Tooth protection instrument

Abstract

The utility model belongs to the field of tooth care, and relates to a tooth protection instrument, a singlechip is connected with a display screen, a buzzer, a key circuit, a power supply, a PWM (Pulse-Width Modulation)-to-DAC (Digital-to-Analog Converter) circuit and a pulse constant-current source generating circuit, the PWM-to-DAC circuit is connected with the pulse constant-current source generating circuit, and the pulse constant-current source generating circuit comprises a constant-current operational amplifier circuit and a pulse control circuit. The resistor R9 is connected with the non-inverting input end of the operational amplifier U5, the output end of the operational amplifier U5 is connected with the resistor R13, the capacitor C8 and the emitting electrode of the triode Q4, the collector electrode of the triode Q4, the capacitor C8, the R29, the R15 and the inverting input end of the operational amplifier U5 are connected, the R13 is connected with the grid electrode of the MOS tube Q1, the source electrode of the Q1 is connected with the R15 and the R16, and a pin 1 of the analog switch U6 inputs PWM signals. According to the utility model, the square wave output signal pulse constant current is accurate and controllable, so that fluorine ions penetrate into tooth tissues under the action of a direct-current pulse electric field, and the effect of protecting teeth is achieved.

Description

Technical Field

[0001] The utility model belongs to the technical field of tooth care, and in particular relates to a tooth protection instrument. Background Art

[0002] When performing tooth care, the prior art is to apply sodium fluoride solution to the tooth surface by dipping a cotton swab in the solution. The sodium fluoride solution is applied manually, which has the problem of incomplete and uneven application.

[0003] In addition, the cotton strip in the mouth mold can be immersed in sodium fluoride solution, and the instrument can provide direct current pulse current for fluoride penetration. Under the action of the electric field, the sodium fluoride solution ionizes fluoride ions and enters the tooth tissue, which plays a role in protecting teeth, making good teeth better and bad teeth not developing. This method of caring for teeth through instruments must solve the technical problem of precise control of pulse constant current, and corresponding improvements need to be made to the existing constant current source generation circuit. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a tooth protection device. The technical solution adopted by the utility model is as follows:

[0005] A tooth protector comprises a single-chip microcomputer and a load J1, wherein the single-chip microcomputer is electrically connected to a power supply, a PWM to DAC circuit and a pulse constant current source generating circuit respectively, the power supply is electrically connected to the PWM to DAC circuit and the pulse constant current source generating circuit respectively, and the PWM to DAC circuit is electrically connected to the pulse constant current source generating circuit; the pulse constant current source generating circuit, one end of a resistor R9 inputs a DA signal, the other end of R9 is connected to one end of a resistor R10, the other end of R10 is grounded, one end of a capacitor C23 is connected to one end of R9, the other end of C23 is grounded, the other end of R9 is simultaneously connected to the same-direction input end of an operational amplifier U5, the positive power input end of U5 and one end of a capacitor C24 are connected to a 3.3V power supply, the other end of C24 is grounded, the negative power input end of U5 is grounded, the output end of U5 is connected to one end of a resistor R13, one end of a capacitor C8 and a transistor Q4 The emitter of Q4 is connected, the base of Q4 is connected to one end of resistor R29, the collector of Q4, the other end of C8, the other end of R29, one end of resistor R15 and the reverse input end of U5 are connected, the other end of R13 is connected to the gate of MOS tube Q1, the source of Q1 is connected to the other end of R15 and one end of resistor R16, the other end of R16 is grounded, pin 1 of analog switch U6 inputs PWM signal, pin 4 of U6 inputs DA1 signal, pin 6 of U6 is suspended, pin 5 of U6 is connected to one end of resistor R14, the other end of R14 is connected to the reverse input end of U5, pin 2 of U6 is connected to a 3.3V power supply, pin 3 of U6 is grounded, the drain of Q1 is connected to one end of load J1, the other end of J1 is connected to the cathode of light-emitting diode D21, the anode of D21 is connected to one end of fuse F1, and the other end of F1 is connected to a positive voltage of 24V.

