Red flashing lamp for rail transit maintenance

Abstract

The utility model provides a red flashing light for rail transit maintenance, which is applied to the technical field of warning lights and comprises a backup battery unit, a main control chip, a driving circuit and an LED light source. The backup battery unit is used for supplying power to the main control chip and comprises a battery cell, an anti-reverse connection circuit and a charging and discharging protection circuit, and the anti-reverse connection circuit is used for preventing reverse connection when the battery cell is connected to the circuit board; the charging and discharging protection circuit is used for cutting off the input current of the battery cell when the battery cell is overcharged or cutting off the output current when the battery cell is overdischarged; the driving circuit is used for amplifying the driving signal output by the main control chip, so that the LED light source is in a constant-current state; a key control unit is further connected between the backup battery unit and the main control chip, and the key control unit achieves power-on control or power-off control of the red flashing light through a key. The battery cell is managed through the backup battery unit and the key control unit, so that the power consumption and the safety of the whole machine are reduced, and the service life of the battery cell is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of warning lights, and in particular relates to a red flashing light for rail transit maintenance. Background Art

[0002] Warning lights are generally used to maintain road safety, electrical equipment warnings, etc. Among them, warning lights are indispensable equipment in rail transit industry maintenance.

[0003] At present, the red flashing lights used in the maintenance of the entire rail transit industry have internal chips that continue to work and consume the backup battery capacity after being turned off. The battery life of the red flashing lights is relatively short. At the same time, most red flashing lights are charged by series diodes, which can easily swell the backup soft-package lithium batteries, posing certain safety hazards. Utility Model Content

[0004] In view of the above problems in the prior art, the purpose of the utility model is to provide a red flashing light for rail transit maintenance, which manages the battery cells through a backup battery unit and a button control unit, reduces the power consumption and safety of the whole machine, and prolongs the service life of the battery cells.

[0005] A red flashing light for rail transit maintenance, comprising a backup battery unit, a main control chip U4, a drive circuit and an LED light source; the backup battery unit is used to supply power to the main control chip U4, the backup battery unit comprises a battery cell JP1, an anti-reverse connection circuit and a charge and discharge protection circuit, the anti-reverse connection circuit is used to prevent reverse connection when the battery cell JP1 is connected to a circuit board; the charge and discharge protection circuit is used to cut off the input current of the battery cell JP1 when the battery cell JP1 is overcharged or cut off the output current when the battery cell JP1 is over-discharged; the drive circuit is used to amplify the drive signal output by the main control chip U4, so that the LED light source is in a constant current state; a key control unit is also connected between the backup battery unit and the main control chip U4, and the key control unit realizes power-on control or power-off control of the red flashing light by pressing a key.

[0006] Preferably, the key control unit includes a key SW1, a switch tube Q8, and a switch tube Q10. The collector of the switch tube Q8 outputs the whole machine control voltage Vout. After the main control chip U4 detects the long press signal of the key SW1, the IO1 pin of the main control chip U4 outputs a low level. At this time, the key SW1 is released, and the base voltage of the saturated conduction of the switch tube Q10 disappears, the switch tube Q10 is turned off, and the switch tube Q8 is turned off, so that the whole machine control voltage Vout is 0.

[0007] Preferably, the button control unit also includes a resistor R21, a resistor R36, a diode D4, a diode D5, a capacitor C10, a resistor R37, a resistor R38, a resistor R23, and a resistor R39. The button SW1 is connected between the resistor R21 and the resistor R36. The other end of the resistor R21 is connected to the pin 1 of the battery cell JP1, and the other end of the resistor R36 is grounded. The ON / OFF end of the main control chip U4 is connected to a resistor R35. The other end of the resistor R35 is connected to the resistor R36 and the positive electrode of the diode D4. The cathode of the diode D4 is respectively connected to the cathode of the capacitor C10, the cathode of the diode D5, and the cathode of the resistor R 37 is connected, the other end of the capacitor C10 is grounded, the positive electrode of the diode D5 is connected to the IO1 pin of the main control chip U4, the other end of the resistor R37 is respectively connected to the resistor R38 and the base of the switch tube Q10, the other end of the resistor R38 is grounded, the emitter of the switch tube Q10 is grounded, the collector of the switch tube Q10 is connected to the base of the switch tube Q8 through the resistor R39, a resistor R23 is connected between the emitter of the switch tube Q8 and the base of the switch tube Q8, a capacitor C13 is connected between the collector of the switch tube Q8 and the emitter of the switch tube Q10, and the collector of the switch tube Q8 outputs the whole machine control voltage Vout.

