Power supply maintaining module of airborne microprocessor and airborne equipment

Abstract

The invention provides a power supply maintenance module of an airborne microprocessor and airborne equipment, the module comprises a boost circuit, a step-down circuit and a reverse cut-off circuit, a capacitor array is connected between the reverse cut-off circuit and the step-down circuit, the boost circuit comprises a boost module, a first pulse width regulator and a first switch element, the first pulse width regulator adjusts the frequency and the duty ratio of the pulse to realize the turn-on and turn-off time of the first switch element so as to realize the adjustment of the output voltage of the booster circuit; the step-down circuit comprises a step-down module, a second pulse width regulator and a second switch element, and the second pulse width regulator realizes the on and off time of the second switch element by adjusting the frequency and duty ratio of the pulse so as to realize the adjustment of the output voltage of the step-down circuit. The boost circuit is used for charging the capacitor array, the voltage difference between charging and discharging of the capacitor array is increased, more charges can be released after the input power supply is turned off, and the purpose of prolonging the endurance time is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of airborne power supply, and in particular to a power supply maintenance module of an airborne microprocessor and airborne equipment. Background Art

[0002] As the manufacturing industry becomes more and more demanding in terms of modernization and automation, industrial equipment is also developing rapidly.

[0003] During flight, onboard equipment must remain connected within 50ms of a power outage, preventing any system restarts. This can compromise flight safety. To meet this technical requirement, the traditional approach involves using multiple large capacitors in parallel to form a power supply maintenance module for charge storage, providing a brief current flow to the microprocessor during a power outage. This approach requires a large number of capacitors and occupies a large PCB area, making the entire device bulky and heavy, making it difficult to meet the requirements for small and lightweight airborne equipment.

[0004] The core operating voltage of a microprocessor (MCU) is typically 3.3V, which is supplied by a 5V DC / DC power supply. If the DC / DC power supply input voltage falls below 4V, the output voltage will fall below 3.3V, causing the MCU to become unstable and even reboot.

[0005] Therefore, if the MCU needs to operate stably and prevent restarts within 50ms of a power outage, an appropriate capacitor must be added to the 5V side of the power input to ensure that the voltage drop does not fall below 4V during this time. The typical MCU has a maximum operating current of 300mA and an operating voltage of 3.3V. However, to ensure stable operation within 50ms of a power outage, a capacitor with a capacitance of 15mF is required. Since the maximum value of a 16V tantalum capacitor is generally only 1500μF, a minimum of 10 capacitors is required. The area of a single 1500μF capacitor is approximately 11.0mm x 12.5mm. Traditionally, to ensure stable MCU operation within 50ms of a power outage, the required capacitor area is approximately 110mm x 125mm, which is quite large and may not meet the compact and lightweight requirements of airborne equipment. Summary of the Invention

[0006] Based on this, an object of the present invention is to provide a power supply maintenance module for an airborne microprocessor and an airborne device, so as to at least solve the deficiencies in the above-mentioned technology.

[0007] The present invention provides a power supply maintenance module for an airborne microprocessor, comprising a boost circuit, a buck circuit, and a reverse cutoff circuit respectively connected to the boost circuit and the buck circuit, a capacitor array being connected between the reverse cutoff circuit and the buck circuit, and the buck circuit being electrically connected to the airborne microprocessor; The boost circuit includes a boost module, a first pulse width regulator connected to the boost module, and a first switch element arranged in parallel with the boost module. The first pulse width regulator adjusts the frequency and duty cycle of the pulse to achieve the on and off time of the first switch element, thereby adjusting the output voltage of the boost circuit. The step-down circuit includes a step-down module, a second pulse width regulator connected to the step-down module, and a second switching element arranged in series with the step-down module. The second pulse width regulator adjusts the frequency and duty cycle of the pulse to achieve the on and off time of the second switching element, thereby adjusting the output voltage of the step-down circuit.

[0008] Furthermore, the boost module includes a boost voltage input terminal, two boost capacitor groups arranged in parallel, a boost inductor and a boost diode connected in series with the two boost capacitor groups, and the first switching element is arranged in parallel with the two boost capacitor groups and is arranged between the boost inductor and the boost diode.