[0006] Preferably, the DA signal is generated by a PWM to DAC circuit, one end of resistor R70 is connected to the T3C2 input signal, T3C2 is the second channel of the single-chip microcomputer timer, the other end of R70 is connected to one end of resistor R71, the other end of R71 is connected to one end of resistor R72, the other end of R72 is connected to the same-direction input end of the operational amplifier U17A, the reverse input end and the output end of U17A are connected to one end of resistor R76, the positive input end of the power supply of U17A is connected to a 3.3V positive voltage, the negative input end of the power supply of U17A is grounded, one end of capacitors C40 and C41 is connected between R70 and R71, the other end of C40 and C41 is grounded, one end of capacitor C42 is connected between R71 and R72, the other end of C42 is connected to one end of R76, one end of capacitor C43 is connected between R72 and the same-direction input end of U17A, and the other end of C43 is connected to the ground. One end is grounded, the other end of R76 is connected to one end of resistor R77, the other end of R77 is connected to one end of resistor R78, the other end of R78 is connected to the same-direction input terminal of operational amplifier U17B, the positive power input terminal of U17B is connected to 3.3V positive voltage, the negative power input terminal of U17B is grounded, the reverse input and output terminals of U17B are connected to one end of capacitor C48, the other end of C48 is connected between R77 and R78, one end of capacitors C45 and C46 is connected between R76 and R77, the other ends of C45 and C46 are grounded, one end of capacitor C49 is connected between R72 and the same-direction input terminal of U17B, the other end of C49 is grounded, the output terminal of U17B is also connected to one end of capacitor C47 and one end of resistor R79, the other end of C47 is grounded, and the other end of R79 is connected to one end of R9 and one end of C23 in the pulse constant current source generating circuit.

[0007] Preferably, the single chip microcomputer is electrically connected to the display screen, the one-key power on / off circuit, the buzzer and the key circuit respectively.

[0008] Preferably, U5 adopts an operational amplifier of model tlv2211, Q4 adopts a transistor of model N3904 SOT-23, Q1 adopts a MOS tube of model 2N7002 SOT-23, U6 adopts an analog switch of model ADG719, and the single-chip microcomputer adopts a stm8l151k4t6 32PI single-chip microcomputer.

[0009] Preferably, U17A and U17B use operational amplifiers of model Im358.

[0010] Beneficial effects of the utility model:

[0011] The utility model can make the square wave output signal pulse constant current precisely controllable, so that the fluoride ions can fully penetrate into the tooth tissue under the action of the DC pulse electric field, and combine with the calcium salt on the tooth surface to play a role in protecting the teeth. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0013] Figure 1 This is a structural principle diagram of a tooth protection instrument according to an embodiment of the utility model;

[0014] Figure 2 It is a structural schematic diagram of a pulse constant current source generating circuit of an embodiment of the utility model;

[0015] Figure 3 It is a structural schematic diagram of a PWM to DAC circuit according to an embodiment of the utility model. DETAILED DESCRIPTION

[0016] The technical solution of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present utility model, rather than all of the embodiments.

[0017] like Figure 1 As shown, a tooth protector includes an STM single chip microcomputer, the STM single chip microcomputer is electrically connected to a display screen, a one-button switch circuit, a buzzer, a key circuit, a power supply, a PWM to DAC circuit and a pulse constant current source generating circuit, the power supply is electrically connected to the PWM to DAC circuit and the pulse constant current source generating circuit, the PWM to DAC circuit is electrically connected to the pulse constant current source generating circuit, and the pulse constant current source generating circuit is electrically connected to a load. The load J1 acts on the sodium fluoride solution on the cotton strip to provide a DC pulse current signal for the penetration of fluoride, and the sodium fluoride solution ionizes fluoride ions into the tooth tissue under the action of the electric field. The STM single chip microcomputer adopts a stm8l151k4t6 32PI low-power single chip microcomputer.

