CN217055660U - Fan controller with fan fault detection function - Google Patents
Fan controller with fan fault detection function Download PDFInfo
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- CN217055660U CN217055660U CN202220163618.XU CN202220163618U CN217055660U CN 217055660 U CN217055660 U CN 217055660U CN 202220163618 U CN202220163618 U CN 202220163618U CN 217055660 U CN217055660 U CN 217055660U
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Abstract
The utility model discloses a take fan fault detection's fan controller, be in including casing and setting electric components in the casing, electric components includes temperature sensor, voltage converter, ramp signal generator, first hysteresis comparator, the hysteresis comparator of second, the hysteresis comparator of third, amplifier circuit, fan and fan power, wherein temperature sensor's output and voltage converter's input are connected, voltage converter's output and ramp signal generator's output are connected with the negative-going comparison end and the positive comparison end of first hysteresis comparator respectively, the output of first hysteresis comparator is connected with amplifier circuit's input, amplifier circuit's output is connected with fan power's input. The utility model discloses need not MCU and participate in, adopt low-priced NTC as temperature sensor, have fan fault detection, based on core component single-point temperature control, can turn-off energy-conserving linear speed regulation fan control circuit under the low temperature.
Description
Technical Field
The utility model relates to an air-cooled communication technology field, and more specifically relate to a take fan fault detection's fan controller.
Background
On a switch or an ONU MDU (passive optical network multi-user unit), when the heat consumption of the whole machine is high and the natural heat dissipation cannot meet the requirement, a fan is required to be adopted to force air cooling. The temperature of the device depends on the ambient temperature in which the system is located and the efficiency of heat dissipation during the heat dissipation from the chip itself and the air circulation caused by the fan rotation. The operating temperature of the device determines the lifetime of the device. Foreign related researches show that when the temperature of the device exceeds 45 ℃, the service life is reduced by half every time the temperature rises by 10 ℃. For system reliability, a heat dissipation process must be performed. The noise generated by the rotation of the fan and the vibration of the chassis caused by the rotation of the fan are the source of the noise of the equipment. At present, when forced air cooling is adopted on the equipment, the rotating speed of a fan is constant. This, while relatively simple to control, may be problematic when it is to be provided for overseas use. The national standard YD 1816 'telecommunication equipment noise limit value requirement and measurement method' does not have the difference between normal temperature and high temperature, and the European standard EN 300753 'Acoustic noise emitted by telecommunication equipments equations' has the regulations that the noise of a product to be tested is higher at normal temperature and high temperature, and the allowable Acoustic noise at high temperature is higher than that at normal temperature.
When the product is used overseas, because European Union and the like have different requirements on the limit value of audible acoustic noise of ears of people using communication equipment outdoors, the allowable noise limit values at normal temperature and high temperature are different, so that the requirement is forced to be adopted by people, a single rotating speed cannot meet the requirement, when the product rotates at a certain constant low speed, the heat dissipation at high temperature is possibly problematic, and when the product rotates at a certain constant high speed, the noise at normal temperature is possibly problematic. On the other hand, the heat dissipation of the product is not problematic at low temperature, the fan may not need to be started at all, the electric energy is wasted when the fan runs at low temperature, and the total service life of the fan is influenced when the fan continuously rotates for a long time. Moreover, the heat consumption of the existing communication equipment is dynamically changed, the load is different in the daytime and at night, the POE power supply is started or not, the conditions that a multi-channel switch is fully loaded or not are variable, the radio frequency power of the Smallcell small base station is dynamically changed according to the number of users, and the fan speed regulation is carried out by monitoring the temperature point in real time.
In the prior art, common fan speed regulation control is mostly detected based on a multipoint temperature sensor, an MCU participates in temperature control and speed regulation in the whole process, precious MCU resources are occupied, in a determined heat dissipation system, the temperatures of all points in the heat balance system have strong correlation with each other, a user only needs to pay attention to the temperature of a core sensitive component as a monitoring index, namely, single-point temperature monitoring is feasible, multipoint temperature detection can be used as a thorough measure in the initial stage of a product, and multipoint temperature detection is not needed in the later stage of mature product design. In addition, the specialized temperature sensors currently in widespread use are relatively expensive and it is necessary to explore alternatives. Some inexpensive fans have only two power pins to ground, and such fans do not have PWM and fault detection themselves, for which speed regulation and fault detection are also required.
