Ultraviolet sterilization constant current control circuit, air conditioner sterilization device, indoor unit and air conditioner

Abstract

The application provides a kind of ultraviolet sterilization constant current control circuit, air conditioner sterilization device, indoor unit and air conditioner, the base of first triode in the ultraviolet sterilization constant current control circuit is connected with control element, the collector of first triode is connected with working voltage through first resistance, and the emitter of first triode is grounded;The base of second triode is connected with ultraviolet sterilization element, and ultraviolet sterilization element is connected with working voltage, the collector of second triode is connected between first resistance and the collector of first triode, and the emitter of first triode is grounded;Voltage detection element is connected with the emitter of second triode, for detecting target voltage and sending to control element;Control element is used to control the on-off of first triode based on the comparison result of target voltage and preset constant voltage range.The embodiment of the application can make the current of ultraviolet sterilization element constant, thereby improving the stability of circuit, the sterilization effect and service life of ultraviolet sterilization element.

Description

TECHNICAL FIELD

[0001] The present application relates to the air conditioning technical field, specifically, it relates to a kind of ultraviolet sterilization constant current control circuit, air conditioner sterilization device, indoor unit and air conditioner. BACKGROUND

[0002] The function of current air conditioner is more and more rich, and the short wave ultraviolet (Ultraviolet Cradiation, UV) sterilization function of air conditioner also emerges as the times require. The current control circuit of existing air conditioner UV sterilization lamp is usually based on triode design, which uses the switching action of triode to control the current to keep in a certain range. However, the current output by the above-mentioned method has large up-down floating deviation, which affects the sterilization effect and service life of UV sterilization lamp. SUMMARY

[0003] The present application solves the problem of large current floating of existing air conditioner UV sterilization lamp, which leads to unsatisfactory sterilization effect and service life.

[0004] To solve the above problems, the present application provides a kind of ultraviolet sterilization constant current control circuit, including control element, first triode, second triode, ultraviolet sterilization element and voltage detection element;The base of the first triode is connected with the control element, the collector of the first triode is connected with working voltage through the first resistance, and the emitter of the first triode is grounded;The base of the second triode is connected with the ultraviolet sterilization element, the ultraviolet sterilization element is connected with the working voltage, the collector of the second triode is connected between the first resistance and the collector of the first triode, and the emitter of the first triode is grounded;The voltage detection element is connected with the emitter of the second triode, for detecting target voltage and sending to the control element;The control element is used to control the on-off of the first triode based on the comparison result of the target voltage and the preset constant voltage range.

[0005] The present application can detect the actual working voltage of ultraviolet sterilization element, and control the on-off of triode through control element, control the actual working voltage in the preset constant voltage range, make the current of ultraviolet sterilization element constant, so as to improve the stability of circuit, sterilization effect and service life of ultraviolet sterilization element.

[0006] Optionally, it also includes second resistance and third resistance;The second resistance is connected between the emitter of the first triode and ground, and the third resistance is connected between the emitter of the second triode and ground.

[0007] The second resistance and the third resistance in the present application both play the role of voltage division, which can make the second triode controlled to cycle on and off.

[0008] Optionally, the control element controls the first triode to be off when the target voltage is out of the preset constant voltage range, and controls the first triode to be on when the target voltage is in the preset constant voltage range.

[0009] The embodiment of the present application provides a specific way of controlling the on-off of the first triode according to the comparison result of the target voltage and the preset constant voltage range, so that the voltage can be stably controlled near the on voltage of the second triode, and the current through the ultraviolet sterilization element is basically constant.

[0010] Optionally, the upper limit of the preset constant voltage range is the sum of the on voltage of the second triode and a preset value, and the lower limit of the preset constant voltage range is the difference between the on voltage and the preset value.

[0011] The embodiment of the present application provides a specific determination way of the preset constant voltage range, so that the current of the ultraviolet sterilization element is constant, and the stability of the circuit, the sterilization effect and the service life of the ultraviolet sterilization element are improved.