[0018] like Figure 2As shown, the pulse constant current source generating circuit is an improved circuit of a high-precision operational amplifier constant current source, including a constant current operational amplifier circuit and a pulse control circuit. The constant current operational amplifier circuit includes an operational amplifier U5, an analog switch U6, a transistor Q4 and a MOS tube Q1, a DA signal is input to one end of the resistor R9, the other end of R9 is connected to one end of the resistor R10, the other end of R10 is grounded, one end of the capacitor C23 is connected to one end of R9, the other end of C23 is grounded, and the other end of R9 is simultaneously connected to the same-direction input end of the operational amplifier U5. U5 can preferably use an operational amplifier of model tlv2211, the positive input end of the power supply of U5 and one end of the capacitor C24 are connected to a 3.3V power supply, the other end of C24 is grounded, and the negative input end of the power supply of U5 is grounded. The output end of U5 is connected to one end of the resistor R13, one end of the capacitor C8 and the emitter of the transistor Q4, and the transistor Q4 can preferably use a model N3904 The SOT-23 triode, the base of Q4 is connected to one end of the resistor R29, the collector of Q4, the other end of C8, the other end of R29, one end of the resistor R15 and the reverse input end of U5 are connected, the other end of R13 is connected to the gate of the MOS tube Q1, and the MOS tube Q1 can preferably be a 2N7002 SOT-23 MOS tube, the drain of Q1 is connected to one end of the load J1, the other end of J1 is connected to the negative electrode of the light-emitting diode D21, the positive electrode of D21 is connected to one end of the fuse F1, and the other end of F1 is connected to a positive voltage of 24V, which is obtained by a boost circuit, and the boost circuit is a prior art, the source of Q1 is connected to the other end of R15 and one end of the resistor R16, and the other end of R16 is grounded. The core of the pulse control circuit is the analog switch U6. U6 can preferably use an analog switch of model ADG719. Pin 1 of U6 inputs a PWM signal, pin 4 of U6 inputs a DA1 signal, pin 6 of U6 is suspended, pin 5 of U6 is connected to one end of resistor R14, the other end of R14 is connected to the reverse input end of U5, pin 2 of U6 is connected to a 3.3V power supply, and pin 3 of U6 is grounded. Load J1 acts on the sodium fluoride solution on the cotton strip, providing a DC pulse current signal for the penetration of fluoride. Under the action of the electric field, the sodium fluoride solution ionizes fluoride ions and enters the tooth tissue.

[0019] The pulse constant current source generating circuit of the utility model embodiment is based on the constant current circuit and adds a pulse control circuit, introduces different DA1 / DA levels at high and low levels respectively, and uses the characteristics of the operational amplifier itself to form a subtractor, which controls the constant current signal of 0.6ma / 0ma when the square wave signal is at a high level and the constant current signal of 0.3ma / 0ma when the square wave signal is at a low level. The frequency of the pulse circuit is 1k Hz, and the period is 1ms. The difficulty lies in that within each 1ms, the high level time of 500us is a controllable constant current value of 0.3ma / 0.6ma, and the current value of the low level time of 500us is a stable 0ma. Fast switching and accurate switching are required, which requires accurate selection of hardware operational amplifiers and analog switches to design a stable circuit. The role of transistor Q4 is to improve the reaction speed and make the waveform of the pulse more accurate and beautiful.

[0020] The output of this circuit is a pulse voltage based on the 0 point, that is, the high level is a positive voltage and the low level is 0. The value of DA1 is greater than DA. When DA / DA1 are added to the op amp input at the same time, because DA1 is greater than DA, the op amp output is 0. When PWM is high, pin 4 and pin 5 of U6 are connected. At this time, the voltage at the reverse input of U5 is greater than the voltage at the same input. U5 is cut off and the output is 0; when PWM is low, pin 6 and pin 5 of U6 are connected. At this time, the voltage at the reverse input of U5 is equal to the voltage at the same input, and a constant current (0.3 or 0.6, depending on the gear) is output. The innovation is to use the characteristics of the operational amplifier itself to form a subtractor to generate pulses based on the constant current circuit.