SUMMERY OF THE UTILITY MODEL
To the not enough of the above-mentioned technique, the utility model discloses a take fan controller of fan fault detection need not MCU and participates in, adopts low-priced NTC as temperature sensor, has the low temperature based on single-point core component temperature control of fan fault detection and can turn-off and come energy-conserving linear speed regulation fan control circuit under.
The utility model adopts the following technical proposal:
a fan controller with fan fault detection comprises a shell and an electrical assembly arranged in the shell, wherein the electrical assembly comprises a temperature sensor, a voltage converter, a slope signal generator, a first hysteresis comparator, a second hysteresis comparator, a third hysteresis comparator, an amplifying circuit, a fan and a fan power supply, the output end of the temperature sensor is connected with the input end of the voltage converter, the output end of the voltage converter and the output end of the slope signal generator are respectively connected with the negative comparison end and the positive comparison end of the first hysteresis comparator, the output end of the first hysteresis comparator is connected with the input end of the amplifying circuit, the output end of the amplifying circuit is connected with the input end of the fan power supply, and the fan power supply drives the fan to rotate through a motor; the output end of the temperature sensor is also connected with the forward comparison end of the second hysteresis comparator, the output end of the second hysteresis comparator is connected with the triode circuit, and the cut-off end of the triode circuit is connected with the forward comparison end of the third hysteresis comparator.
The utility model discloses in, temperature sensor is NTC temperature sensor, and temperature sensor corresponds 0% ~ 100% duty cycle when 1.25V ~ 2.65V's output voltage.
The utility model discloses in, voltage converter's output voltage is for being not more than 1.4V.
The utility model discloses in, ramp signal generator is based on the window comparator and the ramp signal generating circuit that the integrating circuit formed is put to fortune.
The utility model discloses in, the ramp signal generator includes the integrated circuit of switched capacitor, and the integrated circuit of switched capacitor contains high-gain operational amplifier and parallel connection's of each other high-speed MOS switch and integral capacitance, and the parallelly connected one end of high-speed MOS switch and integral capacitance is connected with high-gain operational amplifier's forward comparator end, and the other end is connected with high-gain operational amplifier's output.
The present invention provides a ramp signal generator that includes a ramp generator circuit including a discrete device.
The present invention is directed to a method of operating a memory device, the method comprising the steps of providing a first hysteresis comparator, providing a second hysteresis comparator, and providing a third hysteresis comparator.
The utility model discloses in, the fault detection circuit is based on transistor's fault detection circuit.
Has the positive and beneficial effects that:
the utility model discloses a take fan fault detection's linear speed control of fan control by temperature change control circuit need not micro-controlled intervention, can accomplish fan control function effectively, does not too much occupy the MCU resource. At a core heat sensitive monitoring point in the system, when the collected temperature is lower, the fan is controlled to have an energy-saving turn-off mode; the cheap negative temperature coefficient thermistor is supported to be used as a temperature sensor; the rotating speed is in direct proportion to the temperature; the fan rotates at a proper rotating speed under the temperature control, the noise is lower than that of full-speed rotation, and the fan can be turned off at a lower temperature, so that the service life of the fan is prolonged; the fault detection circuit is arranged in the fan, so that the fault of the fan which is low in price and does not have self-detection can be detected, and the fault can be reported to the MCU in time.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive exercise, wherein:
fig. 1 is a schematic structural diagram of an electrical component of a fan controller with fan fault detection according to the present invention;
fig. 2 is a schematic diagram of a ramp generating circuit of a fan controller with fan fault detection according to the present invention;
fig. 3 is a schematic diagram of an oscillator circuit in a fan controller with fan fault detection according to the present invention;
fig. 4 is a schematic diagram of a ramp circuit according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of the hysteresis circuit formed by the external MOSFET and the resistor according to the present invention;
fig. 6 is a waveform diagram of a hysteresis comparison circuit of the present invention, in which an external MOSFET and a resistor constitute a hysteresis circuit.
Detailed Description
The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, and it should be understood that the embodiments described herein are merely for purposes of illustration and explanation, and are not intended to limit the invention.
As shown in fig. 1, a fan controller with fan fault detection includes a housing and an electrical component disposed in the housing, where the electrical component includes a temperature sensor, a voltage converter, a ramp signal generator, a first hysteresis comparator, a second hysteresis comparator, a third hysteresis comparator, an amplifying circuit, a fan, and a fan power supply, where an output end of the temperature sensor is connected to an input end of the voltage converter, an output end of the voltage converter and an output end of the ramp signal generator are respectively connected to a negative comparison end and a positive comparison end of the first hysteresis comparator, an output end of the first hysteresis comparator is connected to an input end of the amplifying circuit, an output end of the amplifying circuit is connected to an input end of the fan power supply, and the fan power supply drives the fan to rotate through a motor; the output end of the temperature sensor is also connected with the forward comparison end of the second hysteresis comparator, the output end of the second hysteresis comparator is connected with the triode circuit, and the cut-off end of the triode circuit is connected with the forward comparison end of the third hysteresis comparator.
