Day and night switching circuit of airborne indicator light and control method

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By using MOS tubes and photocouplers in the day and night conversion circuit of the aircraft indicator light, the problems of mechanical wear, high power consumption, large volume and high cost of the relay are solved, and the day and night brightness adjustment effect with high reliability, low power consumption and low cost are achieved.

CN119562411APending Publication Date: 2025-03-04JIANGXI HONGDU AVIATION IND GRP

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Patent Information

Application Number: CN202411810548.2
Authority / Receiving Office: CN · China
Patent Type: Applications(China)
Current Assignee / Owner
Filing Date: 2024-12-10
Publication Date: 2025-03-04

AI Technical Summary

Technical Problem

The use of relays in the day and night conversion circuit of existing aircraft indicator lights has problems such as mechanical wear, high power consumption, large volume and high cost, resulting in low reliability and high power consumption.

Method used

The MOS tube is used as the core device, and the appropriate MOS tube control voltage is obtained through resistive voltage division, and the photocoupler is added for isolation protection to realize day and night brightness adjustment of the indicator light.

Benefits of technology

It improves the reliability and energy efficiency of the circuit, reduces power consumption and cost, and realizes efficient day and night brightness adjustment of the indicator light.

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Abstract

The invention belongs to the field of aircraft design, and particularly relates to a day and night conversion circuit of an airborne indicator lamp, which comprises an MOS (Metal Oxide Semiconductor) tube, a day and night conversion resistor R1, a first divider resistor R2, a second divider resistor R3, a current-limiting resistor R4 and a photoelectric coupler U1, an MOS tube is adopted as a core device, proper MOS tube control voltage is obtained through resistance voltage division, and a photoelectric coupler is added for isolation protection. The adopted devices have the characteristics of high reliability, small size, low power consumption, low cost and easiness in integration, so that the purposes of high reliability, low power consumption and low cost of the circuit are achieved.

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Description

Technical Field

[0001] The invention belongs to the field of aircraft design and relates to a day-night conversion circuit and a control method for an airborne indicator light. Background Art

[0002] To adapt to day and night flights, the indicator lights in the aircraft cockpit must have a day and night conversion function, that is, when the light is strong during the day, the indicator characters and indicator lights in the cockpit need to be brightened; when the light is weak at night, the indicator characters and indicator lights in the cockpit need to be dimmed to avoid causing discomfort to the pilot.

[0003] At present, most aircraft use relays to realize the day and night conversion function of indicator lights. The circuit form is shown in the figure below. The day and night conversion control signal changes the resistance value in the indicator light circuit by controlling the contact and disconnection of the relay to adjust the brightness of the indicator light: when the day and night conversion control end is suspended, the relay is turned on, the resistance decreases, the current increases, and the indicator light becomes brighter, which is the daytime state; when the day and night conversion control end is grounded, the relay is disconnected, the resistance increases, the current decreases, and the indicator light becomes darker, which is the night state.

[0004] However, the use of relay control has the following disadvantages: (1) Relays are composed of mechanical and electromagnetic components, including contacts, mechanical links, levers, springs, windings, iron cores, etc. Therefore, there are inevitable problems of mechanical wear, spring failure or poor contact. As the working time increases, it is easy to get stuck or the contacts do not work, and the long-term reliability is low; (2) High power consumption: Since the electromagnetic coil is used as the driving force for the relay to operate, a large control current (mA level) or voltage (generally ≮18V) is required to activate the electromagnetic coil, and the power consumption is relatively high. As the number of controlled indicator lights increases, the power consumption increases exponentially. (3) Large size: The use of electromagnetic coils and various mechanical components results in a relatively large size and requires a certain height, which has certain requirements for installation space. (4) High cost. The cost of relays is more than ten times that of other electronic components such as resistors, capacitors, and semiconductor devices. Summary of the invention

[0005] Purpose of the Invention

[0006] The purpose of this invention is to design a high-reliability, low-power, low-cost airborne indicator light day and night conversion circuit to achieve the function of adjusting the indicator light brightness according to the day and night conversion control signal. MOS tubes are used as core devices, and the appropriate MOS tube control voltage is obtained through resistor voltage division, and photoelectric couplers are added for isolation protection. The devices used have the characteristics of high reliability, small size, low power consumption, low cost and easy integration, so as to achieve the purpose of high reliability, low power consumption and low cost of the circuit.

