Aero-engine starting ignition fault detection circuit

Abstract

The invention belongs to the technical field of aero-engine starting ignition circuit fault detection, and particularly relates to an aero-engine starting ignition fault detection circuit which is characterized in that a sampling circuit is designed in a discharge loop of an ignition circuit, and a sampled discharge signal is subjected to rectification and signal conversion; and a timing circuit and a time-delay circuit are utilized to output stable resistance values for normal working of the circuit, and if the aero-engine start ignition fault occurs and no sampling signal exists, the corresponding resistance value during the fault is output, so that the detection of the aero-engine start ignition fault is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of aircraft engine starting ignition circuit fault detection, and specifically relates to an aircraft engine starting ignition fault detection circuit. Background Art

[0002] Aircraft engine starting ignition circuit Figure 1 As shown. After the input power supply voltage is filtered by inductor L1, capacitor C1, capacitor C2, and capacitor C3, it provides driving current to transistor Q3 through resistor R2. After transistor Q3 is turned on, the power supply current increases linearly through the primary winding N1 of transformer T1. At this time, the voltage induced by winding N3 of transformer TI provides positive feedback for the conduction of transistor Q3, making the circuit current reach the maximum value I P In the positive feedback process, the current induced in the winding N3 of the transformer TI forms a current loop through the transistor Q3, the resistor R5, the transistor Q1, the diode D5, the potentiometer RP1, the resistor R3, and the resistor R4. Under different input voltages, the voltage drop of the diode D4 will change.

[0003] If the conduction voltage drop of diode D4 increases, the voltage required when transistor Q1 is turned on will increase, so that the voltage drop on potentiometer RP1, resistor R3, and resistor R4 will decrease, and the current in the loop will decrease. If the conduction voltage drop of diode D4 decreases, the voltage required when transistor Q1 is turned on will decrease, so that the voltage drop on potentiometer RP1, resistor R3, and resistor R4 will increase, and the current in the loop will increase. Therefore, transistor Q1 adjusts the current size of the feedback loop, which is equivalent to the role of a variable resistor. When the circuit current reaches the maximum value I P When , transistor Q2 is turned on and transistor Q3 is turned off, which plays a role in current protection.

[0004] When the transistor Q3 is turned off, the reverse voltage induced by the winding N2 of the transformer TI charges the energy storage capacitor C4. When the voltage across the capacitor C4 reaches the breakdown voltage of the discharge tube V1, the discharge tube V1 breaks down and conducts to transmit the high-voltage electric energy stored in the capacitor C4 to the end of the ignition nozzle through the ignition cable for discharge, thereby starting and igniting the aircraft engine.

[0005] Since the ignition nozzle is installed inside the aircraft engine, it is difficult to visually determine whether the aircraft engine starting ignition device is faulty when it is powered on. In view of this, the present application is filed. Summary of the invention

[0006] The purpose of the present application is to provide an aircraft engine starting ignition fault detection circuit, so as to detect whether the aircraft engine starting ignition fails under power supply conditions.

[0007] The technical solution of this application is:

[0008] An aircraft engine starting ignition fault detection circuit includes a resistor R7, a photoelectric isolator U1, a 555 oscillator U2, a transistor Q4, a transistor Q5, a single-pole single-throw normally closed relay J1, a resistor R13, a resistor R15, and a resistor R14;

[0009] The resistor R7 is arranged on the discharge loop of the ignition circuit to collect the discharge signal when the aircraft engine starting ignition device is powered on and working normally;

[0010] Both ends of the resistor R7 are connected to the first and second pins of the input end of the photoelectric isolator U1, and the fourth and third pins of the output end of the photoelectric isolator U1 are connected to the positive and negative electrodes of the power supply VCC;

[0011] The second pin of the 555 oscillator U2 is connected to the fourth pin of the output end of the photoelectric isolator U1, the third pin is connected to the base of the transistor Q4, the collector of the transistor Q4 is connected to the positive electrode of the power supply VCC, and the emitter is connected to the negative electrode of the power supply VCC;

