TWI837674B - Power supply and control method of sterilization function thereof - Google Patents

Abstract

A power supply is provided. The power supply includes: a ultra-violet light module; a rectifier configured to convert an AC voltage into a first DC voltage; a transformer, configured to convert the first DC voltage into an output voltage of the power supply; a first timer, configured to increase a first time count every first time period; a second timer; and a comparison circuit, configured to determine whether an output power of the power supply is less than a predetermined power. When the first time count is equal to a first predetermined time and the output power of the power supply is less than the predetermined power, the comparison circuit drives the second timer to increase a second time count every second time period, and the second timer provides a driving voltage to the UV light module to activate a sterilization function of the power supply.

Description

Power supply and sterilization function control method thereof

The present invention relates to a power supply, and more particularly to a power supply and a method for controlling a sterilization function thereof.

In recent years, antibacterial awareness has risen. The main reason is that there are germs of all sizes in daily life. In addition, due to the COVID-19, this technology has been increasingly promoted. Among the many germs, enterovirus or some hand contact infections are more common. However, electronic products are indispensable in life, especially power supplies, because electronic products must be powered by batteries or power supplies, and batteries also need power supplies to charge, so users often hold or carry power supplies as one of the necessities of daily life.

In view of this, the present invention provides a power supply and a sterilization function control method thereof to solve the above problems.

The present invention provides a power supply, comprising: an ultraviolet lamp module; a rectifier circuit for converting an alternating current voltage into a first direct current voltage; a transformer for converting the first direct current voltage into an output voltage of the power supply; a first timer for increasing a first timing value at a first time interval; a second timer; and a comparison circuit for determining whether the output power of the power supply is less than a predetermined power. When the first timing value is equal to the first predetermined time and the output power of the power supply is less than the predetermined power, the comparison circuit drives the second timer to increase the second timing value every second time interval, and the second timer provides a driving voltage to the ultraviolet light module to activate the sterilization function of the power supply.

In some embodiments, when the first timing value is equal to the first predetermined time, the first timer outputs a first voltage to the first input terminal of the comparison voltage. The output current at the output terminal of the power supply flows through an output capacitor and a detection resistor, and generates a second voltage on the detection resistor, and the second voltage is provided to the second input terminal of the comparison circuit.

In some embodiments, when the comparison circuit determines whether the output power of the power supply is less than a predetermined power, the comparison circuit compares the first voltage and the second voltage. When the second voltage is less than or equal to the first voltage, the comparison circuit outputs a high-level voltage to drive the second timer.

In some embodiments, when the second timing value is equal to the second predetermined time, the second timer stops providing the driving voltage to the ultraviolet light module to turn off the sterilization function of the power supply.

In some embodiments, the second timer generates a fixed current through a negative temperature coefficient resistor to the ground terminal during operation, and generates a third voltage on the negative temperature coefficient resistor to provide to the control terminal of the second transistor, wherein when the rising temperature of the power supply exceeds a predetermined temperature threshold, the third voltage is less than the threshold voltage of the second transistor, and the second transistor is turned off to disconnect the ground path of the ultraviolet lamp module.

In some embodiments, the first DC voltage is provided to the control end of the third transistor through a first resistor and a second resistor. When the power supply is not connected to the AC voltage, the first DC voltage is 0, and the third transistor is turned off to disconnect the ground path of the UV lamp module.

The present invention further provides a method for controlling the sterilization function of a power supply, wherein the power supply includes an ultraviolet light module, a first timer and a second timer. The method includes: using the power supply to convert an alternating current voltage into an output voltage of the power supply; increasing a first timing value of the first timer at every first time interval; when the first timing value is equal to a first predetermined time and the output power of the power supply is less than a predetermined power, driving the second timer to increase the second timing value at every second time interval, and using the second timer to provide a driving voltage to the ultraviolet light module to activate the sterilization function of the power supply.

In some embodiments, the method further includes: when the second timing value is equal to a second predetermined time, using the second timer to stop providing the driving voltage to the ultraviolet light module to turn off the sterilization function of the power supply.

In some embodiments, the power supply further includes: a switch circuit disposed in the ground path of the ultraviolet light module, and the method further includes: when the output voltage is 0, or when the rising temperature of the power supply exceeds a predetermined temperature threshold, or when the power supply is not connected to the alternating current voltage, using the switch circuit to disconnect the ground path of the ultraviolet light module to turn off the sterilization function of the power supply.

