Spacecraft initiating explosive device excitation circuit

Abstract

The invention discloses a spacecraft initiating explosive device excitation circuit which is characterized in that the circuit comprises a pre-charging circuit, a super capacitor circuit, a power-off self-discharging circuit and an explosion switch circuit which are connected in sequence, a super capacitor is charged through a pre-charging current limiting circuit, and an explosion switch connected in series at the rear end of the super capacitor is in a turn-off protection state; when explosion is needed, the explosion switch circuit receives a control signal of the spacecraft, unlocking protection is carried out, the explosion switch is closed, the super capacitor provides millisecond-level instantaneous explosion large current, and the initiating explosive device is exploded. The high-reliability ignition control system has high reliability and radiation resistance, can meet the harsh environment requirement of on-orbit operation of a spacecraft, adopts three-level insurance to realize high-reliability ignition control, and improves the safety and reliability of the system.

Description

Technical Field

[0001] The present invention relates to the field of spacecraft separation devices, and in particular to the field of spacecraft separation pyrotechnic device excitation. Background Art

[0002] In spacecraft separation systems, ignition of explosive devices typically requires a high instantaneous current. Existing solutions rely on the spacecraft's main battery to provide the ignition current directly, but this increases the battery's power rating, size, and weight. However, ignition time for explosive devices only takes milliseconds, so this traditional solution reduces spacecraft efficiency.

[0003] To address these issues, CN113636111A discloses a hybrid spacecraft electromechanical separation signal system, comprising a separation electrical connector, a limit switch, and an integrated electronic unit on the spacecraft. The separation electrical connector provides an electrical separation signal, the limit switch provides a mechanical separation signal, and the integrated electronic unit collects both the electrical and mechanical separation signals to control the operation of the spacecraft's individual units and the detonation of pyrotechnic devices. While this patent improves the reliability of the separation signal, it still leaves room for optimization in the design of the pyrotechnic device detonation circuit, and cannot effectively reduce the power demand on the main battery.

[0004] CN114498820A discloses a pyrotechnic ignition system, including a supercapacitor charging control circuit, a supercapacitor, a pyrotechnic resistor, and an ignition switch. The supercapacitor charging control circuit charges the supercapacitor and controls the ignition switch to close when ignition is required. The pyrotechnic ignition function is achieved by utilizing the high current of the supercapacitor short-circuit discharge. However, in practice, after the main battery and the supercapacitor are directly connected, the ignition current is initially provided by the main battery with a higher voltage, until the main battery voltage is lowered to the supercapacitor voltage during the ignition process. The patent does not explain how the ignition process avoids affecting the bus voltage and current. There is also room for improvement in the reliability of the ignition switch and the ground storage safety design. It cannot fully meet the requirements for igniting pyrotechnics in the spacecraft separation device. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a spacecraft pyrotechnic device excitation circuit.

[0006] The present invention is achieved through the following technical solutions.

[0007] The present invention provides a spacecraft explosive device excitation circuit, comprising a pre-charging circuit, a supercapacitor circuit, a power-off self-discharge circuit, and an ignition switch circuit connected in sequence;

[0008] The pre-charging circuit includes a main battery, the positive electrode of the main battery is respectively connected to the anodes of diode D1 and diode D2, diode D1 is connected to the supercapacitor circuit, the cathode of diode D2 is respectively connected to one end of resistor R1 and resistor R2, resistor R1 is connected to the positive electrode of the primary of the photocoupler U1A, and the negative electrode of the primary of the photocoupler U1A is connected to the negative electrode of the main battery; resistor R2 is connected to the charging current limiting circuit.

[0009] The charging current limiting circuit includes a transistor Q1, the base of which is connected to the negative electrode of the main battery through parallel resistors R3 to R5, the collector of which is connected to the diode D3, the resistor R2, and the gate of the MOS transistor Q2, and the emitter is grounded; the source of the MOS transistor Q2 is connected to the base of the transistor Q1, and the drain is connected to the supercapacitor circuit.

[0010] The supercapacitor circuit includes a polar capacitor C1 , wherein the positive electrode of the polar capacitor C1 is connected to the cathode of the diode D1 , and the negative electrode is connected to the power-off self-discharge circuit and the drain of the MOS tube Q2 .

[0011] The power-off self-discharge circuit includes a transistor Q3, the collector of which is connected to a diode D4, a resistor R6, and a base of the transistor Q4, and the emitter is connected to the negative electrode of the photocoupler secondary U1B. The base of the transistor Q3 and the emitter of the transistor Q4 are connected to the negative electrode of the ignition bus through parallel resistors R7 to R9, and the negative electrode of the ignition bus is also connected to the anode of the diode D4; the base of the transistor Q4 is connected to the photocoupler secondary U1B, and the collector of the transistor Q4 and the resistor R6 are connected to the positive electrode of the ignition bus.

