A switch fan plate with protection measures and protection method

Abstract

The present invention provides a switch fan board with protection measures and a protection method, comprising: a fan board and a plurality of fans; a programmable logic device, a fan board signal connector, an I2C bus extender, a power connector and a protection circuit whose number matches that of the fans are arranged on the fan board; the power connector is connected to the power supply end of each fan, the programmable logic device is connected to the fan through the protection circuit to control the operation of the fan; the protection circuit is provided with a comparison circuit and a voltage stabilizing circuit; each fan is respectively connected to the I2C bus extender, and the fan board signal connector is respectively connected to the I2C bus extender and the programmable logic device. The present invention realizes the effective avoidance of the switch fan board signal overshoot, avoids the fault caused by the signal overshoot, can handle the fault even when the fault occurs, reduces the output overshoot problem of the fan, can improve the reliability of the switch as a whole, and is also beneficial to the service life of the switch.

Description

Technical Field

[0001] The present invention relates to the technical field of switches, and in particular to a switch fan plate with protection measures and a protection method. Background Art

[0002] In the switch system, the fan module and the connected fan board are important components of the entire switch. The reasonable combination of the two is also the actual executor of the entire switch heat dissipation strategy. When the switch fan board is equipped with different fan modules or the fan speed changes at a high frequency, it may cause a large overshoot of the reference voltage output by the fan, which is likely to cause impact or even damage to subsequent chips and circuits, especially the relatively fragile programmable logic devices on the fan board.

[0003] In existing switch systems, the space occupied by the fan board is very limited, so the design requirements for the fan board PCB are also limited. How to reasonably distribute limited components on a board with a limited area is a current problem.

[0004] For fan boards with relatively simple functions, it is unnecessary to use too many large devices or too many integrated chips to reduce the difficulty of layout, which will increase costs. Therefore, how to add risk avoidance measures in a limited layout space is a difficult problem facing hardware engineers. In this case, the priority of overshoot risk is not as high as that of short circuit, static electricity, temperature and other risks, but this does not mean that adding protection overshoot circuits is not necessary or impossible. In addition, the use of fan boards is to undertake the fan modules connected to them. There are many manufacturers of fan modules. When a switch only needs to be equipped with a fan from the same manufacturer, the overshoot problem is likely to be ignored. However, when the switch needs to be equipped with multiple fans, the overshoot problem will occur, and the fan operation will be unstable, affecting the stable and reliable operation of the switch. Summary of the invention

[0005] In order to overcome the above-mentioned deficiencies in the prior art, the present invention provides a switch fan board with protective measures, which can reduce the output overshoot problem of the fan, improve the reliability of the entire switch, and is beneficial to the service life of the switch.

[0006] A switch fan board with protective measures comprises: a fan board and a plurality of fans; the fan board is provided with a programmable logic device, a fan board signal connector, an I2C bus expander, a power connector and protection circuits whose number matches the fans;

[0007] The power connector is connected to the power supply end of each fan, and the programmable logic device is connected to the fan through the protection circuit to control the operation of the fan; the protection circuit is provided with a comparison circuit and a voltage stabilizing circuit;

[0008] Each fan is respectively connected to the I2C bus expander, and the fan board signal connector is respectively connected to the I2C bus expander and the programmable logic device.

[0009] It should be further explained that the comparison circuit includes: a voltage regulator U1, a resistor R1 and a resistor R2;

[0010] The first end of the resistor R1 is connected to the input end of the comparison circuit, and the second end of the resistor R1 is connected to the positive input end of the voltage regulator U1 and the first end of the resistor R2 respectively;

[0011] The negative input terminal of the voltage regulator U1 receives the reference voltage Vref;

[0012] The output end of the voltage regulator U1 is connected to the second end of the resistor R2 and the output end of the comparison circuit respectively.