The following description is a preferred embodiment of the invention, and its purpose is to describe the basic spirit of the invention, but it is not intended to limit the invention. The actual content of the invention must refer to the scope of the following claims.

It must be understood that the words "comprise", "include" and the like used in this specification are used to indicate the existence of specific technical features, numerical values, method steps, operation processes, elements and/or components, but do not exclude the addition of more technical features, numerical values, method steps, operation processes, elements, components, or any combination thereof.

The terms "first", "second", "third", etc. used in the patent application are used to modify the elements in the patent application, and are not used to indicate a priority order, a prior relationship, or that one element precedes another element, or a temporal sequence in performing method steps. They are only used to distinguish elements with the same name.

FIG. 1 is a block diagram of a power supply according to an embodiment of the present invention. In one embodiment, the power supply 100 can be set in a personal computer or a laptop, or a separate external power supply or a mobile power supply, etc., but the present invention is not limited thereto. As shown in FIG. 1, the power supply 100 mainly includes: a rectifier circuit 110, a pulse width modulation (PWM) circuit 120, timers 130 and 140, a comparison circuit 145, a transformer 150, an ultraviolet light module 160 and a switch circuit 170.

The rectifier circuit 110 is used to convert the AC voltage 10 into a first DC voltage and provide the first DC voltage to the pulse width modulation circuit 120, the timer 130 and the transformer 150. The pulse width modulation (PWM) circuit 120 is used to monitor the output state of the transformer 150 and convert the first DC voltage into a voltage pulse signal with a fixed width.

The transformer 150 is used to convert the first DC voltage into the output voltage VO of the power supply, wherein the first DC voltage is greater than the output voltage VO. In addition, the voltage VS is provided to the second input terminal of the comparison circuit 145.

The timer 130 (e.g., a first timer) increases a first time value every first time interval (e.g., 1 hour). Whenever the first time value of the timer 130 is equal to the first predetermined time, the timer 130 provides a voltage V1 to a first input terminal of the comparison circuit 145. The comparison circuit 145 compares the voltage V1 (e.g., a first voltage) with the voltage VS (e.g., a second voltage). When the voltage VS is lower than the voltage V1, it indicates that the output power of the power supply 100 is lower than the preset power (e.g., 1W). At this time, the comparison circuit 145 outputs a high-level voltage to drive the timer 140 to start operation, so as to make relevant judgments on the subsequent activation of the sterilization function of the power supply 100 (e.g., activating the ultraviolet light module 160). When the voltage VS is greater than or equal to the voltage V1, it indicates that the output power of the power supply 100 is greater than the preset power (e.g., 1W). At this time, the sterilization function of the power supply 100 is not activated (e.g., the ultraviolet light module 160 is turned off).

When the timer 140 is driven and starts to operate, the timer 140 (e.g., the second timer) increases the second time value every second time interval (e.g., 1 minute). In addition, when the timer 140 starts to operate, the timer 140 generates a fixed current I1 through a negative temperature coefficient resistor NTC to the ground terminal, and the negative temperature coefficient resistor NTC has a voltage VN to provide to the switch circuit 170.

For example, when the temperature of the power supply 100 is higher, the resistance value of the negative temperature coefficient resistor NTC is lower. When the temperature of the power supply 100 is lower, the resistance value of the negative temperature coefficient resistor NTC is higher. Therefore, when the temperature of the power supply 100 reaches a predetermined temperature, the resistance value of the negative temperature coefficient resistor NTC will drop to a predetermined resistance value, so that the voltage VN is insufficient to drive the corresponding transistor in the switch circuit 170, thereby turning off the sterilization function of the power supply 100 (such as the ultraviolet light module 160).

The switch circuit 170, for example, includes a plurality of transistors connected in series in sequence, and each transistor can be used as a switch corresponding to different judgment conditions to disconnect the ground path of the ultraviolet light module 160, and then turn off the ultraviolet light module 160 to interrupt the sterilization function of the power supply 100, and the details will be described in detail later.

FIG. 2 is a detailed block diagram of the power supply according to the embodiment of FIG. 1 of the present invention. Please refer to FIG. 1 and FIG. 2 at the same time.