[0008] Preferably, the anti-reverse connection circuit includes a resistor R27, a resistor R28, and a MOS tube Q6, one end of the resistor R28 is connected to pin 1 of the battery cell JP1, and the other end is connected to the gate of the MOS tube Q6, the resistor R27 is connected between the gate and the source of the MOS tube Q6, and the drain of the MOS tube Q6 is connected to pin 2 of the battery cell JP1.

[0009] Preferably, the charge and discharge protection circuit includes a protection chip U5, a resistor R29, a capacitor C8, a resistor R30, a resistor R31, a MOS tube Q11, and a MOS tube Q12. The VSS end of the protection chip U5 is connected to the capacitor C8 and the resistor R29 in series. The other end of the resistor R29 is connected to pin 1 of the battery cell JP1. The VSS end of the protection chip U5 is also connected to the source of the MOS tube Q6. The VDD end of the protection chip U5 is connected between the capacitor C8 and the resistor R29. The OD end of the protection chip U5 is connected to the gate of the MOS tube Q11, and the OC end of the protection chip U5 is connected to the gate of the MOS tube Q12. The CS end of the protection chip U5 is connected to the resistor R30 and the resistor R31 in parallel. The other end of the resistor R30 is connected to the source of the MOS tube Q11, and the other end of the resistor R31 is connected to the source of the MOS tube Q12. The drain of the MOS tube Q11 and the drain of the MOS tube Q12 are connected.

[0010] Preferably, the driving circuit includes a resistor R18, a resistor R19, a MOS tube Q4, a resistor R20, a transistor Q7, a transistor Q9, a switch tube Q5, and a resistor R24. The main control chip U4 has a built-in PWM function module. One end of the resistor R18 is connected to the PWM pin of the main control chip U4, and the other end of the resistor R18 is respectively connected to the resistor R19 and the gate of the MOS tube Q4. The other end of the resistor R19 is grounded, the source of the MOS tube Q4 is grounded, the drain of the MOS tube Q4 is respectively connected to the resistor R20, the base of the transistor Q7, and the base of the transistor Q9, the emitter of the transistor Q7 and the emitter of the transistor Q9 are connected and connected to the gate of the switch tube Q5 and the resistor R24, the other end of the resistor R24 ​​is connected to the source of the switch tube Q5, and an LED light source is connected between the collector of the transistor Q9 and the drain of the switch tube Q5.

[0011] Preferably, an overcurrent protection circuit is also connected between the main control chip U4 and the LED light source, and the overcurrent protection circuit includes a resistor R26, a resistor R25, a capacitor C7, and a resistor R22. The resistor R25, the capacitor C7, and the resistor R26 are connected to form a closed loop. The main control chip U4 has a built-in ADC function module, and the resistor R22 is connected between the capacitor C7 and the resistor R25. The other end of the resistor R22 is connected to the ADC2 end of the main control chip U4, and the source of the switch tube Q5 is connected between the resistor R25 and the resistor R26.

[0012] Preferably, the backup battery unit is connected to the charging management circuit, which includes a charging management chip U6 and a charging connector J5. The BAT end of the charging management chip U6 is connected to pin 1 of the battery cell JP1, and the BAT end is also connected to a resistor R32 and a capacitor C9 in series, and the other end of the capacitor C9 is grounded; the ST end of the charging management chip U6 is connected to a resistor R33 and an indicator light LED1 in series, and the other end of the indicator light LED1 is grounded; the IST end of the charging management chip U6 is connected to a resistor R34, and the other end of the resistor R34 is grounded; the VIN end of the charging management chip U6 is connected to the charging connector J5.

[0013] Preferably, a battery sampling circuit is also connected between the backup battery unit and the main control chip U4, and the battery sampling circuit is used to sample the output voltage of the battery cell JP1 through the built-in ADC function module of the main control chip U4 to determine whether the state of the battery cell JP1 is normal; the battery sampling circuit includes a voltage-dividing resistor R15 and a voltage-dividing resistor R16 connected in series, the other end of the voltage-dividing resistor R15 is connected to pin 1 of the battery cell JP1, the other end of the voltage-dividing resistor R16 is grounded, and the voltage-dividing resistor R15 and the voltage-dividing resistor R16 are connected to the ADC1 pin of the main control chip U4.

