Capacitor charging circuit, working method thereof, air conditioner outdoor unit controller and air conditioner

Abstract

The invention provides a capacitor charging circuit and a working method thereof, an air conditioner outdoor unit controller and an air conditioner, in the capacitor charging circuit, an alternating current input end is electrically connected with an input end of a rectifying circuit through a pre-charging resistor, an output end of the rectifying circuit is electrically connected with an electrolytic capacitor, and a short circuit control loop is connected to two ends of the pre-charging resistor in parallel; the short-circuit control loop is provided with a control switch for controlling the short-circuit control loop to be switched on or switched off, and the main control circuit is electrically connected with the control end of the control switch; the number of the short-circuit control loops is at least two, the control switches are relay switches, and the coil resistance value of at least one relay switch is different from that of the other relay switch; the current detection circuit is used for acquiring a working current value of the output end of the rectifying circuit; the main control circuit is used for selecting the maximum contact current to meet the requirement of the working current value according to the working current value and switching on the relay switch with the maximum coil resistance value. The capacitor charging circuit can effectively reduce the power consumption of the relay.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners. Specifically, it relates to a capacitor charging circuit, a working method of the capacitor charging circuit, an outdoor unit controller of an air conditioner applying the capacitor charging circuit, and an air conditioner applying the outdoor unit controller of the air conditioner. Background Art

[0002] Currently, the electrolytic capacitor in the outdoor unit controller of a variable-frequency air conditioner is generally charged first through a PTC thermistor. After being fully charged, the main control chip issues a relay closing command to short-circuit the PTC thermistor and directly supply power to the subsequent circuit. In this process, it is necessary to maintain the relay closed state to continuously supply power, and this is a power consumption point of the outdoor unit controller of the air conditioner. Different specifications of relays have differences in coil resistance values. The smaller the resistance value, the greater the power consumption. However, generally, the maximum contact current allowed by a relay with a large coil resistance value is also lower. Therefore, it is not possible to simply replace the relay with a larger coil resistance value in order to reduce power consumption. The existing solution is to select the specification of the relay according to the maximum working current passing through. However, when the current is small, a large-specification relay is not required, so this approach will also generate more unnecessary power consumption.

[0003] Therefore, it is necessary to consider a more optimized capacitor charging circuit. Summary of the Invention

[0004] The first object of the present invention is to provide a capacitor charging circuit that can effectively reduce the power consumption of the relay.

[0005] The second object of the present invention is to provide a working method of a capacitor charging circuit that can effectively reduce the power consumption of the relay.

[0006] The third object of the present invention is to provide an outdoor unit controller of an air conditioner with a capacitor charging circuit that can effectively reduce the power consumption of the relay.

[0007] The fourth object of the present invention is to provide an air conditioner with a capacitor charging circuit that can effectively reduce the power consumption of the relay.

[0008] To achieve the above first object, the capacitor charging circuit provided by the present invention includes a main control circuit, an AC input terminal, a pre-charge resistor, a short-circuit control loop, a rectification circuit, and an electrolytic capacitor. The AC input terminal is electrically connected to the input terminal of the rectification circuit through the pre-charge resistor. The output terminal of the rectification circuit is electrically connected to the electrolytic capacitor. The short-circuit control loop is connected in parallel across both ends of the pre-charge resistor. The short-circuit control loop is provided with a control switch for controlling the conduction or closing of the short-circuit control loop. The main control circuit is electrically connected to the control end of the control switch. The number of short-circuit control loops is at least two. The control switch is a relay switch. The coil resistance of at least one relay switch is different from that of another relay switch. The capacitor charging circuit further includes a current detection circuit for obtaining the working current value at the output terminal of the rectification circuit and transmitting it to the main control circuit. The main control circuit is configured to select the relay switch with the largest contact current satisfying the working current value requirement and the largest coil resistance to conduct according to the working current value.

[0009] As can be seen from the above solution, the capacitor charging circuit of the present invention sets relay switches with different coil resistances to select the relay switch with the largest contact current satisfying the working current value requirement and the smallest coil resistance to conduct according to the working current value, and conduct different short-circuit control loops, so as to achieve that when the working current is small under the premise that the largest contact current satisfies the working current value requirement, the relay switch with a larger coil resistance is selected to conduct, which can reduce the coil energy loss, effectively reduce the power consumption generated by the relay, and ensure the safety of the circuit at the same time.

[0010] In a further solution, the coil resistances of all relay switches are different from each other.