The utility model discloses in, temperature sensor is NTC temperature sensor, and temperature sensor corresponds 0% ~ 100% duty cycle when 1.25V ~ 2.65V's output voltage.
In a specific embodiment, a temperature sensor consisting of an NTC acquires a current temperature corresponding to a measured voltage at a core temperature sensitive position of the system, subtracts 1.25V from the measured voltage, and compares the subtracted voltage with a ramp signal, thereby generating an inverse PWM signal, wherein the PWM of the signal lower than 0V is 100%. Since the PMOS on condition is the source voltage higher than the gate. We deliberately choose a hysteresis comparator whose output is open drain and pull up the drain to 12V to ensure the necessary turn off of the PMOS. When the measured voltage of the temperature sensor is below 1.25V, the fan is not powered. When the voltage is more than 1.25V, the starting is carried out and the speed is regulated according to the temperature control voltage.
In the above embodiments, the selection of R1 and R2 may depend on the NTC specific parameters. If the NTC is 4.6k Ω at the lowest temperature and 1.1k Ω at the highest temperature, then 75k Ω may be selected for R1 and 1k Ω may be selected for R2.
The utility model discloses in, voltage converter's output voltage is for being not more than 1.4V.
In a specific embodiment, the reverse PWM signal controls the voltage applied to the fan through PMOS to realize continuous temperature control and speed regulation.
The utility model discloses in, ramp signal generator is based on the window comparator and the ramp signal generating circuit that the integrating circuit formed is put to fortune.
In a specific embodiment, the PWM is not implemented on an off-the-shelf chip, but rather the ramp generator is implemented by a switched capacitor integrator or a separate circuit, with a 50Hz clock signal used to reset the integrator.
In a specific embodiment, the ramp generator circuit is used for generating a periodic triangular wave, the periodic triangular wave is controlled by an oscillator clock, and the finally generated periodic triangular wave is used as the modulated signal voltage of the PWM comparator.
The utility model discloses in, the ramp signal generator includes the integrated circuit of switched capacitor, and the integrated circuit of switched capacitor contains high-gain operational amplifier and parallel connection's of each other high-speed MOS switch and integral capacitance, and the parallelly connected one end of high-speed MOS switch and integral capacitance is connected with high-gain operational amplifier's forward comparator end, and the other end is connected with high-gain operational amplifier's output.
In a specific embodiment, the model of the ramp, i.e., the transfer function, is:
in formula (1), A is the gain of the operational amplifier, V ref And I ref Respectively, a reference voltage and a reference current, and C is an integrating capacitance. T is the period of the reset signal. The linearity of the ramp voltage depends mainly on the reference current, which is generated by a constant current mirror. The switch capacitance integrating circuit comprises a high-gain operational amplifier, a high-speed MOS switch, an integrating capacitor and the like. The reset signal controls the MOS switch to determine the operation range of the ramp voltage. The slope of the ramp voltage is determined by the reference current and the capacitance. This circuit is relatively complex. In view of implementation cost, we do not intend to use a switched capacitor integrator circuit to generate the ramp signal.
In the specific embodiment, in the design of the conventional triangle wave generating circuit, the triangle wave generating principle is obtained by using an integrating circuit, and in order to simplify the circuit design as much as possible, the basic idea that can also be adopted is to use a transistor T 1 、T 2 And T 3 Constructed Wilson current source in transistor T 3 The collector forms a stable current-to-capacitance C R Charging and discharging are carried out, wherein the charging is slow when the pulse is at a low level, and the discharging is rapid when the pulse is at a high level. When pulse is continuously input from the input end, voltage is led out from the output end of the capacitor, and slope voltage with a certain period is formed.
The present invention provides a ramp signal generator that includes a ramp generator circuit including a discrete device.
In the embodiment, as shown in fig. 3, the voltage V1 in the circuit is a reference voltage V for ensuring and stabilizing the power supply ref The voltage is 5.0V which is externally applied to ensure the normal operation of the circuit. The 10 terminal is the output terminal of the voltage signal of the ramp generator, the pulse signal generated by the oscillator is connected from the input terminal, the switch of the discharge tube is controlled by the pulse, and the 1 terminal is the external sampling control terminal for controlling the magnitude of the charging current.
