An adaptive UV lamp starting circuit and a starting method thereof

Abstract

The application discloses a self-adaptive UV lamp starting circuit, which comprises a single-chip microcomputer, a fourth rectifier diode, a second transformer, a first current matching capacitor, a second current matching capacitor, a third MOS tube, a fifteenth resistor, a sixteenth resistor and two UV lamps, the gate of the third MOS tube is connected with the single-chip microcomputer, the drain of the third MOS tube is connected with the 5th pin of the second transformer, the 2nd pin of the second transformer is connected with the negative electrode of the fourth rectifier diode, the 11th pin of the second transformer is connected with the 1st pin of one of the UV lamps through the first current matching capacitor C5, and the 1st pin of the other UV lamp is connected with the 8th pin of the second transformer through the second current matching capacitor C9; the application further discloses a self-adaptive UV lamp starting method; the application can realize that one lamp can be adapted to various forms, various powers and various starting voltages, and further reduces processing cost.

Description

Technical Field

[0001] This invention relates to the technical field of germicidal lamps, specifically to an adaptive UV lamp start-up circuit and its start-up method. Background Technology

[0002] Sterilization has become an important means of preventing the spread of the epidemic. UV lamps, using ultraviolet (UV) sterilization components, can effectively inhibit and eliminate residual viruses on the surface of items, making them popular and widely used. However, UV lamps require a power supply. With the wide variety of power supplies available, varying power ratings, and several issues arising during UV lamp use, the following problems exist: 1. Differences in the starting voltage due to manufacturing processes of the UV lamp tubes themselves; 2. Differences in the secondary power supply voltage of the transformer; 3. Tolerances in the transformer winding inductance; 4. Differences in the cold and hot current of the UV lamp tube. Therefore, to address these issues, UV lamps are typically equipped with different types of UV lamp tubes depending on their power and starting voltage, which undoubtedly increases manufacturing and purchasing costs.

[0003] Therefore, it is particularly important to overcome the differences in the starting voltage requirements of different UV lamps, reduce the dependence of the starting voltage of UV lamps on the circuit in different states (cold and hot), and ultimately realize that a UV lamp can be adapted to different power, different starting voltage, different shapes (such as U-shaped tubes, straight tubes), and cold or hot states. Summary of the Invention

[0004] The purpose of this invention is to provide an adaptive UV lamp starting circuit and its starting method, in order to solve the problem mentioned in the background art that current UV lamps are generally equipped with different types of UV lamp tubes according to different power and different starting voltage, which undoubtedly increases the processing cost and the purchase cost for consumers.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an adaptive UV lamp start-up circuit, comprising a microcontroller U1 and a UV start-up unit. The UV start-up unit includes a fourth rectifier diode D4, a second transformer L2, a first current matching capacitor C5, a second current matching capacitor C9, a third MOSFET Q3, a fifteenth resistor R15, a sixteenth resistor R16, and two UV lamps. The fifteenth resistor R15 and the sixteenth resistor R16 are connected in series between the I / O port of the microcontroller U1 and the ground terminal GND to form a current sampling circuit. The common terminal of the fifteenth resistor R15 and the sixteenth resistor R16 is connected to the source of the third MOSFET Q3, and the gate of the third MOSFET Q3 is connected to the source of the microcontroller U1. One I / O port of the microcontroller U1 has the drain of the third MOSFET Q3 connected to pin 5 of the second transformer L2. A second capacitor C8 is connected between pins 1 and 6 of the second transformer L2. Pin 2 of the second transformer L2 is connected to the cathode of the fourth rectifier diode D4. The anode of the fourth rectifier diode D4 is connected to the +12V power supply voltage. The cathode of the fourth rectifier diode D4 is connected to the drain of the third MOSFET Q3 through a seventh capacitor C7. Pins 3 of the two UV lamps are connected to each other. Pin 11 of the second transformer L2 is connected to pin 1 of one of the UV lamps through a first current matching capacitor C5. Pin 1 of the other UV lamp is connected to pin 8 of the second transformer L2 through a second current matching capacitor C9.

[0006] As a preferred option, to ensure greater circuit stability, the gate of the third MOS transistor Q3 is connected to the I / O port of the microcontroller U1 through the twenty-first resistor R21, and the source of the third MOS transistor Q3 is connected to the gate of the third MOS transistor Q3 by a twenty-second resistor R22 to form a pull-down resistor.

[0007] Preferably, as filter capacitors, to ensure a more stable supply voltage, a first filter capacitor EC1, a second filter capacitor EC2, and a sixth filter capacitor C6 are connected in parallel between the +12V supply voltage and the ground terminal GND.