[0009] Furthermore, the step-down module includes a step-down voltage input terminal, two groups of step-down capacitor groups arranged in parallel, a step-down inductor connected in series with the two step-down capacitor groups, and a step-down diode connected in parallel with the two step-down capacitor groups. The second switching element is arranged in series with the two boost capacitor groups, and the step-down diode is arranged between the second switching element and the step-down inductor.

[0010] Furthermore, the capacitor array includes a plurality of tantalum capacitors arranged in parallel, and the capacitance calculation formula of the tantalum capacitor is: ; Where, represents the power of the onboard microprocessor, Indicates working hours, Indicates the operating voltage, Indicates the voltage difference before and after discharge.

[0011] Furthermore, the reverse cutoff circuit includes a reverse cutoff diode, and the cutoff direction of the reverse cutoff diode is the input end, so as to ensure that the current released by the capacitor array only flows to the step-down circuit and finally flows to the load.

[0012] Furthermore, a power supply module is provided between the onboard microprocessor and the step-down circuit, and the power supply module is used to convert the output voltage of the step-down circuit to provide an operating voltage for the onboard microprocessor.

[0013] The present invention also provides an airborne device, comprising the power supply maintenance module of the airborne microprocessor.

[0014] The power supply maintenance module of the airborne microprocessor and the airborne equipment in the present invention utilizes a pulse width regulator to adjust the pulse frequency and duty cycle, thereby regulating the on and off time of the control switch element to adjust the output voltage. A boost circuit is then utilized to charge the capacitor array, increasing the voltage difference between the charging and discharging of the capacitor array. This allows more charge to be released after the input power is turned off, thereby extending the flight time. Furthermore, the capacitor array utilizes only 1 / 9 of the traditional capacitors, significantly saving PCB space and making the airborne equipment smaller and lighter. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a system block diagram of a power maintenance module for an onboard microprocessor in a first embodiment of the present invention; Figure 2 is a schematic diagram of a voltage boost circuit in a first embodiment of the present invention; Figure 3 is a schematic diagram of a capacitor array in a first embodiment of the present invention; Figure 4 is a schematic diagram of a step-down circuit in a first embodiment of the present invention; Figure 5 is a schematic diagram of a reverse cutoff circuit in a first embodiment of the present invention; Figure 6 A circuit test block diagram of a conventional power supply maintenance module according to a first embodiment of the present invention; Figure 7 This is a diagram showing the actual measurement of the maintenance time of the conventional power maintenance module in the first embodiment of the present invention; Figure 8 This is a circuit test block diagram of a power maintenance module of an onboard microprocessor in a first embodiment of the present invention; Figure 9 This is a diagram showing the actual measurement of the maintenance time of the power maintenance module of the onboard microprocessor in the first embodiment of the present invention.

[0016] The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0017] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings. The drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the present invention.

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0019] Example 1 See also Figure 1 , shown is a power supply maintenance module for an airborne microprocessor in a first embodiment of the present invention, comprising a boost circuit, a buck circuit, and a reverse cutoff circuit respectively connected to the boost circuit and the buck circuit, a capacitor array being connected between the reverse cutoff circuit and the buck circuit, and the buck circuit being electrically connected to the airborne microprocessor; The boost circuit includes a boost module, a first pulse width regulator connected to the boost module, and a first switch element arranged in parallel with the boost module. The first pulse width regulator adjusts the frequency and duty cycle of the pulse to achieve the on and off time of the first switch element, thereby adjusting the output voltage of the boost circuit. The step-down circuit includes a step-down module, a second pulse width regulator connected to the step-down module, and a second switching element arranged in series with the step-down module. The second pulse width regulator adjusts the frequency and duty cycle of the pulse to achieve the on and off time of the second switching element, thereby adjusting the output voltage of the step-down circuit.

[0020] Furthermore, the boost module includes a boost voltage input terminal, two boost capacitor groups arranged in parallel, a boost inductor and a boost diode connected in series with the two boost capacitor groups, and the first switching element is arranged in parallel with the two boost capacitor groups and is arranged between the boost inductor and the boost diode.

[0021] Furthermore, the capacitor array includes a plurality of tantalum capacitors arranged in parallel, and the capacitance calculation formula of the tantalum capacitor is: ; Where, represents the power of the onboard microprocessor, Indicates working hours, Indicates the operating voltage, Indicates the voltage difference before and after discharge.

