Timing device for starting an aircraft engine

Abstract

The application relates to a timing device for starting an airplane engine and belongs to the technical field of airplane power devices. The timing device comprises a shell assembly, a circuit board assembly arranged in the shell assembly and used for generating a timing signal required by starting the airplane engine under the triggering of an external signal, and an interface assembly arranged on the shell assembly and used for providing the interface of the external signal input and the timing signal output. The circuit board assembly comprises a main circuit board carrying a timing control main circuit, and the timing control main circuit is realized based on a main timing control circuit, an optoelectronic coupling circuit and a relay circuit. The technical scheme of the application is based on the electronic timing principle, adopts an electronic circuit mode and realizes the airplane engine starting timing device. Compared with the existing mechanical starting timing mechanism, the timing device has better reliability and stability.

Description

Technical Field

[0001] This application belongs to the field of aircraft power plant technology, specifically relating to a timing device for starting an aircraft engine. Background Technology

[0002] The engine starting system is a subsystem of the aircraft power plant, and its function is to start the aircraft engine. To ensure a good start for the aircraft engine (taking a gas turbine engine as an example), relevant equipment needs to rotate the engine compressor and turbine to a certain speed, allowing an appropriate amount of air to enter the engine combustion chamber and mix with the fuel. At the same time, equipment needs to ignite the air / fuel mixture in the engine combustion chamber. During engine starting, these auxiliary devices must work in coordination. Therefore, the aircraft engine starting process is a complex process involving the joint operation of the engine electrical system, fuel system, and other systems. During the starting process, relevant starting control devices need to automatically control the coordinated operation of each starting device according to the time.

[0003] In related technologies, a mechanical starting timing mechanism (or automatic timing mechanism) is used to achieve timing control during engine starting. The timing control principle of the mechanical starting timing mechanism is as follows: the camshaft motor rotates at a constant speed, driving multiple sets of relay contacts to actuate and achieve timing control functions. For example, the timing mechanism of model DS-8A has eight sets of relays controlled by the camshaft motor, and the main timing sequence it achieves is as follows:

[0004] ① 2.5±0.5 seconds after startup, the first relay contact actuates, connecting the 24V power supply;

[0005] ②3.5±0.5S after startup, the second relay contact actuates, causing the armature voltage to rise from 4-6V to 20-26V;

[0006] ③ 15±1 seconds after startup, the third relay contact will activate, changing the starting electrical power regulation mode.

[0007] ④ After 9±0.5 seconds after starting, the fourth relay contact will activate, connecting the oil supply solenoid valve, and at the same time the armature voltage will rise to 29-36V;

[0008] ⑤ 20±1 seconds after starting, the fifth relay contact will activate, and fuel will begin to be supplied to the engine working nozzle and ignited by the igniter, and the combustion chamber will start working.

[0009] ⑥ 25±1 seconds after starting, the sixth relay contact will actuate, disconnecting the power supply to the ignition coil and the starting fuel supply solenoid valve;

[0010] The above starting process should not exceed 42±2 seconds. After the starting process is completed, when the engine speed reaches 5400r / min-5900r / min, the starter power-off switch opens its contacts under the action of lubricating oil at a pressure of 174.4kPa-254.8kPa, thereby disconnecting the power supply to the mechanical starting sequence mechanism. The entire starting system stops working, and all relays reset simultaneously, preparing for the next start.

[0011] The structural principle of the mechanical starting timing mechanism can be found in the technical principles described in the prior art, such as the timer cam structure provided by Chinese Patent CN201310082681 and the mechanical frequency conversion timer provided by CN201410285680.

[0012] However, in actual use, mechanical starting timing mechanisms have a high failure rate. For example, the failure of the DS-8A automatic timing mechanism is mainly concentrated in the electric cam structure and the old JKC series relays.

[0013] Specifically, the timing control in the electric cam structure has poor stability and reliability, and has the following shortcomings: a) large size, many contacts, and is prone to overheating after long-term operation; b) heavy weight due to the presence of motors and old-type relays; c) brushes that are prone to carbon powder splashing, causing malfunctions, etc.

[0014] JKC series relays are short-time duty products. Their main drawbacks are high coil power, high power consumption, and high heat generation. Prolonged use will burn out the product.

[0015] The above factors have led to a high failure rate of the mechanical starting sequence mechanism, which affects the sortie efficiency of the aircraft for normal flight operations.

[0016] Therefore, how to provide a starting timing mechanism or device with higher reliability and stability for aircraft engine starting has become a technical problem that urgently needs to be solved. Summary of the Invention

[0017] To overcome at least some of the problems existing in the related technologies, this application provides a timing device for starting an aircraft engine based on the principle of electronic timing. This device has higher reliability and stability, and solves the technical problem of how to provide a better timing device for starting an aircraft engine.

[0018] To achieve the above objectives, this application adopts the following technical solution:

[0019] This application provides a timing device for starting an aircraft engine, the timing device comprising:

[0020] Housing components;

[0021] A circuit board assembly, disposed within the housing assembly, is used to generate timing signals required for starting the aircraft engine upon triggering by an external signal.

[0022] An interface component, disposed on the housing assembly, is used to provide an interface for the external signal input and the timing signal output;

[0023] The circuit board assembly includes a main circuit board carrying a timing control main circuit, which is implemented based on a main timing control circuit, an optocoupler circuit, and a relay circuit.

[0024] Optionally, the main timing control circuit is implemented based on a main microcontroller chip, and the main microcontroller chip generates timing trigger signals based on the chip's internal timer and outputs them at the chip's corresponding output terminals;

[0025] The optocoupler circuit is a plurality of such circuits, and the plurality of such optocoupler circuits are respectively disposed between the output terminal of the main microcontroller chip and the relay circuit, for the purpose of achieving electrical signal isolation between the main timing control circuit side and the relay circuit side.

[0026] The relay circuit includes multiple relay devices, which are connected to the optocoupler circuit and the interface component to generate the timing signal required for starting the aircraft engine under the combined action of the external signal and the timing trigger signal.

[0027] Optionally, the optocoupler circuit includes seven first optocoupler circuits;

[0028] The first optocoupler circuit includes a first resistor R101, a second resistor R102, a third resistor R103, a first optocoupler G101, and a first transistor T101; in the first optocoupler circuit,

[0029] One end of the first resistor R101 is connected to an output terminal of the main microcontroller chip as the input terminal of the circuit, and the other end is connected to the first terminal of the input side of the first optocoupler G101. The second terminal of the input side of the first optocoupler G101 is connected to the first power supply terminal.

