Double-channel anti-interference liquid crystal display power supply circuit

Abstract

The utility model relates to a double-channel anti-interference liquid crystal display power supply circuit which comprises a battery power supply circuit, a battery control circuit, a power supply voltage VCC, an anti-interference circuit, a liquid crystal display and a liquid crystal display voltage VLCD of the liquid crystal display. The battery power supply circuit is electrically connected with the battery control circuit; the input end of the anti-interference circuit is electrically connected with the battery control circuit and the power supply voltage VCC, and the output end of the anti-interference circuit is electrically connected with the liquid crystal display voltage VLCD. A power supply voltage VCC, an anti-interference circuit, a liquid crystal display and a liquid crystal display voltage VLCD of the liquid crystal display; the device is reasonable in design, compact in structure and convenient to use.

Description

Technical Field

[0001] The utility model relates to a dual-path anti-interference liquid crystal display power supply circuit. Background Art

[0002] In recent years, with the widespread application of smart energy meters, the application scenarios of meters have become more diversified and complex, the circuit environment has become more harsh, and the reliability of meter operation has also faced higher and higher challenges. The utility model mainly solves the problem of screen distortion and ghosting caused by interference on the LCD display of the meter and provides two driving power supply modes: mains and battery.

[0003] In addition, most of the smart meters on the market are equipped with segmented LCD displays, which will be disturbed during meter experiments and normal operation, resulting in screen distortion, increased contrast, and obvious ghosting. At present, some software optimization solutions are used to address this problem, but it cannot be completely solved. There are also solutions that use high-cost LCD display chips, but this increases product costs and cannot completely solve the problem. The utility model not only realizes the seamless switching of dual-channel drive power supplies, but also avoids the problem of LCD screen distortion and ghosting while ensuring costs. It is a convenient, effective, and highly reliable circuit. Utility Model Content

[0004] The technical problem to be solved by the utility model is generally to provide a dual-path anti-interference liquid crystal display power supply circuit.

[0005] In order to solve the above problems, the technical solution adopted by the utility model is:

[0006] The utility model provides a dual-path anti-interference liquid crystal display power supply circuit and an anti-interference method to solve the above problems existing in the prior art.

[0007] The utility model provides a dual-path anti-interference liquid crystal display power supply circuit, comprising a battery power supply circuit, a battery control circuit, a power supply voltage VCC, an anti-interference circuit, and a liquid crystal display voltage V_LCD.

[0008] Furthermore, the battery power supply circuit includes a battery B1, which provides an output voltage of 6 V. The positive electrode of B1 is connected to the emitter of the transistor Q1.

[0009] Furthermore, the battery control circuit control signal CTL_DSPLY is connected to the base of transistor Q2 through resistor R4, and resistor R3 is connected to the base and emitter of transistor Q2. The collector of transistor Q2 is connected to resistor R2, and the other end of R2 is connected to the base of transistor Q1, and resistor R1 is connected to the emitter and base of Q1. The collector of transistor Q1 is connected to the positive electrode of diode D1.

[0010] Furthermore, the supply voltage VCC is output as a normal 5V power supply, and 5V0 is connected to the anode of the diode D2.

[0011] Furthermore, in the anti-interference circuit, the resistor R5 is connected to the cathode of the diode D1, and the other end is connected to V_LCD, R6 is connected to V_LCD and GND, the capacitor C1 is connected to V_LCD and GND, and the magnetic bead L1 is connected to V_LCD and the cathode of the diode D2.

[0012] Furthermore, the liquid crystal display voltage V_LCD is used as a power source for the liquid crystal display.

[0013] Beneficial effects of the utility model:

[0014] The utility model has two power drive circuits to drive the LCD screen to light up, and the battery power supply circuit can be switched through the control circuit to reduce the power consumption. The utility model provides a solution to the problem of LCD screen flower and ghosting caused by excessive contrast, and improves the reliability of the LCD during use.

[0015] The utility model has the advantages of reasonable design, low cost, firmness and durability, safety and reliability, simple operation, time-saving, labor-saving, money-saving, compact structure and convenient use. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a block diagram of the power supply circuit of the utility model.

[0017] Figure 2 It is a circuit diagram of the power supply circuit of the utility model.

[0018] Figure 3 It is a flow chart of the method of the utility model. DETAILED DESCRIPTION

[0019] like Figure 1-3 The utility model provides a dual-channel anti-interference liquid crystal display power supply circuit, including a battery power supply circuit, a battery control circuit, a power supply voltage VCC, an anti-interference circuit, and a liquid crystal display voltage V_LCD.

[0020] The battery power supply circuit is used to supply power to the liquid crystal after the mains power is cut off.

[0021] The battery control circuit is used to control the battery to supply power to the liquid crystal only when the liquid crystal is displayed, so as to reduce power consumption.

[0022] The supply voltage VCC is used for 5V voltage output when powered by AC power.

[0023] The anti-interference circuit is used to filter out interference on the power supply.

[0024] The liquid crystal display voltage V_LCD is used as a power supply voltage for a liquid crystal display chip.

