TWI790712B - Power supply device with sterilization function - Google Patents

Abstract

A power supply device with a sterilization function includes a bridge rectifier, a first capacitor, a transformer, a power switch element, an output stage circuit, a detection circuit, a sterilization circuit, a driving circuit, and a controller. The bridge rectifier generates a rectified voltage according to a first input voltage and a second input voltage. The transformer includes a main coil and a secondary coil. The main coil receives the rectified voltage. The power switch element selectively couples the main coil to a ground voltage according to a clock voltage. The output stage circuit is coupled to the secondary coil, and generates an output voltage. The detection circuit detects a temperature parameter. The driving circuit drives the sterilization circuit. The controller controls the driving circuit according to the temperature parameter, so as to selectively enable or disable the sterilization circuit.

Description

Power supply with sterilization function

The present invention relates to a power supply, in particular to a power supply with a sterilization function.

In recent years, due to the spread of various large-scale infectious diseases, the demand for antibacterial products has gradually increased. For example, Escherichia coli and Staphylococcus aureus grow stronger at temperatures between 30°C and 50°C, and are prone to infect related diseases. In view of this, it is necessary to propose a new solution to overcome the difficulties faced by the previous technology.

In a preferred embodiment, the present invention proposes a power supply with a sterilization function, including: a bridge rectifier, which generates a rectified potential according to a first input potential and a second input potential; a first capacitor, which stores the rectified potential; a transformer, including a main coil and a secondary coil, wherein the transformer has a built-in excitation inductor, and the main coil is used to receive the rectified potential; a power switch, according to a clock potential to selectively The main coil is coupled to a ground potential; an output stage circuit is coupled to the secondary coil and used to generate an output potential; a detection circuit detects a temperature parameter; a sterilization circuit; a drive circuit drives the sterilization circuit; a controller, coupled to the detection circuit, and used to generate the clock potential, wherein the controller controls the driving circuit according to the temperature parameter to selectively enable or disable the sterilization circuit.

In order to make the purpose, features and advantages of the present invention more comprehensible, specific embodiments of the present invention are listed below, together with the accompanying drawings, for detailed description as follows.

Certain terms are used in the specification and claims to refer to particular elements. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This description and the scope of the patent application do not use the difference in name as a way to distinguish components, but use the difference in function of components as a criterion for distinguishing. The words "comprising" and "comprising" mentioned throughout the specification and scope of patent application are open-ended terms, so they should be interpreted as "including but not limited to". The term "approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and achieve the basic technical effect. In addition, the term "coupled" in this specification includes any direct and indirect electrical connection means. Therefore, if it is described that a first device is coupled to a second device, it means that the first device can be directly electrically connected to the second device, or indirectly electrically connected to the second device through other devices or connection means. Two devices.

FIG. 1 is a schematic diagram of a power supply 100 according to an embodiment of the present invention. For example, the power supply 100 can be applied to a desktop computer, a notebook computer, or an all-in-one computer. As shown in Figure 1, the power supply 100 includes: a bridge rectifier 110, a first capacitor C1, a transformer 120, a power switch 130, an output stage circuit 140, a detection circuit 150, a sterilization circuit 160 , a driving circuit 170, and a controller 180. It should be noted that although not shown in FIG. 1 , the power supply 100 may further include other components, such as a voltage regulator and/or a negative feedback circuit.

