CN217160056U - Dental LED light curing machine and control circuit thereof - Google Patents

Abstract

The utility model discloses a dentistry LED photocuring machine and control circuit thereof, this control circuit includes the switch unit, the power inductance, the diode, sampling resistor, feedback amplification unit and the control unit, the first end of switch unit is connected with ground, the second end of switch unit is connected with the first end of power inductance and the first end of diode respectively, the second end of power inductance is connected with sampling resistor's first end, the second end of diode is connected with the first end and the power of load LED lamp respectively, sampling resistor's second end is connected with the second end of load LED lamp, the first input of feedback amplification unit and second input end are connected with sampling resistor's first end and second end respectively, the output of feedback amplification unit is connected with the input of control unit, the output of control unit and the third end connection of switch unit.

Description

A dental LED light curing machine and its control circuit

technical field

The utility model relates to the technical field of medical equipment, in particular to a dental LED light curing machine and a control circuit thereof.

Background technique

Dental LED light curing machine is a device used to polymerize polymer-based filling, repairing and sealing materials next to the dental chair. Rapid and efficient polymerization and curing within a short period of time. There are two main power supply methods for the existing LED light curing machine: one is a power supply with constant power provided by an external power supply (grid power), and the other is powered by an internal power supply (rechargeable battery). Rechargeable battery power supply is more and more widely used in the field of dental light curing machines because it is not bound by external tail wires, it is more flexible in clinical use, and has a long working time after being fully charged.

At present, because the power of the rechargeable battery will decrease during use, it is difficult for the LED light curing machine to maintain a stable light radiation output during operation, which will make the curing degree of the light curing resin uneven or the curing speed is too slow. phenomenon, which greatly affects the polymerization and curing effect of photocurable resins. In order to maintain a stable light radiation output when the LED lamp of the light curing machine is working, the LED light must maintain a stable current input. Therefore, the light curing machine using the internal power supply needs to solve the problem of stable working current of the LED light.

The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

Utility model content

The purpose of the utility model is to provide a dental LED light curing machine and its control circuit, which can provide stable current input for the load LED lamp of the dental LED light curing machine, and ensure the polymerization curing effect of the light curing resin.

In order to achieve the above purpose, one aspect of the present utility model provides a control circuit for a dental LED light curing machine, comprising a switch unit, a power inductor, a diode, a sampling resistor, a feedback amplifier unit and a control unit;

The first end of the switch unit is connected to the ground, the second end of the switch unit is respectively connected to the first end of the power inductor and the first end of the diode, and the second end of the power inductor is connected to the The first end of the sampling resistor is connected, the second end of the diode is respectively connected with the first end of the load LED lamp and the power supply, and the second end of the sampling resistor is connected with the second end of the load LED lamp;

The first input end and the second input end of the feedback amplifying unit are respectively connected with the first end and the second end of the sampling resistor, and the output end of the feedback amplifying unit is connected with the input end of the control unit, using collecting and amplifying the potential difference between the two ends of the sampling resistor;

The output end of the control unit is connected to the third end of the switch unit, for receiving the amplified potential difference from the feedback amplifying unit, and outputting the amplified potential difference according to the potential difference for controlling the switch unit to be turned on or off. off switch control signal.

Preferably, the feedback amplifying unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first operational amplifier and a second operational amplifier;

The first end of the first resistor is connected to the first end of the sampling resistor, the second end of the first resistor is connected to the non-inverting input end of the first operational amplifier, the second resistor and the The first terminals of the third resistors are all connected to the inverting input terminal of the first operational amplifier, the second terminals of the second resistors are connected to ground, and the second terminals of the third resistors are connected to the first operational amplifier. The output terminals of the amplifier are all connected to the first terminal of the fourth resistor, and the second terminal of the fourth resistor is respectively connected to the first terminal of the fifth resistor and the inverting input terminal of the second operational amplifier. , the second end of the fifth resistor and the output end of the second operational amplifier are both connected to the input end of the control unit, and the first end of the sixth resistor is connected to the second end of the sampling resistor , the second end of the sixth resistor is connected to the non-inverting input end of the second operational amplifier.

