LCU equipment low-power-consumption acquisition circuit
By introducing MOS tubes and DC-DC power management chips into the LCU equipment and combining them with optocouplers, the power consumption of the acquisition circuit is reduced, the challenges of equipment heat dissipation and device selection are solved, and low-power acquisition is achieved.
Patent Information
- Application Number
- CN202422804152.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-18
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-11-18
AI Technical Summary
The acquisition circuits of existing LCU devices consume high power, leading to challenges in device heat dissipation and component selection. This is particularly prominent in the two-by-two redundant architecture.
MOS tubes are used as switching circuits in parallel with filtering circuits, combined with DC-DC power management chips and optocouplers to reduce input current and utilize the voltage drive characteristics of MOS tubes to achieve low-power acquisition.
It effectively reduces the power consumption of the single-channel acquisition circuit, reduces the overall heat output of the equipment, and optimizes device selection.
Smart Images
Figure CN223488101U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of vehicle-mounted LCU signal acquisition, and in particular to a low-power acquisition circuit for LCU devices. Background Technology
[0002] As a crucial control device for trains, the LCU (Local Control Unit) essentially replaces the existing relay control system with modern electronic components. Currently, the LCU acquisition circuit uses optocoupler isolation. Due to the minimum current limitation of optocoupler conduction, its drive current is generally above 2mA, resulting in a power consumption of 0.2W in the acquisition circuit. For SIL4-level 3U LCU devices, a two-out-of-two redundant architecture is typically used to ensure system safety and reliability. The DC110V processing circuit can handle up to 288 channels. Although the power consumption of a single acquisition circuit is only about 0.2W, the total maximum input power consumption of the system's acquisition circuit reaches 57.6W. This situation presents significant challenges to equipment heat dissipation and component selection.
[0003] Therefore, reducing the power consumption of a single acquisition circuit is extremely important in order to reduce heat dissipation from the device. Utility Model Content
[0004] To address the aforementioned problems, the present invention aims to provide a low-power acquisition circuit for LCU devices, thereby reducing the power consumption of a single acquisition circuit and reducing overall heat generation in complex LCU devices with a 2x2 redundancy architecture.
[0005] The technical solution includes a power management module and a signal acquisition module. The power management module uses a DC-DC power management chip to generate an ISO 5V optocoupler enable power supply with a current greater than 2mA from the input DC voltage of 5V. The signal acquisition module includes a switching circuit that uses a MOSFET as the input channel for acquiring signals. In the switching circuit, the drain of the MOSFET is connected to the negative terminal of the optocoupler, the source of the MOSFET is connected in parallel with the MOSFET input filter circuit and grounded, and the gate of the MOSFET is connected in series with a voltage divider resistor and a Zener diode to the input signal.
[0006] In the above or some embodiments, the power management module includes a MAW01-05S05 power management chip, and the voltage input terminal and voltage output terminal of the MAW01-05S05 power management chip are both provided with a filter circuit composed of multiple capacitors connected in parallel.
[0007] In the above or some embodiments, the optocoupler is a TLP187, the positive terminal of which is connected to an ISO 5V power supply with a current greater than 2mA input from the power management module; the signal output channel of the optocoupler is connected to the back end of the acquisition circuit.
[0008] In the above or some embodiments, the gate of the MOS transistor is also connected in series with two Zener diodes, which are located between the input filter circuit of the MOS transistor and the voltage divider resistor.
[0009] This technical solution introduces an NMOS transistor and utilizes the voltage drive characteristics of the transistor to reduce the DC110V input current to 0.75mA. At the same time, it uses a DC-DC isolated 5V power supply to ensure that the optocoupler's current is greater than 2mA during operation, thereby reducing input power consumption and addressing the issue of high input power consumption in current acquisition and LCU devices. Attached Figure Description
[0010] Figure 1 This is the circuit schematic diagram of this utility model. Detailed Implementation
[0011] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model.
[0012] In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified.
[0013] The power management module uses a DC-DC power management chip to generate an ISO 5V optocoupler enable power supply with a current greater than 2mA from an input DC voltage of 5V. In the above or some embodiments, the power management module includes a MAW01-05S05 power management chip, and the voltage input and voltage output terminals of the MAW01-05S05 power management chip are equipped with a filter circuit composed of multiple stages of capacitors connected in parallel.
[0014] The voltage input terminal includes capacitors C3 and C4 connected in parallel. The common positive terminal of C3 and C4 is connected to the input voltage of 5V and the VIN+ terminal of the MAW01-05S05 power management chip. The common negative terminal of capacitors C3 and C4 is grounded and connected to the VIN- terminal of the MAW01-05S05 power management chip.
[0015] The voltage output terminal includes parallel capacitors C1 and C2. The common positive terminal of C1 and C2 is connected to the input voltage of 5V and the VOUT+ terminal of the MAW01-05S05 power management chip. The common negative terminal of capacitors C1 and C2 is grounded and connected to the VOUT- terminal of the MAW01-05S05 power management chip.
[0016] The signal acquisition module includes a switching circuit using a 2N7002-7-F MOSFET as the signal input channel. The drain of the MOSFET is connected to the negative terminal of the optocoupler, and the source of the MOSFET is connected in parallel with a grounded MOSFET input filter circuit. The MOSFET input filter circuit includes a capacitor C6 and a resistor R4, with one end of the common terminal of capacitor C6 and resistor R4 grounded. The gate of the MOSFET is connected in series with a voltage divider resistor R3 and a Zener diode D1 to the input signal. The optocoupler is a TLP187, with its positive terminal connected to an ISO 5V, greater than 2mA power supply input from the power management module. The signal output channel of the optocoupler is connected to the back end of the acquisition circuit. Two Zener diodes Z1 and Z2 are also connected in series at the gate of the MOSFET, located between the MOSFET input filter circuit and the voltage divider resistor.
[0017] This technical solution introduces an NMOS transistor and utilizes the voltage drive characteristics of the MOS transistor to reduce the DC110V input current by 0.75mA. At the same time, it uses a DC-DC isolated 5V power supply to ensure that the optocoupler's current is greater than 2mA when it is working, thereby reducing input power consumption and addressing the problem of high input power consumption in current acquisition and LCU devices.
Claims
1. A low-power acquisition circuit for an LCU device, comprising a power management module and a signal acquisition module; characterized in that: The power management module uses a DC-DC power management chip to generate an ISO 5V optocoupler enable power supply with a current greater than 2mA from the input DC voltage of 5V. The signal acquisition module includes a switching circuit that uses a MOSFET as the signal input channel. In the switching circuit, the drain of the MOSFET is connected to the negative terminal of the optocoupler, the source of the MOSFET is connected in parallel with the MOSFET input filter circuit and grounded, and the gate of the MOSFET is connected in series with a voltage divider resistor and a Zener diode to the input signal.
2. The low-power acquisition circuit for an LCU device according to claim 1, characterized in that, The power management module includes a MAW01-05S05 power management chip, and the voltage input and voltage output terminals of the MAW01-05S05 power management chip are equipped with a filter circuit composed of multiple capacitors connected in parallel.
3. The low-power acquisition circuit for an LCU device according to claim 1, characterized in that, The optocoupler is a TLP187, and the positive terminal of the TLP187 is connected to the ISO 5V, greater than 2mA power supply input from the power management module; the signal output channel of the optocoupler is connected to the back end of the acquisition circuit.
4. The low-power acquisition circuit for an LCU device according to claim 1, characterized in that, The gate of the MOS transistor is also connected in series with two Zener diodes, which are located between the input filter circuit of the MOS transistor and the voltage divider resistor.