[0007] Technical Solution

[0008] A day / night conversion circuit for an airborne indicator light, comprising a MOS tube, a day / night conversion resistor R1, a first voltage-dividing resistor R2, a second voltage-dividing resistor R3, a current-limiting resistor R4, and a photoelectric coupler U1;

[0009] The D end of the MOS tube is connected in parallel with the high end of the day / night conversion resistor R1 and then connected to the high end of the power supply; the S end of the MOS tube is connected in parallel with the low end of the resistor R1 and then grounded; the G end of the MOS tube is connected to the low end of the first voltage-dividing resistor R2 and the high end of the second voltage-dividing resistor R3, and then connected to the high end of the optical receiver of the photoelectric coupler U1, the high end of the first voltage-dividing resistor R2 is connected to the power supply Vcc, the low end of the first voltage-dividing resistor R2 is connected to the high end of the second voltage-dividing resistor R3, and the low end of the second voltage-dividing resistor R3 is grounded; the middle lead wires of the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3 are respectively connected to the G end of the MOS tube and the optical receiver of the photoelectric coupler U1; the low end of the optical receiver of the photoelectric coupler U1 is grounded; the H end of the photodiode of U1 is connected to the current-limiting resistor R4 and then to the power supply Vcc, and the L end of the photodiode is connected to the day / night conversion control signal.

[0010] Furthermore, the power source Vcc is one or two, which is determined according to the characteristics of the photocoupler U1 and the MOS tube.

[0011] Furthermore, the high end of the day / night conversion resistor R1 is connected to a load to achieve a day / night brightness adjustment function for the indicator light.

[0012] Furthermore, the MOS tube is specifically NMOS.

[0013] Furthermore, the optocoupler U1 is selected according to the power supply voltage on the aircraft.

[0014] Furthermore, the resistance value of the current limiting resistor R4 is selected according to the photocoupler U1 and the supply voltage.

[0015] Furthermore, the resistance values of the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3 are selected according to the switching characteristics of the MOS tube.

[0016] Furthermore, the resistance value of the day / night conversion resistor R1 is determined according to the day / night brightness requirements on the aircraft.

[0017] A control method for a day / night conversion circuit of an airborne indicator light is as follows:

[0018] During the day, the day / night conversion control signal is suspended, and the optocoupler U1 does not work. At this time, Vcc acts on the G end of the MOS after being divided by the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3. At this time, Vgs>Vth, Vth is the conduction threshold voltage of the MOS tube, and the MOS tube is turned on. At this time, the day / night conversion resistor R1 is short-circuited and does not work. The total resistance in the indicator light circuit decreases, the current increases, and the brightness of the indicator light increases.

[0019] At night, the day and night conversion control signal is grounded, and the optocoupler U1 works. At this time, the light sensitive end is connected, and the low end of the first voltage-dividing resistor R2 is grounded, that is, the second voltage-dividing resistor R3 is short-circuited. At this time, the G end of the MOS tube is grounded, Vgs is 0V, the MOS tube is cut off, and does not work. The day and night conversion resistor R1 is not short-circuited and participates in the control. At this time, the total resistance in the indicator light circuit increases, the current decreases, and the brightness of the indicator light decreases. The beneficial effects of this application are:

[0020] a) High reliability: Using MOS tubes as switches instead of relays improves reliability. MOS tubes have no mechanical parts, no mechanical wear and poor contact problems, and have longer life and higher reliability;

[0021] b) Low power consumption: MOS tubes only require microampere current or relatively small voltage to achieve switching operations, and the switching speed is much higher than that of relays. Therefore, MOS tubes have low power consumption and can improve the energy efficiency of the system.

[0022] c) Small size. MOS tubes can be fixed to the circuit board through surface mounting, which is easy to integrate.

[0023] d) Low cost: MOS tubes have low cost, and only simple peripheral circuits need to be added to realize the conversion function. The cost of the entire circuit is much lower than that of relays. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the day and night conversion circuit of the onboard indicator light;

[0025] Figure 2 Daytime status diagram;

[0026] Figure 3 Night state diagram;

[0027] Figure 4 Schematic diagram of existing circuit structure. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantages of the implementation of the present invention clearer, the technical scheme in the embodiment of the present invention will be described in more detail in combination with the embodiment of the present invention. In the example, the same or similar reference numerals throughout represent the same or similar originals or elements with the same or similar functions. The described embodiments are part of the embodiments of the present invention, not all of them. The embodiments described below by reference are exemplary and intended to be used to explain the present invention, and should not be construed as limitations on the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present invention. The following is a detailed description in combination with the embodiments of the present invention.

