JP4382466B2 - Ordnance control circuit - Google Patents

Description

  The present invention relates to an ordnance control circuit that is mounted on an artificial satellite or rocket and supplies electric power to a pyrotechnic.

  Ordinance control circuits are generally introduced as circuits used in ordnance controllers mounted on artificial satellites and rockets. Pyrotechnics are usually mounted on artificial satellites and rockets, and pyrotechnics ignite when separating rocket fairings and satellites, and when deploying satellite solar cell paddles and antennas. . An apparatus that supplies power when the pyrotechnic is ignited is an ordnance controller, and a circuit that controls the apparatus is an ordnance control circuit.

  A conventional ordnance control circuit is composed of two switches of relays and a current limiting resistor (see, for example, Patent Document 1). Reference numeral 100 in FIG. 4 indicates the configuration of an embodiment of this ordnance control circuit.

  In FIG. 4, the terminals T1 to T4 are all connected to the positive terminal of the constant voltage power source EB, and the terminal T5 is connected to the negative terminal of the constant voltage power source EB. Terminals T6 to T9 are sequentially connected to the anode terminals of the first to fourth crater products EED1 to EED4, respectively, and terminals T10 to T13 are sequentially connected to the negative terminals of the first to fourth crater products EED1 to EED4, respectively. Yes. Terminals T14 and T15 are connected to an ignition command signal source (not shown).

  The ordnance control circuit 100 includes one ignition command relay composed of a contact k0 and a contact drive unit K0, and a pair of contacts (k1A, k2B), (k2A, k3B) each corresponding to a crater product EED1, EED2, EED3, EED4. ), (K3A, k4B), (k4A, k1B) and the contact relays K1, K2, K3, K4, and four current limiting resistors RCL1 to RCL4.

  Both ends of the contact drive unit K0 are connected to the terminals T14 and T15, one end of the contact k0 is connected to all of the terminals T1 to T4, and the other end is connected to all one ends of the contact drive units K1 to K4. The other ends of the contact driving units K1 to K4 are all connected to the terminal T5.

  One ends of the contacts k1A to k4A are connected to terminals T1 to T4 via current limiting resistors RCL1 to RCL4, respectively, and the other ends are connected to terminals T6 to T9. Further, one ends of the contacts k1B to k4B are all connected to the terminal T5, and the other ends are connected to the terminals T13, T12, T11, and T10, respectively.

  When the ignition command signal is applied to the contact drive unit K0 of the ignition command relay, the contact k0 is closed and the four contact drive units K1 to K4 operate simultaneously. At this time, since all the contacts (k1A, k1B) to (k4A, k4B) of the ignition relays are closed, the ignition currents IE1 to IE4 flow to the crater products EED1 to EED4, and the intended operation is achieved.

  The present invention is devised so that ignition relays connected to both ends of each of the crater products EED1 to EED4 are driven by different contact driving units. As a result, even if one of the contact drive parts of the ignition relay malfunctions and the ignition relay closes, none of the crater products EED1 to EED4 will be ignited.

JP-A-10-016900 (first page to fourth page, FIG. 1)

  However, in the conventional ordnance control circuit described above, a large ignition current flows through the power transmission line, so that there is a first problem that parts used in this line become large.

  In addition, there is a second problem that a time lag in power transmission to the pyrotechnics cannot be controlled because of a large variation in the contact feeling time of the mechanical relay used in the power transmission line. Further, in the case of a mechanical relay, there is a possibility of fusion of contacts due to arc discharge or the like, and there is a third problem that the function is impaired.

  Further, in the case of the mechanical relay, there is a fourth problem that the contact is closed due to external factors such as vibration, and the pyrotechnic is ignited by mistake.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an ordnance control circuit that is small in size, has high reliability, and can easily perform temporal control.