Preferably, the feedback amplifying unit further includes a first capacitor, and the first end and the second end of the first capacitor are respectively connected to the first end and the second end of the sampling resistor.

Preferably, the first capacitor is a ceramic capacitor.

Preferably, the switch unit is a MOS transistor.

Preferably, the gate of the MOS transistor is connected to the output end of the control unit, the drain of the MOS transistor is connected to the first end of the power inductor, and the source of the MOS transistor is connected to ground.

Preferably, the diode is a Schottky diode.

Preferably, it also includes a second capacitor;

The first end of the second capacitor is connected to the second end of the power inductor, and the second end of the second capacitor is connected to the power supply.

Preferably, the second capacitor is an electrolytic capacitor.

Another aspect of the present invention provides a dental LED light curing machine, comprising the above-mentioned control circuit for the dental LED light curing machine.

The utility model at least has the following beneficial effects:

The utility model collects and amplifies the potential difference between the two ends of the sampling resistor through the feedback amplifying unit, and the control unit receives the amplified potential difference from the feedback amplifying unit, and judges the magnitude of the current flowing through the load LED lamp according to the potential difference, and outputs the corresponding output. The switch control signal used to control the on or off of the switch unit to adjust the current of the load LED lamp, so as to provide a stable current input for the load LED lamp of the dental LED light curing machine, and ensure the polymerization and curing of the light curing resin. Effect.

Description of drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description These are only some embodiments described in the present utility model. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 is a schematic structural diagram of a control circuit for a dental LED light curing machine in an embodiment of the present invention;

2 is a circuit schematic diagram of a control circuit for a dental LED light curing machine in an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example.

It should be noted that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for the purpose of illustration only and do not represent the only embodiment.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which the present invention belongs. The terms used in the description of the present invention are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The first aspect of the embodiment of the present invention provides a control circuit for a dental LED light curing machine, please refer to FIG. 1 and FIG. 2 , the control circuit includes a switch unit 10, a power inductor 20, a diode 30, a sampling resistor 40, a feedback amplifying unit 50 and control unit 60;

The first end of the switch unit 10 is connected to the ground, the second end of the switch unit 10 is connected to the first end of the power inductor 20 and the first end of the diode 30 respectively, and the second end of the power inductor 20 is connected to the first end of the sampling resistor 40 The second end of the diode 30 is connected to the first end of the load LED lamp and the power supply respectively, and the second end of the sampling resistor 40 is connected to the second end of the load LED lamp;

The first input end and the second input end of the feedback amplifying unit 50 are respectively connected with the first end and the second end of the sampling resistor 40, and the output end of the feedback amplifying unit 50 is connected with the input end of the control unit 60 for sampling the sampling resistor The potential difference between the two ends of 40 is amplified;

The output end of the control unit 60 is connected to the third end of the switch unit 10 for receiving the amplified potential difference from the feedback amplifying unit 50 and outputting a switch control signal for turning on or off the switch unit 10 according to the potential difference.

In the embodiment of the present invention, the control unit 60 can use the control module that comes with the dental LED light curing machine, and can control the on or off of the switch unit 10 by outputting a switch control signal such as a PWM pulse signal. When the dental LED light curing machine is working, the control unit 60 outputs a PWM pulse signal with a certain duty cycle. When the switch unit 10 is turned on, the current output by the positive pole of the power supply passes through the load LED light, the sampling resistor 40 and the power inductor 20 in sequence. , and then flows to the ground (the negative pole of the power supply) through the first end of the switch unit 10. At this time, the power inductor 20 has a current flowing through it and converts the electrical energy into magnetic field energy; when the switch unit 10 is turned off, the power inductor 20 converts the magnetic field energy into It is electric energy and supplies power to the load LED light through the diode 30 . The feedback amplifying unit 50 collects and amplifies the potential difference between the two ends of the sampling resistor 40 in real time. After receiving the amplified potential difference from the feedback amplifying unit 50, the control unit 60 judges the magnitude of the current flowing through the load LED light according to the potential difference, and uses It is compared with the preset current. Since the duty cycle of the PWM pulse signal is different, the on and off times of the switch unit 10 are also different, and the output current can be controlled by controlling the duty cycle of the PWM pulse signal. Therefore, when the current of the load LED lamp is less than the preset current, the control unit 60 can increase the duty cycle of the PWM pulse signal, thereby increasing the current of the load LED lamp; when the current of the load LED lamp is greater than the preset current, the control unit 60 can increase the duty cycle of the PWM pulse signal. 60 can reduce the duty cycle of the PWM pulse signal, thereby reducing the current of the load LED lamp, so that the purpose of constant control of the current of the load LED lamp can be achieved, and then the optical radiation output of the dental LED light curing machine can be constantly controlled.