[0008] Preferably, as a filter capacitor to ensure a more stable transmission voltage, the microcontroller U1 is model CMS79FT736. A +5V power supply voltage is connected to pin 10 of the microcontroller U1. A third filter capacitor EC3 and a tenth filter capacitor C10 are connected in parallel between the +5V power supply voltage and the ground terminal GND.

[0009] Preferably, in order to ensure a simple power supply voltage structure and more stable output, the +12V power supply voltage is formed by the mains power through a rectifier and voltage regulator switching power supply. The rectifier and voltage regulator switching power supply includes a rectifier, a power chip IC1, a first transformer L1, a first unidirectional voltage regulator D1, and an output filter circuit connected in sequence.

[0010] Preferably, the power chip IC1 is model PN6359.

[0011] As a preferred option, a filter circuit is added to filter out AC components, making the output DC smoother. The +5V power supply voltage is obtained by regulating the output of the +12V power supply voltage through the power regulator chip IC1 in conjunction with the third capacitor C3, the fourth capacitor C4 and the fifth filter capacitor EC5. The model of the power regulator chip IC1 is CJ78M05.

[0012] As a preferred embodiment, in order to achieve the functions of sound reminder, display and fan cooling, a buzzer display circuit, a fan drive circuit, a coil heating circuit and an LED display circuit are also connected to the microcontroller U1.

[0013] This invention also discloses an adaptive UV lamp start-up method, comprising using the aforementioned adaptive UV lamp start-up circuit, characterized by the following steps: S1. First, the UV lamp is initially powered by a hot lamp, that is, the UV lamp is started using 50% of the normal voltage. S2, and perform a delay operation for a time t, then start the UV lamp with normal voltage. Simultaneously, sample the current of the UV lamp in its current starting state after the operation, that is, sample the current of the secondary winding of the second transformer L2 through the microcontroller U1, and define it as I. 实 , S3. The microcontroller has a pre-stored current reference value I0. The I obtained in step S2 is used to... 实 The current reference value I0 is compared to determine whether the UV lamp has started normally; S4. If I at this time 实 If the current reference value I0 is equal to the current value, it means that the UV lamp is starting normally. Maintain the starting voltage at this time and exit. S5. If I at this time 实 If the current is less than the reference value I0, it indicates that the UV lamp is in an abnormal start-up. At this time, the starting voltage of the UV lamp is finally adjusted by adjusting the pulse, and the process returns to step S4 to achieve the effect of adaptive start-up of the UV lamp.

[0014] Preferably, the delay time t in step S2 is in the range of 5-10s.

[0015] Compared with the prior art, the beneficial effects of the present invention are: the present invention determines whether the UV lamp has been successfully started by sampling the UV lamp's operating current. If it is not successfully started, the starting voltage of the UV lamp is finely adjusted by the microcontroller pulse method to adapt to the UV lamp tube under different conditions, thereby achieving the effect of adaptive starting of the UV lamp. Ultimately, one lamp can be adapted to multiple forms, multiple power levels, and multiple starting voltages, further improving the processing cost. Attached Figure Description

[0016] Figure 1 This is a circuit diagram of the UV start-up unit in Embodiment 1. Figure 2 This is a circuit diagram of the microcontroller and peripheral circuits in Embodiment 1. Figure 3 This is a circuit diagram of the rectifier and regulator switching power supply and the power regulator chip in Embodiment 1. Figure 4 This is a circuit diagram of the buzzer display circuit in Embodiment 1. Figure 5 This is a circuit diagram of the fan drive circuit in Embodiment 1. Figure 6 This is a circuit diagram of the coil heating circuit in Embodiment 1. Figure 7 This is a circuit diagram of the LED display circuit in Embodiment 1. Figure 8 This is a flowchart of an adaptive UV lamp start-up method in Embodiment 1.

[0017] In the diagram: 1. UV start-up unit; 2. UV lamp; 3. Rectifier and regulated switching power supply; 4. Rectifier; 5. Output filter circuit; 6. Buzzer display circuit; 7. Fan drive circuit; 8. Coil heating circuit; 9. LED display circuit. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0019] Example 1: Please see Figure 1-7This invention provides an adaptive UV lamp start-up circuit, including a microcontroller U1 and a UV start-up unit 1. The UV start-up unit 1 includes a fourth rectifier diode D4, a second transformer L2, a first current matching capacitor C5, a second current matching capacitor C9, a third MOSFET Q3, a fifteenth resistor R15, a sixteenth resistor R16, and two UV lamps 2. The fifteenth resistor R15 and the sixteenth resistor R16 are connected in series between the I / O port of the microcontroller U1 and the ground terminal GND to form a current sampling circuit. The common terminal of the fifteenth resistor R15 and the sixteenth resistor R16 is connected to the source of the third MOSFET Q3, and the gate of the third MOSFET Q3 is connected to one of the microcontrollers U1. The drain of the third MOSFET Q3 is connected to pin 5 of the second transformer L2. A second capacitor C8 is connected between pins 1 and 6 of the second transformer L2. Pin 2 of the second transformer L2 is connected to the cathode of the fourth rectifier diode D4. The anode of the fourth rectifier diode D4 is connected to the +12V power supply voltage. The cathode of the fourth rectifier diode D4 is connected to the drain of the third MOSFET Q3 through a seventh capacitor C7. Pins 3 of the two UV lamps 2 are connected to each other. Pin 11 of the second transformer L2 is connected to pin 1 of one of the UV lamps 2 through a first current matching capacitor C5. Pin 1 of the other UV lamp 2 is connected to pin 8 of the second transformer L2 through a second current matching capacitor C9.