[0012] The base of transistor Q5 is connected to the emitter of transistor Q4, the collector is connected to the positive electrode of power supply VCC, the emitter is connected to the negative electrode of power supply VCC, and the collector is connected to the control end of single-pole single-throw normally closed relay J1;

[0013] The discharge signal sampled by the resistor R7 is converted into a negative pulse after being photoelectrically isolated, triggering the second pin of the 555 oscillator U2, outputting a high-level signal at the third pin, thereby turning on the transistors Q4 and Q5, and converting the single-pole single-throw normally closed relay J1 to a normally open state;

[0014] When the SPST normally closed relay J1 is in the normally open state, the resistors R15 and R14 are connected and a normal resistance signal is output, which corresponds to the normal operation of the aircraft engine starting ignition device when it is powered on;

[0015] When the SPST normally closed relay J1 is in the normally closed state, the resistor R13 is connected and the output resistance value corresponds to the aircraft engine starting ignition fault.

[0016] According to at least one embodiment of the present application, in the above-mentioned aircraft engine starting ignition fault detection circuit, a diode D10 and a resistor R8 are connected between the resistor R7 and the positive electrode of the control end of the photoelectric isolator U1, and a capacitor C5, a capacitor C6 and a resistor R9 are connected between the positive electrode of the control end of the photoelectric isolator U1;

[0017] The connection node of the capacitor C5, the capacitor C6, and the resistor R9 on the positive electrode of the control end of the photoelectric isolator U1 is located between the diode D10 and the resistor R8.

[0018] According to at least one embodiment of the present application, in the above-mentioned aircraft engine starting ignition fault detection circuit, the emitter of the transistor Q4 is connected to the negative electrode of the power supply VCC through the capacitor C9.

[0019] According to at least one embodiment of the present application, in the above-mentioned aircraft engine starting ignition fault detection circuit, the sixth and seventh pins of the 555 oscillator U2 are connected to the positive electrode of the power supply VCC through the resistor R11, and the second pin is connected to the negative electrode of the power supply VCC through the capacitor C7.

[0020] According to at least one embodiment of the present application, in the above-mentioned aircraft engine starting ignition fault detection circuit, the fourth and eighth pins of the 555 oscillator U2 are connected to the positive electrode of the power supply VCC, the first pin is connected to the negative electrode of the power supply VCC, and the fifth pin is connected to the negative electrode of the power supply VCC through the capacitor C8.

[0021] According to at least one embodiment of the present application, in the above-mentioned aircraft engine starting ignition fault detection circuit, the fourth pin of the output end of the photoelectric isolator U1 is connected to the positive electrode of the power supply VCC through the resistor R10.

[0022] According to at least one embodiment of the present application, in the above-mentioned aircraft engine starting ignition fault detection circuit, a resistor R12 is arranged between the emitter of the transistor Q4 and the base of the transistor Q5.

[0023] This application has at least the following beneficial technical effects:

[0024] Provided is an aircraft engine starting ignition fault detection circuit. A sampling circuit is designed in the discharge loop of the ignition circuit to rectify and convert the sampled discharge signal. A timing circuit and a delay circuit are used to output a stable resistance value for the normal operation of the circuit. If the aircraft engine starting ignition fault occurs and there is no sampling signal, the resistance value corresponding to the fault is output, thereby realizing the detection of the aircraft engine starting ignition fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of an existing aircraft engine starting ignition circuit;

[0026] Figure 2 It is a schematic diagram of an aircraft engine starting ignition fault detection circuit provided by an embodiment of the present application;

[0027] Figure 3 Schematic diagram of the resistor R7 in the aircraft engine starting ignition fault detection circuit provided in the embodiment of the present application, which is set in the aircraft engine starting ignition fault detection circuit

[0028] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0029] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0030] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0031] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0032] When the aircraft engine starting ignition device is powered on and working normally, the ignition nozzle end discharges, and a large current is generated in the ignition circuit discharge loop. Based on this, the present application provides an aircraft engine starting ignition fault detection circuit, such as Figure 1 As shown, the output resistance value is used to determine whether the ignition device is working normally, thereby realizing the detection of the aircraft engine starting ignition failure.

