A partitioned power supply system for an intrinsically safe LED display screen for mine

Abstract

This application provides a zoned power supply system for an intrinsically safe LED display screen used in mining, belonging to the field of power supply technology for intrinsically safe equipment used in mining. The technical problem to be solved is that existing systems cannot achieve independent zoned power limiting, fault isolation, and dynamic power supply control. The technical solution adopted to solve this problem is as follows: it includes a main power supply module, the output of which is electrically connected to the input of at least two zoned power supply modules, and the output of each zoned power supply module is electrically connected to a display terminal. The zoned power supply module includes an input protection unit, an active power limiting unit, an enable control unit, a step-down voltage regulator unit, and an output protection unit. The input protection unit is electrically connected to the active power limiting unit, the active power limiting unit is electrically connected to the enable control unit, the enable control unit is electrically connected to the step-down voltage regulator unit, and the step-down voltage regulator unit is electrically connected to the output protection unit. This application is applied in a mining environment.

Description

Technical Field

[0001] This application relates to the field of intrinsically safe power supply technology for mining equipment, and in particular to a zoned power limiting power supply system for an intrinsically safe LED display screen for mining. Background Technology

[0002] Currently, most LED displays used in mines employ a centralized power supply structure, with a single power module providing unified power to the entire display. Because the mine environment contains flammable and explosive media such as methane and coal dust, mining equipment must meet intrinsically safe explosion-proof requirements, imposing strict limitations on voltage, current, energy storage, and temperature rise during equipment operation.

[0003] In existing technologies, large-size LED displays typically consume high power. When a local LED module experiences a short circuit, overload, or driver failure, the centralized power supply structure can cause a large current to flow into the fault area instantaneously, easily generating electrical sparks and localized overheating, posing a safety hazard. Furthermore, existing mining LED display equipment often lacks regional energy isolation capabilities. When a single area fails, it can easily affect the overall stability of the screen and reduce equipment reliability.

[0004] Therefore, there is a need for an intrinsically safe LED display power supply system for mining applications that can achieve regional independent power limiting, fault isolation, and dynamic power supply control. Summary of the Invention

[0005] To address the aforementioned technical issues, this application proposes a zoned power supply system for an intrinsically safe LED display screen used in mining.

[0006] The technical solution adopted in this application is: a zoned power supply system for an intrinsically safe LED display screen for mining, including a main power supply module, the output terminal of the main power supply module being electrically connected to the input terminals of at least two zoned power supply modules, and the output terminal of each zoned power supply module being electrically connected to a display terminal. The zoned power supply module includes an input protection unit, an active power limiting unit, an enable control unit, a step-down voltage regulator unit, and an output protection unit. The input protection unit is electrically connected to the active power limiting unit, the active power limiting unit is electrically connected to the enable control unit, the enable control unit is electrically connected to the step-down voltage regulator unit, and the step-down voltage regulator unit is electrically connected to the output protection unit.

[0007] Furthermore, the circuit structure of the input protection unit and the active power limiting unit is as follows: The positive terminal of diode D2 is connected in parallel to pin 2 of connector J1 and then connected to the input power supply VIN. Pin 1 of connector J1 is grounded. The negative terminal of diode D2 is connected to the positive terminal of diode D3. The negative terminal of diode D3 is connected in parallel to one end of resistor R5. The emitter of transistor Q2 is connected to one end of resistor R6 and then to one end of resistor R3. The other end of resistor R5 is connected in parallel to the base of transistor Q2 and then connected to the source of field-effect transistor Q5. The collector of transistor Q2 is connected in parallel to the gate of field-effect transistor Q5, and the other end of resistor R6 is connected to the collector of transistor Q3. The other end of resistor R3 is connected in parallel to one end of capacitor C2, and one end of resistor R7 is connected to the base of transistor Q3. The drain of MOSFET Q5 is connected to the input power supply, the emitter of transistor Q3 is connected to one end of resistor R9, the other end of resistor R9 is connected in parallel to the other end of capacitor C2, and the other end of resistor R7 is grounded.