[0011] Thus, setting all relay switches to different resistances facilitates control.

[0012] In a further solution, the short-circuit control loop further includes a drive circuit. The main control circuit is electrically connected to the control end of the relay switch through the drive circuit.

[0013] Thus, by setting the drive circuit to control the conduction and closing of the relay switch, the stability of control is improved.

[0014] In a further solution, the drive circuit includes a triode. The control end of the triode is electrically connected to the main control circuit. The output end of the triode is electrically connected to the first coil end of the relay switch.

[0015] Thus, by setting the triode to control the control end of the relay switch, the stability of control can be ensured.

[0016] In a further solution, the pre-charge resistor is a PTC thermistor

[0017] It can be seen that by using a PTC thermistor as the pre-charge resistor, when the current in the circuit exceeds a certain threshold, the resistance value of the PTC thermistor will increase sharply, thereby limiting the further increase of the current and protecting the circuit from damage.

[0018] To achieve the above second object, the working method of the capacitor charging circuit provided by the present invention includes: after completing the charging of the electrolytic capacitor, the main control circuit obtains the working current value detected by the current detection circuit; the main control circuit turns on the corresponding relay switch according to the current range in which the working current value is located.

[0019] As can be seen from the above solution, the working method of the capacitor charging circuit of the present invention turns on the corresponding relay switch according to the current range in which the working current value is located after completing the charging of the electrolytic capacitor, selects the relay switch with the largest contact current meeting the working current value requirement and the smallest coil resistance value to turn on according to the working current value, and turns on different short-circuit control circuits, which can achieve that when the largest contact current meets the working current value requirement, when the working current is small, the relay switch with a larger coil resistance value is selected, which can reduce the coil energy loss, effectively reduce the power consumption generated by the relay, and ensure the safety of the circuit at the same time.

[0020] In a further solution, the relay switches are sorted in ascending order of coil resistance value, and the current range corresponding to each relay switch satisfies the following relationship: Where, I Jmin is the lower limit value of the current range corresponding to the Jth relay switch, I Jmax is the upper limit value of the current range corresponding to the Jth relay switch, and I MJ is the maximum contact current of the Jth relay switch.

[0021] It can be seen that by setting the current range corresponding to each relay switch, it can meet the switching conduction of different relay switches according to different working currents. At the same time, I Jmin < I (J-1)max , I Jmax > I (J+1)min can prevent the situation of switching back and forth between relay J and relay J + 1 or relay J - 1.

[0022] In a further solution, after completing the charging of the electrolytic capacitor, before the main control circuit obtains the working current value detected by the current detection circuit, the relay switch with the largest maximum contact current and the largest coil resistance value is turned on.

[0023] It can be seen that by turning on the relay switch with the largest maximum contact current and the largest coil resistance value among all relay switches before obtaining the working current value detected by the current detection circuit, the safety of power supply can be ensured and the circuit can be prevented from being burned out due to excessive working current.

[0024] In a further solution, the step of turning on the corresponding relay switch according to the current range in which the working current value is located includes: if the working current value does not fall within the current ranges corresponding to all the relay switches, then maintain the relay switch with the largest contact current and the largest coil resistance turned on.

[0025] Thus, it can be seen that if the working current value does not fall within the current ranges corresponding to all the relay switches, it is considered that the current working current value is relatively large, and it is necessary to maintain the relay switch with the largest contact current and the largest coil resistance turned on to avoid damage to the circuit.

[0026] In a further solution, the step of completing the charging of the electrolytic capacitor includes: when the charging duration for charging the electrolytic capacitor is greater than or equal to a preset duration, it is considered that the charging of the electrolytic capacitor is completed.

[0027] Thus, it can be seen that by judging whether the charging duration exceeds the preset duration to confirm whether the charging of the electrolytic capacitor is completed, it is possible to simplify the circuit structure without detecting the circuit.

[0028] To achieve the above third object, the outdoor unit controller of the present invention includes a capacitor charging circuit, and the capacitor charging circuit applies the above capacitor charging circuit.

[0029] To achieve the above fourth object, the present invention provides an air conditioner, including an outdoor unit controller of the air conditioner, and the outdoor unit controller of the air conditioner applies the above outdoor unit controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is the circuit schematic diagram of an embodiment of the capacitor charging circuit of the present invention.

[0031] Figure 2 is the circuit schematic diagram of a specific example of an embodiment of the capacitor charging circuit of the present invention.