The bridge rectifier 110 can generate a rectified potential VR according to a first input potential VIN1 and a second input potential VIN2 . Both the first input potential VIN1 and the second input potential VIN2 can come from an external input power source, wherein an AC voltage with any frequency and any amplitude can be formed between the first input potential VIN1 and the second input potential VIN2 . For example, the frequency of the AC voltage can be about 50Hz or 60Hz, and the root mean square value of the AC voltage can be from 90V to 264V, but it is not limited thereto. The first capacitor C1 can store the rectified potential VR. The transformer 120 includes a primary coil 121 and a secondary coil 122 , wherein the transformer 120 has a built-in magnetizing inductor LM. Both the primary winding 121 and the magnetizing inductor LM can be located on the same side of the transformer 120 (e.g., the primary side), while the secondary winding 122 can be located on the opposite side of the transformer 120 (e.g., the secondary side, which can be isolated from the primary side). open). The main coil 121 can be used to receive the rectified potential VR. The output stage circuit 140 is coupled to the secondary coil 122 and can generate an output potential VOUT in response to the rectified potential VR. For example, the output potential VOUT can be a DC potential, and its potential level can be between 18V and 20V, but it is not limited thereto. The power switch 130 can selectively couple the main coil 121 to a ground potential VSS (eg, 0V) according to a clock potential VA. For example, if the clock potential VA is a high logic level (for example: logic “1”), the power switch 130 can couple the main coil 121 to the ground potential VSS (that is, the power switch 130 can approximate on a short-circuit path); on the contrary, if the clock potential VA is a low logic level (for example: logic "0"), the power switch 130 will not couple the main coil 121 to the ground potential VSS (that is, the power switching device 130 can be approximated as an open path). The detection circuit 150 can detect a temperature parameter TE. For example, the temperature parameter TE can be determined according to the temperature of any element in the power supply 100 . The driving circuit 170 can be used to drive the sterilization circuit 160 . The controller 180 is coupled to the detection circuit 150 and used for generating the clock potential VA. The controller 180 can control the driving circuit 170 according to the temperature parameter TE to selectively enable or disable the sterilization circuit 160 . In some embodiments, if the temperature parameter TE indicates that the ambient temperature of the power supply 100 is between 30 degrees Celsius and 50 degrees Celsius, the sterilization circuit 160 will be enabled and generate intermittent ultraviolet rays (Ultraviolet, UV); On the contrary, if the temperature parameter TE indicates that the ambient temperature of the power supply 100 is not between 30 degrees Celsius and 50 degrees Celsius (for example: exceeding 50 degrees Celsius or less than 30 degrees Celsius), the sterilization circuit 160 will be disabled and will not produce any UV rays. Under this design, the power supply 100 can perform corresponding sterilization operations according to different ambient temperatures, which not only provides an automatic disinfection function, but also effectively protects the health of users.

FIG. 2 is a schematic diagram showing a power supply 200 according to another embodiment of the present invention. Figure 2 is similar to Figure 1. In the embodiment of FIG. 2, the functions of an output stage circuit 240, a detection circuit 250, a sterilization circuit 260, a drive circuit 270, and a controller 280 of the power supply 200 are all adjusted, as follows mentioned. The detection circuit 250 can detect the temperature parameter TE, which includes a first parameter T1 related to the bridge rectifier 110 and a second parameter T2 related to the transformer 120 . The sterilization circuit 260 includes a first sterilizer 261 and a second sterilizer 263 . The driving circuit 270 includes a first driver 271 and a second driver 272, which can be used to drive the first sterilizer 261 and the second sterilizer 263 respectively. The controller 280 can control the first driver 271 according to the first parameter T1 to selectively enable or disable the first sterilizer 261 . For example, if the first parameter T1 indicates that the temperature of the bridge rectifier 110 is between 30° C. and 50° C., the first sterilizer 261 is enabled and generates intermittent ultraviolet rays. In addition, the controller 280 can further control the second driver 272 according to the second parameter T2 to selectively enable or disable the second sterilizer 263 . For example, if the second parameter T2 indicates that the temperature of the transformer 120 is between 30°C and 50°C, the second sterilizer 263 will be enabled and generate intermittent ultraviolet rays. In other words, according to the first parameter T1 and the second parameter T2, the first sterilizer 261 and the second sterilizer 263 can operate independently of each other to sterilize different areas of the power supply 200 respectively. On the other hand, the output stage circuit 240 further generates an output current IOUT, which can be continuously monitored by the controller 280 . For example, if the output current IOUT is greater than or equal to a current threshold value ITH, it means that the power supply 200 is in a state of full power, and the controller 280 will force the sterilization circuit 260 to be disabled to save power; otherwise, if the output current IOUT is less than the current threshold value ITH, the controller 280 will not perform any forcing operations. The rest of the features of the power supply 200 in FIG. 2 are similar to the power supply 100 in FIG. 1 , so both embodiments can achieve similar operational effects.