As can be seen from the above, the control circuit for the dental LED light curing machine provided by the embodiment of the present invention collects and amplifies the potential difference between the two ends of the sampling resistor through the feedback amplifying unit, and the control unit receives the amplified potential difference from the feedback amplifying unit, and According to the potential difference, the magnitude of the current flowing through the load LED lamp is judged, and the switch control signal for controlling the switch unit to be turned on or off is output accordingly, so as to adjust the magnitude of the current of the load LED lamp, so as to be able to cure the dental LED light. The load LED light of the machine provides a stable current input to ensure the polymerization and curing effect of the light-curing resin.

As a preferred embodiment of the present invention, the feedback amplifying unit 50 includes a first resistor R3, a second resistor R4, a third resistor R6, a fourth resistor R8, a fifth resistor R9, a sixth resistor R7, a first operational amplifier IC1A, and a the second operational amplifier IC1B;

The first end of the first resistor R3 is connected to the first end of the sampling resistor R2, the second end of the first resistor R3 is connected to the non-inverting input end of the first operational amplifier IC1A, the first end of the second resistor R4 and the third resistor R6 The terminals are connected to the inverting input terminal of the first operational amplifier IC1A, the second terminal of the second resistor R4 is connected to the ground, the second terminal of the third resistor R6 and the output terminal of the first operational amplifier IC1A are connected to the fourth resistor R8 The first end of the fourth resistor R8 is connected to the first end of the fifth resistor R9 and the inverting input end of the second operational amplifier IC1B respectively, the second end of the fifth resistor R9 is connected to the second operational amplifier The output terminals of IC1B are all connected to the input terminal of the control unit 60, the first terminal of the sixth resistor R7 is connected to the second terminal of the sampling resistor, and the second terminal of the sixth resistor R7 is connected to the non-inverting input terminal of the second operational amplifier IC1B .

In the embodiment of the present invention, the second end of the sampling resistor R2 is connected to the positive electrode of the power supply through the resistor R1. When the load LED lamp has current passing through, the sampling resistor R2 will have current passing through, even if the two ends of the sampling resistor R2 generate a potential difference E1=U _I2 -U _I1 , the potential difference is amplified by the first operational amplifier and the second operational amplifier and denoted as U _FB . Then there are:

In the specific implementation, the resistance value of the feedback amplifying unit can be designed as R4=R9, R6=R8, then:

Since the feedback amplifying unit adopts a two-stage operational amplifier, the input impedance of each signal source is infinite, which is more accurate and reliable in data acquisition and operation, which can further ensure constant control of the current of the load LED lamp; at the same time, Compared with using a single operational amplifier, it is more convenient to select and debug resistors, and no resistor matching is required.

As a preferred embodiment of the present invention, the feedback amplifying unit 50 further includes a first capacitor C2, and the first end and the second end of the first capacitor C2 are respectively connected to the first end and the second end of the sampling resistor R2. In specific implementation, the first capacitor C2 can be a ceramic capacitor, which has the advantages of small size, high withstand voltage and good frequency characteristics.

As a preferred embodiment of the present invention, the switch unit 10 is a MOS transistor. In specific implementation, the switch unit 10 may include a MOS transistor Q1 and a resistor R5, the gate of the MOS transistor Q1 is connected to the output end of the control unit 60, the drain of the MOS transistor Q1 is connected to the first end of the power inductor L1, and the MOS transistor Q1 The source of the resistor R5 is connected to the ground, and the two ends of the resistor R5 are respectively connected to the gate of the MOS transistor Q1 and the ground. It can be understood that the MOS transistor Q1 is an N-channel MOS transistor.

