A voltage detection circuit of a heat dissipation fan and a refrigeration equipment

Abstract

The utility model provides a kind of voltage detection circuit and refrigeration equipment of radiating fan, it is related to household appliance technical field, for realizing the working voltage detection of radiating fan.The voltage detection circuit includes: drive module and voltage detection module;One end of drive module is connected with the first end of radiating fan, the other end of drive module is connected with the first pin of controller, one end of voltage detection module is connected with the first end of radiating fan, the other end of voltage detection module is connected with the second pin of controller;Wherein: drive module, for receiving the control signal of controller, control signal is used to control the switch state of radiating fan;Voltage detection module is used to obtain the working voltage signal of radiating fan, and according to working voltage signal conversion obtains feedback voltage signal, and feedback voltage signal is transmitted to second pin, feedback voltage signal is the voltage signal that meets the measurement range of second pin.

Description

Technical Field

[0001] This utility model relates to the field of household appliance technology, and in particular to a voltage detection circuit for a cooling fan and a refrigeration device. Background Technology

[0002] In home appliances, cooling fans are crucial heat dissipation components, effectively preventing damage from overheating and significantly impacting the lifespan and performance of these appliances. However, if a cooling fan malfunctions, the internal power devices will continue operating, preventing timely heat dissipation and leading to excessively high device temperatures. This not only affects performance but can also cause overheating and damage. Therefore, directly and accurately detecting the cooling fan's operating voltage is essential for identifying its operational status. Abnormal operating voltage directly reflects issues such as power supply problems, winding faults, or stalled operation. Thus, detecting the operating voltage is vital for ensuring the reliability and safety of home appliances. Utility Model Content

[0003] This invention provides a voltage detection circuit and refrigeration device for cooling fans, used to detect the operating voltage of the cooling fan.

[0004] In a first aspect, this utility model provides a voltage detection circuit for a cooling fan, comprising: a drive module and a voltage detection module; one end of the drive module is connected to a first end of the cooling fan, and the other end of the drive module is connected to a first pin of a controller; one end of the voltage detection module is connected to the first end of the cooling fan, and the other end of the voltage detection module is connected to a second pin of the controller; wherein: the drive module is used to receive a control signal from the controller, the control signal being used to control the switching state of the cooling fan, the switching state including on or off; the voltage detection module is used to acquire the operating voltage signal of the cooling fan, and convert it into a feedback voltage signal based on the operating voltage signal, and transmit the feedback voltage signal to the second pin, the feedback voltage signal being a voltage signal conforming to the measurement range of the second pin.

[0005] In this invention, a voltage detection module is designed into the voltage detection circuit. This module can acquire the operating voltage signal of the cooling fan, thereby realizing the detection of the cooling fan's operating voltage. Furthermore, a feedback voltage signal is transmitted to the second pin. Since the feedback voltage signal is a voltage signal converted from the operating voltage signal and conforms to the measurement range of the second pin, the problem of controller damage due to excessively high voltage signals is effectively avoided.

[0006] In one possible implementation, the voltage detection module includes at least two voltage divider resistors connected in series. One end of the first voltage divider resistor is connected to the first end of the cooling fan, and one end of the second voltage divider resistor is connected to the ground terminal. The voltage divider output terminals of the at least two voltage divider resistors are connected to the second pin. The at least two voltage divider resistors are used to convert the operating voltage signal into a feedback voltage signal that conforms to the measurement range of the second pin.

[0007] In this embodiment, by setting at least two voltage divider resistors in the voltage detection module, the working voltage signal is proportionally reduced to a measurement range suitable for the second pin, so that the feedback voltage signal measured by the second pin is always within the measurement range of the second pin, thus avoiding the problem of the controller being damaged due to the working voltage signal of the cooling fan being too high.

[0008] In one possible implementation, the drive module includes a first switching element and an equivalent resistor; wherein one end of the equivalent resistor is connected to a first end of the cooling fan, the other end of the equivalent resistor is connected to the collector of the first switching element, the emitter of the first switching element is connected to the ground terminal, and the base of the first switching element is connected to the first pin; wherein the first switching element is configured to receive a high-level signal from the controller via the first pin, the high-level signal being used to control the first switching element to be in a conducting state, thereby controlling the cooling fan to be in an on state; or, the first switching element is configured to receive a low-level signal from the controller via the first pin, the low-level signal being used to control the first switching element to be in a disconnected state, thereby controlling the cooling fan to be in a closed state.

