An aeroengine start ignition fault detection circuit

Abstract

The application 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. A sampling circuit is designed in a discharge loop of an ignition circuit, rectification and signal conversion are performed on a sampled discharge signal, a timing circuit and a delay circuit are used to output stable resistance values for normal operation of the circuit, if a starting ignition fault of the aero-engine occurs, no sampling signal is output, and corresponding resistance values are output when a fault occurs, so that detection of the starting ignition fault of the aero-engine is realized.

Description

Technical Field

[0001] This application belongs to the field of aircraft engine starting and ignition circuit fault detection technology, specifically relating to an aircraft engine starting and ignition fault detection circuit. Background Technology

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

[0003] If the forward voltage drop of diode D4 increases, the voltage required for transistor Q1 to conduct will increase. This reduces the voltage drop across potentiometer RP1, resistor R3, and resistor R4, thus decreasing the current in the circuit. Conversely, if the forward voltage drop of diode D4 decreases, the voltage required for transistor Q1 to conduct will decrease. This increases the voltage drop across potentiometer RP1, resistor R3, and resistor R4, thus increasing the current in the circuit. Therefore, transistor Q1 adjusts the current in the feedback loop, acting like a variable resistor. When the circuit current reaches its maximum value I... P When the transistor Q2 is turned on, transistor Q3 is turned off, thus providing current protection.

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

[0005] Since the ignition electrode is installed inside the aircraft engine, it is difficult to visually determine whether the aircraft engine starting ignition device is malfunctioning when it is powered on. Therefore, this application is made. Summary of the Invention

[0006] The purpose of this application is to provide an aircraft engine start-up ignition fault detection circuit, which can detect whether the aircraft engine start-up ignition is faulty under power supply conditions.

[0007] The technical solution of this application is:

[0008] An aero-engine starting ignition fault detection circuit, comprising a resistor R7, an opto-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, a resistor R14;

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

[0010] The first and second pins of the input end of the opto-isolator U1 are connected between the two ends of the resistor R7, and the fourth and third pins of the output end of the opto-isolator U1 are connected to the positive and negative poles 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 opto-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;

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

[0013] After the discharge signal collected by the resistor R7 is optically isolated, it is converted into a negative pulse, triggering the second pin of the 555 oscillator U2, outputting a high-level signal at the third pin, thereby making the transistor Q4 and the transistor Q5 conductive, and making the single-pole single-throw normally closed relay J1 change to a normally open state;

[0014] When the single-pole single-throw normally closed relay J1 is in the normally open state, the resistor R15 and the resistor R14 are connected, and a normal resistance signal is output, corresponding to the normal power supply of the aero-engine starting ignition device;

[0015] When the single-pole single-throw normally closed relay J1 is in the normally closed state, the resistor R13 is connected, and a resistance value is output, corresponding to the aero-engine starting ignition fault.

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

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

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

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

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

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

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

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

[0024] The present application provides an aero-engine starting ignition fault detection circuit. A sampling circuit is designed in the discharge loop of the ignition circuit. The sampled discharge signal is rectified and converted. A timing circuit and a delay circuit are used to output stable resistance values for normal operation of the circuit. If the aero-engine starting ignition fails, there is no sampling signal, and the corresponding resistance value is output when a fault occurs. Thus, the detection of the aero-engine starting ignition fault is realized. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 FIG. 1 is a schematic diagram of a prior aero-engine starting ignition circuit;

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

[0027] Figure 3 FIG. 3 is a schematic diagram of the resistor R7 in the aero-engine starting ignition fault detection circuit provided by an embodiment of the present application;

[0028] For better illustrating the embodiments, some components in the drawings can be omitted, enlarged or reduced, and do not represent the actual product size. In addition, the drawings are only used for illustrative description and cannot be understood as a limitation to the present application. DETAILED DESCRIPTION

[0029] In order to make the technical solutions of the present application and its advantages clearer, the technical solutions of the present application will be further clearly and completely described in detail below in combination with the drawings. It should be understood that the specific embodiments described herein are only part of the embodiments of the present application, which are only used to explain the present application, but not to limit the present application. It should be noted that, for the convenience of description, only parts related to the present application are shown in the drawings, and other related parts can be referred to the general design.

[0030] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present application should be the general meaning understood by the general technical personnel in the field to which the present application belongs. The words indicating the position used in the description of the present application are only used to indicate the relative direction or positional relationship, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly. In the description of the present application, "including" indicates that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, and other elements or objects are not excluded.

[0031] In addition, it should be further noted that, unless otherwise explicitly specified and limited, the "installation", "connection" and other similar words used in the description of the present application should be understood in a broad sense, for example, the connection can be fixed connection, or detachable connection; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, and the person skilled in the art can understand the specific meaning of the present application according to the specific circumstances.

[0032] When the ignition device of the aero-engine is normally powered, the end of the ignition electrode discharges, and a large current is generated on the discharge loop of the ignition circuit. Based on this, the present application provides an aero-engine starting ignition fault detection circuit, as shown in Figure 1 The resistance value of the output is used to judge whether the ignition device works normally, so as to realize the detection of the aero-engine starting ignition fault.

[0033] The resistance R7 is a sampling resistance, which is arranged on the discharge loop of the ignition circuit, as shown in Figure 3 When the ignition device of the aero-engine is normally powered, a large voltage will be generated across the resistance R7, which is a discharge signal.

[0034] The first and second pins of the input end of the opto-isolator U1 are connected across the resistance R7, and the fourth and third pins of the output end of the opto-isolator U1 are connected to the positive and negative poles of the power supply VCC.