[0022] In specific implementation, according to the above formula, when the power consumption (P) of the onboard microprocessor (MCU) and the power-off working time ( ), and operating voltage ( ) remains unchanged, by increasing To reduce the capacitance used purpose. Known Low-end voltage The minimum voltage of the DC / DC power supply for the MCU is 4V and cannot be changed, so it can only be raised High high-side voltage If Increase to 13V, then Based on the above calculations, the minimum capacitance required to maintain the MCU's power-off operation for 50ms is 1680uF (formula below). This is only 1 / 9 of the original 15mF capacitor.

[0023] ; In this embodiment, a power supply module is provided between the onboard microprocessor and the step-down circuit. The power supply module is used to convert the output voltage of the step-down circuit to provide an operating voltage for the onboard microprocessor.

[0024] Furthermore, the power supply maintenance modules in this embodiment are respectively a boost circuit, a capacitor array, a reverse cutoff circuit, and a step-down circuit. Figure 1 The leftmost side of the circuit is the 5V power input, and the rightmost side is the 4V output, which supplies the DC-DC power input of the microprocessor. The 5V power input on the left is boosted by a boost circuit to a suitable voltage for powering the capacitor array, where the charge is stored in the capacitors. The voltage is then stepped down by a buck circuit to the microprocessor's DC-DC power supply, where it is converted to the 3.3V operating voltage suitable for the microprocessor. Furthermore, to prevent the capacitor array from discharging toward the 5V input stage to the left when power is removed, a reverse blocking circuit is added to ensure that current flows only toward the microprocessor.

[0025] Specifically, the circuit diagram of the boost circuit is as follows Figure 2 As shown in the figure, the 5V power input terminal on the far left is the power supply, the 13V power output terminal after boosting is on the far right, and the boost circuit is in the middle. The boost circuit mainly consists of inductor L1, MOSFET Q2, diode D1, capacitor C1 and PWM pulse width regulator U1. The main functions of each component are as follows: Inductor L1 is the core energy storage component in the boost circuit. When the switch tube Q2 is turned on, the inductor absorbs electrical energy from the 5V power supply and converts it into magnetic energy for storage. When the switch tube Q2 is turned off, the inductor releases magnetic energy and converts it into electrical energy. Its induced electromotive force is superimposed on the input voltage to increase the output voltage.

[0026] MOSFET Q2 is a switching element whose switching control terminal is controlled by a PWM pulse width modulator. When the input PWM pulse width modulator is at a high level, it is turned on; otherwise, it is turned off. The on and off switching controls the charging and discharging of L1.

[0027] Diode D1 is a fast switching diode. When Q2 is turned on, it prevents the current of C1 from flowing back to the cathode. When Q2 is turned off, it allows the current to flow to C1 and the load, thus playing a freewheeling role.

[0028] Capacitors C1 and C4 are used to filter the output voltage to make the output power more stable and reduce voltage ripple. C1 should be a capacitor with large capacity to mainly filter out low-frequency ripple, and C4 should be a capacitor with small capacity to mainly filter out high-frequency ripple.

[0029] The PWM pulse width regulator is composed of a timer (555) and generates a PWM pulse for controlling the on and off time of the MOSFET Q2. The timer (555) is externally equipped with a resistor and a capacitor that can adjust the frequency and duty cycle of the output PWM pulse. By adjusting the frequency and duty cycle of the PWM pulse, the on and off time of the MOSFET Q2 is adjusted and the output voltage is finally adjusted.

[0030] Among them, tantalum capacitors are selected in capacitor arrays because of their large capacity and high safety factor. Figure 3 shown. In this embodiment, the step-down module includes a step-down voltage input terminal, two groups of step-down capacitor groups arranged in parallel, a step-down inductor connected in series with the two step-down capacitor groups, and a step-down diode connected in parallel with the two step-down capacitor groups. The second switching element is arranged in series with the two boost capacitor groups, and the step-down diode is arranged between the second switching element and the step-down inductor.