[0012] The ignition switch circuit includes a protection switch K1 and an ignition switch K3 connected in series to the positive pole of the ignition bus, and a protection switch K2 and an ignition switch K4 connected in series to the negative pole of the ignition bus. The ignition switch K3 and the ignition switch K4 are respectively connected to the positive and negative poles of the pyrotechnic device.

[0013] The resistance of the resistor R1 is 1 kΩ.

[0014] The diode D2 is a transient voltage suppressor (TVS) diode with a reverse breakdown voltage of 18V.

[0015] The beneficial effects of the present invention are as follows: A pre-charge current-limiting circuit charges the supercapacitor, while a pyrotechnic switch connected in series with the supercapacitor is in a closed protective state. When pyrotechnics are needed, the pyrotechnic switch circuit receives a control signal from the spacecraft, unlocks the protection, and closes the pyrotechnic switch. The supercapacitor provides a millisecond-level instantaneous pyrotechnic current, igniting the explosive device. This system offers high reliability and radiation resistance, meeting the rigorous environmental requirements of spacecraft in orbit. Furthermore, a three-level fuse ensures highly reliable ignition control, enhancing the safety and reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the circuit principle of the present invention. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0018] The disclosed spacecraft pyrotechnic ignition device utilizes aerospace-grade components, offering high reliability and radiation resistance, meeting the demanding environmental requirements of spacecraft in-orbit. Furthermore, the device integrates pre-charging, power-off self-discharge, an ignition switch, and a supercapacitor circuit. Its compact structure allows it to be placed within the same compartment as the pyrotechnic device requiring separate ignition, facilitating the separate ignition of the pyrotechnic device. Furthermore, the device utilizes a three-level fuse for highly reliable ignition control, enhancing system safety and reliability.

[0019] The present invention uses a supercapacitor as the ignition power source, which can provide instantaneous large current within milliseconds to meet the needs of ignition of explosives. At the same time, it avoids the defects of traditional solutions that directly use main batteries to provide ignition current, thereby increasing battery power, volume and weight.

[0020] Furthermore, the pre-charge circuit includes a main battery, the positive electrode of which is connected to the anodes of diodes D1 and D2, respectively. Diode D1 is connected to the supercapacitor circuit, and the cathode of diode D2 is connected to one end of resistors R1 and R2, respectively. Resistor R1 is connected to the positive electrode of the primary photocoupler U1A, and the negative electrode of the primary photocoupler U1A is connected to the negative electrode of the main battery. Resistor R2 is connected to a charging current-limiting circuit. The pre-charge circuit's charging power source is the spacecraft's main battery, with an output voltage of 15V. Charging the supercapacitor through the pre-charge current-limiting circuit effectively utilizes the time before the spacecraft takes flight, preventing instantaneous high current shocks to the main battery and reducing the power demand on the main battery. During ground storage and maintenance, after power-on testing is completed and the power is turned off, the supercapacitor can also be quickly discharged through the discharge circuit to ensure ground storage safety.

[0021] Furthermore, the charging current limiting circuit includes a transistor Q1, the base of which is connected to the negative electrode of the main battery through parallel resistors R3 to R5, the collector is connected to the diode D3, the resistor R2, and the gate of the MOS transistor Q2, and the emitter is grounded; the source of the MOS transistor Q2 is connected to the base of the transistor Q1, and the drain is connected to the supercapacitor circuit.

[0022] The supercapacitor circuit includes a polar capacitor C1 , wherein the positive electrode of the polar capacitor C1 is connected to the cathode of the diode D1 , and the negative electrode is connected to the power-off self-discharge circuit and the drain of the MOS tube Q2 .

[0023] The power-off self-discharge circuit includes a transistor Q3, the collector of which is connected to a diode D4, a resistor R6, and a base of the transistor Q4, and the emitter is connected to the negative electrode of the photocoupler secondary U1B. The base of the transistor Q3 and the emitter of the transistor Q4 are connected to the negative electrode of the ignition bus through parallel resistors R7 to R9, and the negative electrode of the ignition bus is also connected to the anode of the diode D4; the base of the transistor Q4 is connected to the photocoupler secondary U1B, and the collector of the transistor Q4 and the resistor R6 are connected to the positive electrode of the ignition bus.

[0024] The ignition switch circuit includes a protection switch K1 and an ignition switch K3 connected in series to the positive pole of the ignition bus, and a protection switch K2 and an ignition switch K4 connected in series to the negative pole of the ignition bus. The ignition switch K3 and the ignition switch K4 are respectively connected to the positive and negative poles of the pyrotechnic device.

[0025] The resistance of the resistor R1 is 1 kΩ.