[0013] It should be further explained that the voltage stabilizing circuit includes: a current limiting resistor R3 and a voltage stabilizing diode D1;

[0014] The first end of the current limiting resistor R3 is connected to the positive electrode of the power supply, and the second end of the current limiting resistor R3 is connected to the cathode of the voltage regulator tube D1 and the positive power supply end of the programmable logic device respectively;

[0015] The anode of the voltage regulator tube D1 and the negative power supply terminal of the programmable logic device are grounded respectively.

[0016] It should be further explained that the I2C bus expander is connected to a temperature sensor and a storage for sensing temperature information of the fan board;

[0017] The temperature sensor and the storage are connected to the programmable logic device through an I2C bus expander respectively.

[0018] It should be further explained that the programmable logic device is connected to a JTAG module.

[0019] The power connector is connected to the power supply end of the fan through the eFuse module.

[0020] It should be further explained that a status indicator light is also provided on the fan board, and the programmable logic controller is connected to each fan via the status indicator light, and is used to display the status information of each fan via the status indicator light.

[0021] The present invention also provides a method for protecting a fan board of a switch, the method comprising:

[0022] The switch fan board is powered on;

[0023] The comparison circuit of the protection circuit generates a comparison voltage V0 which is greater than the normal working voltage V1 of the voltage regulator;

[0024] When the comparison voltage V0 is less than the current reference voltage Vref of the voltage stabilizing circuit, the programmable logic device controls the voltage stabilizing circuit to be in a voltage stabilizing state;

[0025] The programmable logic device also detects the magnitude relationship between the comparison voltage V0 and the current reference voltage Vref through the protection circuit, and controls the enable output of the fan board.

[0026] It should be further explained that the negative input terminal of the voltage regulator U1 receives the reference voltage Vref;

[0027] The positive input terminal of the voltage regulator U1 receives the input voltage Vin;

[0028] When the input voltage Vin is higher than the reference voltage Vref, the output circuit Vout of the voltage regulator U1 is at a high level, and the fan works normally;

[0029] When the input voltage Vin is lower than the reference voltage Vref, the output circuit Vout of the voltage regulator U1 is at a low level, and the fan stops working.

[0030] It should be further explained that the input voltage in the voltage stabilizing circuit of the protection circuit is Vi, the output voltage is Vo, and the voltage across the voltage stabilizing tube D1 is Vz;

[0031] When the input voltage Vi increases, the output voltage Vo rises, which increases the reverse voltage of the voltage regulator D1, increases the current flowing through the voltage regulator D1, and increases the current flowing through the current limiting resistor R3. The voltage drop on the current limiting resistor R3 will increase, so that the voltage drop of the Vi increment is consumed on the current limiting resistor R3, so that the output voltage Vo remains unchanged;

[0032] On the contrary, when the input voltage Vi decreases, the output voltage Vo will decrease, causing the reverse voltage of the Zener diode D1 to decrease, and the reverse current flowing through the Zener diode D1 will also decrease. The current of the current limiting resistor R3 will decrease, and the voltage drop across the current limiting resistor R3 will become smaller. After the voltage of Vo rises and stabilizes, the output voltage Vo remains unchanged.

[0033] It can be seen from the above technical solutions that the present invention has the following advantages:

[0034] The switch fan board with protection measures and the protection method provided by the present invention include: a fan board and multiple fans; the fan board is provided with a programmable logic device, a fan board signal connector, an I2C bus expander, a power connector and protection circuits whose number matches that of the fans; the present invention realizes the effective avoidance of the switch fan board signal overshoot, avoids the fault caused by the signal overshoot, and can handle the fault even when the fault occurs, reduces the output overshoot problem of the fan, can improve the reliability of the switch as a whole, and is also beneficial to the service life of the switch.

[0035] In the present invention, since the front end of the comparison circuit is a fan, as long as the fan works normally, the comparison voltage of the system will not be lower than our reference voltage. The purpose of adding the comparison circuit is to overcome overshoot, and the prominence of overshoot must be higher than the reference voltage, so the existence of the comparison circuit can ensure that once overshoot occurs, the output Vout can always be guaranteed to be a high-level stable voltage.