[0030] The first terminal of the output side of the first optocoupler G101 is connected to the second power supply terminal. The second terminal of the output side of the first optocoupler G101 is connected to the base of the first transistor T101 through the second resistor R102. The base of the first transistor T101 is also connected to the ground terminal together with the emitter of the first transistor T101 through the third resistor R103. The collector of the first transistor T101 is connected to the relay circuit as the output terminal of the circuit.

[0031] Optionally, the optocoupler circuit further includes a second optocoupler circuit;

[0032] The second optocoupler circuit includes a fourth resistor R104, a fifth resistor R105, a sixth resistor R106, a seventh resistor R107, a first capacitor C101, a second capacitor C102, a second optocoupler G102, and a second transistor T102; in the second optocoupler circuit,

[0033] One end of the fourth resistor R104 is connected to an output terminal of the main microcontroller chip as the input terminal of the circuit, and the other end is connected to the first terminal of the input side of the second optocoupler G102. The second terminal of the input side of the second optocoupler G102 is connected to the first power supply terminal.

[0034] The first terminal of the output side of the second optocoupler G102 is connected to the second power supply terminal. The second terminal of the output side of the second optocoupler G102 is connected to the base of the second transistor T102 through the fifth resistor R105. The base of the second transistor T102 is also connected to the ground terminal along with the emitter of the second transistor T102 through the sixth resistor R106. The collector of the second transistor T102 serves as the output terminal of this circuit and is connected to the relay circuit.

[0035] The second terminal of the output side of the second optocoupler G102 is also connected to one end of the seventh resistor R107, and the other end of the seventh resistor R107 is connected to the ground terminal through the first capacitor C101 and the second capacitor C102 respectively.

[0036] Optionally, the interface component includes a first connector CZ1, a second connector CZ2, and a third connector CZ3;

[0037] The relay circuit includes a first relay K1, a second relay K2, a third relay K3, a fourth relay K4, a fifth relay K5, a sixth relay K6, a seventh relay K7, and an eighth relay K811, each having one set of contacts; and a first contact relay J1, a second contact relay J2, a third contact relay J3, a fourth contact relay J4, and a fifth contact relay J5, each having two or more sets of contacts. In the relay circuit,

[0038] The coil of the first relay K1 is connected to the output terminal of the second optocoupler circuit, and the coils of the second relay K2, the third relay K3, the fourth relay K4, the fifth relay K5, the sixth relay K6, the seventh relay K7, and the eighth relay K81 are each connected to the output terminal of the first optocoupler circuit.

[0039] The normally closed contact of the first relay K1 is connected to terminal 8 of the second connector CZ2. The normally open contact of the first relay K1, the common contact of the sixth relay K6, the normally open contact of the sixth group of contacts of the first relay J1, and the first coil terminal of the third relay J3 are all connected to terminal 4 of the first connector CZ1. The second coil terminal of the third relay J3 is connected to the ground terminal.

[0040] The normally open contact of the second relay K2 is connected to the second terminal of the third connector CZ3. The common contact of the second relay K2 is shared with the common contact of the third relay K3, the common contact of the fourth relay K4, and the normally open contact of the fifth group of contacts of the first contact relay J1.

[0041] The normally open contact of the third relay K3 is connected to terminal 7 of the third connector CZ3, and the normally closed contact of the third relay K3 is connected to the normally open contact of the second group of contacts of the second contact relay J2.

[0042] The normally closed contact of the fourth relay K4 is connected to terminal 1 of the third connector CZ3, and the normally open contact of the fourth relay K4 is connected to the first terminal of the coil of the second contact relay J2. The second terminal of the coil of the second contact relay J2 is connected to the ground terminal.

[0043] The normally closed contact of the fifth relay K5 is connected to the sixth terminal of the second connector CZ2, and the common contact of the fifth relay K5 is connected to the normally open contact of the fourth group of contacts of the first contact relay J1.

[0044] The normally open contact of the sixth relay K6 is connected to the first terminal of the coil of the fifth relay J5, and the second terminal of the coil of the fifth relay J5 is connected to the ground terminal.

[0045] The common terminal of the seventh relay K7 is connected to the normally open terminal of the first group of contacts of the first contact relay J1. The normally closed terminal of the seventh relay K7, the first coil terminal of the first contact relay J1, and the normally closed terminal of the first group of contacts of the third contact relay J3 are all connected to the sixth terminal of the first connector CZ1.

[0046] The normally closed contact of the eighth relay K81 is connected to the fourth terminal of the second connector CZ2. The common contact of the eighth relay K81 is connected to the common terminal of the first group of contacts of the fourth relay J4. The normally open contact of the eighth relay K81 is shared with the common terminal of the first group of contacts of the second relay J2, the normally open terminal of the first group of contacts of the fourth relay J4, the common terminal of the fourth group of contacts of the first relay J1, the common terminal of the fifth group of contacts of the first relay J1, the common terminal of the sixth group of contacts of the first relay J1, the first terminal of the first connector CZ1, the normally open terminal of the first group of contacts of the third relay J3, the seventh terminal of the second connector CZ2, and the common terminal of the second group of contacts of the third relay J3.

[0047] The common terminal of the first group of contacts of the third contact relay J3 is connected to both the first terminal of the second connector CZ2 and the fourth terminal of the third connector CZ3. The normally closed terminal of the second group of contacts of the third contact relay J3 is connected to the second terminal of the first connector CZ1.

[0048] The common terminal of the third group of contacts of the first contact relay J1 is connected to the normally closed terminal of the first group of contacts of the fourth contact relay J4. The common terminal of the second group of contacts of the first contact relay J1 is shared with the fifth terminal of the first connector CZ1, the common terminal of the first group of contacts of the fifth contact relay J5, and the common terminal of the second group of contacts of the fifth contact relay J5.

[0049] The common terminal of the first group of contacts of the first contact relay J1 is connected to the eighth terminal of the first connector CZ1, and the second terminal of the coil of the first contact relay J1 is used to connect to the second terminal of the second connector CZ2.