The following embodiments will introduce the detailed structure and operation of the power supply 100 or 200 . It must be understood that these drawings and descriptions are examples only and are not intended to limit the scope of the present invention.

FIG. 3 is a schematic diagram showing a power supply 300 according to an embodiment of the present invention. In the embodiment of FIG. 3 , the power supply 300 has a first input node NIN1, a second input node NIN2, and an output node NOUT, and includes a bridge rectifier 310, a first capacitor C1, and a transformer 320 , a power switcher 330 , an output stage circuit 340 , a detection circuit 350 , a sterilization circuit 360 , a drive circuit 370 , and a controller 380 . The first input node NIN1 and the second input node NIN2 of the power supply 300 can respectively receive the first input potential VIN1 and the second input potential VIN2 from an external input power source, and the output node NOUT of the power supply 300 can output an output potential VOUT to an electronic device (not shown).

The bridge rectifier 310 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The first diode D1 has an anode and a cathode, wherein the anode of the first diode D1 is coupled to the first input node NIN1, and the cathode of the first diode D1 is coupled to a first node N1 To output a rectified potential VR. The second diode D2 has an anode and a cathode, wherein the anode of the second diode D2 is coupled to the second input node NIN2 , and the cathode of the second diode D2 is coupled to the first node N1 . The third diode D3 has an anode and a cathode, wherein the anode of the third diode D3 is coupled to a second node N2, and the cathode of the third diode D3 is coupled to the first input node NIN1 . The fourth diode D4 has an anode and a cathode, wherein the anode of the fourth diode D4 is coupled to a third node N3, and the cathode of the fourth diode D4 is coupled to the second input node NIN2 .

The first capacitor C1 has a first end and a second end, wherein the first end of the first capacitor C1 is coupled to the first node N1 to receive and store the rectified potential VR, and the second end of the first capacitor C1 is coupled to a ground potential VSS.

The transformer 320 includes a primary coil 321 and a secondary coil 322 , wherein the transformer 320 has a built-in magnetizing inductor LM. The magnetizing inductor LM can be an inherent component produced when the transformer 320 is manufactured, and it is not an external independent component. Both the primary winding 321 and the magnetizing inductor LM can be located on the same side of the transformer 320 , while the secondary winding 322 can be located on the opposite side of the transformer 320 . The main coil 321 has a first end and a second end, wherein the first end of the main coil 321 is coupled to the first node N1 to receive the rectified potential VR, and the second end of the main coil 321 is coupled to a first node N1. Four nodes N4. The magnetizing inductor LM has a first terminal and a second terminal, wherein the first terminal of the magnetizing inductor LM is coupled to the first node N1, and the second terminal of the magnetizing inductor LM is coupled to the fourth node N4 . The secondary coil 322 has a first terminal and a second terminal, wherein the first terminal of the secondary coil 322 is coupled to a fifth node N5, and the second terminal of the secondary coil 322 is coupled to a common node NCM. For example, the common node NCM can be regarded as another ground potential, which can be the same as or different from the aforementioned ground potential VSS.

The power switch 330 includes a first transistor M1. The first transistor M1 can be an N-type metal oxide semiconductor field effect transistor. The first transistor M1 has a control end (for example: a gate), a first end (for example: a source), and a second end (for example: a drain), wherein the control of the first transistor M1 The terminal can receive a clock potential VA from the controller 380, the first terminal of the first transistor M1 is coupled to the ground potential VSS, and the second terminal of the first transistor M1 is coupled to the fourth node N4. For example, the clock potential VA can be maintained at a fixed potential when the power supply 300 is initialized, and can provide a periodic clock waveform after the power supply 200 enters a normal use stage.

