LED railway signal light system and its intelligent lighting unit

Abstract

This invention discloses an LED railway signal light system and its intelligent lighting unit. In this intelligent lighting unit, the control module obtains the detection results of corresponding LED beads and their circuits from the fault detection module. Based on the detection results of the two LED beads and their circuits, when a first condition is met, the two constant current drive modules control the two LED beads to alternately be lit. When a second condition is met, the corresponding constant current drive module controls the normal LED bead to remain constantly lit, and an alarm is triggered by the alarm module. When neither the first nor the second condition is met, the power control module controls the two constant current drive modules to stop working, thereby triggering the first alarm. Implementing this technical solution reduces the failure rate and operating costs, and improves lifespan and working efficiency.

Description

Technical Field

[0001] This invention relates to the field of railway signal lights, and more particularly to an LED railway signal light system and its intelligent lighting unit. Background Technology

[0002] Currently, railway signal lights use tungsten filament light sources and contain both main and auxiliary circuits. Their lighting monitoring and control devices monitor and control the operation of both circuits, automatically switching to the auxiliary circuit and triggering an alarm when the main circuit fails. However, existing lighting monitoring and control devices have the following problems: 1) Due to the two circuits, only the main circuit operates continuously, while the auxiliary circuit remains inactive for extended periods, leading to a high failure rate and short lifespan; 2) The main and auxiliary circuits cannot switch automatically in real time; 3) They lack self-monitoring capabilities, requiring regular on-site inspections by professional technicians. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide an LED railway signal light system and its intelligent lighting unit, addressing the shortcomings of existing technologies such as high failure rate, short lifespan, inability to switch autonomously, and the need for regular inspection by professional personnel.

[0004] The technical solution adopted by this invention to solve its technical problem is as follows: An intelligent lighting unit for an LED railway signal light system is constructed, connected to a railway signal bulb containing two LED beads and a first alarm device installed at the front end. This unit includes a power supply module, a control module, an alarm module, a power control module, two constant current drive modules, and two fault detection modules.

[0005] The control module obtains the detection results of the corresponding LED beads and their circuits from the fault detection module. Based on the detection results of the two LED beads and their circuits, when the first condition is met, the control module controls the two LED beads to alternately be lit up through the two constant current drive modules; when the second condition is met, the control module controls the normal LED beads to be constantly lit up through the corresponding constant current drive modules, and the alarm module sounds an alarm; when neither the first condition nor the second condition is met, the control module controls the two constant current drive modules to stop working, thereby triggering the first alarm to sound an alarm.

[0006] The first condition is: both LED beads and their circuits are normal;

[0007] The second condition is: one of the LED beads and its circuit is normal, and the other LED bead or its circuit has an open circuit fault or the other LED bead has a light decay fault.

[0008] Preferably, the constant current driving module includes a constant current driving chip, a first switching transistor, an inductor, and a current sensing resistor. The power supply terminal of the constant current driving chip is connected to the positive terminal of the power supply of the power control module. The brightness adjustment terminal of the constant current driving chip is connected to the corresponding LED control output terminal of the control module. The driving terminal of the constant current driving chip is connected to the control terminal of the first switching transistor. The first terminal of the first switching transistor is connected to the negative terminal of the corresponding LED through the inductor. The second terminal of the first switching transistor is grounded through the current sensing resistor, and the second terminal of the first switching transistor is also connected to the current sensing terminal of the constant current driving chip.

[0009] Preferably, the fault detection module includes an amplifier and a comparator, wherein the input terminal of the amplifier is connected to the second terminal of the first switching transistor of the corresponding constant current drive module, the output terminal of the amplifier is connected to the first input terminal of the comparator, the second input terminal of the comparator receives a reference voltage, and the output terminal of the comparator is connected to the fault detection input terminal of the control module.

[0010] Preferably, the alarm module includes a first push-pull circuit and a second alarm, wherein the first input terminal of the first push-pull circuit is connected to the first fault output terminal of the control module, the second input terminal of the first push-pull circuit is connected to the second fault output terminal of the control module, the positive output terminal of the first push-pull circuit is connected to the first terminal of the relay coil of the second alarm, and the negative output terminal of the first push-pull circuit and the second terminal of the relay coil of the second alarm are grounded together.