[0050] The first terminal of the coil of the fourth contact relay J4 is connected to the normally open terminal of the second group of contacts of the first contact relay J1. The second terminal of the coil of the fourth contact relay J4 is connected to the ground terminal. The common terminal of the second group of contacts of the fourth contact relay J4 is shared with the normally open terminal of the second group of contacts of the fifth contact relay J5 and the third terminal of the third connector CZ3. The normally open terminal of the second group of contacts of the fourth contact relay J4 is connected to the public terminal of the second group of contacts of the second contact relay J2.

[0051] The normally open terminal of the first group of contacts of the second contact relay J2 is connected to the third terminal of the second connector CZ2 and the fifth terminal of the third connector CZ3. The common terminal of the third group of contacts of the second contact relay J2 is connected to the sixth terminal of the third connector CZ3. The normally open terminal of the third group of contacts of the second contact relay J2 is connected to the normally open terminal of the first group of contacts of the fifth contact relay J5.

[0052] Optionally, the circuit board assembly further includes a sub-circuit board for carrying a fault output circuit; the fault output circuit includes:

[0053] The secondary timing control circuit is used to generate the reference timing trigger signal required for fault detection;

[0054] Multiple comparison circuits are used to respectively compare the timing trigger signal on the main circuit board with the reference timing trigger signal on the sub-circuit board;

[0055] The fault alarm and disconnection circuit is used to respond to the output indication level of the comparison circuit and trigger the generation of a fault alarm signal to be transmitted externally.

[0056] Optionally, the secondary timing control circuit is implemented based on a secondary microcontroller chip, which has the same configuration as the primary microcontroller chip, and both chips are powered on and started simultaneously; the comparator circuit is implemented based on a rectifier bridge circuit.

[0057] The fault alarm and disconnection circuit includes a first contact first sub-relay J101, a first contact second sub-relay J102, and a first contact third sub-relay J103; in the fault alarm and disconnection circuit:

[0058] The first terminal of the coil of the first contact first sub-relay J101, the first terminal of the coil of the first contact second sub-relay J102, and the first terminal of the coil of the first contact third sub-relay J103 are all connected to the first terminal of the first connector CZ1. The second terminals of the coils of the first contact first sub-relay J101 and the first terminal of the coil of the first contact second sub-relay J102 are used to receive the output indication of the comparison circuit. The second terminal of the coil of the first contact third sub-relay J103 is used to connect to the normally open terminal of the fifth group of contacts of the first contact relay J1.

[0059] The normally open terminal of the first group of contacts of the first contact first branch relay J101 is connected to the second terminal of the coil of the first contact first branch relay J101. The common terminal of the first group of contacts of the first contact first branch relay J101 and the common terminal of the second group of contacts of the first contact first branch relay J101 are connected to the ground terminal. The normally open terminal of the second group of contacts of the first contact first branch relay J101 is connected to the third terminal of the first connector CZ1.

[0060] The normally closed contact of the first contact relay J102 is connected in series between the second terminal of the coil of the first contact relay J1 and the second terminal of the second connector CZ2.

[0061] The normally open contact of the first contact third sub-relay J103 is connected to the first end of the coil of the first contact third sub-relay J103. The common contact of the first contact third sub-relay J103 is connected to the 8th end of the third connector CZ3.

[0062] Optionally, the circuit board assembly further includes a protective circuit board carrying a protective circuit;

[0063] The protection circuit is connected to the pins of each connector and is used for lightning indirect effect protection based on the signal type of the pin, as well as for protection management of the power supply of the device according to the power characteristics requirements of the aircraft.

[0064] The application employs the above technical solution and has at least the following beneficial effects:

[0065] In this application's technical solution, the timing device includes a housing assembly; a circuit board assembly disposed within the housing assembly, used to generate timing signals required for aircraft engine starting upon external signal triggering; and an interface assembly disposed on the housing assembly, used to provide an interface for external signal input and timing signal output. The circuit board assembly includes a main circuit board carrying a timing control main circuit, which is implemented based on a main timing control circuit, an optocoupler circuit, and a relay circuit. This application's technical solution, based on electronic timing principles and employing electronic circuitry, implements an aircraft engine starting timing device, offering better reliability and stability compared to existing mechanical starting timing mechanisms.

[0066] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from an examination of the following, or may be learned from the practice of the invention. Attached Figure Description

[0067] The accompanying drawings are used to provide a further understanding of the technical solutions of this application or the prior art, and constitute a part of the specification. The drawings illustrating embodiments of this application, together with the embodiments of this application, are used to explain the technical solutions of this application, but do not constitute a limitation on the technical solutions of this application.

[0068] Figure 1 A schematic diagram illustrating the structure of a timing device for starting an aircraft engine provided in one embodiment of this application;

[0069] Figure 2 This is an exploded view of the structure of a timing device for starting an aircraft engine in one embodiment of this application;

[0070] Figure 3 This is a schematic diagram of a portion of the circuit principle of the main circuit board in one embodiment of this application. Figure 1 ;

[0071] Figure 4 This is a schematic diagram of the circuit principle of the first optocoupler circuit in one embodiment of this application;

[0072] Figure 5This is a schematic diagram of the circuit principle of the second optocoupler circuit in one embodiment of this application;

[0073] Figure 6 This is a schematic diagram of a portion of the circuit principle of the main circuit board in one embodiment of this application. Figure 2 ;

[0074] Figure 7 This is a schematic diagram of the circuit principle of the sub-circuit board in one embodiment of this application;

[0075] Figure 8 This is a schematic block diagram of the timing device in one embodiment of this application.

[0076] In the diagram, 100 is the housing assembly; 200 is the circuit board assembly; 210 is the main circuit board; 220 is the secondary circuit board; 230 is the protective circuit board; and 300 is the interface assembly. Detailed Implementation

[0077] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0078] As described in the background section, the aircraft engine starting process is a complex process in which the engine's electrical system, fuel system, and other systems work together. During the starting process, relevant starting control devices are required to automatically control the coordinated operation of each starting device according to the time.

[0079] In related technologies, a mechanical starting timing mechanism (or automatic timing mechanism) is used to control the timing during engine starting. However, in practical applications, mechanical starting timing mechanisms suffer from a high failure rate, affecting the sortie efficiency of aircraft during normal flight operations. Therefore, how to provide a starting timing mechanism or device with higher reliability and stability for aircraft engine starting has become an urgent technical problem to be solved.