[0026] The diode D2 is a transient voltage suppressor (TVS) diode with a reverse breakdown voltage of 18V.

[0027] The pre-charge circuit's charging power source is the spacecraft's main battery, with an output voltage of 15V. The reverse charging protection circuit primarily uses a diode as the primary switching device. When the input voltage is applied, diode D1 conducts, allowing the circuit to operate normally. If the supercapacitor circuit is reversely connected, diode D1 cuts off, preventing the supercapacitor circuit from forming a loop and malfunctioning, effectively preventing the hazards of reverse connection and backflow. The current limiting circuit consists of transistor Q1, diode D3, MOS transistor Q2, and resistors R2, R3, and R4. By adjusting the resistance values of resistors R2, R3, and R4, the charging current of the energy storage capacitor is varied, limiting the charging current to a certain range.

[0028] The supercapacitor circuit includes a large-capacity capacitor component C1, which uses a SCPC2.7V25F supercapacitor manufactured by Zhuzhou Hongda, with a single unit capacitance of 25F and a rated voltage of 2.7V. In this example, C1 uses seven single supercapacitors connected in series to form a 3.57F capacitor. Two additional units are connected in parallel to create a 7.14F capacitor with a withstand voltage of 18.9V to meet the required output power. The supercapacitor charging process is as follows: When a 15V DC input voltage is applied, the primary side of the optocoupler U1A conducts, and the secondary side of the optocoupler U1B conducts, setting the collector voltage of transistor Q4 to zero. Q4 is then turned off, disabling the constant-current discharge circuit. MOS transistor Q2 is turned on by resistor R2, and the energy storage capacitor, along with resistors R3, R4, and R5, forms a current limiting circuit with transistor Q1. Adjusting the resistance values of resistors R2, R3, and R4 changes the charging current of the energy storage capacitor, limiting it to 1A.

[0029] The power-off self-discharge circuit includes resistors R6, R7, R8, and R9, diode D4, MOS transistors Q3 and Q4, and optocoupler U1B. When the main battery input voltage is lost, the gate of MOS transistor Q2 loses power, shutting down Q2 and disabling the charging circuit. Optocoupler primary U1A shuts down, U1B does not conduct, and transistor Q4, driven by resistor R6, conducts, activating the constant-current discharge circuit. The discharge circuit uses resistors R7, R8, and R9, along with transistor Q3, to form a current-limiting circuit. Adjusting the resistance values of resistors R7, R8, and R9 changes the discharge current of the constant-current discharge circuit until the energy storage capacitor voltage drops below 1V. When the discharge circuit is designed for a 0.3A constant-current discharge, the capacitor voltage is fully discharged after approximately 15 minutes.

[0030] The ignition switch circuit includes a protective switch K1 and ignition switch K3 for the pyrotechnic device's positive busbar, and a protective switch K2 and ignition switch K4 for the pyrotechnic device's negative busbar. Upon receiving a release command, the ignition switch circuit preemptively connects the protective switches K1 and K2 for the pyrotechnic device's positive and negative busbars. Upon receiving an ignition command, the ignition switch circuit connects the ignition switches K3 and K4 for the pyrotechnic device's positive and negative busbars, powering the pyrotechnic device and igniting it. The switch utilizes a JGX-73MA solid-state relay manufactured by Guizhou Aerospace Electric Co., Ltd., with eight ignition paths and a rated operating voltage of 5V.

[0031] The negative pole of the supercapacitor in the circuit is not directly connected to the negative pole of the main battery and is limited by the pre-charge current limiting circuit. Therefore, no additional relay switch is required to disconnect the charging circuit before ignition. This can ensure that the ignition discharge circuit is mainly composed of the energy storage capacitor discharging to the pyrotechnic device through the ignition switch, so that the ignition current is mainly provided by the energy storage capacitor without affecting the main battery bus current and voltage.

[0032] The device adopts three-level insurance to achieve high-reliability ignition control. The first level is capacitor charging control. Only when the capacitor is fully charged can the electric energy required for ignition be stored. The second level is the release instruction. When there is no release instruction control signal, the protection switch of the positive and negative busbars of the pyrotechnic device is disconnected and the line is not energized, and the pyrotechnic device circuit cannot be connected. The third level is the ignition instruction. When the capacitor group is fully charged and the positive and negative busbars of the pyrotechnic device are energized, the ignition instruction is valid, and the ignition switches of the positive and negative busbars of the pyrotechnic device are closed to complete the ignition of the pyrotechnic device.