[0020] As a preferred option, to ensure greater circuit stability, the gate of the third MOS transistor Q3 is connected to the I / O port of the microcontroller U1 through the twenty-first resistor R21, and the source of the third MOS transistor Q3 is connected to the gate of the third MOS transistor Q3 by a twenty-second resistor R22 to form a pull-down resistor.

[0021] Preferably, as filter capacitors, to ensure a more stable supply voltage, a first filter capacitor EC1, a second filter capacitor EC2, and a sixth filter capacitor C6 are connected in parallel between the +12V supply voltage and the ground terminal GND.

[0022] Preferably, as a filter capacitor to ensure a more stable transmission voltage, the microcontroller U1 is model CMS79FT736. A +5V power supply voltage is connected to pin 10 of the microcontroller U1. A third filter capacitor EC3 and a tenth filter capacitor C10 are connected in parallel between the +5V power supply voltage and the ground terminal GND.

[0023] Preferably, in order to ensure a simple power supply voltage structure and more stable output, the +12V power supply voltage is formed by the mains power through a rectifier and regulated switching power supply 3. The rectifier and regulated switching power supply 3 includes a rectifier 4, a power chip IC1, a first transformer L1, a first unidirectional voltage regulator D1, and an output filter circuit 5 connected in sequence.

[0024] Figures 1-7 EC1, EC2, and C6 are all filter capacitors; D4 is a rectifier diode to prevent abnormalities in the back-end circuit from affecting the front-end power supply; C7, C8, and the second transformer L2 form an LC oscillation circuit; C5 and C9 are current matching capacitors; UV1 and UV2 are connected to two UV lamps; the fifteenth resistor R15 and the sixteenth resistor R16 form a current sampling circuit; the CHECK pin network is connected to the microcontroller's I / O port; the third MOSFET Q3 is a MOSFET; the twenty-second resistor R22 is a pull-down resistor; and the twenty-first resistor R21 is used to eliminate parasitic inductance on the PCB.

[0025] Preferably, the power chip IC1 is model PN6359.

[0026] As a preferred option, a filter circuit is added to filter out AC components, making the output DC smoother. The +5V power supply voltage is obtained by regulating the output of the +12V power supply voltage through the power regulator chip IC1 in conjunction with the third capacitor C3, the fourth capacitor C4 and the fifth filter capacitor EC5. The model of the power regulator chip IC1 is CJ78M05.

[0027] As a preferred embodiment, in order to achieve the functions of sound reminder, display and fan cooling, a buzzer display circuit 6, a fan drive circuit 7, a coil heating circuit 8 and an LED display circuit 9 are also connected to the microcontroller U1.

[0028] Please see Figure 8 This embodiment also discloses an adaptive UV lamp start-up method, including the aforementioned adaptive UV lamp start-up circuit, characterized by the following steps: S1. First, the UV lamp is initially supplied with a primary pulse voltage using the hot lamp method. The reason for hot lamp operation is that the UV lamp has a particularly large current at the moment of cold start. If the normal operating voltage is used to start it at the beginning, it will pull down the power supply voltage of the UV lamp control circuit, causing the entire control unit to malfunction. Therefore, the hot lamp method is used. Specifically, the UV lamp is started with 50% of the normal voltage. This is called the hot lamp method. S2, and perform a delay operation for a time t, then start the UV lamp 2 with normal voltage. At the same time, sample the current of the UV lamp 2 in its current starting state after the operation, that is, sample the current of the secondary winding of the second transformer L2 through the microcontroller U1, and define it as I. 实 The method for obtaining the normal voltage described in this embodiment is as follows: If the UV lamp is a new product (new lamp tube), a minimum voltage that can ensure the normal start-up of all UV lamps is obtained by trial production of 100 sets. It can also be higher than the start-up voltage of the hot lamp method (such as about 1.4 times the hot lamp voltage, it is better to be smaller than larger, and then the voltage is adjusted according to the current to obtain the normal voltage). S3. The microcontroller has a pre-stored current reference value I0. The I obtained in step S2 is used to... 实 The current reference value I0 is compared to determine whether UV lamp 2 has started normally; S4. If I at this time 实 If the current reference value I0 is equal to the current value, it means that UV lamp 2 is starting normally at this time. Maintain the starting voltage at this time and exit. S5. If I at this time 实 If the current is less than the reference value I0, it indicates that the UV lamp 2 is in an abnormal start-up. At this time, the starting voltage of the UV lamp 2 is finally adjusted by adjusting the pulse, and the process returns to step S4 to achieve the effect of adaptive start-up of the UV lamp 2.