[0080] In response to this, this application proposes a timing device for starting an aircraft engine, such as... Figure 1 and Figure 2 As shown, in one embodiment, the timing device for starting an aircraft engine according to this application includes:

[0081] Housing assembly 100, for example, Figure 1 , 2 As shown, the outer casing assembly 1 is box-shaped, and a mounting ear structure is provided on the lower side of one side of the box to facilitate installation and fixation.

[0082] The circuit board assembly 200, which is disposed within the housing assembly 100, is used to generate timing signals required for starting the aircraft engine upon triggering by an external signal.

[0083] Interface component 300, disposed on housing component 100, is used to provide an interface for external signal input and timing signal output, such as... Figure 2 As shown, the interface component here consists of three aviation connectors (it should be noted that the electrical connection lines between the circuit board assembly and the interface assembly are...). Figure 1 and Figure 2 (not shown in the image);

[0084] In this embodiment, the circuit board assembly 200 includes a main circuit board 210 carrying a timing control main circuit. The timing control main circuit is implemented based on a main timing control circuit, an optocoupler circuit, and a relay circuit. For example, such as Figure 2 As shown, the circuit board assembly 200 can be mounted and fixed inside the housing assembly via a support column structure.

[0085] It is readily understood by those skilled in the art that, given the output requirements, electronic circuits (such as timing circuits based on a 555 timer or timing generation circuits based on a microcontroller) can generate relevant timing signals (such as the timing signals output by the DS-8A timing mechanism mentioned in the background art). Based on this, optocoupler circuits and relay circuits can be used to achieve isolation and meet the switching and breaking capacity requirements, thus fully meeting the timing control requirements for aircraft engine starting. Furthermore, it is readily understood that higher-performance relay devices, such as J-series relays, can be used in the aforementioned relay circuits to avoid the drawbacks of using JKC-series relays in mechanical timing mechanisms as described in the background art.

[0086] Based on this technical concept, this application proposes the aforementioned timing device for starting an aircraft engine. Based on the principle of electronic timing, it adopts an electronic circuit method to realize the aircraft engine starting timing device, which has better reliability and stability compared with the existing mechanical starting timing mechanism.

[0087] Furthermore, it should be noted that when the output requirements are known, relevant timing signals can be generated using electronic circuits (such as timing circuits based on 555 timers, timing generation circuits based on microcontrollers, etc.). The principles of the methods involved can be found in existing publicly available technical materials, and this application does not involve any improvement of the relevant methods.

[0088] To facilitate understanding of the technical solution of this application, another embodiment will be used to describe the technical solution of this application below.

[0089] like Figure 1 and Figure 2As shown, the timing device for starting the aircraft engine in this embodiment includes:

[0090] Housing assembly 100;

[0091] The circuit board assembly 200, which is disposed within the housing assembly 100, is used to generate timing signals required for starting the aircraft engine upon triggering by an external signal.

[0092] Interface component 300, which is disposed on housing component 100, is used to provide an interface for external signal input and timing signal output;

[0093] In this embodiment, the circuit board assembly 200 includes a main circuit board 210 carrying a timing control main circuit. The timing control main circuit includes a main timing control circuit, an optocoupler circuit, and a relay circuit, meaning that the timing control main circuit is implemented based on the main timing control circuit, the optocoupler circuit, and the relay circuit.

[0094] Specifically, in this embodiment, the main timing control circuit is based on the main microcontroller chip (such as...). Figure 3 As shown in the U1 diagram, the main microcontroller generates timing trigger signals based on the chip's internal timer and outputs them at the corresponding output terminals of the chip.

[0095] Optocoupler circuit (e.g.) Figure 3 The circuit based on optocouplers G1-G8 consists of multiple optocouplers, which are respectively set between the output of the main microcontroller chip and the relay circuit to achieve electrical signal isolation between the main timing control circuit side and the relay circuit side.

[0096] A relay circuit includes multiple relay devices (such as...) Figure 3 K1-K8 in the middle, Figure 6 In the J1-J5 section, multiple relay devices are connected to optocoupler circuits and interface components to generate the timing signals required for aircraft engine starting under the combined action of external signals and timing trigger signals.

[0097] For example, such as Figure 3 As shown, the optocoupler circuit includes seven first optocouplers (corresponding to...). Figure 3 (Circuits based on G2-G8 in China);

[0098] like Figure 4 As shown, the first optocoupler circuit includes a first resistor R101, a second resistor R102, a third resistor R103, a first optocoupler G101, and a first transistor T101; in the first optocoupler circuit,

[0099] One end of the first resistor R101 serves as the input terminal of the circuit. Figure 4(As shown in Figure A) is connected to one output terminal of the main microcontroller chip (e.g. Figure 5 One end of the microcontroller chip's I / O pin P1.1 is connected to the first terminal of the first optocoupler G101's input side, and the second terminal of the first optocoupler G101's input side is connected to the first power supply terminal VCC1.

[0100] The first terminal of the output side of the first optocoupler G101 is connected to the second power supply terminal VCC2. The second terminal of the output side of the first optocoupler G101 is connected to the base of the first transistor T101 through the second resistor R102. The base of the first transistor T101 is also connected to the ground terminal GND along with the emitter of the first transistor T101 through the third resistor R103. The collector of the first transistor T101 serves as the output terminal of this circuit. Figure 4 (As shown in Figure B) Connect to the relay circuit.

[0101] Furthermore, to meet different isolation requirements, such as Figure 3 As shown, the optocoupler circuit also includes a second optocoupler circuit (corresponding to...). Figure 3 (Circuit implemented based on G1 in China);

[0102] like Figure 5 As shown, the second optocoupler circuit includes a fourth resistor R104, a fifth resistor R105, a sixth resistor R106, a seventh resistor R107, a first capacitor C101, a second capacitor C102, a second optocoupler G102, and a second transistor T102; in the second optocoupler circuit,

[0103] One end of the fourth resistor R104 serves as the input terminal of this circuit. Figure 5 (As shown in Figure C) One end is connected to one output terminal of the main microcontroller chip, and the other end is connected to the first terminal of the input side of the second optocoupler G102. The second terminal of the input side of the second optocoupler G102 is connected to the first power supply terminal VCC1.