[0012] Optionally, the preset value is less than 1% of the on voltage.

[0013] The embodiment of the present application provides a value range of the preset value, so that the working current of the ultraviolet sterilization element is controlled in a very small range of the on voltage of the second triode, and the constant current working of the ultraviolet sterilization element is accurately ensured.

[0014] Optionally, the circuit further comprises a fourth resistor, and the fourth resistor is connected between the base of the first triode and the control element.

[0015] In the embodiment of the present application, the fourth resistor plays a role of protecting the first triode.

[0016] Optionally, the triode is an NPN type triode.

[0017] In the embodiment of the present application, the triode can be an NPN type triode which is commonly used, and is easy to obtain, so that the implementation cost is low.

[0018] The embodiment of the present application provides an air conditioner sterilization device comprising the ultraviolet sterilization constant current control circuit.

[0019] The embodiment of the present application provides an indoor unit comprising the ultraviolet sterilization device.

[0020] The embodiment of the present application provides an air conditioner comprising the indoor unit.

[0021] The air conditioner sterilization device, the indoor unit and the air conditioner provided by the embodiment of the present application can achieve the same technical effects as the ultraviolet sterilization constant current control circuit. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 This is a schematic diagram of the existing UVC sterilization control circuit.

[0023] Figure 2 This is a schematic diagram of a constant current control circuit for ultraviolet sterilization provided in an embodiment of the present invention. Detailed Implementation

[0024] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] Figure 1 A schematic diagram of an existing UVC sterilization control circuit is shown. This circuit uses transistors Q1 and Q2 to control the current passing through the UVC lamp, but it suffers from the problem of insufficient current constantness.

[0026] like Figure 1 As shown, the base of transistor Q2 is connected to point A between resistor R2 and the collector of transistor Q1, and the base of transistor Q1 is connected to point B between resistor R4 and the emitter of transistor Q2. The two transistors can be turned on and off sequentially, controlling the current through the UVC lamp within a certain range. Specifically, the control principle is as follows:

[0027] 1. Initially, the voltage at point A gradually increases. When the base voltage of transistor Q2 exceeds the forward voltage V... Q When transistor Q2 is turned on, current flows through the UVC lamp, and the UVC lamp starts to work. At this time, transistor Q1 does not meet the turn-on condition.

[0028] 2. The voltage at point B gradually increases. When the base voltage of transistor Q1 exceeds the forward voltage drop V... Q At this time, transistor Q1 is turned on, and the branch between resistor R2, transistor Q1, and ground is connected. The voltage drop at point A causes transistor Q2 to no longer meet the conduction condition, and transistor Q2 is turned off. At this time, the voltage at point B begins to drop to V. Q Next, transistor Q1 is turned off, and then steps 1 and 2 are repeated.

[0029] During the switching process of the transistor, the voltage is at the transistor's forward voltage drop V. Q The UVC lamp floats left and right; the current I = V. Q / R4. In this process, the current is kept constant solely by relying on the switching of the transistor and the voltage drop relationship, resulting in imprecise control and large fluctuations.

[0030] This invention provides a constant current control circuit for ultraviolet sterilization, which uses an MCU to control the switching of a transistor to keep the current of the UVC lamp constant, thereby improving the stability of the circuit and the sterilization effect and lifespan of the UVC lamp.

[0031] The ultraviolet sterilization constant current control circuit comprises a control element, a first triode, a second triode, an ultraviolet sterilization element and a voltage detection element.

[0032] The base of the first triode is connected with the control element, the collector of the first triode is connected with a working voltage through a first resistor, and the emitter of the first triode is grounded. The base of the second triode is connected with the ultraviolet sterilization element, the ultraviolet sterilization element is connected with the working voltage, the collector of the second triode is connected between the first resistor and the collector of the first triode, and the emitter of the first triode is grounded. The first triode and the first resistor form a first branch between the working voltage and the ground, and the second triode and the ultraviolet sterilization element form a second branch between the working voltage and the ground. The ultraviolet sterilization element is exemplarily a UVC lamp.