[0036] After the voltage stabilization circuit of the present invention performs voltage stabilization, the voltage output to the programmable logic device will be clamped in a stable state to ensure no overshoot fluctuation. Since the comparison circuit plus the voltage stabilization circuit does not occupy the layout space of the fan board, it will not generate excessive device costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solution of the present invention, the accompanying drawings required for use in the description will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0038] Figure 1 The schematic diagram of the switch fan board with protective measures is shown;

[0039] Figure 2 For comparison circuit diagram;

[0040] Figure 3 This is the voltage stabilizing circuit diagram;

[0041] Figure 4 The figure is a flow chart of the protection method of the switch fan board. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] The present invention provides a switch fan plate with protection measures, such as Figure 1As shown, it includes: a fan board and multiple fans; the fan board is provided with a programmable logic device, a fan board signal connector, an I2C bus expander, a power connector and protection circuits whose number matches the fans; the power connector is connected to the power supply end of each fan, the programmable logic device is connected to the fan through the protection circuit to control the operation of the fan; the protection circuit is provided with a comparison circuit and a voltage stabilizing circuit; each fan is respectively connected to the I2C bus expander, and the fan board signal connector is respectively connected to the I2C bus expander and the programmable logic device.

[0044] It can be understood that the fan board involved in the present invention is used on a switch, which can be used to connect a fan. Since multiple fans are connected inside the switch and there are many fan manufacturers, if a switch is equipped with multiple fans from different manufacturers, overshoot problems will occur, resulting in unstable fan operation and affecting the stable and reliable operation of the switch.

[0045] In the above-mentioned system of the present invention, the overshoot prevention function is achieved by setting a protection circuit, that is, a comparison circuit and a voltage stabilizing circuit.

[0046] The comparison circuit is used to generate a comparison voltage V0 greater than the normal working voltage V1 of the voltage stabilizer; the comparison voltage is V0; when the reference voltage V0 is less than the current reference voltage Vref of the voltage stabilizer circuit, the programmable logic device controls the voltage stabilizer circuit to be in a stable state. When the switch fan board is powered on, the programmable logic device controls the enabling of the fan board by controlling the protection circuit to detect the magnitude relationship between the comparison voltage V0 and the current reference voltage Vref, thereby realizing the anti-overshoot protection of the fan board, so that the fan board will not output an excessively high voltage, thereby avoiding damage to the subsequent circuit.

[0047] The programmable logic device involved in the present invention can be implemented by using at least one of an application specific integrated circuit (ASIC), a digital signal processor (DSP), a digital signal processing device (DSPD), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microcontroller, a microprocessor, and an electronic unit designed to perform the functions described herein. In some cases, such an implementation can be implemented in a controller.

[0048] In the above-mentioned system of the present invention, if Figure 2As shown, the comparison circuit includes: a voltage regulator U1, a resistor R1 and a resistor R2; the first end of the resistor R1 is connected to the input end of the comparison circuit, and the second end of the resistor R1 is respectively connected to the positive input end of the voltage regulator U1 and the first end of the resistor R2; the negative input end of the voltage regulator U1 receives the reference voltage Vref; the output end of the voltage regulator U1 is respectively connected to the second end of the resistor R2 and the output end of the comparison circuit.

[0049] That is to say, the protection circuit implemented according to the improvement of the present invention is divided into two parts: a comparison circuit and a voltage stabilization circuit. Figure 2 The figure shows a comparison circuit. The advantage of this comparison circuit is that it has good anti-interference ability and can guarantee a stable output level for general signal jitter. The input voltage is Vin as shown in the figure. The most critical part of the comparison circuit is Vref, which is the so-called reference voltage. If the reference voltage is input at the negative end and the input voltage Vin is input at the positive end, the comparison voltage is higher than the reference voltage, and the op amp output Vout is the high level we need. On the contrary, if the comparison voltage is lower than the reference voltage, the op amp output Vout is a low level. In this case, the entire circuit will be stagnant. However, since the front end of the comparison circuit is a fan, as long as the fan works normally, the system's comparison voltage will not be lower than our reference voltage. The addition of the comparison circuit is to overcome overshoot. The prominence of the overshoot must be higher than the reference voltage, so the existence of the comparison circuit can ensure that once overshoot occurs, the output Vout can always be a high-level stable voltage. The threshold of Vref can be specifically defined according to the use of resistors or diodes.