The rectifier circuit 110 includes rectifier diodes D1-D4, a resistor R1 and an input capacitor CIN. The rectifier diodes D1-D4 can, for example, form a bridge full-wave rectifier, and when combined with the input capacitor CIN, the AC voltage 10 can be converted into a first DC voltage at the node N1. A person with ordinary knowledge in the technical field of the present invention should be able to understand the operation of the bridge full-wave rectifier, so the details are not described in detail here.

The transformer 150 includes a magnetizing inductor LM, a primary winding NP, and a secondary winding NS. The first DC voltage can obtain a conversion voltage after passing through the transformer 150, and the conversion voltage can obtain an output voltage VO at a node N3 after passing through an output diode DO. In some embodiments, the number of turns of the primary winding NP and the secondary winding NS are, for example, 40 turns and 2 turns, respectively, but the present invention is not limited thereto.

In addition, the node N3 has an output current IO, which flows through the output capacitor CO and the detection resistor RO, and the detection resistor RO generates a voltage VS to provide to the reverse input terminal of the comparison circuit 145. In some embodiments, the output capacitor CO can be, for example, 1000 (error value ±20%), and the detection resistor RO can be, for example, 1 ohm (error value ±1%), but the present invention is not limited thereto.

The first DC voltage at the node N1 is provided to the voltage input terminal VCC of the pulse width modulation circuit 120 and the voltage input terminal VIN1 of the timer 130 through the resistor R1. When the power supply 100 is connected to the AC voltage 10, the voltage input terminal VIN1 of the timer 130 can obtain sufficient driving voltage to start operation. The timer 130 (for example, a first timer) increases the first timing value every first time interval (for example, 1 hour). Whenever the first timing value of the timer 130 is equal to the first predetermined time, the timer 130 provides the voltage V1 to the non-inverting input terminal of the comparison circuit 145. If the first timing value of the timer 130 has not reached the first predetermined time, the voltage V1 is 0. In some embodiments, the first predetermined time is, for example, 24 hours, but the present invention is not limited thereto.

The comparison circuit 145 can be implemented by an operational amplifier, for example, but the present invention is not limited thereto. The comparison circuit 145 compares the voltage V1 (for example, the first voltage) and the voltage VS (for example, the second voltage). When the voltage VS is lower than the voltage V1, it indicates that the output power of the power supply 100 is less than the predetermined power (for example, 1W). At this time, the comparison circuit 145 outputs a high-level voltage to be input to the voltage input terminal VIN2 of the timer 140 to drive the timer 140 to start operation, so as to make relevant judgments on the subsequent activation of the ultraviolet lamp module 160 of the power supply 100. When the voltage VS is greater than or equal to the voltage V1, it indicates that the output power of the power supply 100 is greater than a predetermined power (e.g., 1W). At this time, the ultraviolet lamp module 160 of the power supply 100 does not operate to avoid affecting the performance of the power supply 100.

For example, when the timer 140 is driven and starts to operate, the timer 140 (e.g., the second timer) increases the second timing value every second time interval (e.g., 1 minute). When the timer 140 starts to operate, the timer 140 generates a fixed current I1 through a negative temperature coefficient resistor NTC to the ground terminal, and the negative temperature coefficient resistor NTC has a voltage VN at the node N4 to provide to the control end of the transistor QX2 of the switch circuit 170. When the second timing value of the timer 140 is equal to the second predetermined time, the voltage output terminal V2 of the timer 140 stops providing the driving voltage to the ultraviolet light module 160 to turn off the sterilization function. In some embodiments, the second predetermined time is, for example, 30 minutes, but the present invention is not limited thereto. It should be noted that a person skilled in the art can adjust the first time interval, the second time interval, the first predetermined time, and the second predetermined time according to actual conditions.

The ultraviolet lamp module 160, for example, includes a plurality of light-emitting diodes (LEDs) 161 that can emit ultraviolet light, wherein the ground path of the light-emitting diodes 161 in the ultraviolet lamp module 160 passes through a switch circuit. The switch circuit 170 includes transistors QX1, QX2, and QX3, and the transistors QX1, QX2, and QX3 are connected in series in sequence to control the ground path of the ultraviolet lamp module 160. In this embodiment, transistors QX1 to QX3 all serve as switches. The output voltage VO of the node N3 is provided to the control end of the transistor QX1, the voltage VN of the node N4 is provided to the control end of the transistor QX2, and the voltage VC of the node N2 is provided to the control end of the transistor QX3 through the resistor R2.