[0029] Example 1

[0030] The circuit diagram is shown in the attached figure Figure 1 As shown in FIG. 1 , the circuit is composed of a MOS tube, voltage-dividing resistors R2 and R3, a photocoupler U1, and a current-limiting resistor R4. The MOS tube is used as a switch tube and is the core device for realizing the day and night conversion function. The photocoupler U1 can isolate external circuit faults and protect the MOS tube. The voltage-dividing resistors R2 and R3 are used to output a suitable voltage for the conduction of the MOS tube so that it works in a switching state. The current-limiting resistor R4 is used to provide a suitable current so that the photocoupler U1 works within its current limit.

[0031] The circuit connection relationship is as follows:

[0032] a) MOS tube: The D end of the MOS tube is connected in parallel with the high end of the day / night conversion resistor R1 and then connected to the high end of the power supply; the S end of the MOS tube is connected in parallel with the low end of the resistor R1 and then grounded; the G end of the MOS tube is connected to the low end of the resistor R2 and the high end of R3, and then connected to the high end of the optical receiver of the photocoupler U1.

[0033] b) The high end of the voltage divider resistor R2 is connected to the power supply Vcc, the low end is connected to the resistor R3 and then to the ground, and the middle point lead wire is connected to the G end of the MOS tube and the optical receiver of the optocoupler U1.

[0034] c) The low end of the optical receiver of the photocoupler U1 is grounded; the H end of the photodiode of U1 is connected to the current limiting resistor R4 and then to the power supply Vcc, and the L end of the photodiode is connected to the day and night switching control signal.

[0035] Example 2

[0036] The day / night conversion circuit of the onboard indicator light includes a MOS tube, a day / night conversion resistor R1, a first voltage-dividing resistor R2, a second voltage-dividing resistor R3, a current-limiting resistor R4, and a photoelectric coupler U1;

[0037] The D end of the MOS tube is connected in parallel with the high end of the day / night conversion resistor R1 and then connected to the high end of the power supply; the S end of the MOS tube is connected in parallel with the low end of the resistor R1 and then grounded; the G end of the MOS tube is connected to the low end of the first voltage-dividing resistor R2 and the high end of the second voltage-dividing resistor R3, and then connected to the high end of the optical receiver of the photoelectric coupler U1, the high end of the first voltage-dividing resistor R2 is connected to the power supply Vcc, the low end of the first voltage-dividing resistor R2 is connected to the high end of the second voltage-dividing resistor R3, and the low end of the second voltage-dividing resistor R3 is grounded; the middle lead wires of the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3 are respectively connected to the G end of the MOS tube and the optical receiver of the photoelectric coupler U1; the low end of the optical receiver of the photoelectric coupler U1 is grounded; the H end of the photodiode of U1 is connected to the current-limiting resistor R4 and then to the power supply Vcc, and the L end of the photodiode is connected to the day / night conversion control signal.

[0038] Furthermore, the power source Vcc is one or two, which is determined according to the characteristics of the photocoupler U1 and the MOS tube.

[0039] Furthermore, the high end of the day / night conversion resistor R1 is connected to a load to achieve a day / night brightness adjustment function for the indicator light.

[0040] Furthermore, the MOS tube is specifically NMOS.

[0041] Furthermore, the optocoupler U1 is selected according to the power supply voltage on the aircraft.

[0042] Furthermore, the resistance value of R4 is selected according to the optocoupler U1 and the supply voltage.

[0043] Furthermore, the resistance values of R2 and R3 are selected according to the switching characteristics of the MOS tube.

[0044] Furthermore, the resistance value of R1 is determined according to the day and night brightness requirements on the aircraft.

[0045] A control method for a day / night conversion circuit of an airborne indicator light is as follows:

[0046] During the day, the day / night conversion control signal is suspended, and the optocoupler U1 does not work. At this time, Vcc acts on the G terminal of the MOS after being divided by the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3. At this time, Vgs>Vth, Vth is the conduction threshold voltage of the MOS tube, and the MOS tube is turned on. At this time, the day / night conversion resistor R1 is short-circuited and does not work. The total resistance in the indicator light circuit decreases, the current increases, and the brightness of the indicator light increases. The equivalent circuit diagram is as follows Figure 2 shown.