[0021] The DA1 signal is obtained by power supply voltage division. The voltage division circuit is a prior art. The DA signal is generated by the PWM to DAC circuit of the previous stage, such as Figure 3As shown, the PWM to DAC circuit is formed by cascading two Butterworth third-order low-pass filters to form a sixth-order low-pass filter circuit, one end of resistor R70 is connected to the T3C2 input signal, T3C2 is the second channel of the single-chip timer, the other end of R70 is connected to one end of resistor R71, the other end of R71 is connected to one end of resistor R72, the other end of R72 is connected to the same-direction input end of operational amplifier U17A, U17A can preferably use an operational amplifier of model Im358, the reverse input and output ends of U17A are connected to one end of resistor R76, the positive input end of the power supply of U17A is connected to a 3.3V positive voltage, the negative input end of the power supply of U17A is grounded, one end of capacitors C40 and C41 is connected between R70 and R71, the other ends of C40 and C41 are grounded, one end of capacitor C42 is connected between R71 and R72, the other end of C42 is connected to one end of R76, and one end of capacitor C43 is connected to the same-direction input end of R72 and U17A. The other end of C43 is grounded, the other end of R76 is connected to one end of resistor R77, the other end of R77 is connected to one end of resistor R78, the other end of R78 is connected to the same-direction input end of operational amplifier U17B, U17B can preferably use an operational amplifier of model Im358, the positive input end of U17B is connected to a 3.3V positive voltage, the negative input end of U17B is grounded, the reverse input end and output end of U17B are connected to one end of capacitor C48, and the other end of C48 is connected to the same-direction input end of operational amplifier U17B. One end is connected between R77 and R78, one end of capacitors C45 and C46 is connected between R76 and R77, the other ends of C45 and C46 are grounded, one end of capacitor C49 is connected between R72 and the same-direction input end of U17B, the other end of C49 is grounded, the output end of U17B is also connected to one end of capacitor C47 and one end of resistor R79, the other end of C47 is grounded, and the other end of R79 is connected to one end of R9 and one end of C23 in the pulse constant current source generating circuit.

[0022] The PWM to DAC circuit of the embodiment of the utility model is a circuit for generating the control signal DA. Due to the lack of DAC function of the single-chip microcomputer itself, the general single-chip microcomputer has at most three DAC outputs, and some single-chip microcomputers do not even have DAC. The PWM to DAC circuit of the utility model can provide a single-channel six DAC signal. The solution is to use the single-chip microcomputer's own more PWM signals plus an operational amplifier to generate the DAC signal itself. The advantage is that it is more cost-effective and has higher precision. The utility model uses the PWM to DAC circuit to expand the DAC signal output by the single-chip microcomputer DAC, and can better output high-precision pulse signals. The sixth-order filter circuit composed of two groups of third-order filters can ensure the accuracy and reliability of the DC component.

[0023] The tooth protector of the embodiment of the utility model is a combination of a constant current circuit and an analog switch to form a 1 kHz pulse constant current source circuit. The PWM to DAC circuit generates a DAC DC signal for voltage setting, and corresponds to the value of the constant current. The principle of the tooth protector of the embodiment of the utility model is: the rectangular square wave output signal is controlled by a constant current, and its positive half-wave is independently output by the output circuit and connected to the human body. When the selected time is reached, the single-chip microcomputer stops outputting the waveform. The tooth protector of the embodiment of the utility model realizes timing, square wave pulse output, button adjustment of current setting, button adjustment of time setting, and one-button power on and off.

[0024] In the embodiments of the utility model, the technical features not described in detail are all existing technologies or conventional technical means and will not be described in detail here.

[0025] Finally, it should be noted that the above embodiments are only specific implementation methods of the present utility model, which are used to illustrate the technical solution of the present utility model, rather than to limit it, and the protection scope of the present utility model is not limited thereto. Those skilled in the art should understand that any technician familiar with the technical field can modify the technical solution recorded in the above embodiments within the technical scope disclosed by the present utility model, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solution deviate from the spirit and scope of the technical solution of the embodiment of the present utility model, and should be covered within the protection scope of the present utility model.