For example, transistor QX1 is used for output voltage detection. When the output voltage of the power supply 100 is 0 (ie, no output voltage), transistor QX1 is turned off, so the ground path of the ultraviolet light module 160 is disconnected, and the sterilization function of the power supply 100 is interrupted.

Transistor QX2 is used for temperature detection. When the timer 140 is running, it can detect the temperature of the power supply 100. When the temperature of the power supply 100 rises above 35 degrees, it means that the power supply 100 is used again (that is, it provides power to the load device), and the power consumption of the ultraviolet light module 160 will directly affect the performance of the power supply 100, so the ultraviolet light module 160 needs to be turned off to avoid affecting the performance of the power supply 100.

In detail, the temperature detection mechanism is implemented by using a negative temperature coefficient resistor (NTC). When the temperature of the power supply 100 is higher, the resistance value of the negative temperature coefficient resistor (NTC) is lower. When the temperature of the power supply 100 is lower, the resistance value of the negative temperature coefficient resistor (NTC) is higher. Once the power supply 100 is used, the temperature of the power supply 100 usually rises rapidly. Therefore, when the temperature of the power supply 100 rises from room temperature (approximately 25 degrees Celsius) to a predetermined temperature (e.g., 60 degrees Celsius) (e.g., the temperature rise exceeds the predetermined temperature threshold), the resistance value of the negative temperature coefficient resistor NTC will drop to a predetermined resistance value, so that the voltage VN is insufficient to drive the corresponding transistor QX2 in the switching circuit 170 (e.g., VN＜Vt, where Vt is the threshold voltage of the transistor QX2), so the ground path of the ultraviolet lamp module 160 is disconnected, and the sterilization function of the power supply 100 will be interrupted.

Transistor QX3 is used for input voltage detection. When the power supply 100 is not connected to the AC voltage 10, the voltage VC provided to the control end of transistor QX3 is 0. At this time, transistor QX3 is turned off, the ground path of the ultraviolet light module 160 is disconnected, and the sterilization function of the power supply 100 is interrupted.

FIG. 3 is a flow chart of a method for controlling the sterilization function of a power supply according to an embodiment of the present invention. Please refer to FIGS. 1 to 3 at the same time.

In step 310, the first time value of the first timer (e.g., timer 130) is increased by a first time interval. For example, when the power supply 100 is connected to the AC voltage 10, the voltage input terminal VIN1 of the timer 130 can obtain a sufficient driving voltage to start operating. The timer 130 (e.g., the first timer) increases the first time value every first time interval (e.g., 1 hour).

In step 320, it is determined whether the first timing value is equal to the first predetermined time. If the first timing value is not equal to the first predetermined time, the process returns to step 310. If the first timing value is equal to the first predetermined time, the process proceeds to step 330. For example, whenever the first timing value of the timer 130 is equal to the first predetermined time, the timer 130 provides a voltage V1 to the non-inverting input terminal of the comparison circuit 145. If the first timing value of the timer 130 has not yet reached the first predetermined time, the voltage V1 is 0. In some embodiments, the first predetermined time is, for example, 24 hours, but the present invention is not limited thereto.

In step 330, it is determined whether the output power is less than the predetermined power. When the output power is less than the predetermined power (i.e., the voltage VS is less than the voltage V1), step 340 is executed. When the output power is less than the predetermined power (i.e., the voltage VS is greater than or equal to the voltage V1), the process returns to step 330. For example, the output current IO flows through the output capacitor CO and the detection resistor RO, and generates the voltage VS at the node N5.

Because the resistance value of the detection resistor RO is properly designed, when the output power is less than the preset power (i.e., the voltage VS is lower than the voltage V1), the comparison circuit 145 outputs a high-level voltage to be input to the voltage input terminal VIN2 of the timer 140 to start the drive timer 140 to perform the subsequent related judgment of starting the ultraviolet light module 160 of the power supply 100. When the output power is less than the preset power (i.e., the voltage VS is greater than or equal to the voltage V1), it means that the output power of the power supply 100 is greater than the preset power (e.g., 1W). At this time, the ultraviolet light module 160 of the power supply 100 does not operate to avoid affecting the performance of the power supply 100.