[0050] For the voltage stabilizing circuit involved in the present invention, Figure 3 As shown, it includes: a current limiting resistor R3 and a voltage regulator D1; the first end of the current limiting resistor R3 is connected to the positive electrode of the power supply, and the second end of the current limiting resistor R3 is respectively connected to the cathode of the voltage regulator D1 and the positive power supply end of the programmable logic device; the anode of the voltage regulator D1 and the negative power supply end of the programmable logic device are respectively grounded.

[0051] In the switch fan board system, the voltage stabilization circuit can automatically adjust the DC output voltage to stabilize when voltage fluctuations or load changes occur. The load here is the programmable logic device at the back end of the protection circuit in the fan board, or it can be other components. In the voltage stabilization circuit, Vi is the input voltage; Vo is the output voltage, that is, the voltage Vz across the voltage regulator tube (the circuit is in parallel). When the load resistance remains unchanged and the input voltage Vi increases, the output voltage Vo will rise, causing the reverse voltage of the voltage regulator tube D1 to increase slightly, and the current flowing through the voltage regulator tube D1 will increase, so the current flowing through the current limiting resistor R3 will increase, and the voltage drop on the current limiting resistor R3 will increase, so that most of the voltage drop of the Vi increment is consumed on the current limiting resistor R3, so that the output voltage Vo remains basically unchanged. On the contrary, when the load resistance remains unchanged and the input voltage Vi decreases, the output voltage Vo will decrease, causing the reverse voltage of the voltage regulator D1 to decrease, and the reverse current flowing through the voltage regulator D1 will also decrease slightly. Therefore, the current flowing through the current limiting resistor R3 will decrease, and the voltage drop on the current limiting resistor R3 will become smaller, so that the voltage of Vo will rise again. After stabilization, the voltage Vo remains basically unchanged. After such a voltage stabilization action, the voltage output to the programmable logic device will be clamped in a stable state to ensure no overshoot fluctuations. Since this combination of comparison circuit plus voltage stabilization circuit is very simple, it will not occupy the layout space of the fan board, nor will it generate excessive device costs. Therefore, especially when placed in the fan board, the specific switch fan board system topology can be designed and used according to the actual application situation.

[0052] Furthermore, the I2C bus expander is connected with a temperature sensor and a storage device for sensing the temperature information of the fan board; the temperature sensor and the storage device are respectively connected to the programmable logic device through the I2C bus expander. The user can understand the operating status of the fan board and the operating status of the switch, and the storage device plays a role in storing data.

[0053] In order to be able to program the programmable logic device, the programmable logic device is connected to a JTAG module. During the operation of the fan, in order to allow the user to understand the operating status of the fan, a status indicator light is also provided on the fan board. The programmable logic device is connected to each fan through the status indicator light to display the status information of each fan through the status indicator light. The status indicator light can include a green light for the operating status and a red light for stopping the operation. A fault light can also be set.

[0054] The fan board can also be equipped with an eFuse module based on the link where the power connector supplies power to the fan. The use of Efuse can reduce the power consumption of the chip and increase the controllability of the chip, which can improve the safety of the fan board. The use of Efuse technology can also reduce the manufacturing cost. The power connector is connected to the power supply end of the fan through the eFuse module.

[0055] In this way, the switch fan board with protection measures provided by the present invention can effectively avoid the switch fan board system signal overshoot, avoid the fault caused by signal overshoot to a certain extent, and can effectively analyze the fault even when it occurs.

