Fan speed regulation control and fault detection circuit

Abstract

The utility model relates to the technical field of control circuits, in particular to a fan speed regulation control and fault detection circuit which comprises a fan speed regulation unit and a fault detection unit, the fan speed regulation unit mainly comprises a main control chip, a triode Q5 and a capacitor C49, an FAN-PWM end is arranged on the main control chip, and the fault detection unit comprises a comparator U19, a resistor R108 and an FAULT output end. On-off of a triode Q5 is controlled through square wave signals with different duty ratios sent by a main control chip, different direct-current stable voltages are output to a capacitor C49 for charging, then a fan motor can output quota power only under the quota voltage, if the power supply voltage of the fan motor is lower than the rated working voltage of the fan, the rotating speed can be reduced, and the fan can be powered on. Therefore, working modes of different gears and different rotating speeds are realized; when the fan works normally, the pin 7 of the comparator U19 outputs a high level signal, when the fan breaks down, the pin 7 of the comparator U19 outputs a low level signal, and at the moment, the main control chip closes a power supply starting-up enable signal, so that the effects of fault detection and product protection are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of control circuits, in particular to a fan speed regulation and fault detection circuit. Background Art

[0002] In today's fast-acting power supply industry, heat dissipation and noise are crucial issues. To minimize the size of electronic equipment and maintain high conversion efficiency, heat dissipation must be considered in the design. A common approach is to use a transistor switching circuit, connecting the transistor to the fan's control line and controlling the transistor's on / off state to achieve fan on / off control. However, these disadvantages are significant. First, the fan must have speed regulation, which increases the cost compared to a standard two-wire fan. Second, while maintaining cost control, standard two-wire fans cannot control scenarios requiring fan speed adjustment, such as those requiring noise control while also taking into account heat dissipation. Furthermore, these fans are unable to accommodate both environmental requirements and achieve precise control.

[0003] Therefore, designing a hardware to achieve ordinary fan adjustment and a product that can be compatible with noise control and fine heat dissipation is an inevitable demand in the current electronic equipment, switching power supply, portable energy storage and other industries. Utility Model Content

[0004] In order to overcome the defects of the prior art, the purpose of the present invention is to provide a fan speed control and fault detection circuit.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is implemented as follows: a fan speed control and fault detection circuit, including a fan speed control unit and a fault detection unit, the fan speed control unit including a main control chip, a transistor Q6, a transistor Q5, an inductor L10, a diode D25, a capacitor C49, a capacitor C86, a resistor R29 and a resistor R122, the main control chip is provided with a FAN-PWM terminal, the FAN-PWM terminal is connected to pin 1 of the transistor Q6 through the resistor R29, the pin 2 of the transistor Q6 is connected to the input terminal of the transistor Q5 through the resistor R122, the output terminal of the transistor Q5 is connected to the capacitor C49 and the capacitor C86 through the inductor L10, and the pin 3 of the transistor Q6 is grounded;

[0006] The fault detection unit includes a comparator U19, a resistor R108, a capacitor C140, a resistor R113, a diode D26 and a FAULT output end. The input end of the resistor R108 is connected to the capacitor C49, the output end of the resistor R108 is connected to pin 5 of the comparator U19, and pin 7 of the comparator U19 is connected to the capacitor C140, the resistor R113, the diode D26 and the FAULT output end.

[0007] Preferably, the transistor Q5 is a switching transistor, which is used to chop the input DC power supply to form a square wave.

[0008] Preferably, a resistor R30 and a capacitor C88 are further connected to the output end of the resistor R29 , and one end of the capacitor C88 is connected to pin 1 of the transistor Q6 , and the other end is connected to pin 3 of the transistor Q6 .

[0009] Preferably, the output end of the capacitor C49 is connected to one or two fans.

[0010] Preferably, when the FAN-PWM end sends a 100% duty cycle square wave signal, the fan power supply is 12Vdc, when the FAN-PWM end sends an 80% duty cycle square wave signal, the fan power supply is 9.6Vdc, and when the FAN-PWM end sends a 60% duty cycle square wave signal, the fan power supply is 7.2Vdc.

[0011] Preferably, when the fan is working normally, pin 7 of the comparator U19 outputs a high level signal, and when the fan fails, pin 7 of the comparator U19 outputs a low level signal.

[0012] Preferably, the model of the transistor Q5 is KS4318DB, the model of the transistor Q6 is SS8050, the model of the comparator U19 is LM2903, the model of the diode D26 is BAV99, and the model of the diode D25 is ES2DSMB.