[0032] Figure 3 is the flowchart of an embodiment of the working method of the capacitor charging circuit of the present invention.

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] Embodiment of the capacitor charging circuit:

[0035] Such as Figure 1As shown in the figure, in this embodiment, the capacitor charging circuit includes a main control circuit 1, an AC input terminal AC-L, a pre-charge resistor R, a short-circuit control loop 2, a rectification circuit 3, and an electrolytic capacitor C1. The AC input terminal AC-L is electrically connected to the input terminal of the rectification circuit 3 through the pre-charge resistor R. The output terminal of the rectification circuit 3 is electrically connected to the electrolytic capacitor C1. The short-circuit control loop 2 is connected in parallel across both ends of the pre-charge resistor R. Preferably, the pre-charge resistor R is a PTC thermistor. By using a PTC thermistor as the pre-charge resistor R, when the current in the circuit exceeds a certain threshold, the resistance value of the PTC thermistor will increase sharply, thereby limiting the further increase of the current and protecting the circuit from damage.

[0036] The short-circuit control loop 2 is provided with a control switch for controlling the conduction or closing of the short-circuit control loop 2. The main control circuit 1 is electrically connected to the control end of the control switch. In this embodiment, the number of short-circuit control loops 2 is at least two, and the control switch is a relay switch K. The coil resistance value of at least one relay switch K is different from that of another relay switch K. Preferably, the coil resistance values of all relay switches K are different from each other. The number of short-circuit control loops 2 can be set as needed. For example, as Figure 2 shown, the number of short-circuit control loops 2 is two.

[0037] The short-circuit control loop 2 further includes a drive circuit 21. The main control circuit 1 is electrically connected to the control end of the relay switch K through the drive circuit 21. By setting the drive circuit 21 to control the conduction and closing of the relay switch K, the stability of the control is improved. In this embodiment, the drive circuit 21 includes a triode Q. The control end of the triode Q is electrically connected to the main control circuit 1 through a terminal CRL-1. The output end of the triode Q is electrically connected to the first coil end of the relay switch K. Preferably, the triode Q is an NPN triode.

[0038] The capacitor charging circuit further includes a current detection circuit 3. The current detection circuit 3 is used to obtain the working current value at the output end of the rectification circuit 3 and transmit it to the main control circuit 1. The main control circuit 1 selects the relay switch K with the largest contact current that meets the working current value requirement and the largest coil resistance value to conduct according to the working current value. The current detection circuit 3 adopts a well-known current detection circuit and will not be elaborated here. The maximum contact current refers to the maximum current value that the contact of the relay switch K can withstand under normal working conditions.

[0039] See Figure 3 , when the capacitor charging circuit of this embodiment is working, first, step S1 is executed to complete the charging of the electrolytic capacitor C1. When the capacitor charging circuit is powered on, it is necessary to first charge the electrolytic capacitor C1. At this time, all short-circuit control loops 2 are disconnected, and the electrolytic capacitor C1 is charged using the path of the pre-charge resistor R.

[0040] In this embodiment, the steps to complete the charging of the electrolytic capacitor C1 include: when the charging duration of the electrolytic capacitor C1 is greater than or equal to a preset duration, it is considered that the charging of the electrolytic capacitor C1 is completed. Among them, the preset duration can be set in advance according to experimental data. By judging whether the charging duration exceeds the preset duration, it can be confirmed whether the charging of the electrolytic capacitor C1 is completed, and there is no need to detect the circuit, thus simplifying the circuit structure.

[0041] After completing the charging of the electrolytic capacitor C1, step S2 is executed, and the main control circuit 1 controls the relay switch K with the largest contact current and the largest coil resistance to conduct. After completing the charging of the electrolytic capacitor C1, power needs to be supplied to the subsequent circuit. At this time, in order to reduce the influence of the pre-charge resistor R on the circuit, the path of the pre-charge resistor R needs to be short-circuited. Therefore, a short-circuit control loop 2 needs to be conducted to short-circuit the path of the pre-charge resistor R. In order to avoid excessive current at the start of power supply, at this time, the relay switch K with the largest contact current and the largest coil resistance among all relay switches K is controlled to conduct, which can ensure the safety of power supply and avoid burning out the circuit due to excessive working current.

[0042] After controlling the relay switch K with the largest contact current and the largest coil resistance to conduct, step S3 is executed, and the main control circuit 1 obtains the working current value detected by the current detection circuit 3. In order to make the largest contact current of the conducted relay switch K adapt to the working current value of the circuit, the working current value of the circuit needs to be monitored in real time. Therefore, the working current value at the output end of the rectifier circuit 3 is obtained through the current detection circuit 3.