[0033] The voltage detection element is connected with the emitter of the second triode and is used for detecting a target voltage and sending the target voltage to the control element. The target voltage corresponds to an actual working current of the ultraviolet sterilization element.

[0034] The control element is used for controlling the on-off of the first triode based on a comparison result of the target voltage and a preset constant voltage range. The control element controls the first triode to be turned off when the target voltage is out of the preset constant voltage range, and controls the first triode to be turned on when the target voltage is in the preset constant voltage range. The upper limit of the preset constant voltage range is the sum of a turn-on voltage of the second triode and a preset value, and the lower limit of the preset constant voltage range is the difference between the turn-on voltage and the preset value. The preset value is exemplarily less than 1% of the turn-on voltage, and the control element is exemplarily a microcontroller unit (MCU).

[0035] When the circuit starts to work, the base voltage of the second triode gradually rises to be greater than the turn-on voltage of the second triode, the second triode is turned on, and the control element controls the first triode to be turned off. In this case, the second branch is turned on, and the first branch is turned off. When the target voltage detected by the voltage detection element is greater than the upper limit of the preset constant voltage range, the control element controls the first triode to be turned on. In this case, the first branch is turned on, the base voltage of the second triode drops to be less than the turn-on voltage of the second triode, the second triode is turned off, the target voltage detected by the voltage detection element drops, and when the target voltage is less than the upper limit of the preset constant voltage range, the control element controls the first triode to be turned off, the first branch is turned off, and the base voltage of the second triode gradually rises again, so that the above process is repeated. The voltage can be stably controlled near the turn-on voltage of the second triode, and the current passing through the ultraviolet sterilization element is basically constant.

[0036] The ultraviolet sterilization constant current control circuit provided by the embodiment of the present application can detect the actual working voltage of the ultraviolet sterilization element, control the on-off of the triode through the control element, control the actual working voltage within the preset constant voltage range, and make the current of the ultraviolet sterilization element constant, thereby improving the stability of the circuit, the sterilization effect of the ultraviolet sterilization element and the service life of the ultraviolet sterilization element.

[0037] Optionally, the ultraviolet sterilization constant current control circuit further comprises a second resistor and a third resistor. The second resistor is connected between the emitter of the first triode and the ground, and the third resistor is connected between the emitter of the second triode and the ground. The second resistor and the third resistor both function as voltage division. It should be noted that the relationship between the resistance value of the second resistor and the resistance value of the ultraviolet sterilization element needs to allow the voltage between them (i.e. the target voltage) to rise to be greater than the turn-on voltage of the second triode, and the relationship between the resistance value of the third resistor and the resistance value of the first triode needs to allow the voltage between them (i.e. the base voltage of the second triode) to drop to be less than the turn-on voltage of the second triode, so that the second triode is controlled to cycle on and off.

[0038] Optionally, the ultraviolet sterilization constant current control circuit further comprises a fourth resistor connected between the base of the first triode and the control element, for protecting the first triode.

[0039] Optionally, the first triode and the second triode can be commonly used NPN type triodes, which are commonly used and easy to obtain, and have low implementation cost.

[0040] Figure 2 The structure schematic diagram of the ultraviolet sterilization constant current control circuit provided by the embodiment of the present application is shown, which shows that the MCU is used to control the switching of the triodes Q1 and Q2, the voltage detection element outputs a signal to the MCU, and the resistors R1, R2, R3 and R4 can control the current passing through the UVC lamp to be constant current. Exemplarily, the precise control of the MCU ensures that the working current of the UVC lamp is constant current, and the floating range is not more than 0.1 mA.

[0041] The working process of the constant current control circuit controlled by the MCU is as follows:

[0042] 1. At the beginning, when the voltage at point A gradually rises, Q2 is turned on when Q2 meets the turn-on voltage drop V Q , current flows through the UVC lamp, and the UVC lamp starts to work. At this time, the MCU controls Q1 to be turned off;

[0043] 2. The voltage at point B detected by the voltage detection signal is V R4 ; when the MCU detects that the voltage value of V R4 is 1.01V Q , at this time, the MCU controls Q1 to be turned on, and Q2 does not meet the turn-on condition, and Q2 is turned off.