[0009] In this embodiment, a transistor is used as the first switching element, which can quickly and timely respond to the controller's control signal for the cooling fan. Moreover, compared with mechanical relays, transistors are less prone to electromagnetic interference, have no mechanical wear problems, and have a longer lifespan.

[0010] In one possible implementation, the difference between the sum of the resistance values ​​of the at least two voltage divider resistors and the resistance value of the equivalent resistor is greater than or equal to a preset threshold; or, the voltage detection module further includes a second switching element, one end of which is connected to the first end of the cooling fan, and the other end of which is connected to one end of the first voltage divider resistor; wherein: the second switching element is used to control the conduction state of the voltage detection module.

[0011] Because one end of the cooling fan is connected to the drive module and the other end to the power supply, the presence of the voltage detection module means that even when the first switching element is off, a current path still forms at one end of the cooling fan through the voltage detection module, preventing the first switching element from controlling the cooling fan's on / off function. Therefore, by ensuring the difference between the sum of the resistances of at least two voltage divider resistors and the equivalent resistance is greater than or equal to a preset threshold, the impedance of this path is significantly increased, minimizing the cooling fan's operating current and thus shutting it off. Alternatively, a second switching element can be incorporated into the voltage detection module to work in conjunction with the first switching element: when the first switching element is off, the second switching element is simultaneously controlled to open, thereby shutting down the cooling fan.

[0012] In one possible implementation, the drive module further includes a current-limiting resistor, one end of which is connected to the second pin, and the other end of which is connected to the base of the first switching element; wherein: the current-limiting resistor is used to limit the current flowing out of the first pin to within the safe range of the first pin, and to ensure that the base current flowing into the first switching element satisfies the conduction condition of the first switching element.

[0013] By connecting a current-limiting resistor in series between the controller and the first switching element, the current flowing out of the first pin can be limited to the safe range of the first pin, avoiding damage to the chip due to excessive current. Furthermore, the current flowing into the base of the first switching element is controlled so that the current flowing into the first switching element meets the conduction condition of the first switching element, thereby achieving the purpose of controlling the first switching element to conduct.

[0014] In one possible implementation, the drive module further includes a pull-down resistor, one end of which is connected to the base of the first switching element, and the other end of which is connected to the emitter of the first switching element; wherein the pull-down resistor is used to discharge the charge stored in the base-emitter junction of the first switching element.

[0015] In the first switching element, a junction capacitance exists between the base and emitter. When the controller outputs a high-level signal, this junction capacitance is in a charging state and stores a certain amount of charge. When the controller outputs a low-level signal, the first switching element is required to turn off. However, the charge in the junction capacitance cannot be released instantaneously, causing the first switching element to fail to turn off quickly, or even mis-turning on due to residual charge. Therefore, by connecting a pull-down resistor in parallel between the base and emitter, a charge discharge circuit is formed, thereby discharging the charge stored in the junction capacitance (base-emitter junction), thus achieving the goal of quickly turning off the first switching element and improving the turn-off speed and reliability of the first switching element.

[0016] In one possible implementation, the voltage detection module further includes a filtering module, one end of which is connected to the voltage divider output of the at least two voltage divider resistors, and the other end of which is connected to the second pin; wherein the filtering module is used to filter out interference signals in the feedback voltage signal.

[0017] By incorporating a filtering module into the voltage detection module, high-frequency noise and interference components in the feedback voltage signal can be effectively filtered out, enabling the controller to acquire a more stable and pure voltage signal. This improves the measurement accuracy of the feedback voltage signal and significantly enhances the accuracy of determining the operating status of the cooling fan.

[0018] In one possible implementation, the filtering module includes a filter resistor and a filter capacitor. One end of the filter resistor is connected to the voltage divider output terminal, and the other end of the filter resistor is connected to the second pin. One end of the filter capacitor is connected to the second pin, and the other end of the filter capacitor is connected to the ground terminal.

[0019] By using a filter module composed of filter resistors and filter capacitors, noise suppression and smoothing of the feedback voltage signal are achieved, thereby effectively filtering out high-frequency interference and reducing signal fluctuations, providing the controller with a stable and clean feedback voltage signal.

[0020] In one possible implementation, the voltage detection circuit further includes a diode, one end of which is connected to a first end of the cooling fan, and the other end of which is connected to a second end of the cooling fan; wherein the diode is used to discharge the freewheeling current generated inside the cooling fan when the cooling fan is turned off.