[0014] Preferably, a step-down circuit is also connected between the backup battery unit and the main control chip U4, and the step-down circuit is used to convert the voltage output by the battery cell JP1 and then connect it to the main control chip U4 to provide a stable voltage; the step-down circuit includes a voltage regulator U3, a capacitor C4, a capacitor C5 and a capacitor C12, the VIN end of the voltage regulator U3 is connected to the capacitor C4, the other end of the capacitor C4 is grounded, the VOUT end of the voltage regulator U3 outputs a power supply constant voltage VCC, the VOUT end of the voltage regulator U3 is also connected to a capacitor C5, a capacitor C12, a resistor R17, and a resistor R1 in parallel, the other end of the capacitor C5 is grounded, the other end of the capacitor C12 is connected to a capacitor C6, the other end of the capacitor C6 is connected to the RST end of the main control chip U4, the capacitors C6 and C12 are grounded, the other end of the resistor R17 is connected to the RST end of the main control chip U4, the other end of the resistor R1 is connected to LED2, and the other end of LED2 is connected to the IO3 end of the main control chip U4.

[0015] The beneficial effects of the utility model are as follows: the red flashing light for rail transit maintenance manages the battery cells through the backup battery unit and the key control unit, reduces the power consumption and safety of the whole machine, and prolongs the service life of the battery cells. Specifically, the anti-reverse connection circuit is used to effectively prevent the battery cells from being connected in reverse polarity; the charge and discharge protection circuit is used to perform power-off protection when the battery cells are abnormally charged and discharged; through the key function configuration of the key control unit, the red flashing light can be turned on and off with one key, and the current consumption of the whole machine after shutdown is approximately zero, which can reduce the current consumption of the whole machine and prolong the service life and endurance of the battery cells; in addition, the charging management circuit adjusts the charging current so that the whole machine has a small current charging mode such as trickle, which can also effectively prolong the service life of the battery cells.

[0016] High-frequency PWM constant-current dimming is achieved through the built-in PWM function module of the main control chip. At the same time, the driving circuit is used to amplify the PWM signal to drive the LED light source, which ensures the lighting effect of the LED light source while enhancing the battery life. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0018] Figure 1 It is a structural block diagram of the utility model;

[0019] Figure 2 It is a circuit diagram of the utility model;

[0020] Figure 3 It is the work flow chart of the utility model. DETAILED DESCRIPTION

[0021] Embodiment 1

[0022] like Figure 1 As shown, a red flashing light for rail transit maintenance includes a backup battery unit, a main control chip U4, a drive circuit and an LED light source. The backup battery unit includes a battery cell JP1, the backup battery unit is used to supply power to the main control chip U4, and the drive circuit is used to amplify the drive signal output by the main control chip U4 to put the LED light source in a constant current state. A key control unit is also connected between the backup battery unit and the main control chip U4, and the key control unit realizes the power-on control or power-off control of the red flashing light through a key.

[0023] In this embodiment, the main control chip U4 is an 8051 single-chip microcomputer. The LED light source uses a straw hat lamp as the light source, which increases its luminous area by more than 3 times compared with traditional LED lamp beads, with high luminous intensity and good light efficiency. The battery JP1 uses parallel 18650 steel core lithium batteries, which have high impact resistance, and can improve the safety of the whole machine while increasing the battery capacity.

[0024] Specifically, Figure 2 As shown, the key control unit includes a key SW1, a switch tube Q8, and a switch tube Q10. The collector of the switch tube Q8 outputs the whole machine control voltage Vout. After the main control chip U4 detects the long press signal of the key SW1, the IO1 pin of the main control chip U4 outputs a low level. At this time, the key SW1 is released, and the base voltage of the saturated conduction of the switch tube Q10 disappears, the switch tube Q10 is turned off, and the switch tube Q8 is turned off, so that the whole machine control voltage Vout is 0.

[0025] Specifically, the button control unit also includes a resistor R21, a resistor R36, a diode D4, a diode D5, a capacitor C10, a resistor R37, a resistor R38, a resistor R23, and a resistor R39. The button SW1 is connected between the resistor R21 and the resistor R36. The other end of the resistor R21 is connected to pin 1 of the battery cell JP1, and the other end of the resistor R36 is grounded.