[0029] Preferably, the delay time t in step S2 is in the range of 5-10s.

[0030] During operation, the UV lamp is initially supplied with a primary pulse voltage using a hot-lamp method. After a certain period, the UV lamp is then started with a normal voltage. Simultaneously, the current of the UV lamp during normal operation is sampled to determine if the UV lamp has started normally. If it has not started normally, the starting voltage of the UV lamp is finely adjusted via a microcontroller using a pulse method. In short, this invention mainly uses a microcontroller to sample the current of the secondary winding of the transformer to determine the starting status of the UV lamp, thereby overcoming the following four problems existing in the prior art. Ultimately, it can adapt to the starting process of UV lamps under different conditions, achieving the effect of adaptive starting of the UV lamp. Finally, it enables a single lamp to adapt to multiple forms, multiple power levels, and multiple starting voltages, further improving processing costs.

[0031] 1. The difference in ignition voltage caused by the manufacturing process of the UV lamp itself will result in different voltages required to start the UV lamp.

[0032] 2. Difference in the secondary power supply voltage of the transformer; 3. Tolerances for transformer winding inductance; 4. The difference in current between cold and hot states of UV lamps; Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adaptive UV lamp start-up method, comprising an adaptive UV lamp start-up circuit, the adaptive UV lamp start-up circuit comprising a microcontroller (U1) and a UV start-up unit (1), the UV start-up unit (1) comprising a fourth rectifier diode (D4), a second transformer (L2), a first current matching capacitor (C5), a second current matching capacitor (C9), a third MOSFET (Q3), a fifteenth resistor (R15), a sixteenth resistor (R16), and two UV lamps (2), the fifteenth resistor (R15) and the sixteenth resistor (R16) being connected in series between the I / O port of the microcontroller (U1) and the ground terminal (GND) to form a current sampling circuit, and the common terminal of the fifteenth resistor (R15) and the sixteenth resistor (R16) being connected to the source of the third MOSFET (Q3), the gate of the third MOSFET (Q3) being connected to... One I / O port of the microcontroller (U1) has the drain of the third MOS transistor (Q3) connected to pin 5 of the second transformer (L2). A second capacitor (C8) is connected between pins 1 and 6 of the second transformer (L2). Pin 2 of the second transformer (L2) is connected to the cathode of the fourth rectifier diode (D4). The anode of the fourth rectifier diode (D4) is connected to the +12V power supply voltage. The cathode of the fourth rectifier diode (D4) is connected to the drain of the third MOS transistor (Q3) through a seventh capacitor (C7). Pins 3 of the two UV lamps (2) are connected to each other. Pin 11 of the second transformer (L2) is connected to pin 1 of one of the UV lamps (2) through a first current matching capacitor (C5). Pin 1 of the other UV lamp (2) is connected to pin 8 of the second transformer (L2) through a second current matching capacitor (C9). The feature is that: Specifically, the following steps are included: S1. First, the UV lamp is initially powered by a hot lamp, that is, the UV lamp is started using 50% of the normal voltage. S2, and perform a delay operation, with a delay time of t, and then start the UV lamp (2) with normal voltage. At the same time, sample the current of the UV lamp (2) in the current starting state after the action, that is, sample the current of the secondary winding of the second transformer (L2) through the microcontroller (U1) and define it as Ireal. S3. The microcontroller has a pre-stored current reference value I0. The I value obtained in step S2 is compared with the current reference value I0 to determine whether the UV lamp (2) is started normally. S4. If the actual current value I0 is equal to the current reference value I0, it means that the UV lamp (2) is starting normally and maintaining the starting voltage at this time. Exit. S5. If the actual current value I is less than the current reference value I0, it means that the UV lamp (2) is in an abnormal start-up. At this time, the starting voltage of the UV lamp (2) is finally adjusted by adjusting the pulse, and the process returns to step S4 to achieve the effect of adaptive start-up of the UV lamp (2).

2. The adaptive UV lamp start-up method according to claim 1, characterized in that: The delay time t in step S2 ranges from 5 to 10 seconds.

Images