In step 340, the ultraviolet light module 160 is activated. For example, when the comparison circuit 145 outputs a high voltage to the voltage input terminal VIN2 of the timer 140, the timer 140 starts to operate. At this time, the voltage output terminal V2 of the timer 140 can provide a driving voltage to the ultraviolet light module 160, so that the ultraviolet light module 160 starts to emit light to activate the sterilization function.

In step 350, the second time value of the second timer (e.g., timer 140) increases by the second time interval. For example, when the timer 140 is driven and starts to operate, the timer 140 (e.g., the second timer) increases the second time value every second time interval (e.g., 1 minute).

In step 360, it is determined whether the temperature rise of the power supply is greater than a predetermined temperature threshold. When the temperature rise of the power supply is greater than the predetermined temperature threshold, this process ends. When the temperature rise of the power supply is less than or equal to the predetermined temperature threshold, step S370 is executed.

For example, when the timer 140 starts to operate, the timer 140 generates a fixed current I1 through a negative temperature coefficient resistor NTC to the ground terminal, and the negative temperature coefficient resistor NTC has a voltage VN at the node N4 to provide to the transistor QX2 of the switch circuit 170. When the temperature of the power supply 100 is higher, the resistance value of the negative temperature coefficient resistor NTC is lower. When the temperature of the power supply 100 is lower, the resistance value of the negative temperature coefficient resistor NTC is higher. Once the power supply 100 is used, the temperature of the power supply 100 usually rises rapidly. Therefore, when the temperature of the power supply 100 rises from room temperature (approximately 25 degrees Celsius) to a predetermined temperature (e.g., 60 degrees Celsius) (i.e., the rising temperature exceeds the predetermined temperature threshold), the resistance value of the negative temperature coefficient resistor NTC will drop to a predetermined resistance value, so that the voltage VN is insufficient to drive the corresponding transistor QX2 in the switching circuit 170, so that the ground path of the ultraviolet lamp module 160 is disconnected, and the sterilization function of the power supply 100 will be interrupted.

In step 370, determine whether the second timing value is equal to the second predetermined time. When the second timing value is equal to the second predetermined time, the process ends. When the second timing value is not equal to the second predetermined time, return to step 350. For example, when the second timing value of the timer 140 is equal to the second predetermined time, the voltage output terminal V2 of the timer 140 stops providing the driving voltage to the ultraviolet light module 160 to turn off the sterilization function of the power supply 100. In some embodiments, the above-mentioned second predetermined time is, for example, 30 minutes, but the present invention is not limited to this. When the process of Figure 3 ends, both timers 130 and 140 will be reset.

In summary, the present invention provides a power supply and a sterilization function control method thereof, which can activate the sterilization function of the power supply according to the time and the output power of the power supply, and can also determine whether to interrupt the sterilization function according to the input voltage, the output voltage and the temperature of the power supply. Therefore, the power supply and the sterilization function control method of the present invention can take into account the sterilization function without affecting the performance of the power supply, thereby increasing the user experience.

Although the present invention is disclosed as above with the preferred embodiments, it is not intended to limit the scope of the present invention. Any person with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be defined by the scope of the attached patent application.

10: AC voltage 100: Power supply 110: Rectifier circuit 120: PWM circuit 130, 140: Timer 145: Comparison circuit 150: Transformer 160: UV lamp module 161: LED 170: Switching circuit 310~330: Steps V1, V2, VC, VN, VS: Voltage VO: Output voltage I1: Fixed current NTC: Negative temperature coefficient resistor D1~D4: Rectifier diode N1~N5: Node R1, R2: Resistor RO: Detection resistor CI: Input resistor CO: Output resistor DO: Output diode IO: Output current GND: ground terminal VCC, VIN1, VIN2: voltage input terminal GD1: ground control terminal Q1, QX1, QX2, QX3: transistor LM: magnetizing inductor NP: primary winding group NS: secondary winding group

FIG. 1 is a block diagram of a power supply according to an embodiment of the present invention. FIG. 2 is a detailed block diagram of a power supply according to the embodiment of FIG. 1 of the present invention. FIG. 3 is a flow chart of a method for controlling the sterilization function of a power supply according to an embodiment of the present invention.