The invention described in claim 1 is a source electrode mounted on an artificial satellite or rocket and connected to an input terminal (1 in FIG. 1) to which a power supply voltage is input in an ordnance control circuit for supplying power to a pyrotechnic . And a first field effect transistor (3 in FIG. 1) in which a first resistor (8 in FIG. 1) is connected between the gate electrode and the gate electrode of the first field effect transistor and a ground potential. A first switch (10 in FIG. 1) connected in series with a second resistor (9 in FIG. 1) and a third resistor (FIG. 1) between the source electrode and the drain electrode of the first field effect transistor. 4), the drain electrode is connected to the output terminal (2 in FIG. 1) that outputs power to the pyrotechnic, and a fourth resistor (in FIG. 1) is connected between the source electrode and the gate electrode. 12) a second field effect transistor connected via 5), the emitter electrode is connected to the drain electrode of the first field effect transistor, the base electrode is connected to the source electrode of the second field effect transistor, and the collector electrode is connected to the gate electrode of the second field effect transistor. A second switch (14 in FIG. 1) connected in series with a transistor (11 in FIG. 1) and a fifth resistor (13 in FIG. 1) between the gate electrode of the second field effect transistor and the ground potential. And an ordnance control circuit.

  A second aspect of the invention is an ordnance control circuit according to the first aspect of the invention, wherein a mechanical switch is used as at least one of the first switch and the second switch.

  The invention described in claim 3 is the ordnance control circuit according to the invention described in claim 1, characterized in that semiconductor switches are used for the first switch and the second switch.

The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the gate of the first field effect transistor and the second resistor, and the gate of the second field effect transistor An ordnance control circuit, wherein a resistor is provided between each of the fifth resistors .

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the first circuit comprising the first field effect transistor and the first switch, and the second field effect. It consists of a plurality of second circuits consisting of transistors, transistors, and second switches, and the emitter electrodes of all transistors in the second circuit are connected to the drains of the first field effect transistors in the first circuit. This is an ordnance control circuit characterized by the above.

  In the ordnance control circuit configured as described above, a third resistor for current detection is interposed on the power transmission line, and the second field effect transistor is turned on by the output of the first transistor that is turned on in response to the voltage drop of this resistor. By opening and closing, relatively small parts can be used.

  Also, by connecting the first field effect transistor and the second field effect transistor in series between the input and output terminals, even if one of the field effect transistors malfunctions due to an electrical factor, Since ignition current does not flow, erroneous ignition can be prevented.

  Furthermore, by making the power transmission path switch a field effect transistor and making it a control circuit, the time lag of power transmission to the pyrotechnics can be controlled and the error can be reduced.

  Further, in the case of a mechanical relay, contact fusion due to generated arc discharge or the like is eliminated, and reliability can be improved. It is also possible to prevent malfunction due to external factors such as vibration.

  The first effect of the present invention is that the switch between the input terminal 1 and the output terminal 2 is formed as a control circuit using a field effect transistor, so that the timing error of power supply to the pyrotechnics is relatively small, and mechanical. This means that it is possible to prevent a short circuit failure due to fusion caused by arc discharge of the contact, and to prevent malfunction due to external factors such as vibration. In addition, since two field effect transistors are connected in series between the input terminal 1 and the output terminal 2, it is possible to prevent erroneous ignition of the pyrotechnics due to an electrical malfunction.

  The second effect of the present invention is that the resistor 4 is interposed between the field effect transistor 3 and the field effect transistor 5, and the field effect transistor 5 is output by the output of the constant current driving transistor 11 which is turned on in accordance with the voltage drop of the resistor. Since the constant current control is performed by adjusting the voltage between the gate and the source, the voltage across the current detection resistor 4 can be set to the ON voltage of the transistor, so that the heat generation of the resistor 4 can be suppressed to a relatively small scale. This means that small parts can be used.

  FIG. 1 shows the best mode for carrying out the ordnance control circuit of the present invention, wherein 1 is an input terminal connected to a power source 7 and 2 is an output terminal connected to a pyrotechnic 6.

  A source electrode of the field effect transistor 3 is connected to the input terminal 1. A resistor 8 is connected between the source electrode and the gate electrode of the field effect transistor 3, and one end of the resistor 9 is connected to the gate electrode of the field effect transistor 3. Furthermore, the other end of the resistor 9 is connected to one end of the switch 10, and the other end of the switch 10 is grounded.