The ramp generator circuit operates such that the discharge tube T is operated when a low level signal of an oscillator pulse is inputted from the input terminal 5 、T 6 Cut-off, after a stable voltage is applied to terminal 1, transistor T 7 And T 8 On, according to the mirror principle of the Wilson current source, transistor T 3 Is conducted and provided to the capacitor C R Charging, the voltage on the capacitor rises; when the high level signal of the oscillator pulse is input from the input terminal, the transistor T 5 、T 6 On, the capacitor C R And discharging, and gradually reducing the voltage on the capacitor. With the oscillator periodically pulsed in, a stable triangular wave output voltage is formed at terminal 10. Adjusting the applied voltage V and the resistance R 3 ，R 4 Can adjust the charging current I of the capacitor C . In the capacitor C R If the current provided by the current source for charging the capacitor is I C Initial value of capacitor voltage V CR When the voltage is equal to 0, a linear relationship between the capacitor voltage v (t) and time can be obtained:
in another embodiment, the clock signal is generated as follows:
an oscillator is generally used to generate a repetitive electrical signal (sine wave or square wave), and a circuit formed by the oscillator is called an oscillation circuit, and the oscillation circuit can convert a direct current into an alternating current signal with a certain frequency and output the alternating current signal. The oscillators are of various types, and can be divided into self-excited oscillators and separately excited oscillators according to an oscillation excitation mode; the circuit can be divided into a resistance-capacitance oscillator, an inductance-capacitance oscillator, a crystal oscillator, a phonological oscillator and the like according to the circuit structure; the oscillator can be divided into sine wave, square 4 wave, sawtooth wave and other oscillators according to the output waveform. Oscillators are widely used in the electronic industry, medical treatment, scientific research, and the like.
In the PWM power management chip circuit, an oscillator circuit is widely used. The oscillator circuit in the PWM chip generates a pulse by the charging and discharging process of the capacitor, and the pulse is used as the clock of the circuit to determine the period of the whole control circuit.
When designing an oscillator circuit, the period of the circuit is considered to be controlled by controlling the size of an external capacitor. The circuit design utilizes a comparator circuit, one end of the comparator circuit is kept constant, the other end of the comparator circuit is connected with a charging capacitor, when the charging voltage of the capacitor reaches a certain value, the comparator is turned over, the capacitor is discharged by the circuit at the moment, a pulse can be formed at the output end of the comparator circuit, if the capacitor is discharged, the voltage is reduced, the comparator is turned over again, and the capacitor is charged, so that a stable and periodic output pulse is formed. As shown in fig. 4, the circuit expresses parameters of each element in the circuit by using the following relational expression:
in this embodiment, R5 is 5.4k, when R6 is 10k ohms, Vtri is set to 1.35V, and V1 is 2.5V; when the oscillation frequency is set to 50Hz and C3 is selected to be 1000pF, R7 is 9.3 mhos.
The present invention is directed to a method for generating a first hysteresis comparator, a second hysteresis comparator and a third hysteresis comparator.
In the specific embodiment, most comparators are designed with a hysteresis circuit, and the hysteresis voltage is usually 5mV to 10 mV. The internal hysteresis circuit can avoid the output oscillation of the comparator caused by the parasitic feedback of the input end. However, the internal hysteresis circuit can prevent the comparator from self-oscillation, but is easily submerged by external noise with large amplitude. In this case, the external hysteresis needs to be added to improve the anti-interference performance of the system. In a specific embodiment two MOSFETs and a resistor network are used to adjust the threshold for positive and negative polarity as shown in fig. 5. Specifically, a hysteresis circuit is constituted by the external MOSFET and the resistor, as shown in fig. 6. After the input/output voltage waveform, if necessary, it can be passed through a resistor R 1 、R 2 Selecting P 1 The comparator sets the extended hysteresis voltage 50mV against a 1.25V threshold, i.e., V th1 ＝1.275V，V th2 1.225V. While the comparator P 0 And P 2 The 10mV hysteresis voltage difference inside the hysteresis comparator is adopted.