[0047] At night, the day / night conversion control signal is grounded, and the optocoupler U1 works. At this time, the light sensitive end is connected, and the low end of the first voltage-dividing resistor R2 is grounded, that is, the second voltage-dividing resistor R3 is short-circuited. At this time, the G end of the MOS tube is grounded, Vgs is 0V, the MOS tube is cut off, and does not work. The day / night conversion resistor R1 is not short-circuited and participates in the control. At this time, the total resistance in the indicator light circuit increases, the current decreases, and the brightness of the indicator light decreases. The equivalent circuit diagram is as follows Figure 3 shown.

[0048] It is understood by those skilled in the art that, unless otherwise defined, all terms (including technical terms and scientific terms) used herein have the same meaning as the general understanding of ordinary technicians in the field to which the present invention belongs. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and unless defined as here, will not be interpreted with idealized or overly formal meanings. The specific implementation methods described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the present invention. Within the spirit and principle of the present invention, any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment of equivalent changes for application in other fields, but any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the technical solution content of the present invention, any modification, equivalent replacement, improvement, etc., made according to the technical essence of the present invention, should be included in the protection scope of the present invention.

Claims

1. A day and night conversion circuit for an airborne indicator light, characterized in that: It includes a MOS tube, a day / night conversion resistor R1, a first voltage-dividing resistor R2, a second voltage-dividing resistor R3, a current-limiting resistor R4, and a photoelectric coupler U1; The D end of the MOS tube is connected in parallel with the high end of the day / night conversion resistor R1 and then connected to the high end of the power supply; the S end of the MOS tube is connected in parallel with the low end of the resistor R1 and then grounded; the G end of the MOS tube is connected to the low end of the first voltage-dividing resistor R2 and the high end of the second voltage-dividing resistor R3, and then connected to the high end of the optical receiver of the photoelectric coupler U1, the high end of the first voltage-dividing resistor R2 is connected to the power supply Vcc, the low end of the first voltage-dividing resistor R2 is connected to the high end of the second voltage-dividing resistor R3, and the low end of the second voltage-dividing resistor R3 is grounded; the middle lead wires of the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3 are respectively connected to the G end of the MOS tube and the optical receiver of the photoelectric coupler U1; the low end of the optical receiver of the photoelectric coupler U1 is grounded; the H end of the photodiode of U1 is connected to the current-limiting resistor R4 and then to the power supply Vcc, and the L end of the photodiode is connected to the day / night conversion control signal.

2. The circuit according to claim 1, characterized in that The power source Vcc can be one or two, which is determined according to the characteristics of the photocoupler U1 and the MOS tube.

3. The circuit according to claim 2, characterized in that The high end of the day / night conversion resistor R1 is connected to a load to achieve the day / night brightness adjustment function of the indicator light.

4. The circuit according to claim 3, characterized in that The MOS tube is specifically NMOS.

5. The circuit according to claim 4, characterized in that The optocoupler U1 is selected according to the aircraft's onboard power supply voltage.

6. The circuit according to claim 5, characterized in that The resistance value of the current limiting resistor R4 is selected according to the optocoupler U1 and the supply voltage.

7. The circuit according to claim 6, characterized in that The resistance values of the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3 are selected according to the switching characteristics of the MOS tube.

8. The circuit according to claim 7, characterized in that The resistance value of the day / night conversion resistor R1 is determined according to the day / night brightness requirements on the aircraft.

9. The circuit control method according to claim 1, characterized in that: The details are as follows: During the day, the day / night conversion control signal is suspended, and the optocoupler U1 does not work. At this time, Vcc acts on the G terminal of the MOS after being divided by the first voltage-dividing resistor R2 and the second voltage-dividing resistor R3. At this time, Vgs>Vth, Vth is the conduction threshold voltage of the MOS tube, and the MOS tube is turned on; at this time, the day / night conversion resistor R1 is short-circuited and does not work; the total resistance in the indicator light circuit decreases, the current increases, and the brightness of the indicator light increases; At night, the day-night conversion control signal is grounded, and the optocoupler U1 works. At this time, the light sensitive end is connected, and the low end of the first voltage-dividing resistor R2 is grounded, that is, the second voltage-dividing resistor R3 is short-circuited; at this time, the G end of the MOS tube is grounded, Vgs is 0V, the MOS tube is cut off, and does not work; the day-night conversion resistor R1 is not short-circuited and participates in the control; at this time, the total resistance in the indicator light circuit increases, the current decreases, and the brightness of the indicator light decreases.