[0008] Furthermore, the buck regulator unit uses a buck chip U1, and the circuit structure of the enable control unit and the buck regulator unit is as follows: One end of capacitor C3 is connected in parallel to the input power supply, and one end of capacitor C4, one end of capacitor C5, and one end of resistor R10 are connected to pin 8 of step-down chip U1. The other end of capacitor C3 is connected in parallel to the other end of capacitor C4, and the other end of capacitor C5 is grounded. The other end of resistor R10 is connected in parallel to one end of resistor R11, and pin 2 of connector J3 is connected to pin 1 of step-down chip U1. The other end of resistor R11 is connected in parallel to pins 3 and 10 of step-down chip U1, and pin 1 of connector J3 is grounded. Pin 4 of the step-down chip U1 is connected to one end of resistor R12, and the other end of resistor R12 is connected to the input power supply. Pin 9 of the step-down chip U1 is grounded. Pin 7 of the step-down chip U1 is connected to one end of resistor R13. The other end of resistor R13 is connected to one end of capacitor C6. The other end of capacitor C6 is connected in parallel to pin 6 of the step-down chip U1 and then connected to one end of inductor L1. The other end of inductor L1 is connected in parallel to one end of resistor R15, one end of capacitor C8, one end of capacitor C9, and pin 1 of connector J2 is connected to the input power supply. The other end of resistor R15 is connected in parallel to one end of resistor R16, and then connected to one end of resistor R14. The other end of resistor R14 is connected to capacitor C7. Capacitor C7 is connected in parallel to the other end of resistor R16. One end of resistor R17 is then connected to pin 2 of step-down chip U1. The other end of resistor R17 is grounded, the other end of capacitor C8 is connected in parallel to the other end of capacitor C9, and pin 2 of connector J2 is grounded.

[0009] Furthermore, the circuit structure of the output protection unit is as follows: The cathode of Zener diode D1 is connected in parallel to the anode of unidirectional thyristor Q1, one end of capacitor C1, the cathode of Zener diode D4, the anode of unidirectional thyristor Q4, and one end of resistor AR1 are connected to the input power supply. The anode of Zener diode D1 is connected in parallel to one end of resistor R1 and then connected to one end of resistor R2. The other end of resistor R1 is connected in parallel to the cathode of unidirectional thyristor Q1, the other end of capacitor C1, one end of resistor R4, the cathode of unidirectional thyristor Q4, and the cathode of light-emitting diode ALED1, and then grounded. The other end of resistor R2 is connected to the control terminal of unidirectional thyristor Q1. The anode of Zener diode D4 is connected in parallel to one end of resistor R8 and then to the other end of resistor R4. The other end of resistor R8 is connected to the control terminal of unidirectional thyristor Q4. The other end of resistor AR1 is connected to the anode of light-emitting diode.

[0010] Furthermore, the main power supply module includes an AC input unit, a power conversion unit, a dual overcurrent and overvoltage protection unit, and a TVS surge protection unit. The AC input unit is electrically connected to the power conversion unit, the power conversion unit is electrically connected to the dual overcurrent and overvoltage protection unit, and the dual overcurrent and overvoltage protection unit is electrically connected to the TVS surge protection unit.

[0011] Furthermore, the chip used in the power conversion unit is power module M1, and the circuit structure of the AC input unit and the power conversion unit is as follows: Pin 1 of power module M1 is connected to pin 2 of connector P1, pin 2 of power module M1 is connected to pin 1 of connector P1, pin 3 of power module M1 is connected in parallel to one end of capacitor C21, one end of capacitor C22, and the positive terminal of electrolytic capacitor C24 is connected to the input power supply. Pin 4 of power module M1 is connected in parallel to the other end of capacitor C21, the other end of capacitor C22, and the negative terminal of electrolytic capacitor C24, and then grounded.