The output stage circuit 340 includes a fifth diode D5, a second capacitor C2, and a first resistor R1. The fifth diode D5 has an anode and a cathode, wherein the anode of the fifth diode D5 is coupled to the fifth node N5, and the cathode of the fifth diode D5 is coupled to the output node NOUT. The second capacitor C2 has a first terminal and a second terminal, wherein the first terminal of the second capacitor C2 is coupled to the output node NOUT, and the second terminal of the second capacitor C2 is coupled to a sixth node N6 . The first resistor R1 has a first end and a second end, wherein the first end of the first resistor R1 is coupled to the sixth node N6 to output a sensing potential VS to the controller 380, and the first resistor The second end of the device R2 is coupled to the common node NCM. The output stage circuit 340 can further generate an output current IOUT, which can flow through the first resistor R1, and the sensing potential VS can be proportional to the output current IOUT.

The detection circuit 350 includes a first NTC resistor RN1 , a second NTC resistor RN2 , a third NTC resistor RN3 , and an averaging circuit 352 . For example, when the ambient temperature rises, the resistance value of each negative temperature coefficient resistor will decrease; conversely, when the ambient temperature decreases, the resistance value of each negative temperature coefficient resistor will increase. The first negative temperature coefficient resistor RN1 has a first terminal and a second terminal, wherein the first terminal of the first negative temperature coefficient resistor RN1 is coupled to the second node N2 to output a first potential V1 to the controller 380, and the second terminal of the first negative temperature coefficient resistor RN1 is coupled to the ground potential VSS. The second negative temperature coefficient resistor RN2 has a first terminal and a second terminal, wherein the first terminal of the second negative temperature coefficient resistor RN2 is coupled to the third node N3 to output a second potential V2 to the controller 380, and the second terminal of the second negative temperature coefficient resistor RN2 is coupled to the ground potential VSS. The first potential V1 and the second potential V2 can be used to indicate the temperature of the bridge rectifier 310 . The third negative temperature coefficient resistor RN3 has a first end and a second end, wherein the first end of the third negative temperature coefficient resistor RN3 is used to output a third potential V3 to the controller 380, and the third negative The second end of the temperature coefficient resistor RN3 is coupled to the ground potential VSS. The averaging circuit 352 is coupled to the first terminal and the second terminal of the magnetizing inductor LM, and is used for generating an average current IAV about the magnetizing inductor LM, wherein the average current IAV flows through the third negative temperature coefficient resistor RN3. For example, the average circuit 352 can detect the average value of the current passing through the magnetizing inductor LM, and accordingly generate the average current IAV, wherein the current value of the average current IAV is a constant value and exactly equal to the average value of the current passing through the magnetizing inductor LM . The third potential V3 can be used to indicate the temperature of the transformer 320 .

In some embodiments, the controller 380 can further generate a first control potential VC1 and a second control potential VC2 according to the first potential V1 , the second potential V2 , and the third potential V3 . For example, if the first potential V1 or the second potential V2 is between 1V and 3.5V, it means that the temperature of the bridge rectifier 310 is between 30°C and 50°C, and the controller 380 can output the level The first control potential VC1 is up to 15V; otherwise, the first control potential VC1 will remain at a low logic level. For another example, if the third potential V3 is between 1V and 3.5V, it means that the temperature of the transformer 320 is between 30°C and 50°C. At this time, the controller 380 can output a second voltage with a level as high as 15V. control potential VC2; otherwise, the second control potential VC2 is maintained at a low logic level.