  The drain electrode of the field effect transistor 3 is connected to the emitter electrode of the transistor 11, and the resistor 4 is connected between the base and emitter of the transistor 11. Further, the base of the transistor 11 is connected to the source electrode of the field effect transistor 5, and the resistor 12 is connected between the base and collector of the transistor 11. The collector electrode of the transistor 11 is connected to the gate electrode of the field effect transistor 5, and is connected to one end of the switch 14 through the resistor 13, and the other end of the switch 14 is grounded. The drain electrode of the field effect transistor 5 is connected to the output terminal 2.

  The operation of the present embodiment configured as described above will be described below.

  When the switch 10 is closed, a current flows through the resistors 8 and 9 due to the voltage applied from the power source 7 to the input terminal 1. At this time, the gate potential of the field effect transistor 3 is determined by the voltage dividing ratio of the resistor 8 and the resistor 9, and the field effect transistor 3 is turned on while the gate-source voltage is maintained at the ON voltage or higher. Therefore, the voltage applied from the power supply 7 to the input terminal 1 is output to the source electrode of the field effect transistor 5.

  When the switch 14 is closed in a state where the field effect transistor 3 is turned on and a voltage is applied to the source electrode of the field effect transistor 5, the gate-source of the field effect transistor 5 is maintained at or above the on voltage by the same operation as described above. The field effect transistor 5 is turned on, and power is supplied from the output terminal 2 to the pyrotechnic 6.

  On the other hand, when the switch 14 is open, the gate-source voltage of the field effect transistor 5 is equal to or lower than the on voltage, and the field effect transistor 5 is off. Therefore, even if the switch 10 is closed in this state, power is not supplied to the pyrotechnic 6.

  Even if the switch 14 is closed, if the switch 10 is open, the field effect transistor 3 is off, and the voltage applied from the input terminal 1 cannot be transmitted to the source electrode of the field effect transistor 5, The effect transistor 5 is not turned on, and power is not supplied to the pyrotechnic 6.

  Thus, in order to supply power to the pyrotechnic 6, it is necessary to close both the switch 9 and the switch 10, so that power is not accidentally supplied to the pyrotechnic 6. I have to.

  Further, after the pyrotechnic 6 is ignited, there is a possibility that the circuit may be short-circuited by burning residue or the like and an overcurrent flows in the power transmission path. When an overcurrent flows, the potential difference between both ends of the resistor 4 increases by the increased current. When this potential difference reaches the on-voltage of the transistor 11, the transistor 11 is turned on. For this reason, the voltage between the gate and source of the field effect transistor 5 provided by the resistors 12 and 13 is lowered to a level that can be maintained at a current value at which the transistor 11 is turned on by the voltage drop of the resistor 4. Control will be performed.

  FIG. 2 shows an embodiment 1 of the ordnance control circuit according to the present invention, in which 1 is an input terminal connected to a power source 7 and 2 is an output terminal connected to a pyrotechnic.

  A source electrode of the field effect transistor 3 is connected to the input terminal 1, and a resistor 8 and a Zener diode 19 are connected between the source electrode and the gate electrode of the field effect transistor 3. One end of the resistor 9 is connected to the gate electrode of the field effect transistor 3, and the other end of the resistor 9 is connected to one end of the contact of the latching relay 23.

  The other end of the contact of the latching relay 23 is grounded, one end of the driving coil 10A of the latching relay 23 is connected to the external signal input terminal 21, and one end of the driving coil 10B of the latching relay 23 is connected to the external signal input terminal 22, and the driving coil 10A. And the other end of 10B is grounded. When a signal is input to the external signal input terminal 21, it is driven by the drive coil 10A and the contact of the latching relay 23 is closed. On the other hand, when a signal is input to the external signal input terminal 22, it is driven by the drive coil 10B and the contact of the latching relay 23 is opened.

  The drain electrode of the field effect transistor 3 is connected to the emitter electrode of the transistor 11, and the resistor 4 is connected between the base and emitter of the transistor 11. Further, the base of the transistor 11 is connected to the source electrode of the field effect transistor 5, and the resistor 12 and the Zener diode 20 are connected between the base and collector of the transistor 11.