[0012] Furthermore, the dual overcurrent and overvoltage protection unit uses overcurrent and overvoltage protection chips MK1 and MK2. The circuit structure of the dual overcurrent and overvoltage protection unit and the TVS surge protection unit is as follows: Pin 1 of the overcurrent and overvoltage protection chip MK1 is connected in parallel to one end of resistor R30, and pin 1 of connector J11 is connected to the input power supply. Pin 2 of the overcurrent and overvoltage protection chip MK1 is connected to the other end of resistor R30, pin 11 of the overcurrent and overvoltage protection chip MK1 is grounded, and pin 8 of the overcurrent and overvoltage protection chip MK1 is connected to pin 11 of the overcurrent and overvoltage protection chip MK2. Pin 7 of the overcurrent and overvoltage protection chip MK1 is connected in parallel to pin 2 of connector J11, one end of resistor R31, and pin 1 of the overcurrent and overvoltage protection chip MK2 is connected to pin 1 of connector J12. Pin 2 of the overcurrent and overvoltage protection chip MK2 is connected to the other end of resistor R31, pin 7 of the overcurrent and overvoltage protection chip MK2 is connected in parallel to pin 2 of connector J12, and one end of inductor L21 is connected to the cathode of Schottky diode D21. The anode of Schottky diode D21 is connected in parallel to the other end of inductor L21, one end of transient suppression diode TVS1, one end of transient suppression diode TVS2, and pin 1 of connector P4 is connected to the input power supply. The other end of the transient suppression diode TVS1 is connected in parallel to the 8th pin of the overcurrent and overvoltage protection chip MK2, and the other end of the transient suppression diode TVS2 is connected to the ground after pin 2 of connector P4.

[0013] Furthermore, the buck converter U1 is model number TPS56637RPAR, and the power module M1 is model number MP-U36S12-PS.

[0014] The advantages of this application over existing technologies are as follows: by using a regionally independent energy-limiting design, it reduces the energy released at a single point under fault conditions, reduces the risk of electrical sparks, and improves intrinsic safety; when a fault occurs in a local area, the remaining areas can still operate normally, improving the continuity of mine information display and system stability; by using dynamic power supply regulation and zonal control, it reduces the probability of local high temperature generation; by using soft start and surge suppression structures, it reduces the impact of large currents during equipment startup; and it can meet the long-term stable operation requirements under high humidity, high dust, and high interference environments. Attached Figure Description

[0015] The following description, in conjunction with the accompanying drawings, further illustrates this application: Figure 1 This is a schematic diagram of the circuit structure of this application; Figure 2 This is a circuit diagram of the main power supply module in this application; Figure 3 The circuit diagrams for the input protection unit and the active power limiting unit in this application are shown below. Figure 4 This is a circuit diagram of the enable control unit and the buck regulator unit in this application; Figure 5 This is a circuit diagram of the output protection unit in this application; In the diagram: 1 is the main power supply module, 11 is the AC input unit, 12 is the power conversion unit, 13 is the dual overcurrent and overvoltage protection unit, 14 is the TVS surge protection unit, 2 is the zoned power supply module, 21 is the input protection unit, 22 is the active energy limiting unit, 23 is the enable control unit, 24 is the step-down voltage regulation unit, 25 is the output protection unit, and 3 is the display terminal. Detailed Implementation

[0016] like Figures 1 to 5As shown, this application provides a zoned power supply system for an intrinsically safe LED display screen for mining, including a main power supply module 1. The output terminal of the main power supply module 1 is electrically connected to the input terminals of at least two zoned power supply modules 2, and the output terminal of each zoned power supply module 2 is electrically connected to a display terminal 3. The main power supply module 1 includes an AC input unit 11, a power conversion unit 12, a dual overcurrent and overvoltage protection unit 13, and a TVS surge protection unit 14. The AC input unit 11 is electrically connected to the power conversion unit 12, the power conversion unit 12 is electrically connected to the dual overcurrent and overvoltage protection unit 13, and the dual overcurrent and overvoltage protection unit 13 is electrically connected to the TVS surge protection unit 14. The power conversion unit 12 uses a power module M1, model MP-U36S12-PS. The circuit structure of the AC input unit 11 and the power conversion unit 12 is as follows: Pin 1 of power module M1 is connected to pin 2 of connector P1, pin 2 of power module M1 is connected to pin 1 of connector P1, pin 3 of power module M1 is connected in parallel to one end of capacitor C21, one end of capacitor C22, and the positive terminal of electrolytic capacitor C24, and then connected to the input power supply; pin 4 of power module M1 is connected in parallel to the other end of capacitor C21, the other end of capacitor C22, and the negative terminal of electrolytic capacitor C24, and then grounded.