[0056] Based on the above switch fan board with protection measures, the present invention also provides a protection method for the switch fan board, such as Figure 4 As shown, the method includes:

[0057] S101, switch fan board powered on;

[0058] S102, the comparison circuit of the protection circuit generates a comparison voltage V0 which is greater than the normal working voltage V1 of the voltage stabilizer;

[0059] S103, when the comparison voltage V0 is less than the current reference voltage Vref of the voltage stabilizing circuit, the programmable logic device controls the voltage stabilizing circuit to be in a voltage stabilizing state;

[0060] S104, the programmable logic device also detects the magnitude relationship between the comparison voltage V0 and the current reference voltage Vref through the protection circuit, and controls the enable output of the fan board. The protection method effectively avoids the overshoot of the switch fan board system signal, avoids the fault caused by the signal overshoot to a certain extent, and can effectively analyze the fault even when the fault occurs.

[0061] Furthermore, the protection circuit in the method is provided with a comparison circuit and a voltage regulator circuit; for the comparison circuit, the negative input terminal of the voltage regulator U1 receives a reference voltage Vref;

[0062] The positive input terminal of the voltage regulator U1 receives the input voltage Vin;

[0063] When the input voltage Vin is higher than the reference voltage Vref, the output circuit Vout of the voltage regulator U1 is at a high level, and the fan works normally;

[0064] When the input voltage Vin is lower than the reference voltage Vref, the output circuit Vout of the voltage regulator U1 is low level, and the fan stops working. The purpose of adding a comparison circuit is to overcome overshoot. The prominence of overshoot must be higher than the reference voltage, so the existence of the comparison circuit can ensure that once overshoot occurs, the output Vout can always be a high-level stable voltage.

[0065] For the voltage stabilizing circuit of the present invention, the input voltage in the voltage stabilizing circuit of the protection circuit is Vi, the output voltage is Vo, and the voltage across the voltage stabilizing tube D1 is Vz;

[0066] When the input voltage Vi increases, the output voltage Vo rises, which increases the reverse voltage of the voltage regulator D1, increases the current flowing through the voltage regulator D1, and increases the current flowing through the current limiting resistor R3. The voltage drop on the current limiting resistor R3 will increase, so that the voltage drop of the Vi increment is consumed on the current limiting resistor R3, so that the output voltage Vo remains unchanged;

[0067] On the contrary, when the input voltage Vi decreases, the output voltage Vo will decrease, causing the reverse voltage of the Zener diode D1 to decrease, and the reverse current flowing through the Zener diode D1 will also decrease. The current of the current limiting resistor R3 will decrease, and the voltage drop across the current limiting resistor R3 will become smaller. After the voltage of Vo rises and stabilizes, the output voltage Vo remains unchanged.

[0068] In this way, the voltage of Vo will rise again. After stabilization, the voltage Vo will remain basically unchanged. After such voltage stabilization, the voltage output to the programmable logic device will be clamped in a stable state to ensure no overshoot fluctuations.

[0069] The units and algorithm steps of each example described in the embodiments disclosed in the switch fan board with protection measures and the protection method provided by the present invention can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0070] The block diagrams shown in the attached drawings of the switch fan board with protection measures provided by the present invention are only functional entities, and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software form, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or micro-programmable logic devices.

[0071] The switch fan board with protection measures and the protection method provided by the present invention are units and algorithm steps of each example described in combination with the embodiments disclosed in this article, and can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are executed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0072] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A switch fan board with protective measures, characterized in that: include: A fan board and a plurality of fans; the fan board is provided with a programmable logic unit, a fan board signal connector, an I2C bus expander, a power connector, and protection circuits matching the number of fans; The power connector is connected to the power supply end of each fan, and the programmable logic device is connected to the fan through the protection circuit to control the operation of the fan; the protection circuit is provided with a comparison circuit and a voltage stabilizing circuit; Each fan is connected to the I2C bus expander respectively, and the fan board signal connector is connected to the I2C bus expander and the programmable logic device respectively; The protection measures for the switch fan board include: The switch fan board is powered on; The comparison circuit of the protection circuit generates a comparison voltage V0 which is greater than the normal working voltage V1 of the voltage regulator; When the comparison voltage V0 is less than the current reference voltage Vref of the voltage stabilizing circuit, the programmable logic device controls the voltage stabilizing circuit to be in a voltage stabilizing state; The programmable logic device also detects the magnitude relationship between the comparison voltage V0 and the current reference voltage Vref through the protection circuit, and controls the enable output of the fan board.