[0026] The ON / OFF end of the main control chip U4 is connected to a resistor R35, the other end of the resistor R35 is connected to a resistor R36 and a positive electrode of a diode D4, the negative electrode of the diode D4 is respectively connected to a capacitor C10, a negative electrode of a diode D5, and a resistor R37, the other end of the capacitor C10 is grounded, the positive electrode of the diode D5 is connected to the IO1 pin of the main control chip U4, the other end of the resistor R37 is respectively connected to a resistor R38 and a base of a switch tube Q10, the other end of the resistor R38 is grounded, the emitter of the switch tube Q10 is grounded, the collector of the switch tube Q10 is connected to the base of the switch tube Q8 through a resistor R39, a resistor R23 is connected between the emitter of the switch tube Q8 and the base of the switch tube Q8, a capacitor C13 is connected between the collector of the switch tube Q8 and the emitter of the switch tube Q10, and the collector of the switch tube Q8 outputs the whole machine control voltage Vout.

[0027] The function of the key SW1 of the key control unit can be set according to specific usage requirements, such as Figure 3 As shown, a workflow is provided after the button SW1 of the red flashing light is configured.

[0028] After lightly touching the button SW1, the red flashing light starts normally. If the LED light source is always on, the red flashing light is in normal working condition. If the LED light source is not always on, the red flashing light needs to be charged.

[0029] When the red flashing light is in normal working condition, lightly touch the button SW1 and the LED light source flashes; when the LED light source is flashing, lightly touch the button SW1 again and the LED light source flashes quickly; when the LED light source flashes quickly, lightly touch the button SW1 again and the system shuts down; it should be noted that when the red flashing light is in normal working condition, long pressing the button SW1 will shut down the system.

[0030] like Figure 2 As shown, the driving circuit includes a resistor R18, a resistor R19, a MOS tube Q4, a resistor R20, a triode Q7, a triode Q9, a switch tube Q5, and a resistor R24. The main control chip U4 has a built-in PWM function module. One end of the resistor R18 is connected to the PWM pin of the main control chip U4, and the other end of the resistor R18 is respectively connected to the resistor R19 and the gate of the MOS tube Q4. The other end of the resistor R19 is grounded, the source of the MOS tube Q4 is grounded, the drain of the MOS tube Q4 is respectively connected to the resistor R20, the base of the triode Q7, and the base of the triode Q9, the emitter of the triode Q7 and the emitter of the triode Q9 are connected and connected to the gate of the switch tube Q5 and the resistor R24, the other end of the resistor R24 ​​is connected to the source of the switch tube Q5, and the collector of the triode Q9 and the drain of the switch tube Q5 are connected to an LED light source.

[0031] The PWM signal generated by the built-in PWM function module of the main control chip U4 is amplified by the MOS tube Q4, the transistor Q7, and the transistor Q9, and then controls the switch tube Q5 to quickly turn on and off, so that the LED light source emits light and works in a high-frequency PWM constant current dimming state, thereby saving energy and extending the battery life of the battery cell JP1.

[0032] Specifically, the working process of the driving circuit is as follows: when the PWM output signal of the main control chip U4 is low within a cycle, the MOS tube Q4 is turned off; due to the pull-up resistor R20, the BE junction of the transistor Q9, the discharge resistor R24, and the current sampling resistor R29 forming a discharge circuit, the transistor Q9 is saturated and turned on, the gate of the switch tube Q5 is high level, the switch tube Q5 is saturated and turned on, and the BV+ of the battery cell JP1 passes through Figure 2 The light source LAMP1 shown, and the drain of the switch tube Q5, the source of the switch tube Q5, and the current sampling resistor R26 form a discharge loop to the ground, thereby lighting the LED light source.

[0033] When the PWM output signal of the main control chip U4 is high within a cycle, the MOS tube Q4 is saturated and turned on; the pull-up resistor R20 and the drain-source of the MOS tube Q4 form a discharge circuit to the ground, the base of the transistor Q7 is at a low level, the transistor Q7 is saturated and turned on, and a discharge circuit is formed to the ground through the emitter collector of the transistor Q7, the gate level of the switch tube Q5 is low, the switch tube Q5 is cut off, and the LED light source is extinguished.

[0034] The driving circuit works in this periodic on and off state, thereby realizing the dimming function of the LED light source.

[0035] Embodiment 2

[0036] like Figure 1 As shown, the structure of this embodiment is basically the same as that of the first embodiment, and the difference is that the backup battery unit of this embodiment includes an anti-reverse connection circuit and a charge and discharge protection circuit, wherein the anti-reverse connection circuit is used to prevent reverse connection when the battery cell JP1 is connected to the circuit board; the charge and discharge protection circuit is used to cut off the input current of the battery cell JP1 when the battery cell JP1 is overcharged or cut off the output current when the battery cell JP1 is over-discharged.