[0017] The dual overcurrent and overvoltage protection unit 13 uses overcurrent and overvoltage protection chips MK1 and MK2. The circuit structure of the dual overcurrent and overvoltage protection unit 13 and the TVS surge protection unit 14 is as follows: pin 1 of the overcurrent and overvoltage protection chip MK1 is connected in parallel to one end of resistor R30, and pin 1 of connector J11 is connected to the input power supply; pin 2 of the overcurrent and overvoltage protection chip MK1 is connected to the other end of resistor R30; pin 11 of the overcurrent and overvoltage protection chip MK1 is grounded; pin 8 of the overcurrent and overvoltage protection chip MK1 is connected to pin 11 of the overcurrent and overvoltage protection chip MK2; pin 7 of the overcurrent and overvoltage protection chip MK1 is connected in parallel to pin 2 of connector J11, one end of resistor R31, and the overcurrent and overvoltage protection chip... Pin 1 of MK2 is connected to pin 1 of connector J12; pin 2 of the overcurrent and overvoltage protection chip MK2 is connected to the other end of resistor R31; pin 7 of the overcurrent and overvoltage protection chip MK2 is connected in parallel to pin 2 of connector J12; one end of inductor L21 is connected to the cathode of Schottky diode D21; the anode of Schottky diode D21 is connected in parallel to the other end of inductor L21; one end of transient voltage suppressor diode TVS1; one end of transient voltage suppressor diode TVS2; pin 1 of connector P4 is connected to the input power supply; pin 8 of the overcurrent and overvoltage protection chip MK2 is connected in parallel to the other end of transient voltage suppressor diode TVS1; the other end of transient voltage suppressor diode TVS2; pin 2 of connector P4 is grounded.

[0018] In the embodiments of this application, the main power supply module 1 is used to receive external AC input power and perform unified conversion, voltage regulation, and distribution of the input power. It adopts a combined structure of "power conversion, dual overcurrent and overvoltage protection, and TVS surge protection," which can effectively improve the power supply safety, stability, and anti-interference capability of the zoned power supply system in complex industrial environments. In actual operation, the main power supply module 1 receives 660V / 127V AC input power and provides stable power output to each zoned power supply module 2. The AC input unit 11 is used to receive external AC input power, with an input voltage of 660V~127V AC. The power supply module M1 is used to convert the input AC power into a stable 12V DC voltage output. Filter capacitors C21 and C22 and an energy storage capacitor C24 are set at the output terminal of the power supply module M1 to reduce output ripple, improve output stability, and form a 12V DC bus output. Specifically, C24 provides large-capacity energy storage to suppress low-frequency voltage fluctuations, C22 is used for medium-frequency ripple filtering, and C21 is used for high-frequency noise decoupling, thereby improving the stability of the subsequent power supply.

[0019] The dual overcurrent and overvoltage protection unit 13 is used to realize multi-level safety protection of the power supply line. Therefore, the overcurrent and overvoltage protection chip MK1 and the overcurrent and overvoltage protection chip MK2 are connected in series to form a dual-level protection structure: the first protection level is implemented by the overcurrent and overvoltage protection chip MK1, which is used for primary current limiting and fault isolation. When an abnormal overcurrent occurs in the output, the first protection level quickly enters the protection state and limits the output current. In actual operation, the overcurrent and overvoltage protection chip MK1 is model MK-BA2. Its Vin terminal is connected to a 12V input power supply, and its Vo+ terminal is used as a first-level controlled output terminal. At the same time, its EN terminal is pulled up or biased through resistor R30, so that the module is in a safe conduction or controlled start-up state in the default state. The overcurrent and overvoltage protection chip MK1 is used to perform primary energy limitation on the input side and realize output limitation or shutdown protection in overcurrent or abnormal state. The second protection stage is implemented by the overcurrent and overvoltage protection chip MK2, which is used for secondary fault cutoff and overvoltage protection. When the zoned energy-limited power supply system detects continuous overcurrent, output short circuit, or abnormal increase in output voltage, the second protection stage further cuts off the output to achieve dual safety protection. The overcurrent and overvoltage protection chip MK2 is also model MK-BA2. Its Vin terminal receives the output voltage of the overcurrent and overvoltage protection chip MK1, its Vo+ terminal serves as the secondary controlled output terminal, and the EN terminal is controlled and biased through resistor R31, so that the second protection stage can independently control the conduction state under the main control signal or abnormal state, thereby achieving further isolation and limitation of energy, forming a two-stage energy-limiting structure in the zoned energy-limited power supply system, and improving the safety redundancy capability under single-point failure conditions.