[0011] Preferably, the power control module includes a second push-pull circuit and a power control relay. The first input terminal of the second push-pull circuit is connected to the third fault output terminal of the control module, the second input terminal of the second push-pull circuit is connected to the fourth fault output terminal of the control module, the positive output terminal of the second push-pull circuit is connected to the first terminal of the coil of the power control relay, the negative output terminal of the second push-pull circuit and the second terminal of the coil of the power control relay are grounded together, the moving contact of the power control relay switch is the positive terminal of the drive power supply, the normally open contact of the power control relay switch is connected to the positive terminal of the LED power supply of the power module, and the normally closed contact of the power control relay switch is floating. Moreover, when the moving contact is connected to the normally closed contact, the first alarm will sound an alarm because the current of its relay coil is lower than the pull-in current.

[0012] Preferably, it further includes:

[0013] An indication module connected to the control module for indicating status based on the output signal of the control module.

[0014] Preferably, the indicator module includes a first LED indicator, a second LED indicator, and a third LED indicator. The positive terminals of the first LED indicator, the second LED indicator, and the third LED indicator are respectively connected to the power supply voltage. The negative terminals of the first LED indicator, the second LED indicator, and the third LED indicator are respectively connected to the corresponding output terminals of the control module. The first LED indicator lights up when the first LED bead fails, the second LED indicator lights up when the second LED bead fails, and the third LED indicator flashes when the intelligent lighting unit is operating normally.

[0015] Preferably, the power module includes a transformer, a first rectifier bridge, a second rectifier bridge, and a DC / DC converter. The two input terminals of the transformer are connected to an AC power source. The output terminal of the transformer is connected to the input terminals of the first rectifier bridge and the second rectifier bridge, respectively. The output terminal of the first rectifier bridge is connected to the input terminal of the DC / DC converter, and the output terminal of the DC / DC converter is a control power supply terminal. The output terminal of the second rectifier bridge is an LED power supply terminal.

[0016] Preferably, it further includes:

[0017] The first SPD protection module is used to protect the connected AC power supply from lightning surges.

[0018] The second SPD protection module is used to provide lightning surge protection for the two constant current drive modules.

[0019] The present invention also constructs an LED railway signal light system, connected to a first alarm device installed at the front end, comprising:

[0020] A railway signal bulb containing two LED beads;

[0021] The intelligent lighting unit according to any one of claims 1-9.

[0022] The technical solution of this invention, by adopting modular processing, using a dual-loop automatic cyclic switching working mode instead of a single-loop long-term working mode, and using an automatic detection scheme instead of manual periodic on-site inspection, ensures stable and efficient operation. It reduces the failure rate and increases service life. Moreover, since professional technical maintenance personnel are no longer required to conduct periodic on-site inspections, it greatly improves work efficiency and reduces operating costs, and eliminates safety hazards caused by human factors, truly achieving an intelligent system. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0024] Figure 1 This is a logic structure diagram of Embodiment 1 of the LED railway signal light system of the present invention;

[0025] Figures 2A to 2M This is a circuit diagram of a first embodiment of the intelligent lighting unit of the present invention. Detailed Implementation

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] Figure 1 This is a logical structure diagram of an embodiment of the LED railway signal light system of the present invention. The LED railway signal light system of this embodiment includes an intelligent lighting unit 100 and a railway signal bulb containing two LED beads 210 and 220. In addition, the LED railway signal light system is also connected to a first alarm 300 installed at the front end.

[0028] The intelligent lighting unit 100 in this embodiment includes a control module 110, two constant current drive modules 121 and 122, two fault detection modules 131 and 132, an alarm module 140, a power supply module 150, and a power control module 160. Furthermore, the LED bead 210 forms one loop with the constant current drive module 121 and the fault detection module 131, and the LED bead 220 forms another loop with the constant current drive module 122 and the fault detection module 132. The control module 110 obtains the detection results of the corresponding LED beads and their circuits from the fault detection modules 131 and 132 (the detection results include short circuit faults, open circuit faults, and light decay faults of LED beads). Based on the detection results of the two LED beads 210 and 220 and their circuits, when the first condition is met (the first condition is that both LED beads and their circuits are normal), the two constant current drive modules 121 and 122 control the two LED beads 210 and 220 to alternately be lit. When the second condition is met (the second condition is that one LED bead and its circuit are normal, and the other LED bead or its circuit has an open circuit fault or a light decay fault), the corresponding constant current drive module controls the normal LED bead to be constantly lit, and the alarm module 140 triggers an alarm. When neither the first condition nor the second condition is met, the power control module 160 controls the two constant current drive modules 121 and 122 to stop working, thereby triggering the first alarm 300 to trigger an alarm. It should be noted that the first alarm 300 is located at the front end (main control room), and its relay drive coil is connected in series with the primary winding of the transformer of the power module. When the two constant current drive modules 121 and 122 stop working, the two LED beads 210 and 220 do not light up, the current of the entire intelligent lighting unit decreases, and the first alarm is triggered because the current on its relay drive coil is much lower than the pull-in current.