[0025] Further Figure 2 When the mains power is off, the battery B1 supplies power to the LCD chip. The battery power supply is controlled by the battery control circuit. When CTL_DSPLY is at a low level, the base of transistor Q2 is at a low level through the current limiting resistor R4. At this time, the emitter and collector are not conducting. The bias resistor R3 is used to ensure the state of the base. When transistor Q2 is not conducting, the base of transistor Q1 is connected to the positive electrode 6V of the battery, that is, the emitter of Q1, through the bias resistor R1, and is at a high level. At this time, the emitter and collector of Q1 are also in a non-conducting state, and the battery does not supply power to the LCD chip. The current limiting resistor R2 is used to protect the base of transistor Q1. When CTL_DSPLY is at a high level, the base of transistor Q2 connected through the current limiting resistor R4 is at a high level. At this time, the collector and emitter of Q2 are conducting. At this time, GND is connected to the current limiting resistor R2 and then connected to the base of Q1, and the base level of Q1 becomes low. The emitter and collector of Q1 are turned on, and the battery B1 supplies power to the LCD chip through the diode D1 and the current-limiting resistor R5. When the AC power is supplied, CTL_DSPLY is always in a low level state to ensure that the battery does not supply power to the LCD chip. At this time, the LCD chip is powered by 5V0, and V_LCD is supplied through the diode D2 and the magnetic bead L1. The resistor R6 is used to discharge the static electricity accumulation to ensure that the LCD does not have a screen distortion phenomenon. The capacitor C1 and the magnetic bead L1 filter out the fluctuating voltage to ensure the stable output of V_LCD.

[0026] Furthermore, this embodiment also provides an anti-interference method for a dual-path anti-interference liquid crystal display power supply circuit, such as Figure 3 The method includes a method for realizing anti-interference based on a dual-channel anti-interference liquid crystal display power supply circuit as follows:

[0027] T1, interference signal enters the circuit.

[0028] T2, the interference signal is filtered out by the anti-interference circuit magnetic bead L1 and capacitor C1 after passing through the power supply 5V0, and then the discharge resistor R6 will discharge the electrostatic interference.

[0029] T3, after passing through the anti-interference circuit, the voltage is output to V_LCD. The V_LCD voltage is output normally and stably, and the LCD chip drives the LCD characters to display normally.

[0030] The present invention is fully described for a clearer disclosure, and the prior art will not be listed one by one.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit it; although the utility model is described in detail with reference to the above embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features therein with equivalents; it is obvious for those skilled in the art to combine multiple technical solutions of the utility model. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the utility model. The technical contents not described in detail in this utility model are all known technologies.

Claims

1. A dual-channel anti-interference liquid crystal display power supply circuit, characterized in that: It includes a battery power supply circuit, a battery control circuit, a power supply voltage VCC, an anti-interference circuit, a liquid crystal display and a liquid crystal display voltage V_LCD of the liquid crystal display; The battery power supply circuit is electrically connected to the battery control circuit; The input end of the anti-interference circuit is electrically connected to the battery control circuit and the power supply voltage VCC respectively, and the output end is electrically connected to the liquid crystal display voltage V_LCD; The battery control circuit is used to control the power supply of the battery power supply circuit. The premise is that the LCD display displays; Anti-interference circuit, used to filter out interference on the input power supply voltage; The battery control circuit includes a transistor Q2, a transistor Q1 whose emitter is connected to the positive electrode of the battery B1, resistors R1, R2, R3, R4, and a diode D1; The control signal CTL_DSPLY is connected to the base of the transistor Q2 through the resistor R4, and the resistor R3 is connected to the base and emitter of the transistor Q2; the collector of the transistor Q2 is connected to the resistor R2, and the other end of R2 is connected to the base of the transistor Q1, and the resistor R1 is connected to the emitter and base of the transistor Q1; the collector of the transistor Q1 is connected to the positive electrode of the diode D1; The anti-interference circuit includes resistors R5 and R6, capacitor C1, and magnetic bead L1; resistor R5 is connected to the cathode of diode D1, and the other end is connected to V_LCD, resistor R6 is connected to V_LCD and GND, capacitor C1 is connected to V_LCD and GND; magnetic bead L1 is connected to V_LCD and the cathode of diode D2.

2. The dual-channel anti-interference liquid crystal display power supply circuit according to claim 1 is characterized in that: A battery power supply circuit is used to power the LCD display after the mains power is lost; The power supply voltage VCC is used to output a set voltage when the mains is used for power supply; The liquid crystal display voltage V_LCD is used as the power supply voltage of the liquid crystal display chip.

3. The dual-channel anti-interference liquid crystal display power supply circuit according to claim 2 is characterized in that: The battery powered circuit includes a battery B1, which provides an output voltage.

4. The dual-channel anti-interference liquid crystal display power supply circuit according to claim 3 is characterized in that: The power supply voltage VCC includes a diode D2; the output end of the working power supply is connected to the anode of the diode D2.

5. The dual-channel anti-interference liquid crystal display power supply circuit according to claim 4 is characterized in that: The liquid crystal display voltage V_LCD serves as the power supply of the liquid crystal display.

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