[0033] Resistor R7 is a sampling resistor, which is set in the discharge loop of the ignition circuit. Figure 3 As shown, when the aircraft engine starting ignition device is powered on and working normally, a large voltage will be generated across the resistor R7, which is a discharge signal.

[0034] Both ends of the resistor R7 are connected to the first and second pins of the input end of the photoelectric isolator U1 , and the fourth and third pins of the output end of the photoelectric isolator U1 are connected to the positive and negative electrodes of the power supply VCC.

[0035] A diode D10 and a resistor R8 are connected between the resistor R7 and the first pin of the input end of the photoelectric isolator U1, and a capacitor C5, a capacitor C6 and a resistor R9 are connected between the first and second pins of the input end of the photoelectric isolator U1. The connection node of the capacitor C5, the capacitor C6 and the resistor R9 on the first pin of the input end of the photoelectric isolator U1 is between the diode D10 and the resistor R8.

[0036] The resistor R8 is a voltage-dropping resistor, and the diode D10, the capacitor C5, the capacitor C6 and the resistor R9 form a rectification and filtering circuit, which rectifies and filters the discharge signal sampled by the resistor R7, and then isolates it through the photoelectric isolator U1.

[0037] The second pin of the 555 oscillator U2 is connected to the fourth pin of the output end of the photoelectric isolator U1, the third pin is connected to the base of the transistor Q4, the collector of the transistor Q4 is connected to the positive pole of the power supply VCC, and the emitter is connected to the negative pole of the power supply VCC.

[0038] The base of transistor Q5 is connected to the emitter of transistor Q4, the collector is connected to the positive electrode of power supply VCC, the emitter is connected to the negative electrode of power supply VCC, and the collector is connected to the control end of single-pole single-throw normally closed relay J1.

[0039] The discharge signal sampled by the resistor R7 is converted into a negative pulse after rectification, filtering and photoelectric isolation, triggering the second pin of the 555 oscillator U2. Through the timing circuit in the 555 oscillator U2, the third pin of the 555 oscillator U2 is triggered to output a high-level signal for a certain period of time, thereby turning on the transistors Q4 and Q5, and converting the single-pole single-throw normally closed relay J1 to a normally open state.

[0040] When the single-pole single-throw normally closed relay J1 is in the normally open state, the resistors R15 and R14 are connected, and a normal resistance signal is output, that is, the sum of the resistances of the resistors R15 and R14, corresponding to the normal operation of the aircraft engine starting ignition device when it is powered on.

[0041] When the single-pole single-throw normally closed relay J1 is in a normally closed state, the resistor R13 is connected, and the output resistance value, that is, the resistance of the resistor R13, corresponds to the aircraft engine starting ignition failure.

[0042] The aircraft engine starting ignition fault detection circuit disclosed in the above embodiment designs a sampling circuit in the discharge loop of the ignition circuit, rectifies and converts the sampled discharge signal, and uses a timing circuit and a delay circuit to output a stable resistance value for the normal operation of the circuit. If the aircraft engine starting ignition fault occurs and there is no sampling signal, the corresponding resistance value at the time of the fault is output, thereby realizing the detection of the aircraft engine starting ignition fault.

[0043] The aviation engine starting ignition fault detection circuit disclosed in the above embodiment was tested in high and low temperature environments and its performance was stable, meeting the product technical requirements.

[0044] In order to solve the difference in ignition cycle time during the discharge process, capacitor C9 is added to the emitter of transistor Q4. When transistor Q4 is turned off, capacitor C9 can provide power for transistor Q5 to continue to be turned on, ensuring that when the aircraft engine starting ignition device is powered on and working normally, the detection output has the resistance value when it is working normally. When the aircraft engine starting ignition fails and there is no discharge, transistors Q4 and Q5 are in the off state, the single-pole single-throw normally closed relay J1 switches, and the fault detection outputs the resistance value when the fault occurs.

[0045] The sixth and seventh pins of the 555 oscillator U2 are connected to the positive electrode of the power supply VCC through the resistor R11, and the second pin is connected to the negative electrode of the power supply VCC through the capacitor C7, so that the pulse width of the high-level signal output by the third pin of the 555 oscillator U2 can be designed. Specifically, the pulse width of the high-level signal can be designed to be 128ms.