[0029] In this embodiment, the two LED beads and their circuits are not differentiated into primary and secondary. When the first condition (both LED beads and their circuits are normal) is met, the control module automatically switches one LED bead to work for a period of time before automatically switching to the other. This cycle repeats, allowing the two lighting circuits to switch cyclically. When the second condition (one LED bead and its circuit are normal, but the other LED bead or its circuit experiences an open circuit fault or a light decay fault) is met, the system immediately switches to the normal LED bead, and the alarm module issues an alarm signal. If neither the first nor the second condition is met, the two constant current drive modules stop working, and the first alarm 300 at the front end issues an alarm signal.

[0030] The technical solution of this embodiment, by adopting modular processing, using a dual-circuit automatic cyclic switching working mode instead of a single-circuit long-term working mode, and using an automatic detection scheme instead of manual periodic on-site inspection, ensures stable and efficient operation. While reducing the failure rate, it also increases the service life. Moreover, since professional technical maintenance personnel are no longer required to conduct periodic on-site inspections, it greatly improves work efficiency and reduces operating costs, and eliminates safety hazards caused by human factors, truly achieving an intelligent system.

[0031] Furthermore, the intelligent lighting unit also includes an indicator module, a first SPD protection module, and a second SPD protection module. The indicator module is connected to the control module and is used to indicate the status based on the output signal of the control module. The first SPD protection module is used to provide lightning surge protection for the connected AC power supply. The second SPD protection module is used to provide lightning surge protection for the two constant current drive modules.

[0032] Figures 2A to 2M This is a circuit diagram of an embodiment of the intelligent lighting unit of the present invention. The intelligent lighting unit of this embodiment includes a control module, two constant current drive modules, two fault detection modules, an alarm module, a power supply module, a power control module, an indicator module, a first SPD protection module, and a second SPD protection module. The circuit structure and working principle of each module will be described in detail below:

[0033] In this embodiment, combined with Figure 2A and Figure 2BThe power supply module mainly includes transformer U1, first rectifier bridge D2, second rectifier bridge D1, DC / DC converters U3 and U2. Transformer U1 is a multi-input single-output transformer with four voltage input ports: 200V, 210V, 220V, and 230V 50Hz AC input ports. The appropriate input port is selected based on the external input voltage. Transformer U1 outputs 9V AC, and its output terminals are connected to the input terminals of the first rectifier bridge D2 and the second rectifier bridge D1. The output terminal of the first rectifier bridge D2 is connected to the input terminal of DC / DC converter U3. The output terminal DVDD5V of DC / DC converter U3 outputs a 5V supply voltage and is connected to the input terminal of DC / DC converter U2. The output terminal DVDD3V3 of DC / DC converter U2 outputs a 3.3V supply voltage; that is, the output terminal of DC / DC converter U2 is the control power supply terminal. The output terminal of the second rectifier bridge D1 is the positive terminal of the LED power supply and outputs the LED power supply voltage DVDD10. In addition, the positive terminals of electrolytic capacitors C12 and C13 are connected to the positive output terminal of the first rectifier bridge D2, respectively. The positive terminal of electrolytic capacitor C8 and one end of capacitor C9 are connected to the positive output terminal of DC / DC converter U3, respectively. The positive terminal of electrolytic capacitor C10 and one end of capacitor C11 are connected to the positive output terminal of DC / DC converter U2, respectively. The negative terminals of electrolytic capacitors C12, C13, and C8, the other end of capacitor C9, the negative terminal of electrolytic capacitor C10, and the other end of capacitor C11 are grounded. The positive terminals of electrolytic capacitors C5 and C8, one end of capacitor C7, and one end of resistor R9 are connected to the positive output terminal of the second rectifier bridge D1, respectively. The negative terminals of electrolytic capacitors C5 and C8, the other end of capacitor C7, and the other end of resistor R9 are grounded. Resistors R10, R11, and R71 are connected in parallel, with one end connected to the positive terminal (LED+) of the power supply module's drive power supply and the other end grounded.