The driving circuit 370 includes a first driver 371 and a second driver 372, which can be controlled by the first control potential VC1 and the second control potential VC2 respectively. The first driver 371 includes a second resistor R2, a third resistor R3, and a second transistor M2. The second resistor R2 has a first terminal and a second terminal, wherein the first terminal of the second resistor R2 is coupled to a seventh node N7 to receive the first control potential VC1 from the controller 380, and the second resistor R2 The second ends of the two resistors R2 are coupled to an eighth node N8. The second transistor M2 can be an N-type metal oxide semiconductor field effect transistor. The second transistor M2 has a control end (for example: a gate), a first end (for example: a source), and a second end (for example: a drain), wherein the control of the second transistor M2 The terminal is coupled to the eighth node N8, the first terminal of the second transistor M2 is coupled to a ninth node N9, and the second terminal of the second transistor M2 is coupled to the seventh node N7. The third resistor R3 has a first end and a second end, wherein the first end of the third resistor R3 is coupled to the eighth node N8, and the second end of the third resistor R3 is coupled to a The tenth node N10. The second driver 372 includes a fourth resistor R4, a fifth resistor R5, and a third transistor M3. The fourth resistor R4 has a first end and a second end, wherein the first end of the fourth resistor R4 is coupled to an eleventh node N11 to receive the second control potential VC2 from the controller 380, and The second end of the fourth resistor R4 is coupled to a twelfth node N12. The third transistor M3 can be an N-type metal oxide semiconductor field effect transistor. The third transistor M3 has a control end (for example: a gate), a first end (for example: a source), and a second end (for example: a drain), wherein the control of the third transistor M3 The terminal is coupled to the twelfth node N12, the first terminal of the third transistor M3 is coupled to a thirteenth node N13, and the second terminal of the third transistor M3 is coupled to the eleventh node N11 . The fifth resistor R5 has a first end and a second end, wherein the first end of the fifth resistor R5 is coupled to the twelfth node N12, and the second end of the fifth resistor R5 is coupled to The tenth node N10.

The sterilization circuit 360 includes a first sterilizer 361 and a second sterilizer 363 . The first sterilizer 361 includes a plurality of first ultraviolet light-emitting diodes (Light-Emitting Diode) DL1 and a first timing switcher 362 . The first ultraviolet light emitting diodes DL1 are coupled in series between the ninth node N9 and the ground potential VSS. The first timing switcher 362 is coupled in parallel with the first ultraviolet light emitting diodes DL1, wherein the first timing switcher 362 can be turned on and off alternately every first predetermined time TA. The second sterilizer 363 includes a plurality of second ultraviolet light-emitting diodes DL2 and a second timing switcher 364 . The second ultraviolet light emitting diodes DL2 are coupled in series between the thirteenth node N13 and the ground potential VSS. The second timing switcher 364 is coupled in parallel with the second ultraviolet light emitting diodes DL2, wherein the second timing switcher 364 can be turned on and off alternately every second predetermined time TB.

Figure 4 is a schematic diagram showing the current of the ultraviolet light-emitting diode according to an embodiment of the present invention, which can be used to illustrate the flow through the first ultraviolet light-emitting diode DL1 or the second ultraviolet light-emitting diode DL2. current value. If the first control potential VC1 is at a high logic level, the first sterilizer 361 will be enabled by the first driver 371 . At this time, because of the first timing switcher 362, the current passing through the first ultraviolet light-emitting diodes DL1 will be switched every first predetermined time TA to generate intermittent ultraviolet rays. On the other hand, if the second control potential VC2 is at a high logic level, the second sterilizer 363 will be enabled by the second driver 372 . At this time, because of the second timing switcher 364, the current passing through the second ultraviolet light-emitting diodes DL2 will be switched every second predetermined time TB to generate intermittent ultraviolet rays. It should be understood that the design of the discontinuous ultraviolet rays helps to reduce the overall power consumption of the power supply 300 .

In some embodiments, by analyzing the sensing potential VS, the controller 380 can estimate the output current IOUT and confirm whether the power supply 300 is in a full power state. For example, if the controller 380 detects that the sensing potential VS is higher than or equal to a potential threshold value VTH, it means that the power supply 300 is in a state of full power, so the controller 380 will output a disable with a low logic level. The potential VD is connected to the tenth node N10 to forcibly disable the first sterilizer 361 and the second sterilizer 363 at the same time. On the contrary, if the controller 380 detects that the sensing potential VS is lower than the potential threshold VTH, the controller 380 will not output any potential to the tenth node N10 . This full load detection design helps the power supply 300 to pass energy efficiency regulations.