[0013] The beneficial effects of the utility model are:

[0014] The utility model is a circuit for controlling fan speed regulation and fault detection, which mainly includes a fan speed regulation unit and a fault detection unit, wherein the fan speed regulation unit is used to control the fan speed regulation, and the fault detection unit is used to detect whether the fan has a fault, thereby realizing the function of fault detection and protecting the product. The on-off of the transistor Q5 is controlled by the square wave signal of different duty ratios sent by the main control chip, so as to output different DC stable voltages to charge the capacitor C49, and then the fan motor will output the rated power only under the rated voltage. If the power supply voltage is lower than the rated working voltage of the fan, the speed will be reduced and slowed down, thereby realizing the working mode of different gears and different speeds; when the fan is working normally, the 7th pin of the comparator U19 outputs a high-level signal, and when the fan fails, the 7th pin of the comparator U19 outputs a low-level signal. At this time, the main control chip turns off the power on enable signal, thereby achieving the effect of fault detection and protecting the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In the attached figure:

[0016] Figure 1This is a schematic diagram of a fan speed control and fault detection circuit of the utility model;

[0017] Figure 2 This is a circuit diagram of a fan speed control circuit according to the present invention;

[0018] Figure 3 This is a circuit diagram of the fan output fault detection circuit of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is apparent that the embodiments described are only a portion of the embodiments of the utility model, not all of them. The embodiments and features in the embodiments of this application may be combined with each other unless there is a conflict. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the utility model without creative effort are also within the scope of protection of the utility model.

[0020] It should be noted that if the embodiments of the utility model involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0021] In addition, "multiple" means more than two. Furthermore, the technical solutions of the various embodiments may be combined with each other, but this must be based on the premise that they can be implemented by a person of ordinary skill in the art. If the combination of technical solutions is mutually inconsistent or cannot be implemented, it shall be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the utility model.

[0022] Please refer to the instruction manual Figure 1-3The utility model provides a fan speed control and fault detection circuit, including a fan speed control unit and a fault detection unit. The fan speed control unit includes a main control chip, a transistor Q6, a transistor Q5, an inductor L10, a diode D25, a capacitor C49, a capacitor C86, a resistor R29 and a resistor R122. The main control chip is provided with a FAN-PWM terminal, which is connected to the 1st pin of the transistor Q6 through the resistor R29, and the 2nd pin of the transistor Q6 is connected to the input terminal of the transistor Q5 through the resistor R122. The output end of the transistor Q5 is connected to the capacitor C49 and the capacitor C86 through the inductor L10, and the 3rd pin of the transistor Q6 is grounded; the fault detection unit includes a comparator U19, a resistor R108, a capacitor C140, a resistor R113, a diode D26 and a FAULT output end, the input end of the resistor R108 is connected to the capacitor C49, the output end of the resistor R108 is connected to the 5th pin of the comparator U19, and the 7th pin of the comparator U19 is connected to the capacitor C140, the resistor R113, the diode D26 and the FAULT output end.

[0023] The utility model discloses a fan speed control and fault detection circuit, which has a wide range of applications and can be applied to DC-DC power supply modules, energy storage devices, and electronic devices. The circuit mainly comprises a fan speed control unit and a fault detection unit, wherein the fan speed control unit is used to control the fan speed, and the fault detection unit is used to detect whether a fan fault occurs, thereby realizing the fault detection function and protecting the product.

[0024] The fan speed control unit includes a main control chip, transistor Q6, transistor Q5, inductor L10, diode D25, capacitor C49, capacitor C86, resistor R29 and resistor R122. The main control chip (not shown in the figure) is provided with a FAN-PWM terminal, which is connected to pin 1 of transistor Q6 through resistor R29, pin 2 of transistor Q6 is connected to the input terminal of transistor Q5 through resistor R122, the output terminal of transistor Q5 is connected to capacitor C49 and capacitor C86 through inductor L10, and pin 3 of transistor Q6 is grounded. Figure 2 As shown, the working principle of the fan speed control unit is as follows: the circuit uses a square wave signal to control the transistor Q5, so that the transistor Q5 is turned on and off according to the duty cycle control signal issued by the main control chip, and the DC voltage output energy is controlled to charge the capacitor C49, that is, to power the fan connected to the output end; then low-pass filtering is performed, and the different duty cycle square wave signals issued by the main control chip are used to control the on and off of the transistor Q5 to achieve the output of different DC stable voltages to charge the capacitor C49, and then the fan motor will output the rated power (normal operation) only under the rated voltage. If the supply voltage is lower than the rated working voltage of the fan, the speed will be reduced and slowed down, thereby realizing different gears and different speed working modes.

[0025] The fault detection unit includes a comparator U19, a resistor R108, a capacitor C140, a resistor R113, a diode D26 and a FAULT output terminal. The input terminal of the resistor R108 is connected to the capacitor C49, the output terminal of the resistor R108 is connected to the 5th pin of the comparator U19, and the 7th pin of the comparator U19 is connected to the capacitor C140, the resistor R113, the diode D26 and the FAULT output terminal. Figure 3 As shown, the working principle of the fault detection unit is: when the fan stops or stalls, the fan output current is sampled through the sampling resistor R108, and then given to the 5th pin of the comparator U19, and then the 7th pin of the comparator U19 outputs the FAULT high-low level flip signal, which is reported to the main control chip to judge its fan working status. When the fan is working normally, the 7th pin of the comparator U19 outputs a high-level signal. When the fan fails, the 7th pin of the comparator U19 outputs a low-level signal. At this time, the main control chip turns off the power-on enable signal, thereby achieving the effect of fault detection and product protection.

