CN216217657U - High-reliability railway signal light source - Google Patents

Abstract

The utility model discloses a high-reliability railway signal light source which comprises a transformer, a rectifying circuit, a PFC circuit, a PWM (pulse-width modulation) constant-current driving circuit, a protection circuit, an MCU (microprogrammed control Unit) processor and a matrix LED lamp bead, wherein the secondary alternating-current output side of the transformer is connected with the rectifying circuit end, the rectifying circuit is connected with the PFC circuit, the PFC circuit is connected with the PWM constant-current driving circuit, the PWM constant-current driving circuit is connected with the input end of the matrix LED lamp bead and used for providing driving current for the matrix LED lamp bead, the output end of the matrix LED lamp bead is connected with the protection circuit, the protection circuit is connected with the MCU processor, and the MCU processor is also connected with the PWM constant-current driving circuit; the utility model greatly improves the reliability of the railway signal light source.

Description

High-reliability railway signal light source

Technical Field

The utility model relates to the technical field of railway signal mechanisms and extension equipment thereof, in particular to a high-reliability railway signal light source.

Background

At present, the monitoring and alarming of the main filament by the railway signal system are completed by a lighting device (lighting unit) or a lighting relay. The basic working principle of the devices is that the working current of the filament is detected, when the current is lower than the threshold current, the lamp bulb is judged to have a fault, the lamp-out phenomenon caused by the leakage or short circuit of the far end of a power supply line cannot be effectively alarmed, and certain potential safety hazards exist.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems in the prior art, the utility model aims to provide a high-reliability railway signal light source, and the reliability of the railway signal light source is greatly improved.

In order to achieve the purpose, the utility model adopts the technical scheme that: a high-reliability railway signal light source comprises a transformer, a rectifying circuit, a PFC circuit, a PWM constant-current driving circuit, a protection circuit, an MCU processor and a matrix LED lamp bead, wherein the secondary alternating-current output side of the transformer is connected with the rectifying circuit end, the rectifying circuit is connected with the PFC circuit, the PFC circuit is connected with the PWM constant-current driving circuit, the PWM constant-current driving circuit is connected with the input end of the matrix LED lamp bead and used for providing driving current for the matrix LED lamp bead, the output end of the matrix LED lamp bead is connected with the protection circuit, the protection circuit is connected with the MCU processor, and the MCU processor is further connected with the PWM constant-current driving circuit.

As a further improvement of the present invention, an EMC anti-interference circuit is further provided between the secondary ac output side of the transformer and the rectifier circuit.

As a further improvement of the utility model, the rectification circuit is a bridge rectifier.

The utility model has the beneficial effects that:

the LED signal lamp adopts a constant power driving technology, has wide working voltage adaptability, almost constant light emitting power when the power supply voltage is between 7 and 24V, can reduce 80% of electric energy consumption compared with an incandescent lamp with the same lighting effect, has the service life of more than 10 ten thousand hours at normal temperature, greatly reduces the manual workload of maintenance and replacement, and improves the comprehensive benefit; the optical and electrical parameters of the lamp bead operation are detected in real time in the circuit, corresponding response actions are made according to the principle of fault-oriented safety through threshold value comparison, and the safety and reliability of the system are improved.

Drawings

FIG. 1 is a block diagram of a circuit configuration according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a circuit structure of a rectifier circuit and a PFC circuit according to an embodiment of the present invention;

fig. 3 is a schematic circuit structure diagram of the PWM constant current driving circuit according to the embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

Examples

As shown in fig. 1, a highly reliable railway signal light source comprises a transformer QT, a rectifier circuit, a PFC circuit, a PWM constant current driving circuit, a protection circuit, an MCU processor and a matrix LED lamp bead, wherein a secondary ac output side of the transformer is connected to a terminal of the rectifier circuit, the rectifier circuit is connected to the PFC circuit, the PFC circuit is connected to the PWM constant current driving circuit, the PWM constant current driving circuit is connected to an input terminal of the matrix LED lamp bead for providing a driving current for the matrix LED lamp bead, an output terminal of the matrix LED lamp bead is connected to the protection circuit, the protection circuit is connected to the MCU processor, and the MCU processor is further connected to the PWM constant current driving circuit; an EMC anti-interference circuit is further arranged between the secondary alternating current output side of the transformer and the rectifying circuit.

