly released, so that the gate voltage of the NMOS transistor Q1 is quickly released. In this way, the output waveform generated by the on-off of the NMOS transistor Q1 will not be released because the current of the first resistor R1 is too late to affect the on-off time of the NMOS transistor Q1), through the first The PWM pulse signal coupled by a resistor R1C1, the NMOS transistor Q1 controls the voltage on and off at both ends of the triangular inductor L1, and the triangular inductor L1 (28Uh/500uH) boosts the 5V voltage to a pulse voltage of 100V to drive the atomizer P1. The current collection resistor R3 (0.2R is 0.2Ω) is the current collection resistor R3, which is used to collect the current passing through the atomized sheet P1 (the principle is: the voltage at both ends of the resistor R3 is collected by collecting the current, and the current flows through the atomized sheet P1 The NMOS tube Q1 passes through R3. The current flowing through R3 can be regarded as the current flowing through the atomizing sheet P1. When the atomizing sheet P1 is dry-burning, the current increases. It will increase, so the voltage across the current collection resistor R3 will also increase, so the ground voltage of the current collection resistor R3 is equivalent to the current at both ends of the atomization sheet P1), and the ground voltage of the current collection resistor R3 passes through the current limiting resistor R2 (10R is 10Ω) is sent to the 19th pin of STC15W401AS single-chip microcomputer U1 (that is, P1.0 pin), and the P1.0 pin is the analog-to-digital conversion input pin of the single-chip microcomputer. STC15W401AS microcontroller U1 judges whether the atomizer P1 is dry-burning according to the voltage value. If it is dry-burning, the STC15W401AS microcontroller U1 will stop the output of the PWM pulse signal and cut off the driving voltage of the atomizer P1 (equivalent to the current flowing through the atomizer P1. When the current is greater than the preset current, the controller stops generating the PWM signal, so that the NMOS tube Q1 is cut off, so that the atomizer P1 stops working).

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

In this paper, specific examples have been used to illustrate the principle and implementation of the present utility model. The description of the above embodiments is only used to help understand the device of the present utility model and its core idea; meanwhile, for those of ordinary skill in the art, according to Thoughts of the present utility model all have changes in specific implementation and scope of application. To sum up, the contents of this specification should not be understood as limiting the utility model.

Claims (9)

1. A control circuit with current feedback for an atomizing plate is characterized by comprising: the device comprises a controller, an NMOS (N-channel metal oxide semiconductor) tube and a current feedback circuit; the controller and the current feedback circuit are both connected with the NMOS tube, the NMOS tube is connected with the atomizing sheet, and the current feedback circuit is connected with the controller;

the controller is used for generating a PWM signal according to an external signal;

the NMOS tube is used for being switched on when receiving the PWM signal and driving the atomizing sheet to start working;

the current feedback circuit is used for collecting the current flowing through the atomizing sheet and sending the current to the controller;

the controller is further used for stopping generating the PWM signal when the current is larger than the preset current, so that the NMOS tube is cut off, and the atomization piece stops working.

2. The current feedback enabled atomization pad control circuit of claim 1, wherein the current feedback circuit comprises: the current collection resistor and the current limiting resistor; one end of the current collecting resistor is connected with the source electrode of the NMOS tube, and the other end of the current collecting resistor is grounded; one end of the current limiting resistor is connected with one end of the current collecting resistor, and the other end of the current limiting resistor is connected with the controller;

the current collecting resistor is used for collecting the current flowing through the atomizing sheet;

and a current limiting resistor for sending the current to the controller.

3. The atomization plate control circuit with current feedback of claim 1, further comprising: a pulse coupling circuit; one end of the pulse coupling circuit is connected with the controller, and the other end of the pulse coupling circuit is connected with the NMOS tube;

the pulse coupling circuit is used for coupling the PWM signal.

4. The atomization plate control circuit with current feedback of claim 1, further comprising: a voltage amplifying circuit; the first end of the voltage amplifying circuit is connected with the atomizing sheet, the second end of the voltage amplifying circuit is connected with the drain electrode of the NMOS tube and the atomizing sheet, and the third end of the voltage amplifying circuit is connected with a power supply;

and the voltage amplifying circuit is used for boosting the voltage of the power supply to 100V pulse voltage to drive the atomizing sheet to start working when the NMOS tube is switched on.

5. The atomization plate control circuit with current feedback of claim 3, wherein the pulse coupling circuit comprises: a first capacitor and a first resistor; one end of the first capacitor is connected with the controller, and the other end of the first capacitor is connected with one end of the first resistor; the other end of the first resistor is connected with the grid electrode of the NMOS tube, and the other end of the first resistor is grounded.

6. The atomization chip control circuit with current feedback of claim 4, wherein the voltage amplification circuit is a triangular inductor.

7. The atomization plate control circuit with current feedback of claim 1, further comprising: a serial port; the serial port is respectively connected with the controller and external equipment;

the serial port is used for sending an external signal sent by the external equipment to the controller.

8. The atomization plate control circuit with current feedback of claim 4, further comprising: a second capacitor; one end of the second capacitor is connected with the controller and the power supply, the other end of the second capacitor is connected with the controller, and the other end of the second capacitor is grounded;

the second capacitor is used for filtering the controller.

9. The atomization plate control circuit with current feedback of claim 3, wherein the controller is an STC15W401AS single chip microcomputer;

the P3.0 pin and the P3.1 pin of the STC15W401AS single chip microcomputer are used for receiving the external signal, the P3.6 pin of the STC15W401AS single chip microcomputer is connected with one end of the pulse coupling circuit, and the P1.0 pin of the STC15W401AS single chip microcomputer is connected with the current feedback circuit.

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