[0021] When the cooling fan is turned off, a large reactive electromotive force is generated inside the fan, resulting in a freewheeling current. Therefore, connecting a freewheeling diode in parallel across the cooling fan provides an efficient return path for this freewheeling current, effectively dissipating it and ensuring the fan is shut down properly, thus improving the reliability of the cooling fan's shutdown.

[0022] In a second aspect, the present invention provides a cooling device, including a cooling fan and a voltage detection circuit as described in the first aspect and any possible embodiments.

[0023] The beneficial effects of the second aspect can be referred to in the first aspect and any possible implementation described above, and will not be repeated here. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 1 ;

[0026] Figure 2 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 2 ;

[0027] Figure 3 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 3 ;

[0028] Figure 4 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 4 ;

[0029] Figure 5 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 5 ;

[0030] Figure 6 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 6 ;

[0031] Figure 7 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 7 ;

[0032] Figure 8 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 8 ;

[0033] Figure 9 A schematic diagram of the voltage detection circuit for a cooling fan provided in this embodiment of the present invention. Figure 9 ;

[0034] Figure 10 This utility model provides a schematic diagram of the normal voltage range and abnormal voltage range of a cooling fan. Detailed Implementation

[0035] The technical solution of this utility model will now be described with reference to the accompanying drawings.

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0039] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this utility model and to simplify the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0040] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0041] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or a link; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0042] As home appliances become increasingly miniaturized and power-density-oriented, the power density of inverter boards is constantly improving, placing ever higher demands on the heat dissipation of their internal power components. Currently, cooling fans generally operate in an open-loop mode, with the inverter board only responsible for providing DC operating voltage and drive signals, unable to acquire real-time fan operating status. Against this technological backdrop, direct and accurate detection of the cooling fan's operating voltage has become crucial for identifying its operational status. Abnormal operating voltage can directly reflect problems such as power supply anomalies, winding faults, or stalled operation. Therefore, detecting the operating voltage plays a vital role in ensuring the reliability and safety of home appliances.

[0043] Based on this, the present invention provides a voltage detection circuit for a cooling fan, the voltage detection circuit comprising: a drive module and a voltage detection module; one end of the drive module is connected to a first end of the cooling fan, and the other end of the drive module is connected to a first pin of a controller; one end of the voltage detection module is connected to the first end of the cooling fan, and the other end of the voltage detection module is connected to a second pin of the controller; wherein: the drive module is used to receive a control signal from the controller, the control signal being used to control the switching state of the cooling fan, the switching state including on or off; the voltage detection module is used to acquire the operating voltage signal of the cooling fan, and convert it into a feedback voltage signal based on the operating voltage signal, and transmit the feedback voltage signal to the second pin, the feedback voltage signal being a voltage signal conforming to the measurement range of the second pin.

[0044] In this invention, a voltage detection module is designed in the voltage detection circuit. The working voltage signal of the cooling fan can be obtained through this voltage detection module, thus realizing the detection of the working voltage signal of the cooling fan.

[0045] Furthermore, since the operating voltage signal of the cooling fan is different under different working conditions, the feedback voltage signal is a voltage signal that conforms to the measurement range of the second pin and is converted from the operating voltage signal. Therefore, the operating voltage signal is transmitted to the controller through the second pin so that the controller can determine whether the operating state of the cooling fan is abnormal based on the feedback voltage signal. This enables continuous detection of the operating state of the cooling fan, effectively avoiding the problem of internal components continuing to work and overheating due to the failure to detect fan failure in time, which is conducive to improving the operational reliability and safety of the equipment.

[0046] The voltage detection circuit for a cooling fan provided by this utility model will be described in detail below with reference to the accompanying drawings.

[0047] Please refer to Figure 1 The schematic diagram shows the structure of a voltage detection circuit for a cooling fan provided by this utility model. Figure 1 .like Figure 1As shown, the voltage detection circuit 100 includes a drive module 110 and a voltage detection module 120. One end of the drive module 110 is connected to the first end of the cooling fan 200, and the other end is connected to the first pin 301 of the controller 300. One end of the voltage detection module 120 is connected to the first end of the cooling fan 200, and the other end is connected to the second pin 302 of the controller 300. The first pin 301 of the controller 300 is used to output control signals to the cooling fan 200. The second pin 302 is the analog-to-digital converter (ADC) pin of the controller 300, used to measure the feedback voltage signal transmitted by the voltage detection module 120 to obtain the feedback voltage value.

