Anti-surge discrete magnitude output drive circuit
By introducing surge-resistant design into the discrete output driving circuit of onboard electronic equipment, voltage clamping and overvoltage protection is achieved using components such as voltage regulator tube groups and diodes, the problem of existing circuits being prone to failure when facing voltage surges is solved, and the safety and reliability of the equipment are improved.
Patent Information
- Application Number
- CN202411810163.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-10
- Publication Date
- 2025-04-22
AI Technical Summary
When airborne electronic equipment faces abnormal conditions such as voltage surges, the existing grounded or open-circuit discrete output driving circuit is prone to failure or burnout, and cannot effectively resist voltage surges.
A discrete output driving circuit that resists surges is designed, including a primary switch control circuit, a secondary switch control circuit, an output driving circuit and an overvoltage protection and surge suppression circuit. Voltage clamping and overvoltage energy absorption are achieved through components such as voltage regulator tube groups and diodes.
This circuit can prevent circuit damage by voltage clamping and overvoltage protection when facing surge voltages of more than 50V, thereby improving the safety and reliability of onboard equipment.
Smart Images
Figure CN119865150A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of circuit design of airborne electronic equipment, and in particular to a surge-resistant discrete quantity output drive circuit. Background Art
[0002] Airborne electronic equipment often requires a grounded or open-circuit discrete output drive circuit. The signal source is provided by an external device, and the drive control of the external load is realized through the grounded or open-circuit discrete output drive circuit. Since airborne electronic equipment is often powered by a 28V power supply, its power supply is often taken from the aircraft power supply, and there are abnormal conditions such as voltage surges. When it is used as an external device to provide a signal source to drive the load, it often fails because the drive circuit does not meet the relevant requirements, and even burns out the circuit. Therefore, the grounded or open-circuit discrete output drive circuit of airborne electronic equipment must have the ability to resist voltage surges. Summary of the invention
[0003] In order to improve the safety and reliability of airborne electronic equipment, the embodiment of the present application provides a surge-resistant discrete output drive circuit to output a surge-resistant grounded or open discrete output circuit whose initial state is consistent with the safe state to the controlled product. The circuit has the characteristics of low cost and high reliability, and at the same time has the interface overvoltage surge protection capability, which improves the safety of airborne equipment.
[0004] The embodiment of the present application provides the following technical solution: a surge-resistant discrete output drive circuit, comprising: a primary switch control circuit, a secondary switch control circuit, an output drive circuit, an overvoltage protection and surge suppression circuit;
[0005] The input end of the primary switch control circuit is connected to the +5VTTL input signal, the output end is connected to the input end of the secondary switch control circuit, the output end of the secondary switch control circuit is connected to the input end of the output drive circuit, the output end of the output drive circuit is connected to 28V or an open circuit output, the input end of the overvoltage protection and surge suppression circuit is connected to the output end of the output drive circuit, and the output end of the overvoltage protection and surge suppression circuit is connected to the input end of the output drive circuit;
[0006] The primary switch control circuit includes a first voltage-dividing resistor and a first transistor. After the +5VTTL input signal is divided by the first voltage-dividing resistor, the first transistor is turned on; the secondary switch control circuit includes a second voltage-dividing resistor and a second transistor. The second voltage-dividing resistor is used to divide the connected +15 power supply signal to turn on the second transistor; the output drive circuit includes a current-limiting resistor and a MOS transistor, which are used to make the +15V power supply signal passing through the second transistor pass through the current-limiting resistor and the gate of the MOS transistor to turn on the MOS transistor; the overvoltage protection and surge suppression circuit includes a voltage-stabilizing tube group, and the voltage-stabilizing tube group is used to perform voltage clamping when a surge voltage exceeding 50V is generated at the local / open discrete output drive interface to absorb overvoltage energy.
[0007] According to an embodiment of the present application, in the primary switch control circuit, the first voltage-dividing resistor includes a resistor R3 and a resistor R6, the first transistor includes a transistor Q1, the first end of the resistor R3 is connected to the +5VTTL input signal, the second end of the resistor R3 is connected to the base of the transistor Q1 and the first end of the resistor R6, and the emitter of the transistor Q1 and the second end of the resistor R6 are commonly connected to the ground.
[0008] According to an embodiment of the present application, in the secondary switch control circuit, the second voltage-dividing resistor includes a resistor R1 and a resistor R2, the second transistor includes a transistor Q2, the first end of the resistor R2 is connected to the collector of the transistor Q1, the second end of the resistor R2 is respectively connected to the base of the transistor Q2 and the first end of the resistor R1, and the second end of the resistor R1 is connected to the emitter of the transistor Q2 and then connected to a +15V power supply signal.