[0031] In specific implementation, Figure 4 As shown in the figure, the 13V on the left is the step-down circuit power input, and the 4V on the right is the step-down power output. The center is the main step-down circuit. The step-down circuit mainly consists of inductor L1, MOSFET Q2, diode D1, capacitor C1, and PWM pulse width regulator U1. The main functions of each component are as follows: Inductor L1 is the core energy storage component in the buck circuit. When the switch tube Q2 is turned on, the inductor absorbs electrical energy from the power supply and converts it into magnetic energy for storage. When the switch tube Q2 is turned off, the inductor releases magnetic energy and converts it into electrical energy, which serves as a temporary power supply to the load.

[0032] MOSFET Q2 is a switching element whose switching control terminal is controlled by a PWM pulse width modulator. When the input PWM pulse width modulator is at a high level, it is turned on; otherwise, it is turned off. The on and off switching controls the charging and discharging of L1.

[0033] Diode D1 is a fast switching diode. It has no effect when Q2 is turned on. When Q2 is turned off and L1 serves as a temporary power supply, it allows the current of L1 to flow back to the negative electrode of L1, thus playing a freewheeling role.

[0034] Capacitors C1 and C4 are used to filter the output voltage to make the output power more stable and reduce voltage ripple. C1 should be a capacitor with large capacity to mainly filter out low-frequency ripple, and C4 should be a capacitor with small capacity to mainly filter out high-frequency ripple.

[0035] The PWM pulse width regulator is composed of a timer (555) and generates a PWM pulse for controlling the on and off time of the MOSFET Q2. The timer (555) is externally equipped with a resistor and a capacitor that can adjust the frequency and duty cycle of the output PWM pulse. By adjusting the frequency and duty cycle of the PWM pulse, the on and off time of the MOSFET Q2 is adjusted and the output voltage is finally adjusted.

[0036] Furthermore, the reverse cutoff circuit includes a reverse cutoff diode, and the cutoff direction of the reverse cutoff diode is the input end, so as to ensure that the current released by the capacitor array only flows to the step-down circuit and finally flows to the load.

[0037] See also Figure 5 The reverse cutoff circuit is composed of a diode, and the cutoff direction is the input end, which ensures that the current released by the capacitor array can only flow to the step-down circuit and finally flow to the load RL.

[0038] The boost circuit and buck circuit in the power supply maintenance module are simulated and verified as follows: 1) Boost circuit simulation: Will Figure 2 The boost circuit diagram in is input into the simulation software for simulation. When the power input on the left is 5V, the output voltage of the boost end on the right is 13.05V, which meets the boost requirement of this application.

[0039] 2) Buck circuit simulation: Will Figure 4 The step-down circuit diagram in is input into the simulation software for simulation. When the power input on the left is 13V, the output voltage of the step-down end on the right is 4.02V, which meets the step-down requirements of this application.

[0040] In order to maintain the reliability of the measured data, this embodiment uses the same circuit board for verification. Therefore, the capacitance value C of the circuit board is fixed and cannot be changed. The same method is used to verify the same 50ms using different capacitor values C. According to the calculation formula of the capacitor value, we know and is proportional to, so by changing ,Measurement To verify the correctness of this application, change the above capacitor value calculation formula to the following formula: ; Based on the above content, =1V , =9V , ： = 1:9 .

[0041] ; ; By changing To verify the results, according to the following formula, C, P, U Under certain circumstances, If the test gets : = 1:9 can prove the correctness of this application.

[0042] ; Where, express The power supply time for MCU under the following conditions: express The power supply time for MCU under the following conditions: 、 The capacitance values of the capacitors used in the two tests are: 、 are the voltage values of the two tests respectively, express Power under conditions; express Power under conditions; Considering that the step-up and step-down conversion efficiency is not 100%, the general PWM conversion power efficiency is about 92%, so here we can take ≈1.08 , so the theoretical time ratio can be calculated: ; The traditional microprocessor power maintenance circuit is tested. The power input terminal is set to not add the MCU power maintenance module, and the power supply circuit does not pass through the step-up and step-down modules. The test block diagram is as follows: Figure 6 As shown in the figure, oscilloscope probes 1 and 2 are connected to the MCU power input and 5V power output respectively. Use probe 2 for falling edge triggering. When switch S1 is turned on, the simulated power failure is triggered, and the power-on time is measured through probe 1.

[0043] The measured picture is as follows Figure 7 As shown, after turning on switch S1, probe 2 is triggered by the lower edge, and probe 1 measures the power supply holding time. It is 2.4ms.