[0048] The drive module 110 receives control signals from the controller 300, which control the on / off state of the cooling fan 200, including on and off states. The voltage detection module 120 acquires the operating voltage signal of the cooling fan 200, converts it into a feedback voltage signal, and transmits the feedback voltage signal to the second pin 302. The operating voltage signal indicates the operating state of the cooling fan 200, including normal and abnormal states. The feedback voltage signal is a voltage signal that conforms to the measurement range of the second pin 302 of the controller 300; the abnormal state can be understood as the state when the cooling fan malfunctions.

[0049] For example, the controller 300 can output a control signal to the drive module 110 via the first pin 301. Correspondingly, the drive module 110 receives the control signal from the controller 300 via the first pin 301 to control the cooling fan 200 to be in an on or off state. This control signal can be a high-level signal or a low-level signal; different levels control different on / off states of the cooling fan 200. For example, a high-level control signal controls the cooling fan 200 to be on, while a low-level control signal controls the cooling fan 200 to be off.

[0050] When the cooling fan 200 is on, the voltage detection module 120 continuously detects the operating voltage signal of the cooling fan 200, converts the operating voltage signal into a feedback voltage signal, and transmits it to the second pin 302. The second pin 302 then measures the feedback voltage signal to obtain a feedback voltage value. The controller 300 can determine whether the operating state of the cooling fan 200 is abnormal based on this feedback voltage value and a pre-stored reference voltage range. The reference voltage range can be obtained by converting the operating voltage range of the cooling fan 200 under normal operating conditions, and the conversion method for the reference voltage range is the same as that for the feedback voltage value. In other words, when the feedback voltage value is within the reference voltage range, the cooling fan 200 is in normal operating condition. When the feedback voltage value is not within the reference voltage range, the cooling fan 200 is in an abnormal operating state.

[0051] In this invention, a voltage detection module is designed in the voltage detection circuit. This voltage detection module can continuously acquire the operating voltage signal of the cooling fan, thereby realizing the continuous detection of the operating voltage of the cooling fan.

[0052] Furthermore, since the operating voltage signal of the cooling fan differs under different operating conditions, the feedback voltage signal obtained from the conversion under different operating conditions also differs. Based on this, by transmitting the feedback voltage signal to the second pin, the controller can continuously detect the operating status of the cooling fan through the feedback voltage signal. This effectively avoids the problem of internal components continuing to work and overheating due to the failure to detect fan failure in time, which is conducive to improving the operational reliability and safety of the equipment.

[0053] In one possible implementation, since the power supply voltage of the cooling fan is typically 12V or 15V in practical applications, while the measurement range of the controller's ADC pin is typically 0V to 5V or 0V to 3.3V, a voltage divider circuit can be incorporated into the voltage detection module to reduce the operating voltage signal acquired by the voltage detection module to a feedback voltage signal that matches the controller's measurement range in order to prevent damage to the controller.

[0054] In some embodiments, the voltage detection module includes at least two voltage divider resistors connected in series. One end of the first voltage divider resistor is connected to the first end of the cooling fan, one end of the second voltage divider resistor is connected to ground, and the voltage divider output terminals of the at least two voltage divider resistors are connected to a second pin. The at least two voltage divider resistors are used to convert the operating voltage signal into a feedback voltage signal that conforms to the measurement range of the second pin. The resistance values ​​of the at least two voltage divider resistors are related to the measurement range of the second pin, but this embodiment does not limit this.

[0055] For example, please refer to Figure 2 This is a schematic diagram of the voltage detection circuit for a cooling fan provided in an embodiment of this application. Figure 2 .like Figure 2 As shown, the voltage detection module 120 includes two voltage divider resistors R1 and R2. One end of R1 is connected to the first terminal of the cooling fan 200, and one end of R2 is connected to the ground terminal GND. The voltage divider output terminal between R1 and R2 is connected to the second pin 302. It should be understood that... Figure 2 The voltage detection module 120 is used as an example, which includes two voltage divider resistors. However, in practical applications, the voltage detection module may include more voltage divider resistors. This application does not limit this.

[0056] When the cooling fan is on, the voltage detection module can obtain the operating voltage signal of the cooling fan. Since the voltage detection module includes at least two voltage divider resistors, the feedback voltage signal output by the voltage divider output terminal is equivalent to a voltage signal that is reduced by a certain ratio to the operating voltage signal, so that the feedback voltage signal meets the measurement range of the second pin, thus avoiding damage to the controller due to the operating voltage signal of the cooling fan being too high.