[0020] An inductor L21 is connected in series on the output side of the overcurrent and overvoltage protection chip MK2 to limit the rate of change of the output current and suppress transient inrush current. Transient suppression diodes TVS1 and TVS2 (SMBJ14CA) are connected in parallel between the output terminals Vo+ and Vo- to quickly conduct when surge voltage, electrostatic discharge, or inductive surge occurs at the output terminal, discharging the transient high energy to the circuit reference ground, thereby protecting the safe operation of the display terminal 3 and the intrinsically safe mining equipment. Finally, after being limited by the overcurrent and overvoltage protection chips MK1 and MK2, current-limited by the inductor L1, clamped by the Schottky diode D21, and surge-absorbed by the transient suppression diodes TVS1 and TVS2, the output is output through connector P4.

[0021] TVS surge protection unit 14 is located at the output terminal of the circuit and includes transient suppression diodes TVS1 and TVS2. TVS surge protection unit 14 absorbs surge voltage, electrostatic discharge, and transient spikes in the line, preventing external abnormal voltages from entering the zoned power supply module 2. Simultaneously, a Schottky diode D21 is provided on the output side for reverse isolation and freewheeling protection, improving the reliability of the zoned power supply system. The protected DC output is output to the zoned power supply module 2 through an interface, providing a stable power supply to the display terminal 3.

[0022] The above structure realizes a multi-level energy limiting path between AC input and output, enabling the main power supply module 1 to release energy in stages when a short circuit, overcurrent or transient impact occurs, avoiding the risk of large energy release caused by a single point of failure, and improving the stability and safety of the system in the high humidity, high dust and strong electromagnetic interference environment of the mine.

[0023] The zoned power supply module 2 includes an input protection unit 21, an active power limiting unit 22, an enable control unit 23, a step-down voltage regulator unit 24, and an output protection unit 25. The input protection unit 21 is electrically connected to the active power limiting unit 22, the active power limiting unit 22 is electrically connected to the enable control unit 23, the enable control unit 23 is electrically connected to the step-down voltage regulator unit 24, and the step-down voltage regulator unit 24 is electrically connected to the output protection unit 25.

[0024] The circuit structure of the input protection unit 21 and the active power limiting unit 22 is as follows: The anode of diode D2 is connected in parallel to pin 2 of connector J1 and then to the input power supply VIN. Pin 1 of connector J1 is grounded. The cathode of diode D2 is connected to the anode of diode D3. The cathode of diode D3 is connected in parallel to one end of resistor R5, the emitter of transistor Q2, one end of resistor R6, and then one end of resistor R3. The other end of resistor R5 is connected in parallel to the base of transistor Q2 and then to the source of field-effect transistor Q5. The collector of transistor Q2 is connected in parallel to the gate of field-effect transistor Q5. The other end of resistor R6 is connected to the collector of transistor Q3. The other end of resistor R3 is connected in parallel to one end of capacitor C2. One end of resistor R7 is connected to the base of transistor Q3. The drain of field-effect transistor Q5 is connected to the input power supply. The emitter of transistor Q3 is connected to one end of resistor R9. The other end of resistor R9 is connected in parallel to the other end of capacitor C2. The other end of resistor R7 is then grounded.

[0025] The buck regulator unit 24 uses a buck chip U1, model TPS56637RPAR. The circuit structure of the enable control unit 23 and the buck regulator unit 24 is as follows: one end of capacitor C3 is connected in parallel to the input power supply; one end of capacitor C4, one end of capacitor C5, and one end of resistor R10 are connected to pin 8 of buck chip U1; the other end of capacitor C3 is connected in parallel to the other end of capacitor C4, and the other end of capacitor C5 is grounded; the other end of resistor R10 is connected in parallel to one end of resistor R11, and pin 2 of connector J3 is connected to pin 1 of buck chip U1; the other end of resistor R11 is connected in parallel to pins 3 and 10 of buck chip U1, and pin 1 of connector J3 is grounded; pin 4 of buck chip U1 is connected to one end of resistor R12, and the other end of resistor R12 is connected to the input power supply. Pin 9 of the step-down chip U1 is grounded. Pin 7 of the step-down chip U1 is connected to one end of resistor R13. The other end of resistor R13 is connected to one end of capacitor C6. The other end of capacitor C6 is connected in parallel to pin 6 of the step-down chip U1 and then to one end of inductor L1. The other end of inductor L1 is connected in parallel to one end of resistor R15, one end of capacitor C8, one end of capacitor C9, and then to pin 1 of connector J2, which is connected to the input power supply. The other end of resistor R15 is connected in parallel to one end of resistor R16 and then to one end of resistor R14. The other end of resistor R14 is connected to capacitor C7. Capacitor C7 is connected in parallel to the other end of resistor R16. One end of resistor R17 is connected to pin 2 of the step-down chip U1. The other end of resistor R17 is grounded. The other end of capacitor C8 is connected in parallel to the other end of capacitor C9 and then to pin 2 of connector J2, which is grounded.