[0009] According to an embodiment of the present application, the secondary switch control circuit further includes a resistor R4, a first end of the resistor R4 is connected to the collector of the transistor Q2, and a second end of the resistor R4 is connected to ground.
[0010] According to an embodiment of the present application, in the output drive circuit, the current limiting resistor includes a resistor R5, the MOS tube includes an NMOS tube Q3, the first end of the resistor R5 is connected to the collector of the transistor Q2, and the second end of the resistor R5 is connected to the gate of the NMOS tube Q3.
[0011] According to an embodiment of the present application, the overvoltage protection and surge suppression circuit also includes a diode D1, the voltage regulator group includes a voltage regulator diode Z1, a voltage regulator diode Z2 and a voltage regulator diode Z3, the negative end of the diode D1 is connected to the collector of the transistor Q2, the positive end of the diode D1 is connected to the positive end of the voltage regulator diode Z2, the negative end of the voltage regulator diode Z2 is connected to the positive end of the voltage regulator diode Z3, the negative end of the voltage regulator diode Z3 is connected to the source of the NMOS tube Q3, the negative end of the voltage regulator diode Z1 is connected to the second end of the resistor R5, and the positive end of the voltage regulator diode Z1 is connected to ground.
[0012] According to an embodiment of the present application, the overvoltage protection and surge suppression circuit also includes a fuse FU1, a first end of the fuse FU1 is connected to the negative end of the voltage regulator diode Z3 and the source of the NMOS tube Q3, and a second end of the fuse FU1 is connected to an external output drive signal.
[0013] According to an embodiment of the present application, the transistor Q1 is of NPN type, the transistor Q2 is of PNP type, the MOS tube Q3 is of NMOS type, the resistors R1 and R2 are of 10k / F range, the resistor R3 is of 20k / F range, the resistor R4 is of 15k / F range, the resistor R5 is of 1k / F range, the resistor R6 is of 4.7k / F range, and the Zener diodes Z1, Z2, and Z3 are all 16V Zener diodes.
[0014] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above-mentioned technical solutions adopted in the embodiments of this specification include at least: a surge-resistant grounded or open-circuit discrete quantity output circuit in the embodiments of the present invention outputs a safe state (open circuit) to the controlled product when the product power-on operation logic is loaded until the logic is not running and when the product is powered off or other abnormal conditions occur, thereby enhancing the safety and reliability of the circuit with improved adaptability. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0016] Figure 1 It is a schematic diagram of the overall structure of the discrete quantity output drive circuit for surge protection according to an embodiment of the present invention;
[0017] Figure 2 The figure is a connection diagram of a discrete quantity output drive circuit for surge protection according to an embodiment of the present invention. DETAILED DESCRIPTION
[0018] The embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0019] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.
[0020] like Figure 1-Figure 2 As shown, an embodiment of the present invention provides a surge-resistant discrete output drive circuit, comprising: a primary switch control circuit, a secondary switch control circuit, an output drive circuit, and an overvoltage protection and surge suppression circuit; the input end of the primary switch control circuit is connected to a +5VTTL input signal, and the output end is connected to the input end of the secondary switch control circuit, the output end of the secondary switch control circuit is connected to the input end of the output drive circuit, the output end of the output drive circuit is connected to 28V or an open-circuit output, the input end of the overvoltage protection and surge suppression circuit is connected to the output end of the output drive circuit, and the output end of the overvoltage protection and surge suppression circuit is connected to the input end of the output drive circuit; the primary switch control circuit includes The second-level switch control circuit includes a first voltage-dividing resistor and a first transistor, and the +5VTTL input signal is divided by the first voltage-dividing resistor to turn on the first transistor; the second-level switch control circuit includes a second voltage-dividing resistor and a second transistor, and the second voltage-dividing resistor is used to divide the connected +15 power supply signal to turn on the second transistor; the output drive circuit includes a current-limiting resistor and a MOS transistor, which are used to make the +15V power supply signal passing through the second transistor pass through the current-limiting resistor and the gate of the MOS transistor to turn on the MOS transistor; the overvoltage protection and surge suppression circuit includes a voltage-stabilizing tube group, and the voltage-stabilizing tube group is used to perform voltage clamping when a surge voltage exceeding 50V is generated at the local / open discrete output drive interface to absorb overvoltage energy.