[0057] In one possible implementation, the drive module may include a first switching element and an equivalent resistor. By controlling the first switching element to turn on or off, the cooling fan can be controlled to turn on or off. The equivalent resistor can be understood as an equivalent model of the cooling fan. By detecting the voltage across the equivalent resistor, the operating voltage of the cooling fan can be obtained.

[0058] Please refer to Figure 3 This is a schematic diagram of the voltage detection circuit for a cooling fan provided in an embodiment of this application. Figure 3 .like Figure 3 As shown, the drive module 110 includes a first switching element N1 and an equivalent resistor R3. One end of the equivalent resistor R3 is connected to the first end of the cooling fan 200, the other end of the equivalent resistor R3 is connected to the collector of the first switching element N1, the emitter of the first switching element N1 is connected to the ground terminal GND, and the base of the first switching element N1 is connected to the first pin 301.

[0059] The second terminal of the cooling fan 200 is connected to the power supply VDC, which provides the power supply voltage for the cooling fan 200. The power supply VDC can provide a power supply voltage of 12V, 15V, or other values, and this embodiment of the application does not limit this.

[0060] The first switching element is configured to receive a high-level signal from the controller via a first pin, the high-level signal being used to control the first switching element to be in a conducting state, thereby controlling the cooling fan to be in an on state; or, the first switching element is configured to receive a low-level signal from the controller via a first pin, the low-level signal being used to control the first switching element to be in a disconnected state, thereby controlling the cooling fan to be in a off state.

[0061] Since the collector of the first switching element is directly short-circuited to ground when it is turned on, it will cause the first switching element to burn out instantly. Therefore, adding an equivalent resistor can also protect the first switching element.

[0062] In one possible implementation, since the second end of the cooling fan is connected to the power supply VDC, when the first switching element is in the off state, the drive module connected to the first end of the cooling fan is disconnected. However, the cooling fan is still connected to the voltage detection module, forming a current path, causing the first switching element to not function as a control for the cooling fan's switching on and off. Therefore, in order to correctly control the switching state of the cooling fan, the difference between the sum of the resistance values ​​of at least two voltage divider resistors and the resistance value of the equivalent resistance must be greater than or equal to a preset threshold. The preset threshold can be set according to actual needs to ensure that the switching state of the cooling fan can be correctly controlled; this application does not limit this.

[0063] In other words, the sum of the resistances of at least two voltage divider resistors is much greater than the equivalent resistance. For example, with... Figure 3 Taking at least two voltage divider resistors, including R1 and R2, as an example, the sum of the resistances of R1 and R2 is 50KΩ, while the resistance of R3 is 30Ω. The sum of the resistances of R1 and R2 is much greater than the resistance of R3.

[0064] In this embodiment, by increasing the resistance values ​​of at least two voltage divider resistors, the impedance of the path is significantly increased, making the operating current of the cooling fan extremely small, thereby achieving the purpose of shutting down the cooling fan.

[0065] In another possible implementation, the voltage detection module may further include a second switching element, one end of which is connected to the first end of the cooling fan, and the other end of which is connected to one end of the first voltage divider resistor. The second switching element controls the conduction state of the voltage detection module. In other words, the switching state of the cooling fan is controlled by the coordinated operation of the second and first switching elements. The second switching element can be a relay, transistor, mechanical switch, etc., and this embodiment is not limited thereto.

[0066] For example, please refer to Figure 4 This is a schematic diagram of the voltage detection circuit for a cooling fan provided in an embodiment of this application. Figure 4 .like Figure 4 As shown, the voltage detection module 120 also includes a second switching element K1. One end of the second switching element K1 is connected to the first end of the cooling fan 200, and the other end of the second switching element K1 is connected to one end of the voltage divider resistor R1.

[0067] When the first switching element is on, the second switching element is simultaneously turned on; when the first switching element is off, the second switching element is simultaneously turned off. In this way, the cooling fan can be correctly controlled to turn on or off.

[0068] In one possible implementation, each pin of the controller typically has a maximum current limit, for example, ±20mA. If the current to a pin exceeds this maximum current limit, the controller will be permanently damaged. Furthermore, the first switching element requires a sufficiently large base current to turn on. Therefore, to prevent the current flowing out of the first pin from exceeding its maximum current limit, while ensuring that the current flowing into the first switching element meets the turn-on condition, the drive module may also include a current-limiting resistor, one end of which is connected to the second pin, and the other end of which is connected to the base of the first switching element.