[0046] The fourth and eighth pins of the 555 oscillator U2 are connected to the positive electrode of the power supply VCC, the first pin is connected to the negative electrode of the power supply VCC, and the fifth pin is connected to the negative electrode of the power supply VCC through the capacitor C8.

[0047] The fourth pin of the output end of the photoelectric isolator U1 is connected to the positive electrode of the power supply VCC through the resistor R10.

[0048] A resistor R12 is arranged between the emitter of the transistor Q4 and the base of the transistor Q5.

[0049] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. An aircraft engine starting ignition fault detection circuit, characterized in that: Including resistor R7, opto-isolator U1, 555 oscillator U2, transistor Q4, transistor Q5, single-pole single-throw normally closed relay J1, resistor R13, resistor R15, resistor R14; The resistor R7 is arranged on the discharge loop of the ignition circuit to collect the discharge signal when the aircraft engine starting ignition device is powered on and working normally; Both ends of the resistor R7 are connected to the first and second pins of the input end of the photoelectric isolator U1, and the fourth and third pins of the output end of the photoelectric isolator U1 are connected to the positive and negative electrodes of the power supply VCC; The second pin of the 555 oscillator U2 is connected to the fourth pin of the output end of the photoelectric isolator U1, the third pin is connected to the base of the transistor Q4, the collector of the transistor Q4 is connected to the positive electrode of the power supply VCC, and the emitter is connected to the negative electrode of the power supply VCC; The base of transistor Q5 is connected to the emitter of transistor Q4, the collector is connected to the positive electrode of power supply VCC, the emitter is connected to the negative electrode of power supply VCC, and the collector is connected to the control end of single-pole single-throw normally closed relay J1; The discharge signal sampled by the resistor R7 is converted into a negative pulse after being photoelectrically isolated, triggering the second pin of the 555 oscillator U2, outputting a high-level signal at the third pin, thereby turning on the transistors Q4 and Q5, and converting the single-pole single-throw normally closed relay J1 to a normally open state; When the SPST normally closed relay J1 is in the normally open state, the resistors R15 and R14 are connected and a normal resistance signal is output, which corresponds to the normal operation of the aircraft engine starting ignition device when it is powered on; When the SPST normally closed relay J1 is in the normally closed state, the resistor R13 is connected and the output resistance value corresponds to the aircraft engine starting ignition fault.

2. The aircraft engine starting ignition fault detection circuit according to claim 1, characterized in that: A diode D10 and a resistor R8 are connected between the resistor R7 and the positive electrode of the control end of the photoelectric isolator U1, and a capacitor C5, a capacitor C6 and a resistor R9 are connected between the positive electrode of the control end of the photoelectric isolator U1; The connection node of the capacitor C5, the capacitor C6, and the resistor R9 on the positive electrode of the control end of the photoelectric isolator U1 is located between the diode D10 and the resistor R8.

3. The aircraft engine starting ignition fault detection circuit according to claim 2, characterized in that: The emitter of transistor Q4 is connected to the negative electrode of power supply VCC through capacitor C9.

4. The aircraft engine starting ignition fault detection circuit according to claim 3, characterized in that: The sixth and seventh pins of the 555 oscillator U2 are connected to the positive electrode of the power supply VCC through the resistor R11, and the second pin is connected to the negative electrode of the power supply VCC through the capacitor C7.

5. The aircraft engine starting ignition fault detection circuit according to claim 4, characterized in that: The fourth and eighth pins of the 555 oscillator U2 are connected to the positive electrode of the power supply VCC, the first pin is connected to the negative electrode of the power supply VCC, and the fifth pin is connected to the negative electrode of the power supply VCC through the capacitor C8.

6. The aircraft engine starting ignition fault detection circuit according to claim 5, characterized in that: The fourth pin of the output end of the photoelectric isolator U1 is connected to the positive electrode of the power supply VCC through the resistor R10.

7. The aircraft engine starting ignition fault detection circuit according to claim 6, characterized in that: A resistor R12 is arranged between the emitter of the transistor Q4 and the base of the transistor Q5.

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