FIG. 5A is a graph showing the operating characteristics of the first negative temperature coefficient resistor RN1 or the second negative temperature coefficient resistor RN2 according to an embodiment of the present invention. In the embodiment shown in Figure 5A, when the ambient temperature rises from 30 degrees Celsius to 40 degrees Celsius and then to 50 degrees Celsius, the resistance value of the first negative temperature coefficient resistor RN1 or the second negative temperature coefficient resistor RN2 can be reduced from 30Ω to 10Ω and then down to 0.5Ω. FIG. 5B is a graph showing the operating characteristics of the third negative coefficient temperature resistor RN3 according to an embodiment of the present invention. In the embodiment shown in FIG. 5B , when the ambient temperature rises from 30°C to 40°C and then rises to 50°C, the resistance value of the third negative temperature coefficient resistor RN3 can drop from 15Ω to 5Ω and then drop to 1Ω.

In some embodiments, the component parameters of the power supply 300 may be as follows. The inductance of the magnetizing inductor LM can be between 306 μH and 414 μH, preferably about 360 μH. The capacitance of the first capacitor C1 can range from 96 μF to 144 μF, preferably about 120 μF. The capacitance of the second capacitor C2 can range from 544 μF to 816 μF, preferably about 680 μF. The resistance value of the first resistor R1 can be between 0.99Ω and 1.01Ω, preferably about 1Ω. The resistance value of the second resistor R2 can be between 9.5Ω and 10.5Ω, preferably about 10Ω. The resistance value of the third resistor R3 can be between 47.5Ω and 52.5Ω, preferably about 50Ω. The resistance value of the fourth resistor R4 can be between 9.5Ω and 10.5Ω, preferably about 10Ω. The resistance value of the fifth resistor R5 can be between 47.5Ω and 52.5Ω, preferably about 50Ω. The turn ratio of the primary coil 321 to the secondary coil 322 can be between 1 and 100, preferably about 20. The potential threshold VTH may be about 2.37V. The first predetermined time TA may be about 10 seconds. The second predetermined time TB may be about 10 seconds. The above parameter ranges are obtained according to the results of multiple experiments, which help to optimize the sterilization function and the overall power consumption of the power supply 300 .

The present invention proposes a novel power supply, which has a sterilization function. According to the actual measurement results, the power supply with the aforementioned design can effectively eliminate Escherichia coli and Staphylococcus aureus in the environment, so it is very suitable for various devices.

It should be noted that the above-mentioned potential, current, resistance value, inductance value, capacitance value, and other component parameters are not limiting conditions of the present invention. Designers can adjust these settings according to different needs. The power supply of the present invention is not limited to the states shown in FIGS. 1-5. The present invention may only include any one or multiple features of any one or multiple embodiments of Figures 1-5. In other words, not all the illustrated features must be implemented in the power supply of the present invention at the same time. Although the embodiment of the present invention uses a metal oxide half field effect transistor as an example, the present invention is not limited thereto, and those skilled in the art can use other types of transistors, such as junction field effect transistors, or fin Type field effect transistors, etc., and will not affect the effect of the present invention.

Although the present invention is disclosed above with preferred embodiments, it is not intended to limit the scope of the present invention. Anyone skilled in this art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore The scope of protection of the present invention should be defined by the scope of the appended patent application.

100,200,300: Power supply 110,310: bridge rectifier 120,320: transformer 121,321: main coil 122,322: secondary coil 130,330: Power Switcher 140,240,340: output stage circuit 150,250,350: detection circuit 160,260,360: Sterilization circuit 170,270,370: drive circuit 180,280,380: Controller 261,361: First sterilizer 263,363: Second sterilizer 271,371: 1st drive 272,372: Second drive 352: average circuit 362: The first timing switcher 364: Second timing switcher C1: first capacitor C2: second capacitor D1: the first diode D2: second diode D3: The third diode D4: The fourth diode D5: fifth diode DL1: The first UV LED DL2: Second UV Light Emitting Diode IAV: average current IOUT: output current ITH: current threshold LM: Exciting inductor M1: the first transistor M2: second transistor M3: The third transistor N1: the first node N2: second node N3: the third node N4: the fourth node N5: fifth node N6: sixth node N7: seventh node N8: Eighth node N9: ninth node N10: the tenth node N11: eleventh node N12: the twelfth node N13: the thirteenth node NCM: common node NIN1: the first input node NIN2: Second input node NOUT: output node R1: first resistor R2: second resistor R3: Third resistor R4: Fourth resistor R5: fifth resistor T1: first parameter T2: second parameter TA: first established time TB: first established time TE: temperature parameter V1: the first potential V2: second potential V3: the third potential VA: clock potential VC1: the first control potential VC2: the second control potential VD: forbidden potential VIN1: the first input potential VIN2: the second input potential VOUT: output potential VR: rectification potential VS: sensing potential VSS: ground potential VTH: Potential critical value