[0034] In this embodiment, combined with Figure 2A There are four first SPD protection modules, each corresponding to one of the four input ports of transformer U1. Each first SPD protection module includes a varistor, a PTC thermistor, and a safety capacitor. The following description uses the first SPD protection module connected to the 230V AC input port as an example to illustrate the structure of the surge protection module. The varistor R5 is connected between the 230V input port and the neutral line N. One end of the PTC thermistor R1 is connected to the 230V input port, and the other end is connected to one end of the safety capacitor C1. The other end of the safety capacitor C1 is connected to the neutral line N. It should be understood that the structure of the other first SPD protection modules is similar to this surge protection module, and will not be elaborated upon here.

[0035] In this embodiment, combined with Figure 2C and Figure 2DThe control module mainly includes: MCU U5, resistors R12, R18, R21, R22, R23, R30, R32, R33, R34, R35, R64, R65, R66, R72, and capacitors C18, C19, C22, and C23. Resistors R64 and R65, along with pin 27 of MCU U5, constitute the first LED drive signal; resistors R12 and R66, along with pin 26 of MCU U5, constitute the second LED drive signal. Resistors R22 and R30, along with pin 13 of MCU U5, and resistors R21 and R72, along with pin 30 of MCU U5, constitute the drive control pins for the alarm module. Resistors R32 and R35, along with pin 14 of MCU U5, and resistors R33 and R34, along with pin 19 of MCU U5, constitute the control pins for the power control module. Pin 5 of MCU U5 is the RST pin, used for power-on reset. Pin 22 of MCU U5 is connected to the operation indicator pin of the indicator module; pin 20 of MCU U5 is connected to the first LED operation status indicator pin of the indicator module; and pin 21 of MCU U5 is connected to the second LED operation status indicator pin of the indicator module. Pins 10 and 28 of MCU U5 are connected to the detection pins of the two fault detection modules, respectively. Pins 23 and 24 of MCU U5 are programming pins.

[0036] In this embodiment, combined with Figure 2E The constant current drive module corresponding to the first LED mainly includes a constant current drive chip U6, a switching transistor Q1, an inductor L1, and three parallel current sensing resistors R24, R25, and R26. The switching transistor Q1 is a MOSFET. It should be understood that in other embodiments, other types of switching transistors can be used, and the three parallel resistors R24, R25, and R26 can be replaced by resistors with other connection configurations. In this embodiment, the power supply terminal (VDD) of the constant current driver chip U6 is connected to the positive terminal of the drive power supply (LED+) through resistor R13. The brightness adjustment terminal (DIM) of the constant current driver chip U6 is connected to the corresponding LED control output terminal (PWM_LED1) of the control module. The drive terminal (DRV) of the constant current driver chip U6 is connected to the gate of the MOSFET Q1. The drain of the MOSFET Q1 is connected to the negative terminal (LED1-) of the corresponding LED through inductor L1. The source of the MOSFET Q1 is grounded through the parallel current sensing resistors R24, R25, and R26. The source of the MOSFET Q1 is also connected to the current sensing terminal (CS) of the constant current driver chip U6.

[0037] Similarly, combining Figure 2FThe constant current drive module corresponding to the second LED mainly includes a constant current drive chip U7, a switching transistor Q2, an inductor L2, and three parallel current sensing resistors R27, R28, and R29. The switching transistor Q2 is a MOSFET. It should be understood that in other embodiments, other types of switching transistors can be used, and the three parallel resistors R27, R28, and R29 can be replaced by resistors with other connection configurations. In this embodiment, the power supply terminal (VDD) of the constant current driver chip U7 is connected to the positive terminal of the drive power supply (LED+) through resistor R14. The brightness adjustment terminal (DIM) of the constant current driver chip U7 is connected to the corresponding LED control output terminal (PWM_LED2) of the control module. The drive terminal (DRV) of the constant current driver chip U7 is connected to the gate of the MOSFET Q2. The drain of the MOSFET Q2 is connected to the negative terminal (LED2-) of the corresponding LED through inductor L2. The source of the MOSFET Q2 is grounded through the parallel current sensing resistors R27, R28, and R29. The source of the MOSFET Q2 is also connected to the current sensing terminal (CS) of the constant current driver chip U7.