[0026] The circuit structure of the output protection unit 25 is as follows: The cathode of Zener diode D1 is connected in parallel to the anode of unidirectional thyristor Q1, one end of capacitor C1, the cathode of Zener diode D4, the anode of unidirectional thyristor Q4, and one end of resistor AR1, which is then connected to the input power supply. The anode of Zener diode D1 is connected in parallel to one end of resistor R1, which is then connected to one end of resistor R2. The other end of resistor R1 is connected in parallel to the cathode of unidirectional thyristor Q1, the other end of capacitor C1, one end of resistor R4, the cathode of unidirectional thyristor Q4, and the cathode of LED ALED1, which is then grounded. The other end of resistor R2 is connected to the control terminal of unidirectional thyristor Q1. The anode of Zener diode D4 is connected in parallel to one end of resistor R8, which is then connected to the other end of resistor R4. The other end of resistor R8 is connected to the control terminal of unidirectional thyristor Q4. The other end of resistor AR1 is connected to the anode of LED ALED1.

[0027] In the embodiments of this application, the zone power supply control module is used to perform independent power supply control and energy limitation management for each display terminal 3. For example... Figure 3 , Figure 4 , Figure 5 As shown, the zoned power supply system has at least two zoned power supply modules 2. The following description uses one of the zoned power supply modules 2 as an example: like Figure 3 As shown, connector J1 in input protection unit 21 is used to receive the output power from main power supply module 1. Diodes D2 and D3 are used to implement input reverse connection protection and surge suppression. Field-effect transistor Q5 is used to form a low-loss electronic reverse connection protection circuit. Resistor R5 is used for input current limiting and current buffering under abnormal conditions. In actual operation, diodes D2 and D3 are SS34 Schottky diodes, and field-effect transistor Q5 is an ME20P06 P-channel MOSFET. When the input power polarity is normal, field-effect transistor Q5 conducts to achieve low voltage drop power supply. When the input polarity is reversed, field-effect transistor Q5 automatically cuts off, thereby preventing reverse current from entering the zoned energy-limiting power supply system. In active energy-limiting unit 22, transistor Q2 is an MMBT5401 PNP transistor, and transistor Q3 is an MMBT5551 NPN transistor. Transistors Q2 and Q3 together form a dynamic electronic current-limiting control loop. When the output current of the zoned power supply system abnormally increases, transistor Q3 turns on, lowering the base potential of transistor Q2, thereby controlling the conduction level of MOSFET Q5 to limit the supply current. Specifically, resistor R6 controls the base bias of transistor Q2, resistor R7 establishes a detection reference potential, resistor R8 controls the base current of transistor Q3, and resistor R9 stabilizes the operating state of transistor Q3. Capacitor C2 suppresses sudden current changes and high-frequency interference, preventing false triggering. This configuration automatically limits output energy under zone short-circuit or overload conditions, reducing risk.