[0104] The first terminal of the output side of the second optocoupler G102 is connected to the second power supply terminal VCC2. The second terminal of the output side of the second optocoupler G102 is connected to the base of the second transistor T102 through the fifth resistor R105. The base of the second transistor T102 is also connected to the ground terminal GND along with the emitter of the second transistor T102 through the sixth resistor R106. The collector of the second transistor T102 serves as the output terminal of this circuit. Figure 5 (As shown in Figure D) is connected to the relay circuit.

[0105] The second terminal of the output side of the second optocoupler G102 is also connected to one end of the seventh resistor R107, and the other end of the seventh resistor R107 is connected to the ground terminal GND through the first capacitor C101 and the second capacitor C102 respectively.

[0106] In this embodiment, such as Figure 3 and Figure 6 The diagram shown is a schematic illustration of the timing control main circuit; in which, Figure 3 The main timing control circuit is shown. Figure 3 The lower part consists of a microcontroller-based circuit and peripheral support circuits, such as crystal oscillator circuits, power supply circuits, etc., as well as optocoupler circuits. Figure 3 (The middle part of the circuit) Figure 3 upper part and Figure 6 This mainly shows the relay circuit in the timing control main circuit.

[0107] The following is based on Figure 3 and Figure 6 The relay circuit is explained and introduced as follows:

[0108] like Figure 6 As shown, in this embodiment, the interface component includes a first connector CZ1, a second connector CZ2, and a third connector CZ3;

[0109] like Figure 3 As shown, the relay circuit includes a first relay K1, a second relay K2, a third relay K3, a fourth relay K4, a fifth relay K5, a sixth relay K6, a seventh relay K7, and an eighth relay K81, each having a set of contacts, and as shown... Figure 6 As shown, the relay circuit also includes a first contact relay J1, a second contact relay J2, a third contact relay J3, a fourth contact relay J4, and a fifth contact relay J5, each with two or more sets of contacts; in the relay circuit,

[0110] like Figure 3 As shown, the coil of the first relay K1 (referring to the lower end of the coil in the figure) is connected to the output terminal of the second optocoupler circuit (an optocoupler circuit implemented based on G1). The coils of the second relay K2, third relay K3, fourth relay K4, fifth relay K5, sixth relay K6, seventh relay K7, and eighth relay K81 (referring to the lower end of the coil in the figure) are respectively connected to the output terminal of the first optocoupler circuit. It should be noted that the upper end of the coil of the first relay K1 is shared with the normally open contact of the first relay K1, and the upper ends of the coils of the second relays K2 to K8 are shared with the normally open terminals J1-E1 of the fifth group of contacts of the first contact relay J1.

[0111] like Figure 6As shown, the normally closed contact of the first relay K1 is connected to the 8th terminal of the second connector CZ2. The normally open contact of the first relay K1, the common terminal of the contacts of the sixth relay K6, the normally open terminal of the 6th group of contacts of the first contact relay J1, and the first terminal X1 of the coil of the third contact relay J3 are all connected to the 4th terminal of the first connector CZ1. The second terminal X2 of the coil of the third contact relay J3 is connected to the ground terminal.

[0112] like Figure 6 As shown, the normally open contact of the second relay K2 is connected to the second terminal of the third connector CZ3. The common contact of the second relay K2 is shared with the common contact of the third relay K3, the common contact of the fourth relay K4, and the normally open contact of the fifth group of contacts of the first contact relay J1.

[0113] The normally open contact of the third relay K3 is connected to terminal 7 of the third connector CZ3, and the normally closed contact of the third relay K3 is connected to the normally open contact of the second group of contacts of the second contact relay J2.

[0114] The normally closed contact of the fourth relay K4 is connected to terminal 1 of the third connector CZ3. The normally open contact of the fourth relay K4 is connected to terminal X1 of the coil of the second contact relay J2. Terminal X2 of the coil of the second contact relay J2 is connected to the ground terminal.

[0115] The normally closed contact of the fifth relay K5 is connected to the sixth terminal of the second connector CZ2, and the common contact of the fifth relay K5 is connected to the normally open contact of the fourth group of contacts of the first contact relay J1.

[0116] The normally open contact of the sixth relay K6 is connected to the first terminal X1 of the coil of the fifth relay J5, and the second terminal X2 of the coil of the fifth relay J5 is connected to the ground terminal.

[0117] The common terminal of the seventh relay K7 is connected to the normally open terminal of the first group of contacts of the first contact relay J1. The normally closed terminal of the seventh relay K7, the first coil terminal X1 of the first contact relay J1, and the normally closed terminal of the first group of contacts of the third contact relay J3 are all connected to the sixth terminal of the first connector CZ1.

[0118] The normally closed contact of the eighth relay K81 is connected to the fourth terminal of the second connector CZ2. The common contact of the eighth relay K81 is connected to the common terminal of the first group of contacts of the fourth relay J4. The normally open contact of the eighth relay K81 is shared with the common terminal of the first group of contacts of the second relay J2, the normally open terminal of the first group of contacts of the fourth relay J4, the common terminal of the fourth group of contacts of the first relay J1, the common terminal of the fifth group of contacts of the first relay J1, the common terminal of the sixth group of contacts of the first relay J1, the first terminal of the first connector CZ1, the normally open terminal of the first group of contacts of the third relay J3, the seventh terminal of the second connector CZ2, and the common terminal of the second group of contacts of the third relay J3.

[0119] like Figure 6 As shown, the common terminal of the first group of contacts of the third contact relay J3 is connected to both the first terminal of the second connector CZ2 and the fourth terminal of the third connector CZ3. The normally closed terminal of the second group of contacts of the third contact relay J3 is connected to the second terminal of the first connector CZ1.

[0120] The common terminal of the third group of contacts of the first contact relay J1 is connected to the normally closed terminal of the first group of contacts of the fourth contact relay J4. The common terminal of the second group of contacts of the first contact relay J1 is shared with the fifth terminal of the first connector CZ1, the common terminal of the first group of contacts of the fifth contact relay J5, and the common terminal of the second group of contacts of the fifth contact relay J5.