[0021] The surge-resistant grounded or open-circuited discrete quantity output drive circuit of the embodiment of the present invention is suitable for the case where airborne electronic equipment requires grounded or open-circuited discrete quantity output drive and the circuit output is in a safe state when not in operation. The embodiment of the present invention is a surge-resistant grounded or open-circuited discrete quantity output circuit that outputs an initial state consistent with a safe state to a controlled product, and outputs a safe state (open circuit) to the controlled product when the product is powered on and the operation logic is loaded until the logic is not running and when the product is powered off or other abnormal conditions occur, thereby enhancing the safety and reliability of the circuit with improved adaptability.
[0022] In a specific implementation form of the embodiment of the present invention, in the primary switch control circuit, the first voltage-dividing resistor includes a resistor R3 and a resistor R6, the first transistor includes a transistor Q1, the first end of the resistor R3 is connected to the +5VTTL input signal, the second end of the resistor R3 is connected to the base of the transistor Q1 and the first end of the resistor R6, and the emitter of the transistor Q1 and the second end of the resistor R6 are commonly connected to the ground.
[0023] In the secondary switch control circuit, the second voltage-dividing resistor includes a resistor R1 and a resistor R2, the second transistor includes a transistor Q2, the first end of the resistor R2 is connected to the collector of the transistor Q1, the second end of the resistor R2 is connected to the base of the transistor Q2 and the first end of the resistor R1 respectively, the second end of the resistor R1 is connected to the emitter of the transistor Q2 and then connected to a +15V power supply signal. The secondary switch control circuit also includes a resistor R4, the first end of the resistor R4 is connected to the collector of the transistor Q2, and the second end of the resistor R4 is connected to ground.
[0024] Since the states of the input and the drive output of a single-stage are opposite, the embodiment of the present invention uses a two-stage switch of a primary switch control circuit and a secondary switch control circuit to ensure the synchronization of the input and the drive output.
[0025] In the output drive circuit, the current limiting resistor includes a resistor R5, the MOS transistor includes an NMOS transistor Q3, a first end of the resistor R5 is connected to the collector of the transistor Q2, and a second end of the resistor R5 is connected to the gate of the NMOS transistor Q3.
[0026] The overvoltage protection and surge suppression circuit also includes a diode D1, and the voltage regulator group includes a voltage regulator diode Z1, a voltage regulator diode Z2 and a voltage regulator diode Z3. The negative end of the diode D1 is connected to the collector of the transistor Q2, the positive end of the diode D1 is connected to the positive end of the voltage regulator diode Z2, the negative end of the voltage regulator diode Z2 is connected to the positive end of the voltage regulator diode Z3, the negative end of the voltage regulator diode Z3 is connected to the source of the NMOS tube Q3, the negative end of the voltage regulator diode Z1 is connected to the second end of the resistor R5, and the positive end of the voltage regulator diode Z1 is connected to the ground.
[0027] The overvoltage protection and surge suppression circuit further includes a fuse FU1 , a first end of the fuse FU1 is connected to the negative end of the voltage stabilizing diode Z3 and the source of the NMOS tube Q3 , and a second end of the fuse FU1 is connected to an external output drive signal.
[0028] In a specific embodiment, Figure 2 As shown, the circuit specifically includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a resistor R6, a transistor Q1, a transistor Q2, an NMOS transistor Q3, a diode D1, a Zener diode Z1, a Zener diode Z2, a Zener diode Z3, and a fuse FU1;
[0029] Specifically, the first end of resistor R3 is connected to the +5VTTL input signal; the second end is connected to the base of transistor Q1 and the first end of resistor R6; the collector of transistor Q1 is connected to the first end of resistor R2, and the second end of resistor R2 is respectively connected to the base of transistor Q2 and the first end of resistor R1; the second end of resistor R1 is connected to the emitter of transistor Q2 and then connected to the +15V power supply; the collector of transistor Q2 is respectively connected to the first end of resistor R4, the first end of resistor R5 and the negative end of diode D1; the second end of resistor R5 is connected to the voltage regulator The negative end of the diode Z1 is connected to the gate of the NMOS tube Q3; the positive end of the diode D1 is connected to the positive end of the Zener diode Z2; the negative end of the Zener diode Z2 is connected to the positive end of the Zener diode Z3; the negative end of the Zener diode Z3 is connected to the first end of the fuse FU1 and the source of the NMOS tube Q3, and the second end of the fuse FU1 is connected to the external output drive signal; the first end of the resistor R6 is respectively connected to the emitter of the transistor Q1, the second end of the resistor R4, the positive end of the Zener diode Z1 and the drain of the NMOS tube Q3 and are connected to the ground.