[0038] In this embodiment, the fault detection module includes an amplifier and a comparator. The input terminal of the amplifier is connected to the second terminal of the first switching transistor of the corresponding constant current drive module, the output terminal of the amplifier is connected to the first input terminal of the comparator, the second input terminal of the comparator receives a reference voltage, and the output terminal of the comparator is connected to the fault detection input terminal of the control module. Combined with... Figure 2G In the fault detection module corresponding to the first LED, the amplifier consists of resistors R38, R42, and R46 and operational amplifier U8.2, while the comparator consists of resistors R48, R49, and R44 and operational amplifier U8.1. Furthermore, the current detection terminal (LED1_IN) of the constant current driver chip U6 is connected to pin 3 of operational amplifier U8.2 via resistor R38. Pin 2 of operational amplifier U8.2 is connected to ground via resistor R42 and to pin 1 via resistor R46. Pin 1 of operational amplifier U8.2 is connected to pin 5 of operational amplifier U8.1 via resistor R40. Resistors R48 and R49 are connected in series, with one end connected to a 3.3V supply voltage and the other end grounded. The common terminal of resistors R48 and R49 is connected to pin 6 of operational amplifier U8.1, and pin 7 of operational amplifier U8.1 is connected to pin 10 (LED1_ERROR) of MCU U5.

[0039] Similarly, in the fault detection module corresponding to the second LED, the amplifier consists of resistors R39, R43, and R47 and operational amplifier U9.2, while the comparator consists of resistors R50, R51, and R45 and operational amplifier U9.1. Furthermore, the current detection terminal (LED2_IN) of the constant current driver chip U6 is connected to pin 3 of operational amplifier U9.2 via resistor R39. Pin 2 of operational amplifier U9.2 is connected to ground via resistor R43 and to pin 1 via resistor R47. Pin 1 of operational amplifier U9.2 is connected to pin 5 of operational amplifier U9.1 via resistor R41. Resistors R50 and R51 are connected in series, with one end connected to a 3.3V supply voltage and the other end grounded. The common terminal of resistors R50 and R51 is connected to pin 6 of operational amplifier U9.1, and pin 7 of operational amplifier U9.1 is connected to pin 28 (LED2_ERROR) of MCU U5.

[0040] In this embodiment, the alarm module includes a first push-pull circuit and a second alarm. The first input terminal of the first push-pull circuit is connected to the first fault output terminal of the control module, the second input terminal of the first push-pull circuit is connected to the second fault output terminal of the control module, the positive output terminal of the first push-pull circuit is connected to the first terminal of the relay coil of the second alarm, and the negative output terminal of the first push-pull circuit and the second terminal of the relay coil of the second alarm are grounded together. Figure 2H and Figure 2IThe first push-pull circuit mainly consists of MOSFETs Q5 and Q6, transformer T2, diodes D10 and D12, and electrolytic capacitor C28. Furthermore, pins 13 and 30 (PWM1 and PWM2) of MCU U5 are used as control pins (PWM1_A and PWM2_B) of MOSFETs Q5 and Q6 via the MOSFET driver chip U15. The 5V supply voltage is connected to the center tap (pin 3) of the input terminal of transformer T2 through resistor R69 and diode D14. Pin 1 of transformer T2 is connected to the drain of MOSFET Q5, and pin 5 of transformer T2 is connected to the drain of MOSFET Q6. The sources of MOSFETs Q5 and Q6 are connected to ground. Pins 6 and 10 of transformer T2 are connected to the anodes of diodes D10 and D12, respectively. The cathodes of diodes D10 and D12 are connected to the anodes of electrolytic capacitor C28 and diode D11, respectively. Pin 8 of transformer T2, the cathode of electrolytic capacitor C28, and the anode of diode D11 are grounded. The two input terminals of the relay coil of the second alarm K2 are connected to the positive and negative terminals of the electrolytic capacitor C28, respectively. Pins 3 and 4 of the relay of the second alarm K2 are common terminals, pin 1 is normally closed, and pin 6 is normally open. During normal operation, the two MOSFETs Q5 and Q6 are alternately turned on at the same switching frequency of 200kHz, and the duty cycle of each MOSFET is less than 50%, leaving a certain dead time to prevent MOSFETs Q5 and Q6 from turning on simultaneously. The input low DC voltage is inverted into a high-frequency low AC voltage by the push-pull inverter, which is sent to the primary side of the high-frequency transformer T2. Through the coupling of the transformer T2, a high-frequency AC voltage is obtained on the secondary side. After rectification and filtering by the reverse fast recovery diodes D10 and D12, the desired DC voltage is obtained to activate the relay. When any LED bead or its circuit experiences an open circuit fault, or when any LED bead experiences light decay, the normally closed terminal of the relay is closed by controlling the MOSFETs Q5 and Q6 to turn off, generating an alarm signal and triggering the second alarm K2 at the back end.