2. The switch fan plate with protective measures according to claim 1, characterized in that: The comparison circuit includes: a voltage regulator U1, a resistor R1 and a resistor R2; The first end of the resistor R1 is connected to the input end of the comparison circuit, and the second end of the resistor R1 is connected to the positive input end of the voltage regulator U1 and the first end of the resistor R2 respectively; The negative input terminal of the voltage regulator U1 receives the reference voltage Vref; The output end of the voltage regulator U1 is connected to the second end of the resistor R2 and the output end of the comparison circuit respectively.

3. The switch fan board with protection measures according to claim 1, characterized in that: The voltage stabilizing circuit includes: a current limiting resistor R3 and a voltage stabilizing tube D1; The first end of the current limiting resistor R3 is connected to the positive electrode of the power supply, and the second end of the current limiting resistor R3 is connected to the cathode of the voltage regulator tube D1 and the positive power supply end of the programmable logic device respectively; The anode of the voltage regulator tube D1 and the negative power supply terminal of the programmable logic device are grounded respectively.

4. The switch fan plate with protective measures according to claim 1, characterized in that: The I2C bus expander is connected with a temperature sensor and a storage for sensing temperature information of the fan board; The temperature sensor and the storage are connected to the programmable logic device through an I2C bus expander respectively.

5. The switch fan board with protection measures according to claim 1, characterized in that: The programmable logic device is connected with a JTAG module.

6. The switch fan plate with protective measures according to claim 1, characterized in that: The power connector is connected to the power supply end of the fan through the eFuse module.

7. The switch fan plate with protective measures according to claim 1, characterized in that: A status indicator light is also provided on the fan board. The programmable logic controller is connected to each fan through the status indicator light and is used to display the status information of each fan through the status indicator light.

8. The switch fan plate with protection measures according to claim 1, characterized in that: The protection measures for the switch fan board also include: The negative input terminal of the voltage regulator U1 receives the reference voltage Vref; The positive input terminal of the voltage regulator U1 receives the input voltage Vin; When the input voltage Vin is higher than the reference voltage Vref, the output circuit Vout of the voltage regulator U1 is at a high level, and the fan works normally; When the input voltage Vin is lower than the reference voltage Vref, the output circuit Vout of the voltage regulator U1 is at a low level, and the fan stops working.

9. The switch fan plate with protective measures according to claim 1, characterized in that: The protection measures for the switch fan board also include: The input voltage in the voltage stabilizing circuit of the protection circuit is Vi, the output voltage is Vo, and the voltage across the voltage stabilizing tube D1 is Vz; When the input voltage Vi increases, the output voltage Vo rises, which increases the reverse voltage of the voltage regulator D1, increases the current flowing through the voltage regulator D1, and increases the current flowing through the current limiting resistor R3. The voltage drop on the current limiting resistor R3 will increase, so that the voltage drop of the Vi increment is consumed on the current limiting resistor R3, so that the output voltage Vo remains unchanged; On the contrary, when the input voltage Vi decreases, the output voltage Vo will decrease, causing the reverse voltage of the Zener diode D1 to decrease, and the reverse current flowing through the Zener diode D1 will also decrease. The current of the current limiting resistor R3 will decrease, and the voltage drop across the current limiting resistor R3 will become smaller. After the voltage of Vo rises and stabilizes, the output voltage Vo remains unchanged.

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