As a preferred embodiment of the present invention, the diode D1 is a Schottky diode, which has the advantages of high switching frequency and reduced forward voltage.

As a preferred embodiment of the present invention, the control circuit further includes a second capacitor C1, the first end of the second capacitor C1 is connected to the second end of the power inductor L1, and the second end of the second capacitor C1 is connected to the power supply. In specific implementation, the second capacitor C1 can be an electrolytic capacitor. Since the PWM pulse signal is an AC signal after passing through the MOS transistor Q1, the second capacitor C1 can perform filtering to convert the AC signal into a smooth DC signal.

Correspondingly, another embodiment of the present invention provides a dental LED light curing machine, the dental LED light curing machine includes the control circuit for the dental LED light curing machine provided in any of the above embodiments. Through the control circuit, the load LED lamp of the dental LED light curing machine can output a stable current to ensure the polymerization curing effect of the light curing resin.

It should be understood by those skilled in the art that the present invention is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention There will also be various changes and improvements in the new model, which all fall within the scope of the claimed invention. The claimed scope of the present invention is defined by the appended claims and their equivalents.

Claims (10)

1. A control circuit for a dental LED light curing machine is characterized by comprising a switch unit, a power inductor, a diode, a sampling resistor, a feedback amplification unit and a control unit;

a first end of the switch unit is connected with the ground, a second end of the switch unit is respectively connected with a first end of the power inductor and a first end of the diode, a second end of the power inductor is connected with a first end of the sampling resistor, a second end of the diode is respectively connected with a first end of the load LED lamp and the power supply, and a second end of the sampling resistor is connected with a second end of the load LED lamp;

the first input end and the second input end of the feedback amplification unit are respectively connected with the first end and the second end of the sampling resistor, and the output end of the feedback amplification unit is connected with the input end of the control unit and used for collecting and amplifying the potential difference at the two ends of the sampling resistor;

the output end of the control unit is connected with the third end of the switch unit, and is used for receiving the amplified potential difference from the feedback amplification unit and outputting a switch control signal for controlling the switch unit to be switched on or switched off according to the potential difference.

2. The control circuit of claim 1, wherein the feedback amplification unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first operational amplifier, and a second operational amplifier;

the first end of the first resistor is connected with the first end of the sampling resistor, the second end of the first resistor is connected with the non-inverting input end of the first operational amplifier, first ends of the second resistor and the third resistor are connected with an inverting input end of the first operational amplifier, the second end of the second resistor is connected with the ground, the second end of the third resistor and the output end of the first operational amplifier are both connected with the first end of the fourth resistor, a second end of the fourth resistor is respectively connected with a first end of the fifth resistor and an inverting input end of the second operational amplifier, the second end of the fifth resistor and the output end of the second operational amplifier are both connected with the input end of the control unit, and the first end of the sixth resistor is connected with the second end of the sampling resistor, and the second end of the sixth resistor is connected with the non-inverting input end of the second operational amplifier.

3. The control circuit of claim 2, wherein the feedback amplification unit further comprises a first capacitor, and a first terminal and a second terminal of the first capacitor are respectively connected to a first terminal and a second terminal of the sampling resistor.

4. The control circuit of claim 3, wherein the first capacitor is a ceramic capacitor.

5. The control circuit of claim 1, wherein the switching unit is a MOS transistor.

6. The control circuit of claim 5, wherein a gate of the MOS transistor is connected to the output terminal of the control unit, a drain of the MOS transistor is connected to the first terminal of the power inductor, and a source of the MOS transistor is connected to ground.

7. The control circuit of claim 1, wherein the diode is a schottky diode.

8. The control circuit of claim 1, further comprising a second capacitor;

and the first end of the second capacitor is connected with the second end of the power inductor, and the second end of the second capacitor is connected with a power supply.

9. The control circuit of claim 8, wherein the second capacitor is an electrolytic capacitor.

10. A dental LED curing apparatus, comprising the control circuit for a dental LED curing apparatus according to any one of claims 1 to 9.

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