[0041] In this embodiment, the power control module includes a second push-pull circuit and a power control relay. The first input terminal of the second push-pull circuit is connected to the third fault output terminal of the control module, the second input terminal of the second push-pull circuit is connected to the fourth fault output terminal of the control module, the positive output terminal of the second push-pull circuit is connected to the first terminal of the coil of the power control relay K1, and the negative output terminal of the second push-pull circuit and the second terminal of the coil of the power control relay K1 are grounded together. The moving contact (pin 1) of the switch of the power control relay K1 is the positive terminal of the drive power supply (LED+). The normally open contact (pin 3) of switch K1 is connected to the positive terminal of the LED power supply (DVDD10) of the power module. The normally closed contact (pin 4) of the power control relay K1 is left floating. Furthermore, when the moving contact is connected to the normally closed contact, neither of the two constant current drive chips U6 nor U7 receives power supply voltage. Only the MCU operates in the entire intelligent lighting unit. At this time, the primary current of transformer U1 is much less than 10mA. Since the coil of the first alarm is connected in series with the primary winding of the transformer, the first alarm sounds because the current in its relay coil is lower than the pull-in current. Combined with... Figure 2J and Figure 2K The second push-pull circuit mainly consists of MOSFETs Q3 and Q4, transformer T1, diodes D7 and D9, and electrolytic capacitor C26. Furthermore, pins 14 and 19 of MCU U5 (PWM3 and PWM4) are regulated by the MOSFET driver chip U14 and used as control pins (PWM3_A and PWM4_B) for MOSFETs Q3 and Q4. The 5V supply voltage is connected to pin 3 of the input terminal of transformer T1 via diode D13. Pins 1 and 5 of the input terminal of transformer T1 are connected to the drain of MOSFET Q3 and the drain of MOSFET Q4, respectively. The sources of MOSFETs Q3 and Q4 are connected to ground. Pins 6 and 10 of the output terminal of transformer T1 are connected to the anodes of diodes D7 and D9, respectively. The cathodes of diodes D7 and D9 are connected to the anode of electrolytic capacitor C26 and the cathode of diode D8. The cathode of electrolytic capacitor C26 and the anode of diode D8 are grounded. Pin 8 of transformer T1 is grounded. The power control relay has a common terminal (pin 1, i.e., the positive power supply terminal for LED+), a normally closed terminal (pin 4), and a normally open terminal (pin 3), connected to the 10V power supply voltage (DVDD10) output from the second rectifier bridge. This power control module controls the power supply module. If either of the two LEDs or their circuits experiences an open circuit fault, or if either LED or its circuit experiences a short circuit fault, or if both LEDs experience light decay, or if one LED experiences light decay and the other LED or its circuit experiences an open circuit fault, the two constant current drive modules are shut down to minimize the overall circuit current, causing the first alarm in the main control room to sound an alarm because the current is much lower than the pull-in current.

[0042] In this embodiment, combined with Figure 2LThe indicator module includes a first LED indicator L1, a second LED indicator L2, and a third LED indicator L3. The positive terminals of the first LED indicator L1, the second LED indicator L2, and the third LED indicator L3 are connected to a 3.3V power supply voltage. The negative terminals of the first LED indicator L1, the second LED indicator L2, and the third LED indicator L3 are connected to the corresponding output terminals LED1, LED2, and LED3 of the control module, respectively. The first LED indicator L1 illuminates when the first LED bead fails, the second LED indicator L2 illuminates when the second LED bead fails, and the third LED indicator L3 flashes when the intelligent lighting unit is operating normally.

[0043] In this embodiment, combined with Figure 2M The second SPD protection module can provide lightning surge protection for the two constant current drive modules. Specifically, one leg of the ceramic discharge tube D17 is connected to the anodes (LED+OUT) of the two LED beads and is connected to the TVS tube D19 through the resettable fuse F2, forming the anode lightning surge protection circuit for the LED beads. One leg of the ceramic discharge tube D20 is connected to the cathode (LEN1-IN) of the first LED bead and is connected to the TVS tube D21 through the resettable fuse F3, forming the cathode lightning surge protection circuit for the first LED bead. One leg of the ceramic discharge tube D18 is connected to the cathode of the second LED bead and is connected to the TVS tube D22 through the resettable fuse F4, forming the cathode lightning surge protection circuit for the second LED bead. When a lightning strike occurs, the energy is first rapidly released through the corresponding ceramic discharge tube and then through the resettable fuse and the TVS tube, stabilizing the residual voltage within an acceptable range.