[0044] The power supply maintenance module in this application is tested, and the test block diagram is as follows: Figure 8 As shown, the power input terminal is set to add a step-up and step-down circuit, and the oscilloscope is connected to the circuit in the same way as testing a traditional power supply maintenance circuit.

[0045] The measured picture is as follows Figure 9 As shown, after turning on switch S1, probe 2 is triggered by the lower edge, and probe 1 measures the power supply holding time. is 20ms.

[0046] Based on actual test results =20ms, =2.4ms; / =8.3 is consistent with the theoretical value of 8.33, proving the correctness of this application.

[0047] Example 2 Another aspect of the present invention provides an airborne device, comprising the above-mentioned power supply maintenance module for the airborne microprocessor.

[0048] In summary, the power supply maintenance module of the airborne microprocessor and the airborne equipment in the above-mentioned embodiments of the present invention use a pulse width regulator to adjust the pulse frequency and duty cycle, and adjust the on and off time of the control switch element to achieve the effect of adjusting the output voltage, thereby using a boost circuit to charge the capacitor array, increasing the voltage difference between the charging and discharging of the capacitor array, so that more charge can be released after the input power is turned off, thereby achieving the purpose of extending the battery life. Moreover, compared with traditional capacitors, the usage of the capacitor array is only 1 / 9 of that of traditional capacitors, which greatly saves PCB space and can make the airborne equipment smaller and lighter.

[0049] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0050] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A power supply maintenance module for an airborne microprocessor, characterized in that: It includes a boost circuit, a buck circuit, and a reverse cutoff circuit respectively connected to the boost circuit and the buck circuit, a capacitor array is connected between the reverse cutoff circuit and the buck circuit, and the buck circuit is electrically connected to the onboard microprocessor; The boost circuit includes a boost module, a first pulse width regulator connected to the boost module, and a first switch element arranged in parallel with the boost module. The first pulse width regulator adjusts the frequency and duty cycle of the pulse to achieve the on and off time of the first switch element, thereby adjusting the output voltage of the boost circuit. The step-down circuit includes a step-down module, a second pulse width regulator connected to the step-down module, and a second switching element arranged in series with the step-down module. The second pulse width regulator adjusts the frequency and duty cycle of the pulse to achieve the on and off time of the second switching element, thereby adjusting the output voltage of the step-down circuit.

2. The power supply maintenance module for an airborne microprocessor according to claim 1, characterized in that: The boost module includes a boost voltage input terminal, two boost capacitor groups arranged in parallel, a boost inductor and a boost diode connected in series with the two boost capacitor groups, and the first switching element is arranged in parallel with the two boost capacitor groups and is arranged between the boost inductor and the boost diode.

3. The power supply maintenance module for an airborne microprocessor according to claim 2, characterized in that: The step-down module includes a step-down voltage input terminal, two groups of step-down capacitor groups arranged in parallel, a step-down inductor connected in series with the two step-down capacitor groups, and a step-down diode connected in parallel with the two step-down capacitor groups. The second switching element is arranged in series with the two boost capacitor groups, and the step-down diode is arranged between the second switching element and the step-down inductor.

4. The power supply maintenance module for an airborne microprocessor according to claim 1, characterized in that: The capacitor array includes a plurality of tantalum capacitors connected in parallel, and the capacitance calculation formula of the tantalum capacitors is: ； Where, represents the power of the onboard microprocessor, Indicates working hours, Indicates the operating voltage, Indicates the voltage difference before and after discharge.

5. The power supply maintenance module for an airborne microprocessor according to claim 1, characterized in that: The reverse cutoff circuit includes a reverse cutoff diode, and the cutoff direction of the reverse cutoff diode is the input end, so as to ensure that the current released by the capacitor array only flows to the step-down circuit and finally flows to the load.

6. The power supply maintenance module for an airborne microprocessor according to claim 1, characterized in that: A power supply module is provided between the onboard microprocessor and the step-down circuit. The power supply module is used to convert the output voltage of the step-down circuit to provide an operating voltage for the onboard microprocessor.

7. An airborne device, characterized in that: A power supply maintenance module comprising the airborne microprocessor according to any one of claims 1 to 6.

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