[0069] For example, please refer to Figure 5 This is a schematic diagram of the voltage detection circuit for a cooling fan provided in an embodiment of this application. Figure 5 .like Figure 5 As shown, the drive module 110 also includes a current-limiting resistor R4, one end of which is connected to the first pin 301, and the other end of which is connected to the base of the first switching element N1.

[0070] The current-limiting resistor is used to limit the current flowing out of the first pin to within the safe range of the first pin, and to ensure that the base current flowing into the first switching element meets the conduction condition of the first switching element. The maximum current value within the safe range is the maximum current limit of the first pin. The conduction condition of the first switching element is used to indicate that the first switching element enters a saturated conduction state; the conduction condition is specifically related to the base current, collector current, and the DC amplification factor of the first switching element.

[0071] Furthermore, the base current of the first switching element also has a maximum current limit; excessive base current will damage the first switching element. Therefore, the current-limiting resistor is also used to limit the current flowing into the first switching element to within its safe range.

[0072] In one possible implementation, the base-emitter junction of the first switching element stores charge when the first switching element is in the ON state. When the drive signal (high-level signal) is removed, i.e., when the controller outputs a low-level signal through the first pin, the charge in the base-emitter junction is released slowly, resulting in a reduced turn-off speed of the first switching element. Based on this, the drive module may further include a pull-down resistor, one end of which is connected to the base of the first switching element, and the other end of which is connected to the emitter of the first switching element.

[0073] The pull-down resistor is used to discharge the charge stored in the base-emitter junction of the first switching element. In other words, the pull-down resistor helps to discharge the charge stored in the base-emitter junction more quickly, thereby accelerating the turn-off process of the first switching element.

[0074] For example, please refer to Figure 6 This is a schematic diagram of the voltage detection circuit for a cooling fan provided in an embodiment of this application. Figure 6 .like Figure 6 As shown, one end of the pull-down resistor R5 is connected to the base of N1, and the other end of R5 is connected to the emitter of N1.

[0075] In practical applications, the pull-down resistor can also be replaced by an accelerating capacitor, but this application does not limit this.

[0076] In one possible implementation, since the voltage signal is subject to external environmental interference during transmission, such as interference from various electromagnetic factors, the transmitted voltage signal may also contain some interference signals. Therefore, the voltage detection module may further include a filtering module. One end of the filtering module is connected to the voltage divider output of at least two voltage divider resistors, and the other end of the filtering module is connected to a second pin. The filtering module is used to filter out interference signals from the feedback voltage signal.

[0077] For example, please refer to Figure 7 This is a schematic diagram of the voltage detection circuit for a cooling fan provided in an embodiment of this application. Figure 7 .like Figure 7 As shown, one end of the filter module 121 is connected to the voltage divider output terminal, and the other end of the filter module 121 is connected to the second pin 302.

[0078] In one possible implementation, the filtering module can consist of an RC filter circuit. In this case, the filtering module may include a filter resistor and a filter capacitor, with one end of the filter resistor connected to the voltage divider output terminal and the other end of the filter resistor connected to the second pin, one end of the filter capacitor connected to the second pin, and the other end of the filter capacitor connected to the ground terminal.

[0079] For example, please refer to Figure 8This is a schematic diagram of the voltage detection circuit for a cooling fan provided in an embodiment of this application. Figure 8 .like Figure 8 As shown, one end of the filter resistor R6 is connected to the voltage divider output terminal, and the other end of R6 is connected to the second pin 302. One end of the filter capacitor C1 is connected to the second pin 302, and the other end of C1 is connected to the ground terminal GND.

[0080] In one possible implementation, a large reactive electromotive force is generated inside the cooling fan at the moment it is turned off, forming a freewheeling current. Therefore, to discharge this freewheeling current and ensure the reliability of the cooling fan's shutdown, the voltage detection circuit may further include a diode, with one end of the diode connected to a first terminal of the cooling fan and the other end connected to a second terminal of the cooling fan. The diode is used to discharge the freewheeling current generated inside the cooling fan when it is turned off.

[0081] For example, please refer to Figure 9 This is a schematic diagram of the voltage detection circuit for a cooling fan provided in an embodiment of this application. Figure 9 .like Figure 9 As shown, one end of diode D1 is connected to the first end of cooling fan 200, and the other end of diode D1 is connected to the second end of cooling fan 200.