[0043] After obtaining the working current value detected by the current detection circuit 3, step S4 is executed, and the main control circuit conducts the corresponding relay switch K according to the current range where the working current value is located. Conducting the corresponding relay switch K according to the current range where the working current value is located can ensure that the largest contact current of the conducted relay switch K meets the requirements of the working current value.

[0044] In this embodiment, the number of relay switches K is greater than or equal to three, and the relay switches K are sorted according to the coil resistance from small to large, that is, RN < ··· < R2 < R1, where N is the total number of relay switches K. At this time, the largest contact currents of all relay switches K satisfy the following relationship: I MN > ··· > I M2 > I M1 ,I MN represents the largest contact current of the Nth relay switch K. The current range corresponding to each relay switch K can be set in advance according to the specifications of the relay switch K, and the current range corresponding to each relay switch K satisfies the following relationship: Among them, I Jmin is the lower limit value of the current range corresponding to the Jth relay switch K, I Jmaxis the upper limit value of the current range corresponding to the Jth relay switch K, I MJ is the maximum contact current of the Jth relay switch K. By setting the current range corresponding to each relay switch K, it is possible to satisfy the switching conduction of different relay switches K according to different working currents. At the same time, I Jmin <I (J-1)max ,I Jmax >I (J+1)min ,it is possible to prevent the situation of switching back and forth between the Jth relay switch K and the J + 1th relay switch K or the J - 1th relay switch K. I Jmax <I MJ can prevent the upper limit value of the current range corresponding to the Jth relay switch K from being greater than the maximum contact current of the Jth relay switch K.

[0045] In this embodiment, the step of conducting the corresponding relay switch K according to the current range where the working current value is located includes: if the working current value does not fall into the current ranges corresponding to all relay switches K, then maintain the conduction of the relay switch K with the largest maximum contact current and the largest coil resistance. If the working current value does not fall into the current ranges corresponding to all relay switches K, it is considered that the current working current value is relatively large, and it is necessary to maintain the conduction of the relay switch K with the largest maximum contact current and the largest coil resistance to avoid circuit damage.

[0046] As can be seen from the above, the capacitor charging circuit of the present invention sets relay switches K with different coil resistances, selects the relay switch K with the largest contact current meeting the working current value requirement and the smallest coil resistance according to the working current value, and conducts different short - circuit control circuits 2, so that when the maximum contact current meets the working current value requirement, when the working current is relatively small, the relay switch K with a larger coil resistance is selected, which can reduce the coil energy loss, effectively reduce the power consumption generated by the relay switch K, and at the same time ensure the safety of the circuit. For example, under a 12V supply voltage, the specifications of the relay switch K of manufacturer a are: maximum contact current 5A, coil resistance 720Ω, and relay power consumption P1 = 12V * 12V / 720Ω = 0.2W; the specifications of the relay switch K of manufacturer b are: maximum contact current 5A, coil resistance 480Ω, and relay power consumption P1 = 12V * 12V / 480Ω = 0.3W; the specifications of the relay switch K of manufacturer c are: maximum contact current 20A, coil resistance 160Ω, and relay power consumption P2 = 12V * 12V / 160Ω = 0.9W; obviously, when the working current is less than 5A, selecting the relay switch K with a maximum contact current of 5A and a coil resistance of 720Ω has lower power consumption.

[0047] Embodiment of the outdoor unit controller of an air conditioner:

[0048] In this embodiment, the outdoor unit controller of the air conditioner includes a capacitor charging circuit, and the capacitor charging circuit applies the above-mentioned capacitor charging circuit.

[0049] Embodiment of the air conditioner:

[0050] In this embodiment, the air conditioner includes an outdoor unit controller of the air conditioner, and the outdoor unit controller of the air conditioner applies the above-mentioned outdoor unit controller of the air conditioner.

[0051] It should be noted that the above are only the preferred embodiments of the present invention, but the design concept of the invention is not limited thereto. Any non-substantive modifications made to the present invention using this concept also fall within the protection scope of the present invention.