FIG. 1 is a schematic diagram showing a power supply according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing a power supply according to another embodiment of the present invention. FIG. 3 is a schematic diagram of a power supply according to an embodiment of the present invention. FIG. 4 is a schematic diagram showing the current of the ultraviolet light-emitting diode according to an embodiment of the present invention. FIG. 5A is a graph showing the operating characteristics of the first NTC resistor or the second NTC resistor according to an embodiment of the present invention. FIG. 5B is a graph showing the operating characteristics of the third negative coefficient temperature resistor according to an embodiment of the present invention.

100: Power supply

110: Bridge rectifier

120: Transformer

121: Main coil

122: secondary coil

130: Power switcher

140: Output stage circuit

150: Detection circuit

160: Sterilization circuit

170: drive circuit

180: controller

C1: first capacitor

LM: Exciting inductor

TE: temperature parameter

VA: clock potential

VIN1: the first input potential

VIN2: the second input potential

VOUT: output potential

VR: rectification potential

VSS: ground potential

Claims (9)

A power supply with a sterilization function, comprising: a bridge rectifier, which generates a rectified potential according to a first input potential and a second input potential; a first capacitor, which stores the rectified potential; a transformer, including a main coil and a secondary coil, wherein the transformer has a magnetizing inductor built in, and the primary coil is used to receive the rectified potential; a power switch selectively couples the primary coil to a ground according to a clock potential Potential; an output stage circuit, coupled to the secondary coil, and used to generate an output potential; a detection circuit, to detect a temperature parameter; a sterilization circuit; a drive circuit, to drive the sterilization circuit; a controller, coupled connected to the detection circuit and used to generate the clock potential, wherein the controller controls the driving circuit according to the temperature parameter to selectively enable or disable the sterilization circuit; wherein if the temperature parameter indicates the If the ambient temperature of the power supply is between 30°C and 50°C, the sterilization circuit will be enabled and generate intermittent ultraviolet rays; otherwise, the sterilization circuit will be disabled. The power supply as claimed in claim 1, wherein the temperature parameters include a first parameter related to the bridge rectifier and a second parameter related to the transformer, The output stage circuit further generates an output current, and if the output current is greater than or equal to a current critical value, the controller will forcibly disable the sterilization circuit. The power supply as claimed in claim 1, wherein the bridge rectifier includes: a first diode having an anode and a cathode, wherein the anode of the first diode is coupled to a first input node to receive the first input potential, and the cathode of the first diode is coupled to a first node to output the rectified potential; a second diode has an anode and a cathode, wherein the first diode The anode of the second diode is coupled to a second input node to receive the second input potential, and the cathode of the second diode is coupled to the first node; a third diode, having an anode and a cathode, wherein the anode of the third diode is coupled to a second node and the cathode of the third diode is coupled to the first input node; and a fourth diodes having an anode and a cathode, wherein the anode of the fourth diode is coupled to a third node and the cathode of the fourth diode is coupled to the second input node; wherein the first capacitor has a first end and a second end, the first end of the first capacitor is coupled to the first node, and the second end of the first capacitor is coupled to the ground potential. The power supply as described in claim 3, wherein the main coil has a first end and a second end, the first end of the main coil is coupled to the first node to receive the rectified potential, the main coil The second end of the coil is coupled to a fourth node, the excitation The magnetic inductor has a first end and a second end, the first end of the magnetizing inductor is coupled to the first node, the second end of the magnetizing inductor is coupled to the fourth node, the The secondary coil has a first end and a second end, the first end of the secondary coil is coupled to a fifth node, and the second end of the secondary coil is coupled to a common node. The power supply as described in claim 4, wherein the power switch includes: a first transistor having a control terminal, a first terminal, and a second terminal, wherein the control terminal of the first transistor For receiving the clock potential, the first terminal of the first transistor is coupled to the ground potential, and the second terminal of the first transistor is coupled to the fourth node. The power supply as claimed in item 4, wherein the output stage circuit includes: a