[0121] The common terminal of the first group of contacts of the first contact relay J1 is connected to the eighth terminal of the first connector CZ1, and the second terminal of the coil of the first contact relay J1 is used to connect to the second terminal of the second connector CZ2 (it should be noted here that...) Figure 6 The circuit diagram shown is that of a preferred embodiment with fault monitoring function, and in this embodiment... Figure 6 (Short-circuited between secondary board X2+ and secondary board X1-)

[0122] like Figure 6 As shown, in the relay circuit, the first terminal X1 of the coil of the fourth contact relay J4 is connected to the normally open terminal of the second group of contacts of the first contact relay J1; the second terminal X2 of the coil of the fourth contact relay J4 is connected to the ground terminal; the common terminal of the second group of contacts of the fourth contact relay J4 is shared with the normally open terminal of the second group of contacts of the fifth contact relay J5 and the third terminal of the third connector CZ3; and the normally open terminal of the second group of contacts of the fourth contact relay J4 is connected to the public terminal of the second group of contacts of the second contact relay J2.

[0123] The normally open terminal of the first group of contacts of the second contact relay J2 is connected to the third terminal of the second connector CZ2 and the fifth terminal of the third connector CZ3. The common terminal of the third group of contacts of the second contact relay J2 is connected to the sixth terminal of the third connector CZ3. The normally open terminal of the third group of contacts of the second contact relay J2 is connected to the normally open terminal of the first group of contacts of the fifth contact relay J5.

[0124] Based on the specific requirements of the application scenario, as a preferred method to achieve fault monitoring output function, such as... Figure 1 , 2 As shown, the circuit board assembly 200 also includes a sub-circuit board 220 for carrying a fault output circuit;

[0125] like Figure 7 As shown, the fault output circuit includes:

[0126] Sub-timing control circuit ( Figure 7 The lower part (based on a microcontroller and peripheral support circuits) is used to generate the reference timing trigger signal required for fault detection;

[0127] Multiple comparator circuits ( Figure 7 The circuitry on the left middle and upper part is used to compare the timing trigger signal on the main circuit board with the reference timing trigger signal on the sub-circuit board, respectively.

[0128] Fault alarm and disconnection circuit ( Figure 7 The circuit on the right is used to respond to the output indication level of the comparator circuit and trigger the generation of a fault alarm signal to be sent out.

[0129] Specifically, the secondary timing control circuit here is based on a secondary microcontroller chip ( Figure 7 The main microcontroller chip (U1) is configured with the same configuration as the main microcontroller chip (meaning the chip model and the built-in timer setting parameter values ​​are the same), and the two chips are powered on and started at the same time. Therefore, it is obvious that in the application, the main microcontroller chip can output the same signal level as the main microcontroller chip synchronously with the corresponding output pin, that is, the "reference timing trigger signal" pointed out in this application.

[0130] Specifically, such as Figure 7 As shown, the comparator circuit is implemented based on a rectifier bridge circuit (corresponding to...). Figure 7 Circuits implemented based on Z2-Z8;

[0131] As will be readily understood by those skilled in the art, the rectifier bridge here is an equal-arm bridge constructed from four rectifier diodes. Taking Z8 as an example, when there is a potential difference between the two AC input terminals, the rectifier bridge will output a signal, i.e., as shown below. Figure 7 The timing trigger signal represented by network label K8, and the corresponding reference timing trigger signal (corresponding to...) Figure 7When the potential at the upper end of resistor R1 is input to Z8, if a potential difference exists, rectifier bridge Z8 will have an output. This output is used to characterize whether there is an output fault on the main circuit board.

[0132] Furthermore, it should be noted that when a potential difference exists, Figure 7 The third terminal of Z8 outputs a positive voltage. Figure 7 The voltage difference between terminals 3 and 4 of Z8 is controlled by a Zener diode W1. The voltage difference will only be activated when the voltage difference exceeds the rated value of W1. Figure 7 When the optocoupler G1 is turned on, it sends an indication signal to the fault alarm and disconnection circuit. This setting can effectively prevent false alarms caused by line imbalance.

[0133] like Figure 7 As shown, the fault alarm and disconnection circuit in the fault output circuit includes a first contact first relay J101, a first contact second relay J102, and a first contact third relay J103; in the fault alarm and disconnection circuit:

[0134] The first terminal of the coil of the first contact first sub-relay J101, the first terminal of the coil of the first contact second sub-relay J102, and the first terminal of the coil of the first contact third sub-relay J103 are all connected to the first terminal of the first connector CZ1. The second terminals of the coils of the first contact first sub-relay J101 and the first contact second sub-relay J102 are used to receive the output indication of the comparator circuit. The second terminal of the coil of the first contact third sub-relay J103 is used to connect to the normally open terminal J1-E1 of the fifth group of contacts of the first contact relay J1.

[0135] The normally open terminal of the first group of contacts of the first contact first branch relay J101 is connected to the second terminal of the coil of the first contact first branch relay J101. The common terminal of the first group of contacts of the first contact first branch relay J101 and the common terminal of the second group of contacts of the first contact first branch relay J101 are connected to the ground terminal. The normally open terminal of the second group of contacts of the first contact first branch relay J101 is connected to the third terminal CZ1-C of the first connector CZ1.

[0136] The normally closed contact of the first contact second sub-relay J102 is connected in series between the second terminal of the coil of the first contact relay J1 and the second terminal of the second connector CZ2. That is, the normally closed contact pairs of the first contact second sub-relay J102 are respectively connected to the circuit network shown in X2+ and X2- (see details). Figure 6 and Figure 7 (Related parts),

[0137] The normally open contact of the first contact third sub-relay J103 is connected to the first end of the coil of the first contact third sub-relay J103. The common contact of the first contact third sub-relay J103 is connected to the 8th terminal CZ3-H of the third connector CZ3.

[0138] Furthermore, as a preferred option, Figure 7 The fault output circuit shown in the figure also has an RC delay circuit on the output side of the comparator circuit. In practice, a certain delay time (such as 0.5S) can be adjusted and set as the alarm tolerance time to filter out noise interference and avoid false alarms in the system.

[0139] In practice, the resistor and capacitor parameters are selected based on the delay time T = R * C. After the comparator circuit outputs the difference signal, Figure 7 In the circuit, resistor R15 charges capacitor C4. When the voltage across C4 reaches approximately 0.7V (the base turn-on voltage of transistor T1), transistor T1 conducts, activating relays J101 and J102. The normally closed contacts X2+ and X2- of relay J102 open, outputting a cut-off signal to relay J1 in the main circuit. Simultaneously, relay J101 engages, transmitting a fault alarm signal via CZ1-C.