[0030] Among them, the resistor R3 and the resistor R6 form a voltage divider circuit, which divides the +5VTTL input signal, and the resulting signal is sent to the base of the transistor Q1 as the transistor Q1 turn-on voltage signal; the resistor R1 and the resistor R2 form a voltage divider circuit, which divides the +15 power supply signal, and the resulting signal is sent to the base of the transistor Q2 as the transistor Q2 turn-on voltage signal, and at the same time, the resistor R2 is used as a current limiting resistor to ensure the feasibility of the transistors Q1 and Q2 being turned on at the same time; the resistor R4 is used for current limiting when the transistor Q2 is turned on, and at the same time ensures that the NMOS tube Q3 is in a closed state when the transistor Q2 is turned off; the resistor R5 is used for current limiting when the gate of the NMOS tube Q3 is turned on, and the voltage stabilizing diode Z1 ensures that the voltage between the gate and the source of the NMOS tube Q3 is stable and does not break down and damage when the output drive circuit has a 50V overvoltage surge.
[0031] Among them, diode D1, Zener diode Z1, Zener diode Z2, Zener diode Z3 and resistor R5 constitute an overvoltage surge discharge circuit. When the ground / open discrete output drive interface generates a voltage signal exceeding 50V, Zener diode Z1, Zener diode Z2 and Zener diode Z3 are used for clamping to prevent the output drive circuit from driving the interface signal overvoltage causing abnormal circuit operation, thereby ensuring the safety and reliability of the interface circuit; further, diode D1 can prevent the transistor Q2 from being turned on and injecting the +15V power supply signal into the ground / open discrete output drive interface when the circuit is working normally, and fuse FU1 can realize overcurrent protection to prevent abnormal large current from damaging the interface circuit.
[0032] In a specific implementation form of the embodiment of the present invention, the transistor Q1 is of NPN type, the transistor Q2 is of PNP type, the MOS tube Q3 is of NMOS type, the resistors R1 and R2 are of 10k / F range, the resistor R3 is of 20k / F range, the resistor R4 is of 15k / F range, the resistor R5 is of 1k / F range, the resistor R6 is of 4.7k / F range, the diode D1 is an ordinary diode, and the Zener diodes Z1, Z2, and Z3 are all 16V Zener diodes.
[0033] In the embodiment of the present invention, the discrete quantity drive circuit that is grounded or open is enabled by the level of the +5VTTL input signal, and +15V provides power. When the +5VTTL input signal outputs a +5V level, the discrete quantity output drive circuit that is grounded or open is in a grounded state, and when the +5VTTL control signal outputs a 0V level, the discrete quantity output drive circuit that is grounded or open is in an open state.
[0034] When the +5VTTL control signal is not input, since the resistor R6 is grounded, there is no voltage difference between the base and emitter of transistor Q1 and it is in the disconnected state. Furthermore, there is no voltage difference between the base and emitter of transistor Q2 and it is in the disconnected state. Furthermore, there is no voltage difference between the gate and source of the NMOS tube and it is in the disconnected state. At this time, the grounded and open discrete output circuit outputs an open circuit state.
[0035] When the +5VTTL control signal is input, the resistor R3 and the resistor R6 form a voltage divider. After the voltage divider, the base voltage of the transistor Q1 is 0.95V, reaching the transistor Q1 turn-on voltage, and Q1 is turned on. Furthermore, the resistor R1 and the resistor R2 form a voltage divider resistor. After the +15V power supply signal is divided, the base of the transistor Q2 generates a voltage of 7.5V, and the transistor Q2 is turned on. Furthermore, the +15V voltage signal passes through the transistor Q2 and the resistor R5 to the gate of the NMOS tube Q3, and the NMOS tube is turned on. At this time, the grounded and open discrete output circuit outputs the grounded state.
[0036] Zener diode Z1, Zener diode Z2, Zener diode Z3, diode D1, and resistor R5 form a 50V overvoltage protection circuit. When the ground / open discrete output drive interface generates a surge voltage exceeding 50V, the 16V Zener diode Z1, Zener diode Z2, and Zener diode Z3 are connected in series to clamp the voltage and absorb the overvoltage energy. Resistor R5 and fuse FU1 can prevent long-term excessive current from damaging the Zener diode and causing protection failure. Diode D1 can prevent the transistor Q2 from turning on and injecting the +15V power supply signal into the ground / open discrete output drive interface during normal operation of the circuit, and can also provide a certain voltage drop.
[0037] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.