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

[0036] The resistor R8 is a voltage reduction resistor, and the diode D10, the capacitor C5, the capacitor C6 and the resistor R9 constitute a rectifier filter circuit, which rectifies and filters the sampled discharge signal of the resistor R7, and then isolates the discharge signal through the photoelectric isolator U1.

[0037] The second pin of the 555 oscillator U2 is connected to the fourth pin of the photoelectric isolator U1 output end, the third pin is connected to the base of the triode Q4, the collector of the triode 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 the triode Q5 is connected to the emitter of the triode Q4, the collector is connected to the positive pole of the power supply VCC, the emitter is connected to the negative pole of the power supply VCC, and the control end of the single-pole single-throw normally closed relay J1 is connected to the collector.

[0039] After the rectification and filtering of the sampled discharge signal of the resistor R7 and the photoelectric isolation, a negative pulse is converted, which triggers the second pin of the 555 oscillator U2, and through the timing circuit in the 555 oscillator U2, a high-level signal of a certain time is output at the third pin of the 555 oscillator U2, so as to make the triode Q4 and the triode Q5 conduct, and make the single-pole single-throw normally closed relay J1 convert to a normally open state.

[0040] When the single-pole single-throw normally closed relay J1 is in the normally open state, the resistor R15 and the resistor R14 are connected, and a normal resistance signal is output, that is, the sum of the resistances of the resistor R15 and the resistor R14, which corresponds to the normal power-on working of the starting ignition device of the aero-engine.

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

[0042] The above-mentioned embodiment discloses an aero-engine starting ignition failure detection circuit, which 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 normal working of the circuit. If there is no sampling signal due to the starting ignition failure of the aero-engine, a corresponding resistance value is output when a failure occurs, so as to realize the detection of the starting ignition failure of the aero-engine.

[0043] The aero-engine starting ignition fault detection circuit disclosed in the above embodiment is subjected to high-temperature and low-temperature environment test verification, and has stable performance and meets the product technical requirements.

[0044] To solve the difference in ignition cycle time during the discharge process, the capacitor C9 is added to the emitter of the triode Q4. When the triode Q4 is turned off, the capacitor C9 can provide power for the continuous conduction of the triode Q5, ensuring that the detection output is normally working when the aero-engine starting ignition device is normally working. When the aero-engine starting ignition fails and there is no discharge, the triode Q4 and the triode Q5 are in the off state, and the single-pole single-throw normally closed relay J1 switch is actuated, and the resistance value of the fault detection output is in the fault state.

[0045] The sixth and seventh pins of the 555 oscillator U2 are connected to the positive pole of the power supply VCC through the resistor R11, and the second pin is connected to the negative pole 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, and the pulse width of the high-level signal can be specifically designed as 128 ms.

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

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

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

[0049] So far, the technical solution of the present application has been described in combination with the preferred embodiments shown in the drawings. It should be understood by those skilled in the art that the protection scope of the present application is obviously not limited to these specific embodiments. Without deviating from the principles of the present application, those skilled in the art can make equivalent changes or replacements to related technical features, and the technical solutions after these changes or replacements will fall within the protection scope of the present application.

Claims

1. An aircraft engine start ignition fault detection circuit, characterized by, 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; Resistor R7 is arranged on the discharge circuit of the ignition circuit, and is used to collect the discharge signal when the aero-engine starting ignition device is normally powered. The first and second pins of the input end of the opto-isolator U1 are connected between the two ends of the resistor R7. The second pin of the 555 oscillator U2 is connected to the fourth pin of the output end of the opto-isolator U1, and 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. The base of the transistor Q5 is connected to the emitter of the transistor Q4, the collector 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. The resistor R7 converts the sampled discharge signal into a negative pulse after photoelectric isolation, triggers the second pin of the 555 oscillator U2, outputs a high-level signal at the third pin, and then makes the transistors Q4 and Q5 conductive, so that the single-pole single-throw normally closed relay J1 is converted into a normally open state. 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, corresponding to the normal power-on working state of the aero-engine starting ignition device. When the single-pole single-throw normally closed relay J1 is in the normally closed state, the resistor R13 is connected, and a resistance value is output, corresponding to the aero-engine starting ignition failure.

2. The aero-engine starting ignition failure detection circuit according to claim 1, wherein a diode D10 and a resistor R8 are connected between the resistor R7 and the positive pole of the control end of the opto-isolator U1, and a capacitor C5, a capacitor C6 and a resistor R9 are connected between the positive poles of the control end of the opto-isolator U1. The connection node of the capacitor C5, the capacitor C6 and the resistor R9 on the positive pole of the control end of the opto-isolator U1 is between the diode D10 and the resistor R8.

3. The aero-engine starting ignition failure detection circuit according to claim 2, wherein the emitter of the transistor Q4 is connected to the negative pole of the power supply VCC through a capacitor C9.

4. The aero-engine starting ignition failure detection circuit according to claim 3, wherein the sixth and seventh pins of the 555 oscillator U2 are connected to the positive pole of the power supply VCC through a resistor R11, and the second pin is connected to the negative pole of the power supply VCC through a capacitor C7.

5. The aero-engine starting ignition failure detection circuit according to claim 4, wherein the fourth and eighth pins of the 555 oscillator U2 are connected to the positive pole of the power supply VCC, the first pin is connected to the negative pole of the power supply VCC, and the fifth pin is connected to the negative pole of the power supply VCC through a capacitor C8.

6. The aero-engine starting ignition failure detection circuit according to claim 5, wherein the fourth pin of the output end of the opto-isolator U1 is connected to the positive pole of the power supply VCC through a resistor R10. ​ ​ ​ ​ 7. The aircraft engine start igniter fault detection circuit of claim 6, wherein, A resistor R12 is connected between the emitter of the transistor Q4 and the base of the transistor Q5.

Images