  The collector electrode of the transistor 11 is connected to the gate electrode of the field effect transistor 5, is connected to the collector electrode of the transistor 24 through the resistor 13, and the base electrode of the transistor 24 is connected to the external signal input terminal 16. A resistor 15 is connected between the base and emitter of the transistor 24, and the collector electrode of the transistor 24 is grounded. The drain electrode of the field effect transistor 5 is connected to the output terminal 2.

  The operation of the present embodiment configured as described above will be described below.

  When a signal is input from the external signal input terminal 21, it is driven by the drive coil 10 </ b> A to close the contact of the latching relay 23, and a current flows through the resistors 8 and 9 by the voltage applied from the power source 7 to the input terminal 1. At this time, the gate potential of the field effect transistor 3 is determined by the voltage dividing ratio of the resistor 8 and the resistor 9, and the field-effect transistor 3 is turned on while the gate-source voltage is kept equal to or higher than the on-voltage. Therefore, the voltage applied from the power supply 7 to the input terminal 1 is output to the source electrode of the field effect transistor 5.

  When an external signal is input to the external signal input terminal 16 in a state where the field effect transistor 3 is turned on and a voltage is applied to the source electrode of the field effect transistor 5, the transistor 24 is turned on. , 13 through which current flows. At this time, the gate potential of the field effect transistor 5 is determined by the voltage dividing ratio of the resistor 12 and the resistor 13, and the voltage between the gate and the source is maintained at an ON voltage or more, and the field effect transistor 5 is turned on. For this reason, electric power is supplied from the output terminal 2 to the pyrotechnic 6.

  On the other hand, when the transistor 24 is off, the gate-source voltage of the field effect transistor 5 is equal to or lower than the on voltage, and the field effect transistor 5 is off. Therefore, even if the latching relay 23 is closed in this state, power is not supplied to the pyrotechnic 6.

  Even if the transistor 24 is turned on, if the signal is input from the external signal input terminal 22 and the latching relay 23 is opened, the field effect transistor 3 is turned off and the voltage applied from the input terminal 1 is applied. Cannot be transmitted to the source electrode of the field effect transistor 5, the field effect transistor 5 is not turned on, and power is not supplied to the pyrotechnic 6.

As described above, in order to supply power to the pyrotechnic 6, it is necessary to close both the latching relay 23 and the transistor 24, thereby supplying power to the pyrotechnic 6 by mistake. The risk is reduced.
The voltage from the input terminal 1 is not applied to the output terminal 2. The same applies to the latching relay 23. When a signal is input to the external signal terminal 22 and the contact of the latching relay 23 is open, the field effect transistor 3 is off and no voltage is applied to the drain electrode of the field effect transistor 5. .

  In addition, after ignition of the crater 6, there is a possibility that the circuit is short-circuited due to burning residue or the like and an overcurrent flows in the power transmission path. When an overcurrent flows, the potential difference between both ends of the resistor 4 increases by the increased current. When this potential difference reaches the on-voltage between the base and emitter of the transistor 11, the transistor 11 is turned on. For this reason, the voltage between the gate and source of the field effect transistor 5 provided by the resistors 12 and 13 is lowered to a level that can be maintained at a current value at which the transistor 11 is turned on by the voltage drop of the resistor 4. Control will be performed.

  Further, when a load having a capacitance component is connected to the outputs of the field effect transistors 3 and 5 and a sudden charging current flows when the field effect transistors 3 and 5 are turned on, In the case of a sudden short circuit, when the voltage between the gate and source of the field effect transistors 3 and 5 suddenly changes, an oscillation phenomenon that repeats on / off due to the parasitic capacitance of the field effect transistors 3 and 5 occurs.

  In order to prevent this phenomenon, a change in the gate-source voltage of the field-effect transistor 3 can be buffered by providing a resistor 17 between the gate of the field-effect transistor 3 and the gate-side terminal of the gate-source resistor 8. . Similarly, by providing a resistor 18 between the gate of the field effect transistor 5 and the collector of the transistor 11 that determines the gate-source voltage, a change in the gate-source voltage of the field-effect transistor 5 is buffered. be able to.