[0037] Specifically, Figure 2 As shown, the anti-reverse connection circuit includes a resistor R27, a resistor R28, and a MOS tube Q6. One end of the resistor R28 is connected to pin 1 of the battery cell JP1, and the other end is connected to the gate of the MOS tube Q6. The resistor R27 is connected between the gate and the source of the MOS tube Q6, and the drain of the MOS tube Q6 is connected to pin 2 of the battery cell JP1.

[0038] like Figure 2As shown, the charge and discharge protection circuit includes a protection chip U5, a resistor R29, a capacitor C8, a resistor R30, a resistor R31, a MOS tube Q11, and a MOS tube Q12. The VSS end of the protection chip U5 is connected to the capacitor C8 and the resistor R29 in series. The other end of the resistor R29 is connected to the pin 1 of the battery cell JP1. The VSS end of the protection chip U5 is also connected to the source of the MOS tube Q6. The VDD end of the protection chip U5 is connected between the capacitor C8 and the resistor R29. The OD end of the protection chip U5 is connected to the gate of the MOS tube Q11. The OC end of the protection chip U5 is connected to the gate of the MOS tube Q12. The CS end of the protection chip U5 is connected to the resistor R30 and the resistor R31 in parallel. The other end of the resistor R30 is connected to the source of the MOS tube Q11. The other end of the resistor R31 is connected to the source of the MOS tube Q12. The drain of the MOS tube Q11 and the drain of the MOS tube Q12 are connected.

[0039] When overcurrent occurs during the charging or discharging process of the battery cell JP1, the battery cell JP1 is turned off by controlling the conduction of the MOS tubes Q11 and Q12, wherein the resistors R30 and R31 are current detection input resistors, which detect the charging current and the discharging current respectively. Specifically, the charging current is the current flowing through the equivalent resistor after the MOS tube Q12 is turned on, and the discharging current is the current flowing through the equivalent resistor after the MOS tube Q11 is turned on. MOS tubes Q11 and Q12 with different powers and conduction resistances can be selected according to the capacity of the battery cell JP1 and the charge and discharge current.

[0040] In addition, resistor R29 is the current limiting resistor of the protection chip U5, capacitor C8 is the decoupling capacitor 2 of the protection chip U5, and the U5VDD pin of the protection chip is both its power input pin and the detection input pin of the battery cell JP1 voltage, which is used to detect the battery cell JP1 voltage and has the functions of controlling the charging detection and discharge detection of the battery cell JP1, allowing charging to the 0V battery cell JP1, releasing the overcurrent / short-circuit current state, and releasing the over-discharge mode.

[0041] Embodiment 3

[0042] like Figure 1 , Figure 2 As shown, the structure of this embodiment is basically the same as that of the second embodiment, except that: an overcurrent protection circuit is also connected between the main control chip U4 and the LED light source of this embodiment, and the overcurrent protection circuit includes a resistor R26, a resistor R25, a capacitor C7, and a resistor R22. The resistor R25, the capacitor C7, and the resistor R26 are connected to form a closed loop. The main control chip U4 has a built-in ADC function module, and the resistor R22 is connected between the capacitor C7 and the resistor R25. The other end of the resistor R22 is connected to the ADC2 end of the main control chip U4, and the source of the switch tube Q5 is connected between the resistor R25 and the resistor R26.

[0043] The overcurrent protection circuit is used to detect whether the current flowing through the LED lamp beads in the LED light source exceeds the set range, and controls the width of the PWM output pulse according to the size of the detected current, thereby controlling the conduction time of the switch tube Q5 and realizing PID closed-loop control.

[0044] like Figure 2 As shown, the backup battery unit is connected to the charging management circuit, and the charging management circuit includes a charging management chip U6 and a charging connector J5. The BAT end of the charging management chip U6 is connected to pin 1 of the battery cell JP1, and the BAT end is also connected to a resistor R32 and a capacitor C9 in series, and the other end of the capacitor C9 is grounded; the ST end of the charging management chip U6 is connected to a resistor R33 and an indicator light LED1 in series, and the other end of the indicator light LED1 is grounded; the IST end of the charging management chip U6 is connected to a resistor R34, and the other end of the resistor R34 is grounded; the VIN end of the charging management chip U6 is connected to the charging connector J5.

[0045] The resistor R32 and the capacitor C9 form an RC absorption network, and the resistor R34 is used to set the maximum constant current charging current value. By modifying the resistance value of the resistor R34, the rated constant current charging current can be modified.