[0044] The following is combined Figures 2A to 2M The working principle of the intelligent lighting unit in this embodiment is explained as follows: The AC voltage output by the AC power supply is converted into a 9V AC voltage by the transformer U1, and then split into two paths. One path passes through the first rectifier bridge D2, DC / DC converter U3, and U2 in sequence to obtain a 5V DC power supply voltage and a 3.3V DC power supply voltage, thereby powering the control module; the other path passes through the second rectifier bridge D1 to obtain a 10V DC power supply voltage, which powers the two LED beads.

[0045] When the first LED needs to be lit, pin 27 of MCU U5 outputs a high level, causing the constant current driver chip U6 to start working, and pin 26 of MCU U5 outputs a low level, causing the constant current driver chip U7 to stop working. When the constant current driver chip U6 is working, pin 1 outputs a high level, turning on the MOSFET Q1. The 10V DC supply voltage forms a current loop to ground through the first LED, power inductor L1, MOSFET Q1, and current sensing resistors R24, R25, and R26. Based on the voltage drop detected at pin 6, the constant current driver chip U6 adjusts the output frequency of pin 1 to generate a stable current, driving the LED to work normally. Similarly, the working principle is similar when the second LED needs to be lit, and will not be elaborated here.

[0046] In addition, when the intelligent lighting unit is working, the MCU U5 also determines whether the working LED beads and their circuits (constant current drive module and fault detection module circuits) are normal based on the information fed back by the fault detection module. If the working LED beads and their circuits are normal, the PWM signal detected by the MCU U5 through the fault detection module will be within the preset frequency range. If the working LED beads and their circuits experience an open circuit fault, or if the LED beads experience light decay fault, the PWM signal detected by the MCU U5 through the fault detection module will be lower than the lower limit of the preset frequency range. If the working LED beads and their circuits experience a short circuit fault, the PWM signal detected by the MCU U5 through the fault detection module will be higher than the upper limit of the preset frequency range. Taking the first channel as an example, the sampled voltage is amplified by the amplifier circuit and then input to pin 10 of the MCU through the comparator circuit. Furthermore, when the LED beads and their circuits are working normally, the MCU U5 will detect a PWM signal within a certain frequency range (100kHz-250kHz). However, if the LED or its circuit experiences an open circuit fault, or if there are other voltage drop changes due to light decay, the frequency of the detected PWM signal will decrease to less than 100kHz; if the LED or its circuit experiences a short circuit fault, the frequency of the detected PWM signal will be greater than 250kHz. Therefore, the MCU U5 can determine whether the currently lit LED and its circuit are functioning correctly based on the frequency of the detected PWM signal.

[0047] If MCU U5 detects that the second condition is met during operation (one LED and its circuit are normal, and the other LED or its circuit has an open circuit fault or a light decay fault), it controls the second alarm K2 to output an alarm signal through its pins 13 and 30. If MCU U5 detects that neither the first nor the second condition is met during operation (both LEDs or their circuits have open circuit faults, or either LED or its circuit has a short circuit fault, or both LEDs have light decay faults; or one LED has a light decay fault and the other LED or its circuit has an open circuit fault), it controls the power control relay K1 through its pins 14 and 19 to shut off the power to the two LEDs, minimizing the current in the entire circuit, and causing the first alarm in the main control room to sound an alarm because the current is lower than the pull-in current.

[0048] Furthermore, if the MCU U5 is severely interfered with and burns out or breaks down, the LED beads will not work. Simultaneously, the power supply circuit will fail, and the primary current of transformer U1 will drop below 10mA, triggering the first alarm on the primary side. At the same time, the second alarm relay of the intelligent lighting unit, lacking a drive, will automatically drop its contacts to the alarm position, generating a lamp fault alarm. Conversely, if the MCU U5 is working normally, but the alarm module circuit malfunctions, the second alarm will also generate an alarm due to lack of a drive source.