[0028] like Figure 4As shown, the buck converter U1 converts the 12V input voltage to a stable 5V output. Capacitors C3, C4, and C5 are used for input filtering and high-frequency decoupling. Inductor L1 is used for energy storage and filtering. Capacitors C8 and C9 are used for output voltage regulation and ripple reduction. Resistors R14, R15, R16, R17, and capacitor C7 together form a feedback compensation network to stabilize the output voltage and improve the system's dynamic response performance. The EN terminal of the buck converter U1 is connected to the enable control signal EN-1. Resistors R10, R11, and R12 are used to establish an enable control bias network. Through an independent DC-DC buck structure, power supply isolation between areas is achieved, preventing a single area failure from affecting other areas. In actual operation, the buck converter U1 uses the TPS56637 synchronous buck converter chip. like Figure 5 As shown, Zener diodes D1 and D4 are both BZT52B5V6 Zener diodes used for output overvoltage clamping protection; unidirectional thyristor Q1 is used to control the output state; and LED ALED1 is used to indicate the power supply status within the area.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A partitioned power supply system for intrinsically safe LED display screen in mine, characterized in that: It includes a main power supply module (1), the output of which is electrically connected to the input of at least two partition power supply modules (2), and the output of each partition power supply module (2) is electrically connected to a display terminal (3); The partitioned power supply module (2) includes an input protection unit (21), an active power limiting unit (22), an enable control unit (23), a step-down voltage regulator unit (24), and an output protection unit (25). The input protection unit (21) is electrically connected to the active power limiting unit (22), the active power limiting unit (22) is electrically connected to the enable control unit (23), the enable control unit (23) is electrically connected to the step-down voltage regulator unit (24), and the step-down voltage regulator unit (24) is electrically connected to the output protection unit (25).

2. The partitioned power supply system of claim 1, wherein, The circuit structure of the input protection unit (21) and the active power limiting unit (22) is as follows: The positive terminal of diode D2 is connected in parallel to pin 2 of connector J1 and then connected to the input power supply VIN. Pin 1 of connector J1 is grounded. The negative terminal of diode D2 is connected to the positive terminal of diode D3. The negative terminal of diode D3 is connected in parallel to one end of resistor R5. The emitter of transistor Q2 is connected to one end of resistor R6 and then to one end of resistor R3. The other end of resistor R5 is connected in parallel to the base of transistor Q2 and then connected to the source of field-effect transistor Q5. The collector of transistor Q2 is connected in parallel to the gate of field-effect transistor Q5, and the other end of resistor R6 is connected to the collector of transistor Q3. The other end of resistor R3 is connected in parallel to one end of capacitor C2, and one end of resistor R7 is connected to the base of transistor Q3. The drain of MOSFET Q5 is connected to the input power supply, the emitter of transistor Q3 is connected to one end of resistor R9, the other end of resistor R9 is connected in parallel to the other end of capacitor C2, and the other end of resistor R7 is grounded.

3. The zoned power supply system for an intrinsically safe LED display screen for mining, as described in claim 2, is characterized in that... The step-down regulator unit (24) uses a step-down chip U1. The circuit structure of the enable control unit (23) and the step-down regulator unit (24) is as follows: One end of capacitor C3 is connected in parallel to the input power supply, and one end of capacitor C4, one end of capacitor C5, and one end of resistor R10 are connected to pin 8 of step-down chip U1. The other end of capacitor C3 is connected in parallel to the other end of capacitor C4, and the other end of capacitor C5 is grounded. The other end of resistor R10 is connected in parallel to one end of resistor R11, and pin 2 of connector J3 is connected to pin 1 of step-down chip U1. The other end of resistor R11 is connected in parallel to pins 3 and 10 of step-down chip U1, and pin 1 of connector J3 is grounded. Pin 4 of the step-down chip U1 is connected to one end of resistor R12, and the other end of resistor R12 is connected to the input power supply. Pin 9 of the step-down chip U1 is grounded. Pin 7 of the step-down chip U1 is connected to one end of resistor R13. The other end of resistor R13 is connected to one end of capacitor C6. The other end of capacitor C6 is connected in parallel to pin 6 of the step-down chip U1 and then connected to one end of inductor L1. The other end of inductor L1 is connected in parallel to one end of resistor R15, one end of capacitor C8, one end of capacitor C9, and pin 1 of connector J2 is connected to the input power supply. The other end of resistor R15 is connected in parallel to one end of resistor R16, and then connected to one end of resistor R14. The other end of resistor R14 is connected to capacitor C7. Capacitor C7 is connected in parallel to the other end of resistor R16. One end of resistor R17 is then connected to pin 2 of step-down chip U1. The other end of resistor R17 is grounded, the other end of capacitor C8 is connected in parallel to the other end of capacitor C9, and pin 2 of connector J2 is grounded.