[0140] Furthermore, such as Figure 1 and Figure 2 As shown, the circuit board assembly 200 also includes a protective circuit board 230 carrying a protective circuit;

[0141] The protective circuit board 230 is connected to the pins of each connector and is used for lightning indirect effect protection according to the signal type of the pin, as well as for protection management of the power supply of the device according to the characteristics of the aircraft power supply.

[0142] It will be readily understood by those skilled in the art that, in order to achieve the above-mentioned protection objectives, surge suppression circuits, lightning protection devices, EMI filter circuits, etc., can be used to implement the protection circuit board 230. The implementation principles and methods of these circuits and related devices can be found in existing publicly available technical materials, and will not be described in detail here.

[0143] Finally, let me give a general overview of the technical solution of this application, such as... Figure 8 As shown, the timing device in this application transmits signals to external devices (peripheral load devices) via three connectors (CZ1, CZ2, and CZ3). During signal input and output, a protection circuit filters the signals and protects the circuit before connecting to the internal functional circuit. The main timing control circuit is responsible for outputting timing signals, while the fault output circuit is responsible for urgently stopping the timing signal output and sending a fault signal when a system fault occurs. The timing device triggers relay switches according to a specific timing sequence through the main timing control circuit, completing the aircraft engine starting process.

[0144] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0145] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0146] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0147] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0148] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A timing device for starting an aircraft engine, characterized in that, include: Housing components; A circuit board assembly, disposed within the housing assembly, is used to generate timing signals required for starting the aircraft engine upon triggering by an external signal. An interface component, disposed on the housing assembly, is used to provide an interface for the external signal input and the timing signal output; The circuit board assembly includes a main circuit board carrying a timing control main circuit, which is implemented based on a main timing control circuit, an optocoupler circuit, and a relay circuit. The main timing control circuit is implemented based on the main microcontroller chip. The main microcontroller chip generates timing trigger signals based on the chip's internal timer and outputs them at the chip's corresponding output terminals. The optocoupler circuit is a plurality of such circuits, and the plurality of such optocoupler circuits are respectively disposed between the output terminal of the main microcontroller chip and the relay circuit, for the purpose of achieving electrical signal isolation between the main timing control circuit side and the relay circuit side. The relay circuit includes multiple relay devices, which are connected to the optocoupler circuit and the interface component to generate the timing signal required for starting the aircraft engine under the combined action of the external signal and the timing trigger signal. The optocoupler circuit includes seven first optocoupler circuits; The first optocoupler circuit includes a first resistor (R101), a second resistor (R102), a third resistor (R103), a first optocoupler (G101), and a first transistor (T101); in the first optocoupler circuit, One end of the first resistor (R101) is connected to an output terminal of the main microcontroller chip as the input terminal of the circuit, and the other end is connected to the first terminal of the input side of the first optocoupler (G101). The second terminal of the input side of the first optocoupler (G101) is connected to the first power supply terminal. The first terminal of the output side of the first optocoupler (G101) is connected to the second power supply terminal. The second terminal of the output side of the first optocoupler (G101) is connected to the base of the first transistor (T101) through the second resistor (R102). The base of the first transistor (T101) is also connected to the ground terminal together with the emitter of the first transistor (T101) through the third resistor (R103). The collector of the first transistor (T101) is connected to the relay circuit as the output terminal of the circuit.

2. The timing device for starting an aircraft engine according to claim 1, characterized in that, The optocoupler circuit also includes a second optocoupler circuit; The second optocoupler circuit includes a fourth resistor (R104), a fifth resistor (R105), a sixth resistor (R106), a seventh resistor (R107), a first capacitor (C101), a second capacitor (C102), a second optocoupler (G102), and a second transistor (T102); in the second optocoupler circuit, One end of the fourth resistor (R104) is connected to an output terminal of the main microcontroller chip as the input terminal of the circuit, and the other end is connected to the first terminal of the input side of the second optocoupler (G102). The second terminal of the input side of the second optocoupler (G102) is connected to the first power supply terminal. The first terminal of the output side of the second optocoupler (G102) is connected to the second power supply terminal. The second terminal of the output side of the second optocoupler (G102) is connected to the base of the second transistor (T102) through the fifth resistor (R105). The base of the second transistor (T102) is also connected to the ground terminal along with the emitter of the second transistor (T102) through the sixth resistor (R106). The collector of the second transistor (T102) serves as the output terminal of this circuit and is connected to the relay circuit. The second terminal of the output side of the second optocoupler (G102) is also connected to one end of the seventh resistor (R107), and the other end of the seventh resistor (R107) is connected to the ground terminal through the first capacitor (C101) and the second capacitor (C102).