Claims

1. A tooth protection device, comprising a single chip microcomputer and a load J1, characterized in that: The single chip microcomputer is electrically connected to the power supply, the PWM to DAC circuit and the pulse constant current source generating circuit respectively, the power supply is electrically connected to the PWM to DAC circuit and the pulse constant current source generating circuit respectively, and the PWM to DAC circuit is electrically connected to the pulse constant current source generating circuit; The pulse constant current source generating circuit, one end of the resistor R9 inputs the DA signal, the other end of the resistor R9 is connected to one end of the resistor R10, the other end of the resistor R10 is grounded, one end of the capacitor C23 is connected to one end of the resistor R9, the other end of the capacitor C23 is grounded, the other end of the resistor R9 is simultaneously connected to the same-direction input end of the operational amplifier U5, the positive power input end of the operational amplifier U5 and one end of the capacitor C24 are connected to a 3.3V power supply, the other end of the capacitor C24 is grounded, the negative power input end of the operational amplifier U5 is grounded, the output end of the operational amplifier U5 is connected to one end of the resistor R13, one end of the capacitor C8 and the emitter of the transistor Q4, the base of the transistor Q4 is connected to one end of the resistor R29, the collector of the transistor Q4, the other end of the capacitor C8, the other end of the resistor R29 and one end of the resistor R15 and the reverse input end of the operational amplifier U5 The analog switch U6 is connected to the gate of the MOS tube Q1, the source of the MOS tube Q1 is connected to the other end of the resistor R15 and one end of the resistor R16, the other end of the resistor R16 is grounded, the pin 1 of the analog switch U6 inputs the PWM signal, the pin 4 of the analog switch U6 inputs the DA1 signal, the pin 6 of the analog switch U6 is suspended, the pin 5 of the analog switch U6 is connected to one end of the resistor R14, the other end of the resistor R14 is connected to the reverse input end of the operational amplifier U5, the pin 2 of the analog switch U6 is connected to a 3.3V power supply, the pin 3 of the analog switch U6 is grounded, the drain of the MOS tube Q1 is connected to one end of the load J1, the other end of the load J1 is connected to the cathode of the light-emitting diode D21, the anode of the light-emitting diode D21 is connected to one end of the fuse F1, and the other end of the fuse F1 is connected to a positive voltage of 24V.

2. The tooth protection device according to claim 1, characterized in that: The DA signal is generated by a PWM to DAC circuit, one end of resistor R70 is connected to the T3C2 input signal, T3C2 is the second channel of the single-chip microcomputer timer, the other end of resistor R70 is connected to one end of resistor R71, the other end of resistor R71 is connected to one end of resistor R72, the other end of resistor R72 is connected to the same-direction input end of the operational amplifier U17A, the reverse input end and the output end of the operational amplifier U17A are connected to one end of resistor R76, the positive input end of the power supply of the operational amplifier U17A is connected to a 3.3V positive voltage, the negative input end of the power supply of the operational amplifier U17A is grounded, one end of capacitor C40 and one end of capacitor C41 are connected between resistor R70 and resistor R71, the other end of capacitor C40 and one end of capacitor C41 are grounded, one end of capacitor C42 is connected between resistor R71 and resistor R72, the other end of capacitor C42 is connected to one end of resistor R76, one end of capacitor C43 is connected between resistor R72 and the same-direction input end of the operational amplifier U17A, the other end of capacitor C43 is grounded, and resistor The other end of R76 is connected to one end of resistor R77, the other end of resistor R77 is connected to one end of resistor R78, the other end of resistor R78 is connected to the same-direction input of operational amplifier U17B, the positive input of the power supply of operational amplifier U17B is connected to a 3.3V positive voltage, the negative input of the power supply of operational amplifier U17B is grounded, the reverse input and output of operational amplifier U17B are connected to one end of capacitor C48, the other end of capacitor C48 is connected between resistor R77 and resistor R78, capacitor C45 and capacitor One end of C46 is connected between resistor R76 and resistor R77, the other ends of capacitor C45 and capacitor C46 are grounded, one end of capacitor C49 is connected between resistor R72 and the same-direction input end of operational amplifier U17B, the other end of capacitor C49 is grounded, the output end of operational amplifier U17B is also connected to one end of capacitor C47 and one end of resistor R79, the other end of capacitor C47 is grounded, and the other end of resistor R79 is connected to one end of resistor R9 and one end of capacitor C23 in the pulse constant current source generating circuit.

3. The tooth protection device according to claim 2, characterized in that: The single chip microcomputer is electrically connected to the display screen, the one-key on / off circuit, the buzzer and the key circuit respectively.

4. The tooth protector according to any one of claims 1 to 3, characterized in that: The operational amplifier U5 adopts the operational amplifier model tlv2211, the transistor Q4 adopts the transistor model N3904 SOT-23, the MOS tube Q1 adopts the MOS tube model 2N7002 SOT-23, the analog switch U6 adopts the analog switch model ADG719, and the single-chip microcomputer adopts the stm8l151k4t6 32PI single-chip microcomputer.

5. The tooth protection device according to claim 2 or 3, characterized in that: Operational amplifier U17A and operational amplifier U17B use operational amplifiers of model Im358.

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