4. The zoned power supply system for an intrinsically safe LED display screen for mining, as described in claim 3, is characterized in that... The circuit structure of the output protection unit (25) is as follows: The cathode of Zener diode D1 is connected in parallel to the anode of unidirectional thyristor Q1, one end of capacitor C1, the cathode of Zener diode D4, the anode of unidirectional thyristor Q4, and one end of resistor AR1 are connected to the input power supply. The anode of Zener diode D1 is connected in parallel to one end of resistor R1 and then connected to one end of resistor R2. The other end of resistor R1 is connected in parallel to the cathode of unidirectional thyristor Q1, the other end of capacitor C1, one end of resistor R4, the cathode of unidirectional thyristor Q4, and the cathode of light-emitting diode ALED1, and then grounded. The other end of resistor R2 is connected to the control terminal of unidirectional thyristor Q1. The anode of Zener diode D4 is connected in parallel to one end of resistor R8 and then to the other end of resistor R4. The other end of resistor R8 is connected to the control terminal of unidirectional thyristor Q4. The other end of resistor AR1 is connected to the anode of light-emitting diode.

5. The zoned power supply system for an intrinsically safe LED display screen for mining, as described in claim 4, is characterized in that: The main power supply module (1) includes an AC input unit (11), a power conversion unit (12), a dual overcurrent and overvoltage protection unit (13), and a TVS surge protection unit (14). The AC input unit (11) is electrically connected to the power conversion unit (12), the power conversion unit (12) is electrically connected to the dual overcurrent and overvoltage protection unit (13), and the dual overcurrent and overvoltage protection unit (13) is electrically connected to the TVS surge protection unit (14).

6. The zoned power supply system for an intrinsically safe LED display screen for mining, as described in claim 5, is characterized in that... The power conversion unit (12) uses a power module M1 chip. The circuit structure of the AC input unit (11) and the power conversion unit (12) is as follows: Pin 1 of power module M1 is connected to pin 2 of connector P1, pin 2 of power module M1 is connected to pin 1 of connector P1, pin 3 of power module M1 is connected in parallel to one end of capacitor C21, one end of capacitor C22, and the positive terminal of electrolytic capacitor C24 is connected to the input power supply. Pin 4 of power module M1 is connected in parallel to the other end of capacitor C21, the other end of capacitor C22, and the negative terminal of electrolytic capacitor C24, and then grounded.

7. A zoned power supply system for an intrinsically safe LED display screen for mining, as described in claim 6, is characterized in that... The dual overcurrent and overvoltage protection unit (13) uses overcurrent and overvoltage protection chips MK1 and MK2. The circuit structure of the dual overcurrent and overvoltage protection unit (13) and the TVS surge protection unit (14) is as follows: Pin 1 of the overcurrent and overvoltage protection chip MK1 is connected in parallel to one end of resistor R30, and pin 1 of connector J11 is connected to the input power supply. Pin 2 of the overcurrent and overvoltage protection chip MK1 is connected to the other end of resistor R30, pin 11 of the overcurrent and overvoltage protection chip MK1 is grounded, and pin 8 of the overcurrent and overvoltage protection chip MK1 is connected to pin 11 of the overcurrent and overvoltage protection chip MK2. Pin 7 of the overcurrent and overvoltage protection chip MK1 is connected in parallel to pin 2 of connector J11, one end of resistor R31, and pin 1 of the overcurrent and overvoltage protection chip MK2 is connected to pin 1 of connector J12. Pin 2 of the overcurrent and overvoltage protection chip MK2 is connected to the other end of resistor R31, pin 7 of the overcurrent and overvoltage protection chip MK2 is connected in parallel to pin 2 of connector J12, and one end of inductor L21 is connected to the cathode of Schottky diode D21. The anode of Schottky diode D21 is connected in parallel to the other end of inductor L21, one end of transient suppression diode TVS1, one end of transient suppression diode TVS2, and pin 1 of connector P4 is connected to the input power supply. The other end of the transient suppression diode TVS1 is connected in parallel to the 8th pin of the overcurrent and overvoltage protection chip MK2, and the other end of the transient suppression diode TVS2 is connected to the ground after pin 2 of connector P4.

8. The zoned power supply system for an intrinsically safe LED display screen for mining, as described in claim 7, is characterized in that: The buck converter chip U1 is model TPS56637RPAR, and the power module M1 is model MP-U36S12-PS.

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