The utility model discloses in, fan fault detection circuit is the detection circuitry based on transistor. The working principle is as follows: when the temperature exceeds the set threshold temperature Tbr, the comparator P1 outputs a high level, VT is turned on, and the fan starts to operate. The collector current Ic of VT goes through the sensing resistor Rsen to ground, and the voltage Vsen ═ lc × Rsen at the upper end of Rsen. When the motor is normal, the Vsen voltage is greater than the reference voltage of P2, and P2 outputs a high level; when the motor winding is disconnected (or the VT is damaged), Vsen is 0, the reference voltage 300mV of P2 is greater than Vsen, P2 outputs low level, which indicates that the motor is faulty (or the VT is damaged), and the signal is sent to the MCU.
The utility model provides a pair of take fan fault detection's fan control by temperature change linear speed governing control circuit need not micro-controlled intervention, can accomplish fan control function effectively, does not too much occupy the MCU resource. At a core heat sensitive monitoring point in the system, when the collected temperature is lower, the fan is controlled to have an energy-saving turn-off mode; the cheap negative temperature coefficient thermistor is supported to be used as a temperature sensor; the rotating speed is in direct proportion to the temperature; the fan rotates at a proper rotating speed under the temperature control, the noise is lower than that of full-speed rotation, and the fan can be turned off at a lower temperature, so that the service life of the fan is prolonged; the fault detection circuit is arranged in the fan, so that the fault of the fan which is low in price and does not have self-detection can be detected, and the fault can be reported to the MCU in time.
Although specific embodiments of the present invention have been described above, it will be understood by those skilled in the art that these specific embodiments are merely illustrative and that various omissions, substitutions and changes in the form and details of the methods and systems described above may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, it is within the scope of the present invention to combine the steps of the above-described methods to perform substantially the same function in substantially the same way to achieve substantially the same result. Accordingly, the scope of the invention is to be limited only by the following claims.
Claims (7)
1. A take fan fault detection's fan controller, includes the casing and sets up electrical component in the casing, its characterized in that: the electric component comprises a temperature sensor, a voltage converter, a slope signal generator, a first hysteresis comparator, a second hysteresis comparator, a third hysteresis comparator, an amplifying circuit, a fan and a fan power supply, wherein the output end of the temperature sensor is connected with the input end of the voltage converter, the output ends of the voltage converter and the slope signal generator are respectively connected with the negative comparison end and the positive comparison end of the first hysteresis comparator, the output end of the first hysteresis comparator is connected with the input end of the amplifying circuit, the output end of the amplifying circuit is connected with the input end of the fan power supply, and the fan power supply drives the fan motor to rotate; the output end of the temperature sensor is further connected with the forward comparison end of the second hysteresis comparator, the output end of the second hysteresis comparator is connected with the triode circuit, and the cut-off end of the triode circuit is connected with the forward comparison end of the third hysteresis comparator.
2. The fan controller with fan fault detection of claim 1, wherein: the temperature sensor is an NTC temperature sensor, and corresponds to a duty ratio of 0-100% when the output voltage of the temperature sensor is 1.25-2.65V.
3. The fan controller with fan fault detection of claim 1, wherein: the output voltage of the voltage converter is not more than 1.4V.
4. The fan controller with fan fault detection as recited in claim 1, wherein: the ramp signal generator is a ramp signal generating circuit formed on the basis of a window comparator and an operational amplifier integrating circuit.
5. The fan controller with fan fault detection of claim 1, wherein: the ramp signal generator comprises a switched capacitor integrating circuit, the switched capacitor integrating circuit comprises a high-gain operational amplifier, and a high-speed MOS switch and an integrating capacitor which are connected in parallel, one end of the high-speed MOS switch, which is connected in parallel with the integrating capacitor, is connected with a forward comparator end of the high-gain operational amplifier, and the other end of the high-speed MOS switch, which is connected in parallel with the integrating capacitor, is connected with an output end of the high-gain operational amplifier.
6. The fan controller with fan fault detection of claim 1, wherein: the ramp signal generator may also constitute a ramp generator circuit by discrete devices.
7. The fan controller with fan fault detection as recited in claim 1, wherein: the first hysteresis comparator, the second hysteresis comparator and the third hysteresis comparator are all Schmitt triggers.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202220163618.XU CN217055660U (en) | 2022-01-21 | 2022-01-21 | Fan controller with fan fault detection function |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202220163618.XU CN217055660U (en) | 2022-01-21 | 2022-01-21 | Fan controller with fan fault detection function |
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| CN217055660U true CN217055660U (en) | 2022-07-26 |
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| CN202220163618.XU Active CN217055660U (en) | 2022-01-21 | 2022-01-21 | Fan controller with fan fault detection function |
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