[0082] By connecting a freewheeling diode in parallel with the first and second ends of the cooling fan to form a discharge circuit, the reliability of the cooling fan's shutdown is effectively ensured.

[0083] The following is combined with Figure 9 The voltage detection circuit shown illustrates the working principle of a voltage detection circuit.

[0084] When the controller 300 outputs a high-level signal at its first pin 301, N1 is turned on. After N1 is turned on, the current I... FAN The circuit flows from VDC → cooling fan 200 → R3 → collector (C) of N1 → emitter (E) of N1 → GND, and the fan starts to rotate. When N1 is conducting, the Vce voltage is very small, considered to be 0. At this time, the operating voltage signal of the cooling fan is V1 = I. FAN *R3.

[0085] After voltage division by resistors R1 and R2, V1 generates a feedback voltage signal V2, where,

[0086]

[0087] The feedback voltage signal is transmitted to the second pin so that the controller can determine whether the cooling fan is operating abnormally by reading the feedback voltage value measured by the second pin.

[0088] As can be seen from the above formula, the fan current I FAN The magnitude of the feedback voltage is determined by the magnitude of the current I, and the fan current I varies under different abnormal conditions. FAN The differences are as follows. Based on this, the feedback voltage signal can also be used to determine the type of failure in a cooling fan. The main types of cooling fan failures include the following:

[0089] (1) The cooling fan is abnormally open-circuited or disconnected;

[0090] (2) Cooling fan stalled;

[0091] (3) The cooling fan is short-circuited.

[0092] When the cooling fan is abnormally open-circuited or disconnected, the operating current I of the cooling fan is... FAN The current is 0A, the operating voltage is 0V, therefore the feedback voltage is also 0V. When the cooling fan stalls, the operating current I... FAN As the voltage increases, the operating voltage increases, and consequently, the measured feedback voltage value also increases accordingly. When the cooling fan is short-circuited, the operating voltage of the cooling fan equals the supply voltage, and the measured feedback voltage value reaches its maximum value at this time.

[0093] For example, please refer to Figure 10 This diagram illustrates the normal and abnormal voltage ranges of a cooling fan provided by this utility model. Figure 10 As shown in the diagram, the horizontal axis represents the fan speed, and the vertical axis represents the fan's operating voltage. When the fan's operating voltage V_work is within the range of 3.5V ≤ V_work ≤ 8.5V, it indicates the fan is operating normally. When the operating voltage is less than 3.5V or falls within the range of 8.5V < V_work ≤ 10V, it indicates the fan is operating abnormally. It's understood that when the operating voltage is less than 3.5V, it's typically 0V, indicating an open circuit or misconnection, and therefore is not shown in the diagram. When the operating voltage is 8.5V < V_work < 10V, it indicates the fan is stalled. When the operating voltage reaches its maximum value of 10V (supply voltage), it indicates a short circuit.

[0094] Combination Figure 10 Taking the reference voltage range of the cooling fan shown as an example, with the ratio of the feedback voltage signal to the working voltage signal being 1:5 (feedback voltage signal: working voltage signal), the following examples illustrate different fault types of cooling fans corresponding to different feedback voltage signals.

[0095] The ratio of the feedback voltage signal to the working voltage signal is 1:5. The voltage range of the cooling fan under normal working conditions is 3.5V≤V_work≤8.5V. Based on this, the reference voltage range of the feedback voltage value V_FB is 0.7V≤V_FB≤1.7V. The power supply voltage is 10V, and the corresponding maximum feedback voltage value V_FBmax is 2V.

[0096] If the feedback voltage is 0V, the fault type of the cooling fan is abnormal open circuit or missing connection; if the feedback voltage is 1.8V, the fault type of the cooling fan is stalled; if the feedback voltage is 2V, the fault type of the cooling fan is short circuit.

[0097] As can be seen, the voltage detection circuit provided by this invention enables continuous detection of the operating voltage of the cooling fan. By proportionally reducing the operating voltage signal to a feedback voltage signal, the risk of damage to the controller is effectively avoided. Furthermore, by transmitting the converted feedback voltage signal to the controller, the controller can determine whether the operating status of the cooling fan is abnormal based on the feedback voltage signal, thus indirectly achieving continuous detection of the cooling fan's operating status.

[0098] Based on the same concept, this utility model embodiment also provides a cooling device, which includes a cooling fan and the voltage detection circuit described in any of the preceding embodiments, for example, a... Figures 1-9 Any of the voltage detection circuits shown.