fifth diode having an anode and a cathode, wherein the anode of the fifth diode is coupled to the fifth node , and the cathode of the fifth diode is coupled to an output node to output the output potential; a second capacitor has a first end and a second end, wherein the first end of the second capacitor is coupled to the output node, and the second terminal of the second capacitor is coupled to a sixth node; and a first resistor has a first terminal and a second terminal, wherein the first resistor The first end of the resistor is coupled to the sixth node to output a sense potential to the controller, and the second end of the first resistor is coupled to the common node. The power supply as described in claim 6, wherein the detection circuit includes: a first negative temperature coefficient resistor having a first terminal and a second terminal, wherein the first negative temperature coefficient resistor of the first negative temperature coefficient resistor One end is coupled to the second node to output a first potential, and the second end of the first negative temperature coefficient resistor is coupled to the ground potential; a second negative temperature coefficient resistor has a A first terminal and a second terminal, wherein the first terminal of the second negative temperature coefficient resistor is coupled to the third node to output a second potential, and the first terminal of the second negative temperature coefficient resistor Two ends are coupled to the ground potential; a third negative temperature coefficient resistor has a first end and a second end, wherein the first end of the third negative temperature coefficient resistor is used to output a first end three potentials, and the second end of the third negative temperature coefficient resistor is coupled to the ground potential; and an averaging circuit, coupled to the magnetizing inductor, and used to generate an average current about the magnetizing inductor , wherein the average current flows through the third negative temperature coefficient resistor; wherein the controller further generates a first control potential and a second control potential according to the first potential, the second potential, and the third potential potential. The power supply as claimed in item 7, wherein the drive circuit includes a first driver and a second driver; wherein the first driver includes: A second resistor has a first end and a second end, wherein the first end of the second resistor is coupled to a seventh node to receive the first control potential, and the second resistor The second terminal of the second transistor is coupled to an eighth node; a second transistor has a control terminal, a first terminal, and a second terminal, wherein the control terminal of the second transistor is coupled to The eighth node, the first end of the second transistor is coupled to a ninth node, and the second end of the second transistor is coupled to the seventh node; and a third resistor , has a first end and a second end, wherein the first end of the third resistor is coupled to the eighth node, and the second end of the third resistor is coupled to a tenth node; wherein the second driver includes: a fourth resistor having a first end and a second end, wherein the first end of the fourth resistor is coupled to an eleventh node to receive the first Two control potentials, and the second end of the fourth resistor is coupled to a twelfth node; a third transistor has a control end, a first end, and a second end, wherein the first end The control terminal of the tri-transistor is coupled to the twelfth node, the first terminal of the third transistor is coupled to a thirteenth node, and the second terminal of the third transistor is coupled connected to the eleventh node; and a fifth resistor having a first end and a second end, wherein the first end of the fifth resistor is coupled to the twelfth node, and the first The second end of the five resistors is coupled to the tenth node. The power supply as described in claim 8, wherein the sterilization circuit includes a first sterilizer and a second sterilizer; wherein the first sterilizer includes: a plurality of first ultraviolet light-emitting diodes, coupled in series between the ninth node and the ground potential; and a first timing switch coupled in parallel with the first ultraviolet light-emitting diodes, wherein the first timing switch alternates every first predetermined time conduction and disconnection; wherein the second sterilizer includes: a plurality of second ultraviolet light emitting diodes, coupled in series between the thirteenth node and the ground potential; and a second timing switch, connected to the The second ultraviolet light-emitting diodes are coupled in parallel, wherein the second timing switch is alternately turned on and off every second predetermined time; wherein if the controller detects that the sensing potential is higher than or equal to a potential threshold value, the controller outputs a disabling potential with a low logic level to the tenth node to forcibly disable the first sterilizer and the second sterilizer at the same time.

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