[0044] 3, at this time the voltage begins to drop, when drop to 0.99V Q , control Q1 off.

[0045] The above steps are repeated in turn.

[0046] Through the above-mentioned MUC precise control process, in the process of executing the switching of the triode, the voltage is in the range of the triode conduction voltage drop V Q thousandth level, the current I of the UVC lamp = V Q / R4, also accurately ensure in the constant current range.

[0047] The constant current control circuit in the embodiment of the application is based on MCU control, and the constant current control is more accurate; through circuit improvement, it is easy to implement, and the stability of the circuit, the sterilization effect and the service life are improved.

[0048] The embodiment of the application provides a kind of air conditioner sterilization device, including the above-mentioned ultraviolet sterilization constant current control circuit.

[0049] The embodiment of the application provides a kind of indoor unit, including the above-mentioned ultraviolet sterilization device.

[0050] The embodiment of the application provides a kind of air conditioner, including the above-mentioned indoor unit.

[0051] Of course, those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by computer degree to instruct control device, the program can be stored in a computer readable storage medium, the program can include the processes of the above-mentioned method embodiments when executed, wherein the storage medium can be memory, disk, optical disc, etc.

[0052] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application, therefore the protection scope of the present application should be limited by the scope defined in the claims.

[0053] Finally, it should be noted that the terms "first" and "second", and the like, merely denote different ones of the elements under discussion, without necessarily requiring or implying any actual relationship or order between such elements. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0054] Although the present application has been disclosed in its currently best embodiment with reference to the accompanying drawings, it is not to be limited to the details shown. Various modifications can be made in form and details without departing from the spirit and scope of the application. Therefore, the scope of the application is defined with the scope of the appended claims rather than the embodiments shown herein.

Claims

1. An ultraviolet sterilization constant current control circuit, characterized in that, The control element, the first transistor, the second transistor, the ultraviolet sterilization element, the voltage detection element, the second resistor and the third resistor are included. The base of the first transistor is connected with the control element, the collector of the first transistor is connected with the working voltage through the first resistor, and the emitter of the first transistor is grounded. The base of the second transistor is connected with the ultraviolet sterilization element, the ultraviolet sterilization element is connected with the working voltage, the collector of the second transistor is connected between the first resistor and the collector of the first transistor, and the emitter of the first transistor is grounded. The voltage detection element is connected with the emitter of the second transistor, and is used for detecting the target voltage and sending to the control element. The second resistor is connected between the emitter of the first transistor and the ground, and the third resistor is connected between the emitter of the second transistor and the ground. The control element controls the first transistor to be off when the target voltage is out of the preset constant voltage range, and controls the first transistor to be on when the target voltage is in the preset constant voltage range.

2. The ultraviolet sterilization constant current control circuit of claim 1, wherein The upper limit of the preset constant voltage range is the sum of the turn-on voltage of the second transistor and a preset value, and the lower limit is the difference between the turn-on voltage and the preset value.

3. The ultraviolet sterilization constant current control circuit according to claim 2, wherein, The preset value is less than 1% of the turn-on voltage.

4. The ultraviolet sterilization constant current control circuit according to claim 1, wherein, A fourth resistor is further included. The fourth resistor is connected between the base of the first transistor and the control element.

5. The ultraviolet sterilization constant current control circuit according to claim 1, wherein The transistor is an NPN type transistor.

6. An air conditioner sterilizing device, characterized by comprising: The ultraviolet sterilization constant current control circuit of any one of claims 1-5 is included.

7. An indoor unit, characterized by comprising: The air conditioner sterilization device of claim 6 is included.

8. An air conditioner characterized by comprising: The indoor unit of claim 7 is included.

Images