[0046] Embodiment 4

[0047] like Figure 1 , Figure 2 As shown, the structure of this embodiment is basically the same as that of the third embodiment, except that a battery sampling circuit is further connected between the backup battery unit and the main control chip U4 of this embodiment, and the battery sampling circuit is used to sample the output voltage of the battery cell JP1 through the built-in ADC function module of the main control chip U4 to determine whether the state of the battery cell JP1 is normal.

[0048] The battery sampling circuit includes a voltage divider resistor R15 and a voltage divider resistor R16 connected in series, the other end of the voltage divider resistor R15 is connected to pin 1 of the battery cell JP1, the other end of the voltage divider resistor R16 is grounded, and the voltage divider resistor R15 and the voltage divider resistor R16 are connected to the ADC1 pin of the main control chip U4.

[0049] Specifically, a step-down circuit is also connected between the backup battery unit and the main control chip U4, and the step-down circuit is used to convert the voltage output by the battery cell JP1 and then connect it to the main control chip U4 to provide a stable voltage. Among them, the step-down circuit includes a voltage regulator U3, a capacitor C4, a capacitor C5 and a capacitor C12, the VIN end of the voltage regulator U3 is connected to a capacitor C4, the other end of the capacitor C4 is grounded, the VOUT end of the voltage regulator U3 outputs a power supply constant voltage VCC, and the VOUT end of the voltage regulator U3 is also connected to a capacitor C5, a capacitor C12, a resistor R17 and a resistor R1 in parallel, the other end of the capacitor C5 is grounded, the other end of the capacitor C12 is connected to a capacitor C6, the other end of the capacitor C6 is connected to the RST end of the main control chip U4, the capacitor C6 and the capacitor C12 are grounded, the other end of the resistor R17 is connected to the RST end of the main control chip U4, the other end of the resistor R1 is connected to LED2, and the other end of LED2 is connected to the IO3 end of the main control chip U4. LED2 is used to drive the display.

[0050] Working principle: When the red flashing light for rail transit maintenance is used, when the button SW1 is pressed and turned on, a voltage drop is generated on the resistor R36 through the voltage divider circuit composed of the resistor R21 and the resistor R36. On the one hand, the voltage drop is sent to the ON / OFF detection pin of the main control chip U4 through the resistor R35. On the other hand, the discharge circuit composed of the isolation diode D4, the filter capacitor C10, the current limiting resistor R37, the lower voltage divider resistor R38, and the BE structure of the switch tube Q10 makes the switch tube Q10 saturated and turned on. After the switch tube Q10 is saturated and turned on, the conduction voltage drop between its CE poles is about 0.2-0.3V, which is approximately grounded.

[0051] The base of the switch tube Q8 forms a loop to the ground after passing through the bias resistor R23, the lower voltage-dividing resistor R39 and the CE of the switch tube Q8. The voltage divided at the base of the switch tube Q8 is about 1 / 11 of the BV voltage value, thereby ensuring that the switch tube Q8 is fully saturated and turned on. At this time, the VOUT node has an output voltage, which provides a stable VCC working voltage to the main control chip U4 after passing through the step-down circuit. After the low-level reset time set by the resistor R17 and the capacitor C6, the main control chip U4 enters the initialization program, outputs a high level of VCC_ON on its IO1 pin, and after passing through the isolation diode D5, it is sent to the base of the switch tube Q10, thereby maintaining the power supply output of the entire control system.

[0052] When the button SW1 is released, the ON / OFF detection level of the IO2 pin input of the main control chip U4 disappears. When the button SW1 is pressed again, the IO2 pin of the main control chip U4 detects the ON / OFF level and recognizes it as a high level, thereby detecting the pressing of the button SW1. According to the length of time set by the program and the number of single clicks and continuous clicks, it can be defined as different function inputs, thereby realizing one-button multi-function control. Note: The function of the button SW1 can be set according to actual needs.

[0053] The red flashing light works normally after being started, and the PWM signal output by the built-in PWM function module of the main control chip U4 and the driving circuit realize constant current driving of the LED light source.

[0054] When the main control chip U4 recognizes that the button SW1 is long pressed, it enters the shutdown control program, and the VCC_ON high level output of the IO1 pin of the main control chip U4 becomes a low level output. At this time, after the button SW1 is released, the base control voltage used to control the saturation conduction of the switch tube Q10 disappears, so the switch tube Q10 is turned off, and its CE pole is not turned on. The base control conduction condition of the switch tube Q8 disappears, so the switch tube Q8 is also turned off, and there is no voltage output at the VOUT node, the control voltage of the whole machine disappears, and the system shuts down.