3. The timing device for starting an aircraft engine according to claim 2, characterized in that, The interface component includes a first connector (CZ1), a second connector (CZ2), and a third connector (CZ3); The relay circuit includes a first relay (K1), a second relay (K2), a third relay (K3), a fourth relay (K4), a fifth relay (K5), a sixth relay (K6), a seventh relay (K7), and an eighth relay (K81) having one set of contacts, and a first contact relay (J1), a second contact relay (J2), a third contact relay (J3), a fourth contact relay (J4), and a fifth contact relay (J5) having two or more sets of contacts; in the relay circuit, The coil of the first relay (K1) is connected to the output terminal of the second optocoupler circuit, and the coils of the second relay (K2), third relay (K3), fourth relay (K4), fifth relay (K5), sixth relay (K6), seventh relay (K7), and eighth relay (K81) are respectively connected to the output terminal of the first optocoupler circuit. The normally closed contact of the first relay (K1) is connected to terminal 8 of the second connector (CZ2). The normally open contact of the first relay (K1) shares a common terminal with the contacts of the sixth relay (K6), the normally open contact of the sixth group of contacts of the first contact relay (J1), and the first coil terminal of the third contact relay (J3) with terminal 4 of the first connector (CZ1). The second coil terminal of the third contact relay (J3) is connected to the ground terminal. The normally open contact of the second relay (K2) is connected to the second terminal of the third connector (CZ3). The common contact terminal of the second relay (K2) is shared with the common contact terminal of the third relay (K3), the common contact terminal of the fourth relay (K4), and the normally open contact terminal of the fifth group of contacts of the first contact relay (J1). The normally open contact of the third relay (K3) is connected to terminal 7 of the third connector (CZ3), and the normally closed contact of the third relay (K3) is connected to the normally open contact of the second group of contacts of the second contact relay (J2). The normally closed contact of the fourth relay (K4) is connected to terminal 1 of the third connector (CZ3), and the normally open contact of the fourth relay (K4) is connected to the first terminal of the coil of the second contact relay (J2). The second terminal of the coil of the second contact relay (J2) is connected to the ground terminal. The normally closed contact of the fifth relay (K5) is connected to terminal 6 of the second connector (CZ2), and the common contact of the fifth relay (K5) is connected to the normally open contact of the fourth group of contacts of the first contact relay (J1). The normally open contact of the sixth relay (K6) is connected to the first terminal of the coil of the fifth contact relay (J5), and the second terminal of the coil of the fifth contact relay (J5) is connected to the ground terminal. The common terminal of the seventh relay (K7) is connected to the normally open terminal of the first group of contacts of the first contact relay (J1). The normally closed contact of the seventh relay (K7), the first coil terminal of the first contact relay (J1), and the normally closed contact of the first group of contacts of the third contact relay (J3) are all connected to the sixth terminal of the first connector (CZ1). The normally closed contact of the eighth relay (K81) is connected to terminal 4 of the second connector (CZ2). The common contact of the eighth relay (K81) is connected to the common terminal of the first group of contacts of the fourth contact relay (J4). The normally open contact of the eighth relay (K81) is shared with the common terminal of the first group of contacts of the second contact relay (J2), the normally open terminal of the first group of contacts of the fourth contact relay (J4), the common terminal of the fourth group of contacts of the first contact relay (J1), the common terminal of the fifth group of contacts of the first contact relay (J1), the common terminal of the sixth group of contacts of the first contact relay (J1), terminal 1 of the first connector (CZ1), the normally open terminal of the first group of contacts of the third contact relay (J3), terminal 7 of the second connector (CZ2), and the common terminal of the second group of contacts of the third contact relay (J3). The common terminal of the first group of contacts of the third contact relay (J3) is connected to both the first terminal of the second connector (CZ2) and the fourth terminal of the third connector (CZ3). The normally closed terminal of the second group of contacts of the third contact relay (J3) is connected to the second terminal of the first connector (CZ1). The common terminal of the third group of contacts of the first contact relay (J1) is connected to the normally closed terminal of the first group of contacts of the fourth contact relay (J4). The common terminal of the second group of contacts of the first contact relay (J1) is shared with the fifth terminal of the first connector (CZ1), the common terminal of the first group of contacts of the fifth contact relay (J5), and the common terminal of the second group of contacts of the fifth contact relay (J5). The common terminal of the first group of contacts of the first contact relay (J1) is connected to the eighth terminal of the first connector (CZ1), and the second terminal of the coil of the first contact relay (J1) is used to connect to the second terminal of the second connector (CZ2). The first terminal of the coil of the fourth contact relay (J4) is connected to the normally open terminal of the second group of contacts of the first contact relay (J1). The second terminal of the coil of the fourth contact relay (J4) is connected to the ground terminal. The common terminal of the second group of contacts of the fourth contact relay (J4) is shared with the normally open terminal of the second group of contacts of the fifth contact relay (J5) and the third terminal of the third connector (CZ3). The normally open terminal of the second group of contacts of the fourth contact relay (J4) is connected to the public terminal of the second group of contacts of the second contact relay (J2). The normally open terminal of the first group of contacts of the second contact relay (J2) is connected to the third terminal of the second connector (CZ2) and the fifth terminal of the connector (CZ3). The common terminal of the third group of contacts of the second contact relay (J2) is connected to the sixth terminal of the third connector (CZ3). The normally open terminal of the third group of contacts of the second contact relay (J2) is connected to the normally open terminal of the first group of contacts of the fifth contact relay (J5).

4. The timing device for starting an aircraft engine according to claim 3, characterized in that, The circuit board assembly also includes a sub-circuit board for carrying a fault output circuit; The fault output circuit includes: The secondary timing control circuit is used to generate the reference timing trigger signal required for fault detection; Multiple comparison circuits are used to respectively compare the timing trigger signal on the main circuit board with the reference timing trigger signal on the sub-circuit board; The fault alarm and disconnection circuit is used to respond to the output indication level of the comparison circuit and trigger the generation of a fault alarm signal to be transmitted externally.

5. The timing device for starting an aircraft engine according to claim 4, characterized in that, The secondary timing control circuit is implemented based on a secondary microcontroller chip, which has the same configuration as the primary microcontroller chip, and both chips are powered on and started simultaneously; the comparator circuit is implemented based on a rectifier bridge circuit. The fault alarm and disconnection circuit includes a first sub-relay (J101), a second sub-relay (J102), and a third sub-relay (J103); in the fault alarm and disconnection circuit: The first terminal of the coil of the first relay (J101), the first terminal of the coil of the second relay (J102), and the first terminal of the coil of the third relay (J103) are all connected to the first terminal of the first connector (CZ1). The second terminal of the coil of the first relay (J101) and the second terminal of the coil of the second relay (J102) are used to receive the output indication of the comparison circuit. The second terminal of the coil of the third relay (J103) is used to connect to the normally open terminal of the fifth group of contacts of the first contact relay (J1). The normally open terminal of the first group of contacts of the first branch relay (J101) is connected to the second terminal of the coil of the first branch relay (J101). The common terminal of the first group of contacts of the first branch relay (J101) and the common terminal of the second group of contacts of the first branch relay (J101) are connected to the ground terminal. The normally open terminal of the second group of contacts of the first branch relay (J101) is connected to the third terminal of the first connector (CZ1). The normally closed contact of the second relay (J102) is connected in series between the second terminal of the coil of the first contact relay (J1) and the second terminal of the second connector (CZ2). The normally open contact of the third relay (J103) is connected to the first terminal of the coil of the third relay (J103), and the common contact of the third relay (J103) is connected to the 8th terminal of the third connector (CZ3).

6. The timing device for starting an aircraft engine according to claim 1, characterized in that, The circuit board assembly also includes a protective circuit board carrying protective circuitry; The protection circuit is connected to the pins of each connector and is used for lightning indirect effect protection based on the signal type of the pin, as well as for protection management of the power supply of the device according to the power characteristics requirements of the aircraft.

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