10: AC voltage

100: Power supply

110: Rectifier circuit

120:PWM circuit

130, 140: Timer

145: Comparison circuits

150: Transformer

160: UV light module

170:Switching circuit

GND: Ground terminal

V1, V2, VS: voltage

VO: output voltage

I1: Fixed current

NTC: Negative Temperature Coefficient Resistor

Claims (10)

A power supply includes: an ultraviolet light module; a rectifier circuit for converting an alternating current voltage into a first direct current voltage; a transformer for converting the first direct current voltage into an output voltage of the power supply; a first timer for increasing a first timing value at a first time interval; a second timer; and a comparison circuit for determining whether the output power of the power supply is less than a predetermined power; wherein when the first timing value is equal to a first predetermined time and the output power of the power supply is less than the predetermined power, the comparison circuit drives the second timer to increase the second timing value at a second time interval, and the second timer provides a driving voltage to the ultraviolet light module to activate the sterilization function of the power supply. A power supply as claimed in claim 1, wherein when the first timing value is equal to the first predetermined time, the first timer outputs a first voltage to the first input terminal of the comparison circuit; wherein the output current at the output terminal of the power supply flows through an output capacitor and a detection resistor, and generates a second voltage on the detection resistor, and the second voltage is provided to the second input terminal of the comparison circuit. The power supply of claim 2, wherein when the comparison circuit determines whether the output power of the power supply is less than the predetermined power, the comparison circuit compares the first voltage and the second voltage; wherein when the second voltage is less than or equal to the first voltage, the comparison circuit outputs a high-level voltage to drive the second timer. The power supply of claim 1, wherein when the second timing value is equal to the second predetermined time, the second timer stops providing the driving voltage to the ultraviolet light module to turn off the sterilization function of the power supply. The power supply of claim 1 further comprises: a switch circuit disposed in the ground path of the ultraviolet light module, and the switch circuit comprises a first transistor, a second transistor and a third transistor connected in series in sequence; wherein the output voltage is provided to the control end of the first transistor, and when the output voltage is 0, the first transistor is turned off to disconnect the ground path of the ultraviolet light module. A power supply as claimed in claim 5, wherein the second timer generates a fixed current through a negative temperature coefficient resistor to the ground terminal during operation, and generates a third voltage on the negative temperature coefficient resistor to provide to the control terminal of the second transistor; wherein when the rising temperature of the power supply exceeds a predetermined temperature threshold, the third voltage is less than the threshold voltage of the second transistor, and the second transistor is turned off to disconnect the ground path of the ultraviolet lamp module. A power supply as claimed in claim 5, wherein the first DC voltage is provided to the control end of the third transistor through a first resistor and a second resistor; wherein when the power supply is not connected to the AC voltage, the first DC voltage is 0, and the third transistor is turned off to disconnect the ground path of the UV lamp module. A method for controlling the sterilization function of a power supply, the power supply comprising an ultraviolet light module, a first timer and a second timer, the method comprising: using the power supply to convert an alternating voltage into an output voltage of the power supply; increasing a first timing value of the first timer at every first time interval; when the first timing value is equal to a first predetermined time and the output power of the power supply is less than a predetermined power, driving the second timer to increase the second timing value at every second time interval, and using the second timer to provide a driving voltage to the ultraviolet light module to activate the sterilization function of the power supply. As in claim 8, the power supply further comprises a switch circuit disposed on the ground path of the ultraviolet light module, and the method further comprises: when the output voltage is not 0, the rising temperature of the power supply does not exceed the predetermined temperature threshold and the power supply is connected to the alternating voltage, the switch circuit is used to conduct the ground path of the ultraviolet light module to turn on the sterilization function of the power supply. As in claim 8, the power supply further comprises a switch circuit disposed in the ground path of the ultraviolet light module, and the method further comprises: when the output voltage is 0, or when the rising temperature of the power supply exceeds a predetermined temperature threshold, or when the power supply is not connected to the alternating current voltage, the switch circuit is used to disconnect the ground path of the ultraviolet light module to turn off the sterilization function of the power supply.