Claims
1. A surge-resistant discrete output drive circuit, characterized in that: include: Primary switch control circuit, secondary switch control circuit, output drive circuit, overvoltage protection and surge suppression circuit; The input end of the primary switch control circuit is connected to the +5VTTL input signal, the output end is connected to the input end of the secondary switch control circuit, the output end of the secondary switch control circuit is connected to the input end of the output drive circuit, the output end of the output drive circuit is connected to 28V or an open circuit output, the input end of the overvoltage protection and surge suppression circuit is connected to the output end of the output drive circuit, and the output end of the overvoltage protection and surge suppression circuit is connected to the input end of the output drive circuit; The primary switch control circuit includes a first voltage-dividing resistor and a first transistor. After the +5VTTL input signal is divided by the first voltage-dividing resistor, the first transistor is turned on; the secondary switch control circuit includes a second voltage-dividing resistor and a second transistor. The second voltage-dividing resistor is used to divide the connected +15 power supply signal to turn on the second transistor; the output drive circuit includes a current-limiting resistor and a MOS transistor, which are used to make the +15V power supply signal passing through the second transistor pass through the current-limiting resistor and the gate of the MOS transistor to turn on the MOS transistor; the overvoltage protection and surge suppression circuit includes a voltage-stabilizing tube group, and the voltage-stabilizing tube group is used to perform voltage clamping when a surge voltage exceeding 50V is generated at the local / open discrete output drive interface to absorb overvoltage energy.
2. The surge-resistant discrete output drive circuit according to claim 1, characterized in that: In the primary switch control circuit, the first voltage-dividing resistor includes a resistor R3 and a resistor R6, the first transistor includes a transistor Q1, the first end of the resistor R3 is connected to the +5VTTL input signal, the second end of the resistor R3 is connected to the base of the transistor Q1 and the first end of the resistor R6, and the emitter of the transistor Q1 and the second end of the resistor R6 are commonly connected to the ground.
3. The surge-resistant discrete output drive circuit according to claim 2, characterized in that: In the secondary switch control circuit, the second voltage-dividing resistor includes a resistor R1 and a resistor R2, the second transistor includes a transistor Q2, the first end of the resistor R2 is connected to the collector of the transistor Q1, the second end of the resistor R2 is respectively connected to the base of the transistor Q2 and the first end of the resistor R1, and the second end of the resistor R1 is connected to the emitter of the transistor Q2 and then connected to a +15V power supply signal.
4. The surge-resistant discrete output drive circuit according to claim 3, characterized in that: The secondary switch control circuit further includes a resistor R4 , a first end of the resistor R4 is connected to the collector of the transistor Q2 , and a second end of the resistor R4 is connected to the ground.
5. The surge-resistant discrete output drive circuit according to claim 4, characterized in that: In the output drive circuit, the current limiting resistor includes a resistor R5, the MOS transistor includes an NMOS transistor Q3, a first end of the resistor R5 is connected to the collector of the transistor Q2, and a second end of the resistor R5 is connected to the gate of the NMOS transistor Q3.
6. The surge-resistant discrete output drive circuit according to claim 5, characterized in that: The overvoltage protection and surge suppression circuit also includes a diode D1, and the voltage regulator group includes a voltage regulator diode Z1, a voltage regulator diode Z2 and a voltage regulator diode Z3. The negative end of the diode D1 is connected to the collector of the transistor Q2, the positive end of the diode D1 is connected to the positive end of the voltage regulator diode Z2, the negative end of the voltage regulator diode Z2 is connected to the positive end of the voltage regulator diode Z3, the negative end of the voltage regulator diode Z3 is connected to the source of the NMOS tube Q3, the negative end of the voltage regulator diode Z1 is connected to the second end of the resistor R5, and the positive end of the voltage regulator diode Z1 is connected to the ground.
7. The surge-resistant discrete output drive circuit according to claim 6, characterized in that: The overvoltage protection and surge suppression circuit further includes a fuse FU1 , a first end of the fuse FU1 is connected to the negative end of the voltage stabilizing diode Z3 and the source of the NMOS tube Q3 , and a second end of the fuse FU1 is connected to an external output drive signal.
8. The surge-resistant discrete output drive circuit according to claim 6, characterized in that: The transistor Q1 is of NPN type, the transistor Q2 is of PNP type, the MOS tube Q3 is of NMOS type, the resistors R1 and R2 are of 10k / F range, the resistor R3 is of 20k / F range, the resistor R4 is of 15k / F range, the resistor R5 is of 1k / F range, the resistor R6 is of 4.7k / F range, and the Zener diodes Z1, Z2 and Z3 are all 16V Zener diodes.