[0099] It should be understood that the refrigeration equipment may also include other components, such as: housing, refrigeration system (compressor, evaporator and condenser), heater, controller, memory, fan, temperature sensor, humidity sensor, etc., which will not be exemplified here in the embodiments of this application.

[0100] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. A voltage detection circuit for a cooling fan, characterized in that, include: A drive module and a voltage detection module; one end of the drive module is connected to the first end of the cooling fan, and the other end of the drive module is connected to the first pin of the controller; one end of the voltage detection module is connected to the first end of the cooling fan, and the other end of the voltage detection module is connected to the second pin of the controller; wherein: The drive module is used to receive control signals from the controller, the control signals being used to control the on / off state of the cooling fan, the on / off state including on or off; The voltage detection module is used to acquire the operating voltage signal of the cooling fan, convert the operating voltage signal into a feedback voltage signal, and transmit the feedback voltage signal to the second pin. The feedback voltage signal is a voltage signal that conforms to the measurement range of the second pin.

2. The voltage detection circuit according to claim 1, characterized in that, The voltage detection module includes at least two voltage divider resistors connected in series. One end of the first voltage divider resistor is connected to the first end of the cooling fan, one end of the second voltage divider resistor is connected to the ground terminal, and the voltage divider output terminals of the at least two voltage divider resistors are connected to the second pin. The at least two voltage divider resistors are used to convert the operating voltage signal into the feedback voltage signal that conforms to the measurement range of the second pin.

3. The voltage detection circuit according to claim 2, characterized in that, The drive module includes a first switching element and an equivalent resistor; wherein, one end of the equivalent resistor is connected to a first end of the cooling fan, the other end of the equivalent resistor is connected to the collector of the first switching element, the emitter of the first switching element is connected to the ground terminal, and the base of the first switching element is connected to the first pin; wherein... The first switching element is configured to receive a high-level signal from the controller via the first pin, the high-level signal being used to control the first switching element to be in a conducting state, thereby controlling the cooling fan to be in a turned-on state; or, The first switching element is configured to receive a low-level signal from the controller via the first pin. The low-level signal is used to control the first switching element to be in an open state, thereby controlling the cooling fan to be in a closed state.

4. The voltage detection circuit according to claim 3, characterized in that, The difference between the sum of the resistance values ​​of the at least two voltage divider resistors and the resistance value of the equivalent resistance is greater than or equal to a preset threshold; or, The voltage detection module further includes a second switching element, one end of which is connected to the first end of the cooling fan, and the other end of which is connected to one end of the first voltage divider resistor; wherein: The second switching element is used to control the conduction state of the voltage detection module.

5. The voltage detection circuit according to claim 3, characterized in that, The driving module further includes a current-limiting resistor, one end of which is connected to the second pin, and the other end of which is connected to the base of the first switching element; wherein: The current-limiting resistor is used to limit the current flowing out of the first pin to within the safe range of the first pin, and to ensure that the base current flowing into the first switching element meets the conduction condition of the first switching element.

6. The voltage detection circuit according to claim 4, characterized in that, The driving module further includes a pull-down resistor, one end of which is connected to the base of the first switching element, and the other end of which is connected to the emitter of the first switching element; wherein: The pull-down resistor is used to discharge the charge stored in the base-emitter junction of the first switching element.

7. The voltage detection circuit according to claim 2, characterized in that, The voltage detection module further includes a filtering module, one end of which is connected to the voltage divider output of the at least two voltage divider resistors, and the other end of which is connected to the second pin; wherein: The filtering module is used to filter out interference signals in the feedback voltage signal.

8. The voltage detection circuit according to claim 7, characterized in that, The filtering module includes a filter resistor and a filter capacitor. One end of the filter resistor is connected to the voltage divider output terminal, and the other end of the filter resistor is connected to the second pin. One end of the filter capacitor is connected to the second pin, and the other end of the filter capacitor is connected to the ground terminal.

9. The voltage detection circuit according to any one of claims 1-8, characterized in that, The voltage detection circuit further includes a diode, one end of which is connected to a first terminal of the cooling fan, and the other end of which is connected to a second terminal of the cooling fan; wherein... The diode is used to discharge the freewheeling current generated inside the cooling fan when the cooling fan is turned off.

10. A refrigeration device, characterized in that, It includes a cooling fan and a voltage detection circuit as described in any one of claims 1-9.

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