[0055] After the whole system is shut down, except for the charge and discharge protection circuit and the anti-reverse connection circuit which consume energy (about 4-10uA), the other circuits have stopped working and do not consume the energy of the battery cell JP1. Therefore, the current is extremely low in the shutdown state of this red flashing light, which can effectively extend the service life and endurance of the lithium battery.

[0056] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Although the utility model is described in detail with reference to the above embodiments, those skilled in the art can still modify the technical solutions recorded in the above embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A red flashing light for rail transit maintenance, characterized in that: It includes a backup battery unit, a main control chip U4, a drive circuit and an LED light source; the backup battery unit is used to supply power to the main control chip U4, the backup battery unit includes a battery cell JP1, an anti-reverse connection circuit and a charge and discharge protection circuit, the anti-reverse connection circuit is used to prevent the battery cell JP1 from being reversely connected when it is connected to the circuit board; the charge and discharge protection circuit is used to cut off the input current of the battery cell JP1 when the battery cell JP1 is overcharged or cut off the output current when the battery cell JP1 is over-discharged; the drive circuit is used to amplify the drive signal output by the main control chip U4, so that the LED light source is in a constant current state; A key control unit is also connected between the backup battery unit and the main control chip U4, and the key control unit realizes power-on control or power-off control of the red flashing light through keys.

2. The rail transit maintenance red flashing light according to claim 1, characterized in that: The key control unit includes a key SW1, a switch tube Q8, and a switch tube Q10. The collector of the switch tube Q8 outputs a whole machine control voltage Vout. After the main control chip U4 detects a long press signal of the key SW1, the IO1 pin of the main control chip U4 outputs a low level. At this time, the key SW1 is released, and the base voltage of the saturated conduction of the switch tube Q10 disappears, the switch tube Q10 is turned off, and the switch tube Q8 is turned off, so that the whole machine control voltage Vout is 0.

3. The red flashing light for rail transit maintenance according to claim 2, characterized in that: The button control unit further includes a resistor R21, a resistor R36, a diode D4, a diode D5, a capacitor C10, a resistor R37, a resistor R38, a resistor R23, and a resistor R39. The button SW1 is connected between the resistor R21 and the resistor R36. The other end of the resistor R21 is connected to the pin 1 of the battery cell JP1. The other end of the resistor R36 is grounded. The ON / OFF end of the main control chip U4 is connected to a resistor R35, the other end of the resistor R35 is connected to a resistor R36 and a positive electrode of a diode D4, the negative electrode of the diode D4 is respectively connected to a capacitor C10, a negative electrode of a diode D5, and a resistor R37, the other end of the capacitor C10 is grounded, the positive electrode of the diode D5 is connected to the IO1 pin of the main control chip U4, the other end of the resistor R37 is respectively connected to a resistor R38 and a base of a switch tube Q10, the other end of the resistor R38 is grounded, the emitter of the switch tube Q10 is grounded, the collector of the switch tube Q10 is connected to the base of the switch tube Q8 through a resistor R39, a resistor R23 is connected between the emitter of the switch tube Q8 and the base of the switch tube Q8, a capacitor C13 is connected between the collector of the switch tube Q8 and the emitter of the switch tube Q10, and the collector of the switch tube Q8 outputs the whole machine control voltage Vout.

4. The rail transit maintenance red flashing light according to claim 1, characterized in that: The anti-reverse connection circuit includes a resistor R27, a resistor R28, and a MOS tube Q6. One end of the resistor R28 is connected to pin 1 of the battery cell JP1, and the other end is connected to the gate of the MOS tube Q6. The resistor R27 is connected between the gate and the source of the MOS tube Q6, and the drain of the MOS tube Q6 is connected to pin 2 of the battery cell JP1.

5. The red flashing light for rail transit maintenance according to claim 4, characterized in that: The charge and discharge protection circuit includes a protection chip U5, a resistor R29, a capacitor C8, a resistor R30, a resistor R31, a MOS tube Q11, and a MOS tube Q12. The VSS end of the protection chip U5 is connected to the capacitor C8 and the resistor R29 in series. The other end of the resistor R29 is connected to pin 1 of the battery cell JP1. The VSS end of the protection chip U5 is also connected to the source of the MOS tube Q6. The VDD end of the protection chip U5 is connected between the capacitor C8 and the resistor R29. The OD end of the protection chip U5 is connected to the gate of the MOS tube Q11. The OC end of the protection chip U5 is connected to the gate of the MOS tube Q12. The CS end of the protection chip U5 is connected to the resistor R30 and the resistor R31 in parallel. The other end of the resistor R30 is connected to the source of the MOS tube Q11. The other end of the resistor R31 is connected to the source of the MOS tube Q12. The drain of the MOS tube Q11 and the drain of the MOS tube Q12 are connected.