[0026] In a preferred embodiment, referring to Figure 1 and Figure 2 Transistor Q5 in this fan speed control circuit is a switching transistor used to chop the input DC power supply into a square wave. Resistor R30 and capacitor C88 are also connected to the output end of resistor R29. One end of capacitor C88 is connected to pin 1 of transistor Q6, and the other end is connected to pin 3 of transistor Q6. The output end of capacitor C49 is connected to one or two fans.

[0027] The speed-regulating fan of the present application has three different gears, and the fan motor of each gear has a different speed. The gears are specifically:

[0028] First gear: When the FAN-PWM terminal sends a 100% duty cycle square wave signal, the fan power supply is 12Vdc. Second gear: When the FAN-PWM terminal sends an 80% duty cycle square wave signal, the fan power supply is 9.6Vdc.

[0029] Level 3: When the FAN-PWM terminal sends a 60% duty cycle square wave signal, the fan power supply is 7.2Vdc.

[0030] In a preferred embodiment, referring to Figure 1 and Figure 3 In this fan output fault detection circuit, pin 7 of comparator U19 outputs a high-level signal when the fan is operating normally, and a low-level signal when the fan fails. When a fan fails, the main control chip shuts off the fan power signal, automatically shutting down the fan and thus protecting it.

[0031] The model of the transistor Q5 of the fan speed control and fault detection circuit is KS4318DB, the model of the transistor Q6 is SS8050, the model of the comparator U19 is LM2903, the model of the diode D26 is BAV99, and the model of the diode D25 is ES2D SMB.

[0032] The fan speed control and fault detection circuit of the present invention also has the characteristics of using a small number of components in the circuit and low cost. When in use, it can be connected to an ordinary two-wire fan, and the fan noise and heat dissipation can be controlled. To achieve the effect of this application, a traditional ordinary fan needs to add a Buck control chip to reduce the voltage and output different voltages, but adding a Buck control chip will increase the cost; in addition, a three-wire fan with speed regulation can be used to achieve the feature of adjusting the fan speed and reduce the output of noise, but the cost will also increase; however, this application can be used in scenarios where ordinary two-wire fans need to adjust the fan speed, and can also be applied to products that need to perform noise processing and heat treatment. While reducing the control cost, it can also be compatible with the development needs of two environments at the same time.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fan speed control and fault detection circuit, characterized in that: It includes a fan speed regulation unit and a fault detection unit. The fan speed regulation unit includes a main control chip, a transistor Q6, a transistor Q5, an inductor L10, a diode D25, a capacitor C49, a capacitor C86, a resistor R29 and a resistor R122. The main control chip is provided with a FAN-PWM terminal, the FAN-PWM terminal is connected to pin 1 of the transistor Q6 through the resistor R29, the pin 2 of the transistor Q6 is connected to the input terminal of the transistor Q5 through the resistor R122, the output terminal of the transistor Q5 is connected to the capacitor C49 and the capacitor C86 through the inductor L10, and the pin 3 of the transistor Q6 is grounded; The fault detection unit includes a comparator U19, a resistor R108, a capacitor C140, a resistor R113, a diode D26 and a FAULT output end. The input end of the resistor R108 is connected to the capacitor C49, the output end of the resistor R108 is connected to pin 5 of the comparator U19, and pin 7 of the comparator U19 is connected to the capacitor C140, the resistor R113, the diode D26 and the FAULT output end.

2. A fan speed control and fault detection circuit according to claim 1, characterized in that: The transistor Q5 is a switching transistor, which is used to chop the input DC power supply to form a square wave.

3. A fan speed control and fault detection circuit according to claim 1, characterized in that: The output end of the resistor R29 is further connected to a resistor R30 and a capacitor C88 . One end of the capacitor C88 is connected to pin 1 of the transistor Q6 , and the other end is connected to pin 3 of the transistor Q6 .

4. A fan speed control and fault detection circuit according to claim 1, characterized in that: The output end of the capacitor C49 is connected to one or two fans.

5. The fan speed control and fault detection circuit according to claim 1, characterized in that: When the FAN-PWM terminal sends a 100% duty cycle square wave signal, the fan power supply is 12Vdc, when the FAN-PWM terminal sends an 80% duty cycle square wave signal, the fan power supply is 9.6Vdc, and when the FAN-PWM terminal sends a 60% duty cycle square wave signal, the fan power supply is 7.2Vdc.

6. A fan speed control and fault detection circuit according to claim 1, characterized in that: When the fan operates normally, the pin 7 of the comparator U19 outputs a high level signal. When the fan fails, the pin 7 of the comparator U19 outputs a low level signal.

7. A fan speed control and fault detection circuit according to claim 1, characterized in that: The model of the transistor Q5 is KS4318DB, the model of the transistor Q6 is SS8050, the model of the comparator U19 is LM2903, the model of the diode D26 is BAV99, and the model of the diode D25 is ES2D SMB.

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