Claims

1. A capacitor charging circuit, comprising a main control circuit, an AC input terminal, a pre-charging resistor, a short-circuit control loop, a rectifier circuit and an electrolytic capacitor, wherein the AC input terminal is electrically connected to the input terminal of the rectifier circuit through the pre-charging resistor, the output terminal of the rectifier circuit is electrically connected to the electrolytic capacitor, and the short-circuit control loop is connected in parallel to both ends of the pre-charging resistor; the short-circuit control loop is provided with a control switch for controlling the short-circuit control loop to be turned on or off, and the main control circuit is electrically connected to the control terminal of the control switch; characterized in that: The number of the short-circuit control loops is at least two, the control switches are relay switches, and the coil resistance of at least one of the relay switches is different from the coil resistance of another relay switch; The capacitor charging circuit further includes a current detection circuit, which is used to obtain the working current value of the output end of the rectifier circuit and transmit it to the main control circuit; The main control circuit is used to select the relay switch with the maximum contact current to meet the working current value requirement and the largest coil resistance to turn on according to the working current value.

2. The capacitor charging circuit according to claim 1, characterized in that: The coil resistance values ​​of all the relay switches are different.

3. The capacitor charging circuit according to claim 1, wherein: The short-circuit control loop also includes a drive circuit, and the main control circuit is electrically connected to the control end of the relay switch through the drive circuit.

4. The capacitor charging circuit according to claim 3, characterized in that: The driving circuit comprises a transistor, a control end of the transistor is electrically connected to the main control circuit, and an output end of the transistor is electrically connected to a first coil end of the relay switch.

5. The capacitor charging circuit according to any one of claims 1 to 4, characterized in that: The pre-charging resistor is a PTC thermistor.

6. A working method of a capacitor charging circuit, the capacitor charging circuit comprising a main control circuit, an AC input terminal, a pre-charging resistor, a short-circuit control loop, a rectifier circuit and an electrolytic capacitor, the AC input terminal is electrically connected to the input terminal of the rectifier circuit through the pre-charging resistor, the output terminal of the rectifier circuit is electrically connected to the electrolytic capacitor, the short-circuit control loop is connected in parallel to both ends of the pre-charging resistor; the short-circuit control loop is provided with a control switch for controlling the short-circuit control loop to be turned on or off, the main control circuit is electrically connected to the control terminal of the control switch, and is characterized in that: The number of the short-circuit control loops is at least two, the control switch is a relay switch, and the coil resistance of at least one of the relay switches is different from the coil resistance of another relay switch; the capacitor charging circuit also includes a current detection circuit, the current detection circuit is used to obtain the working current value of the output end of the rectifier circuit and transmit it to the main control circuit; the main control circuit is used to select the relay switch with the largest contact current to meet the working current value requirement and the largest coil resistance according to the working current value to turn on; The method comprises: After the electrolytic capacitor is charged, the main control circuit obtains the working current value detected by the current detection circuit; The main control circuit turns on the corresponding relay switch according to the current interval in which the working current value is located.

7. The operating method of the capacitor charging circuit according to claim 6, characterized in that: The total number of the relay switches is greater than or equal to three, and the relay switches are arranged in ascending order according to the coil resistance, and the current interval corresponding to each of the relay switches satisfies the following relationship: Among them, I Jmin is the lower limit of the current interval corresponding to the Jth relay switch, I Jmax is the upper limit of the current interval corresponding to the Jth relay switch, I MJ is the maximum contact current of the Jth relay switch, and N is the total number of the relay switches.

8. The operating method of the capacitor charging circuit according to claim 6, characterized in that: After the electrolytic capacitor is charged, before the main control circuit obtains the working current value detected by the current detection circuit, the relay switch with the largest maximum contact current and the largest coil resistance is controlled to be turned on.

9. The operating method of the capacitor charging circuit according to claim 8, characterized in that: The step of turning on the corresponding relay switch according to the current interval of the working current value comprises: If the working current value does not fall into the current interval corresponding to all the relay switches, the relay switch with the largest maximum contact current and the largest coil resistance is kept turned on.

10. The working method of the capacitor charging circuit according to any one of claims 6 to 9, characterized in that: The steps of charging the electrolytic capacitor include: When the charging time for charging the electrolytic capacitor is greater than or equal to the preset time, it is considered that the charging of the electrolytic capacitor is completed.

11. An air conditioner outdoor unit controller, comprising a capacitor charging circuit, characterized in that: The capacitor charging circuit applies the capacitor charging circuit according to any one of claims 1 to 5.

12. An air conditioner, comprising an air conditioner outdoor unit controller, characterized in that: The air conditioner outdoor unit controller applies the air conditioner outdoor unit controller according to claim 11.

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