6. The rail transit maintenance red flashing light according to claim 1, characterized in that: The driving circuit includes a resistor R18, a resistor R19, a MOS tube Q4, a resistor R20, a transistor Q7, a transistor Q9, a switch tube Q5, and a resistor R24. The main control chip U4 has a built-in PWM function module. One end of the resistor R18 is connected to the PWM pin of the main control chip U4, and the other end of the resistor R18 is respectively connected to the resistor R19 and the gate of the MOS tube Q4. The other end of the resistor R19 is grounded, the source of the MOS tube Q4 is grounded, the drain of the MOS tube Q4 is respectively connected to the resistor R20, the base of the transistor Q7, and the base of the transistor Q9, the emitter of the transistor Q7 and the emitter of the transistor Q9 are connected and connected to the gate of the switch tube Q5 and the resistor R24, the other end of the resistor R24 ​​is connected to the source of the switch tube Q5, and the LED light source is connected between the collector of the transistor Q9 and the drain of the switch tube Q5.

7. The rail transit maintenance red flashing light according to claim 1 or 6, characterized in that: An overcurrent protection circuit is also connected between the main control chip U4 and the LED light source. The overcurrent protection circuit includes a resistor R26, a resistor R25, a capacitor C7, and a resistor R22. The resistor R25, the capacitor C7, and the resistor R26 are connected to form a closed loop. The main control chip U4 has a built-in ADC function module. The resistor R22 is connected between the capacitor C7 and the resistor R25. The other end of the resistor R22 is connected to the ADC2 end of the main control chip U4. The source of the switch tube Q5 is connected between the resistor R25 and the resistor R26.

8. The red flashing light for rail transit maintenance according to claim 1, 2 or 3, characterized in that: The backup battery unit is connected to the charging management circuit, which includes a charging management chip U6 and a charging connector J5. The BAT end of the charging management chip U6 is connected to pin 1 of the battery cell JP1, and the BAT end is also connected to a resistor R32 and a capacitor C9 in series, and the other end of the capacitor C9 is grounded; the ST end of the charging management chip U6 is connected to a resistor R33 and an indicator light LED1 in series, and the other end of the indicator light LED1 is grounded; the IST end of the charging management chip U6 is connected to a resistor R34, and the other end of the resistor R34 is grounded; the VIN end of the charging management chip U6 is connected to the charging connector J5.

9. The red flashing light for rail transit maintenance according to claim 1, characterized in that: A battery sampling circuit is also connected between the backup battery unit and the main control chip U4, and the battery sampling circuit is used to sample the output voltage of the battery cell JP1 through the built-in ADC function module of the main control chip U4 to determine whether the state of the battery cell JP1 is normal; The battery sampling circuit includes a voltage-dividing resistor R15 and a voltage-dividing resistor R16 connected in series, the other end of the voltage-dividing resistor R15 is connected to pin 1 of the battery cell JP1, the other end of the voltage-dividing resistor R16 is grounded, and the voltage-dividing resistor R15 and the voltage-dividing resistor R16 are connected to the ADC1 pin of the main control chip U4.

10. The red flashing light for rail transit maintenance according to claim 1, characterized in that: A step-down circuit is also connected between the backup battery unit and the main control chip U4, and the step-down circuit is used to convert the voltage output by the battery cell JP1 and then connect it to the main control chip U4 to provide a stable voltage; The step-down circuit includes a voltage regulator U3, a capacitor C4, a capacitor C5 and a capacitor C12. The VIN end of the voltage regulator U3 is connected to the capacitor C4, and the other end of the capacitor C4 is grounded. The VOUT end of the voltage regulator U3 outputs a power supply constant voltage VCC. The VOUT end of the voltage regulator U3 is also connected to a capacitor C5, a capacitor C12, a resistor R17 and a resistor R1 in parallel. The other end of the capacitor C5 is grounded, the other end of the capacitor C12 is connected to a capacitor C6, the other end of the capacitor C6 is connected to the RST end of the main control chip U4, the capacitors C6 and C12 are grounded, the other end of the resistor R17 is connected to the RST end of the main control chip U4, the other end of the resistor R1 is connected to LED2, and the other end of LED2 is connected to the IO3 end of the main control chip U4.

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