  Further, the resistor 17 at the gate of the field effect transistor 3 and the resistor 18 at the gate of the field effect transistor 5 buffer the change in the gate potential of each field effect transistor even against a sudden current change such as a load short circuit. It is also possible to prevent oscillation due to the parasitic capacitance of the effect transistors 3 and 5. The Zener diodes 19 and 20 can also protect the gate electrodes of the field effect transistors 3 and 5 from overvoltage.

  In FIG. 2, the positions of the set of the latching relay 23 and the drive coils 10A and 10B and the set of the transistor 24 and the resistors 15 and 16 can be switched. That is, the collector electrode of the transistor 24 is connected to the resistor 9 and the latching relay 23 is connected to the resistor 13. Even in such a configuration, the same description as in the first embodiment can be similarly applied.

  Further, both may be latching relays 23 or both may be transistors 24.

  FIG. 4 shows Embodiment 3 of the ordnance control circuit according to the present invention. This embodiment is an ordnance control circuit constituted by four systems of outputs. Specifically, in the ordnance control circuit shown in FIG. 1, only four portions on the right side from the drain electrode of the field effect transistor 3 are connected in parallel to the drain electrode of the field effect transistor 3.

  According to this configuration, it is possible to simultaneously supply current to the four pyrotechnics 6 while maintaining the effects peculiar to the present invention.

  Such a configuration can be similarly applied to the above-described first and second embodiments.

  Further, in all of the above embodiments, the description has been made on the assumption that a switch, a latching relay, and a transistor are used in a circuit portion for opening and closing a field effect transistor. It is obvious that the effect of the present invention is obtained even if the combination is changed.

The circuit diagram which shows embodiment of the ordnance control circuit of this invention The circuit diagram which shows Example 1 of the ordnance control circuit of this invention FIG. 5 is a circuit diagram showing an ordnance control circuit according to a third embodiment of the present invention. Circuit diagram showing a configuration example of a conventional ordnance control circuit

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input terminal 2 Output terminal 3 Field effect transistor 4 Resistance 5 Field effect transistor 6 Pyrotechnics 7 Power supply 8,9 Resistance 10 Switch 10A Drive coil 10B Drive coil 11 Transistor 12, 13 Resistance 14 Switch 15 Resistance 16 External signal input terminal 17 , 18 Resistor 19, 20 Zener diode 21, 22 External signal input terminal 23 Latching relay 24 Transistor

Claims (5)

In ordnance control circuits mounted on satellites and rockets,
A first field effect transistor in which a first resistor is connected between a source electrode and a gate electrode connected to an input terminal to which a power supply voltage is input;
A first switch connected in series with a second resistor between the gate electrode of the first field effect transistor and a ground potential;
The source electrode and the drain electrode of the first field effect transistor are connected via a third resistor, the drain electrode is connected to an output terminal that outputs power to the pyrotechnic, and the source electrode and A second field effect transistor in which the gate electrodes are connected via a fourth resistor;
A transistor having an emitter electrode connected to the drain electrode of the first field effect transistor, a base electrode connected to the source electrode of the second field effect transistor, and a collector electrode connected to the gate electrode of the second field effect transistor; ,
An ordnance control circuit comprising: a second switch connected in series with a fifth resistor between a gate electrode of the second field effect transistor and a ground potential. 2. The ordnance control circuit according to claim 1, wherein a mechanical switch is used as at least one of the first switch and the second switch. 2. The ordnance control circuit according to claim 1, wherein semiconductor switches are used for the first switch and the second switch. The resistor is provided between the gate of the first field effect transistor and the second resistor, and between the gate of the second field effect transistor and the fifth resistor , respectively. The ordnance control circuit according to any one of claims 1 to 3. A first circuit comprising the first field effect transistor and the first switch according to any one of claims 1 to 4,
A plurality of second circuits comprising the second field effect transistor according to any one of claims 1 to 4, the transistor, and the second switch,
An ordnance control circuit, wherein the emitter electrodes of all the transistors in the second circuit are connected to the drains of the first field effect transistors in the first circuit.

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