[0049] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. An intelligent lighting unit for an LED railway signal light system, connected to a railway signal bulb containing two LED beads and a first alarm device installed at the front end, characterized in that, It includes a power supply module, a control module, an alarm module, a power control module, two constant current drive modules, and two fault detection modules. The power module supplies power to the control module and supplies power to the two LED beads through the power control module and the corresponding constant current drive module. The first alarm is located in the main control room, and its relay drive coil is connected in series with the primary winding of the transformer of the power module. The control module obtains the detection results of the corresponding LED beads and their circuits from the fault detection module. Based on the detection results of the two LED beads and their circuits, when the first condition is met, the control module controls the two LED beads to alternately be lit up through the two constant current drive modules; when the second condition is met, the control module controls the normal LED beads to be constantly lit up through the corresponding constant current drive modules, and the alarm module sounds an alarm; when neither the first condition nor the second condition is met, the control module controls the two constant current drive modules to stop working, thereby triggering the first alarm to sound an alarm. The first condition is: both LED beads and their circuits are normal; The second condition is: one of the LED beads and its circuit is normal, and the other LED bead or its circuit has an open circuit fault or the other LED bead has a light decay fault; The power control module includes a second push-pull circuit and a power control relay. The first input terminal of the second push-pull circuit is connected to the third fault output terminal of the control module, and the second input terminal of the second push-pull circuit is connected to the fourth fault output terminal of the control module. The positive output terminal of the second push-pull circuit is connected to the first terminal of the coil of the power control relay. The negative output terminal of the second push-pull circuit and the second terminal of the coil of the power control relay are grounded together. The moving contact of the power control relay switch is the positive terminal of the drive power supply. The normally open contact of the power control relay switch is connected to the positive terminal of the LED power supply of the power module. The normally closed contact of the power control relay switch is floating. Moreover, when the moving contact is connected to the normally closed contact, the first alarm will sound an alarm because the current in the relay coil is lower than the pull-in current.

2. The intelligent lighting unit according to claim 1, characterized in that, The constant current driving module includes a constant current driving chip, a first switching transistor, an inductor, and a current sensing resistor. The power supply terminal of the constant current driving chip is connected to the positive terminal of the driving power supply of the power control module. The brightness adjustment terminal of the constant current driving chip is connected to the corresponding LED control output terminal of the control module. The driving terminal of the constant current driving chip is connected to the control terminal of the first switching transistor. The first terminal of the first switching transistor is connected to the negative terminal of the corresponding LED through the inductor. The second terminal of the first switching transistor is grounded through the current sensing resistor, and the second terminal of the first switching transistor is also connected to the current sensing terminal of the constant current driving chip.

3. The intelligent lighting unit according to claim 2, characterized in that, The fault detection module includes an amplifier and a comparator. The input terminal of the amplifier is connected to the second terminal of the first switching transistor of the corresponding constant current drive module. The output terminal of the amplifier is connected to the first input terminal of the comparator. The second input terminal of the comparator receives a reference voltage. The output terminal of the comparator is connected to the fault detection input terminal of the control module.

4. The intelligent lighting unit according to claim 1, characterized in that, The alarm module includes a first push-pull circuit and a second alarm. The first input terminal of the first push-pull circuit is connected to the first fault output terminal of the control module, the second input terminal of the first push-pull circuit is connected to the second fault output terminal of the control module, the positive output terminal of the first push-pull circuit is connected to the first terminal of the relay coil of the second alarm, and the negative output terminal of the first push-pull circuit and the second terminal of the relay coil of the second alarm are grounded together.

5. The intelligent lighting unit according to claim 1, characterized in that, Also includes: An indication module connected to the control module for indicating status based on the output signal of the control module.

6. The intelligent lighting unit according to claim 5, characterized in that, The indicator module includes a first LED indicator, a second LED indicator, and a third LED indicator. The positive terminals of the first, second, and third LED indicators are respectively connected to the power supply voltage. The negative terminals of the first, second, and third LED indicators are respectively connected to the corresponding output terminals of the control module. The first LED indicator lights up when the first LED bead fails, the second LED indicator lights up when the second LED bead fails, and the third LED indicator flashes when the intelligent lighting unit is operating normally.

7. The intelligent lighting unit according to claim 1, characterized in that, The power module includes a transformer, a first rectifier bridge, a second rectifier bridge, and a DC / DC converter. The two input terminals of the transformer are connected to an AC power source. The output terminal of the transformer is connected to the input terminals of the first rectifier bridge and the second rectifier bridge, respectively. The output terminal of the first rectifier bridge is connected to the input terminal of the DC / DC converter, and the output terminal of the DC / DC converter is a control power supply terminal. The output terminal of the second rectifier bridge is an LED power supply terminal.

8. The intelligent lighting unit according to claim 1, characterized in that, Also includes: The first SPD protection module is used to protect the connected AC power supply from lightning surges. The second SPD protection module is used to provide lightning surge protection for the two constant current drive modules.

9. An LED railway signal light system, connected to a first alarm device installed at the front end, characterized in that, include: A railway signal bulb containing two LED beads; The intelligent lighting unit according to any one of claims 1-8.

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