In this embodiment, a 12V secondary alternating current power supply output by a transformer QT is converted into a pulsating direct current by a rectifier circuit, and is output to a PWM constant current driving circuit by a PFC circuit (i.e., an active power factor compensation circuit), so as to provide a stable driving current for a matrix LED lamp bead, a protection circuit monitors an operating voltage and current parameter in real time, and supervises an LED operating condition by a direct optical feedback signal, the signal is sent to an MCU processor for threshold judgment, and when the parameter exceeds a set alarm threshold, a fault control signal is output and a fault alarm is given, thereby improving an intelligent level.

In this embodiment, an EMC anti-interference circuit is further provided between the secondary ac output side of the transformer and the rectifier circuit; the EMC anti-interference circuit can effectively suppress power grid noise, improves the anti-interference capability and reliability of electronic equipment, and simultaneously suppresses the interference on other electronic equipment.

As shown in fig. 2, the rectifier circuit in this embodiment is a rectifier bridge stack, a filter capacitor is removed after the rectifier bridge stack to eliminate the current waveform distortion and the phase change caused by the charging of the capacitor, and a chopper circuit converts the pulsating direct current into high-frequency pulses of tens to hundreds of KHz, and then the high-frequency pulses are rectified and filtered, and the direct-current voltage supplies power to the back-end circuit, in the process of AC → DC → AC → DC, and the chopper circuit also operates similarly to a switching power supply.

As shown in FIG. 3, a Boost circuit topology, a constant current driving mode and a PWM switching frequency of 80-800KHz are used for providing stable working current for the matrix LED lamp beads. Input 14V DC power supply_INSmooth filtered and added to L, Q_MD, the Boost circuit outputs about 30V driving voltage through the current sampling resistor R_CSAnd Q_DMControlling MOS tubes to add to matrix LED lamp beads, illuminating the lamp beads, R_ADJ2And R_ADJ1For setting the output current, R_OV2And R_OV1For setting the load open upper limit output voltage.

Its output current

Output voltage

The current monitoring circuit is composed of a sampling resistor and an internal proportional operation circuit, and outputs a current monitoring signal from an 8-pin IMON end, wherein the voltage of the current monitoring signal is as follows:

V_IMON＝14×I_LED×R_CS

will V_IMONThe power load in the power supply circuit is disconnected when the LED does not emit light or the luminous flux is low, and the aims of dynamically monitoring the circuit and giving an alarm in real time are achieved through the linkage of the original alarm system of the railway signal lamp.

In the embodiment, when a circuit fault or a light source fault occurs, the protection circuit acts to disconnect the power supply circuit, isolate the fault to avoid influencing other electric equipment on the same power supply circuit, and prevent the further expansion of the fault.

The MCU processor in the implementation uses an ideogram semiconductor STM8L low-power-consumption microprocessor to execute the functions of operation parameter detection and fault judgment output, the dynamic operation power consumption is less than 150uA/MHz, the highest operation temperature can reach 125 ℃, the working requirement of field limit temperature can be met, an IAR For STM8 development environment is used, and the MCU processor is simple and easy to use.

The above-mentioned embodiments only express the specific embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.

Claims (3)

1. The high-reliability railway signal light source is characterized by comprising a transformer, a rectifying circuit, a PFC circuit, a PWM constant-current driving circuit, a protection circuit, an MCU processor and matrix LED lamp beads, wherein the secondary alternating-current output side of the transformer is connected with the rectifying circuit end, the rectifying circuit is connected with the PFC circuit, the PFC circuit is connected with the PWM constant-current driving circuit, the PWM constant-current driving circuit is connected with the input end of the matrix LED lamp beads and used for providing driving current for the matrix LED lamp beads, the output end of the matrix LED lamp beads is connected with the protection circuit, the protection circuit is connected with the MCU processor, and the MCU processor is further connected with the PWM constant-current driving circuit.

2. The high-reliability railway signal light source of claim 1, wherein an EMC anti-interference circuit is further arranged between the secondary alternating current output side of the transformer and the rectifying circuit.

3. The high reliability railway signal light source of claim 1, wherein the rectification circuit is a bridge rectifier.

Images