[0033] During use, the device is placed within the same cabin as the pyrotechnic device to be separated and detonated. After detonation, it detaches along with the cabin. Before flight, the main battery of the spacecraft is powered on, and a pre-charge current-limiting circuit charges the supercapacitor. The detonation switch, connected in series with the supercapacitor, is in a closed protective state. When detonation is required, the detonation switch circuit receives a control signal from the spacecraft, unlocks the protection, and closes the detonation switch. The supercapacitor provides a high, instantaneous detonation current in milliseconds, detonating the pyrotechnic device.

[0034] Considering the safety of ground storage and maintenance, the stored energy in the supercapacitor circuit must be released as quickly as possible after the ground power-on test is completed and the power is turned off. Therefore, a discharge circuit is required. Considerations must be made to minimize the discharge time after power outage, minimize the discharge current from excessive heating of the device, and at the same time, ensure that the current does not affect normal ignition and discharge. A detection optocoupler is designed. When the main battery input voltage is present, the discharge circuit does not operate. When the ignition command is issued, the supercapacitor circuit only provides the ignition current for the pyrotechnic device discharge. When the input voltage main battery is disconnected, the discharge circuit starts to operate, discharging the capacitor charge. At this point, the product is powered off and the pyrotechnic device ignition will not be executed.

[0035] When in use, the device of the present invention is placed in the same cabin as the pyrotechnic device that needs to be separated and detonated, and is separated along with the cabin after detonation. Before the spacecraft takes off, the main battery is powered on first, and the supercapacitor is charged through the pre-charge current limiting circuit. The detonation switch connected in series at the rear end of the supercapacitor is in the off protection state; when detonation is required, the detonation switch circuit receives the control signal from the spacecraft, unlocks the protection and closes the detonation switch, and the supercapacitor provides a millisecond-level instantaneous detonation current, and the pyrotechnic device is detonated. Using a supercapacitor as a detonation power source can provide instantaneous high current within milliseconds, meeting the needs of pyrotechnic device detonation, while avoiding the defects of the traditional solution of directly using the main battery to provide the detonation current, which increases the battery power, volume and weight.

Claims

1. A spacecraft pyrotechnic device excitation circuit, characterized by: It includes a pre-charging circuit, a supercapacitor circuit, a power-off self-discharge circuit and an ignition switch circuit connected in sequence; The pre-charging circuit includes a main battery, the positive electrode of the main battery is respectively connected to the anodes of diode D1 and diode D2, diode D1 is connected to the supercapacitor circuit, the cathode of diode D2 is respectively connected to one end of resistor R1 and resistor R2, resistor R1 is connected to the positive electrode of the primary of the photocoupler U1A, and the negative electrode of the primary of the photocoupler U1A is connected to the negative electrode of the main battery; resistor R2 is connected to the charging current limiting circuit.

2. The spacecraft explosive device excitation circuit according to claim 1, characterized in that: The charging current limiting circuit includes a transistor Q1, the base of which is connected to the negative electrode of the main battery through parallel resistors R3 to R5, the collector of which is connected to the diode D3, the resistor R2, and the gate of the MOS transistor Q2, and the emitter is grounded; the source of the MOS transistor Q2 is connected to the base of the transistor Q1, and the drain is connected to the supercapacitor circuit.

3. The spacecraft explosive device excitation circuit according to claim 1, characterized in that: The supercapacitor circuit includes a polar capacitor C1 , wherein the positive electrode of the polar capacitor C1 is connected to the cathode of the diode D1 , and the negative electrode is connected to the power-off self-discharge circuit and the drain of the MOS tube Q2 .

4. The spacecraft explosive device excitation circuit according to claim 1, characterized in that: The power-off self-discharge circuit includes a transistor Q3, the collector of which is connected to a diode D4, a resistor R6, and a base of the transistor Q4, and the emitter is connected to the negative electrode of the photocoupler secondary U1B. The base of the transistor Q3 and the emitter of the transistor Q4 are connected to the negative electrode of the ignition bus through parallel resistors R7 to R9, and the negative electrode of the ignition bus is also connected to the anode of the diode D4; the base of the transistor Q4 is connected to the photocoupler secondary U1B, and the collector of the transistor Q4 and the resistor R6 are connected to the positive electrode of the ignition bus.

5. The spacecraft explosive device excitation circuit according to claim 1, characterized in that: The ignition switch circuit includes a protection switch K1 and an ignition switch K3 connected in series to the positive pole of the ignition bus, and a protection switch K2 and an ignition switch K4 connected in series to the negative pole of the ignition bus. The ignition switch K3 and the ignition switch K4 are respectively connected to the positive and negative poles of the pyrotechnic device.

6. The spacecraft explosive device excitation circuit according to claim 1, characterized in that: The resistance of the resistor R1 is 1 kΩ.

7. The spacecraft explosive device excitation circuit according to claim 1, characterized in that: The diode D2 is a transient voltage suppressor (TVS) diode with a reverse breakdown voltage of 18V.

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