Power input circuit for in-vehicle flip screen

Abstract

The utility model relates to the technical field of vehicle-mounted turnover screen, concretely is power input circuit of vehicle-mounted turnover screen, include: input protection unit, switch control unit, voltage stabilizing feedback unit and output filter unit, input protection unit realizes overvoltage, overcurrent protection through two -way voltage stabilizing pipe and fuse, switch control unit takes MOS pipe as the core, and the control circuit that cooperation operational amplifier, triode constitute adjusts power on-off, voltage stabilizing feedback unit utilizes voltage stabilizing pipe and voltage dividing resistance to form closed loop feedback, maintains output voltage stability, output filter unit filters out interference through LC filter circuit. The circuit can adapt to the complex power environment of vehicle-mounted, provides stable, reliable power supply for turnover screen.

Description

Technical Field

[0001] This utility model relates to the field of vehicle-mounted flip screen technology, specifically to the power input circuit of a vehicle-mounted flip screen. Background Technology

[0002] The in-vehicle flip screen is a core component of the in-vehicle multimedia system, and its operational stability directly affects the user experience. However, the in-vehicle power environment is complex: voltage fluctuations and even spike pulse interference can easily occur during vehicle startup and switching of electrical devices; at the same time, in-vehicle circuits are also subject to risks of overvoltage and overcurrent faults. Existing in-vehicle flip screen power input circuits generally suffer from insufficient anti-interference capabilities, inadequate protection functions, and poor output voltage stability, making it difficult to meet the high reliability requirements of flip screens and seriously affecting their lifespan and performance.

[0003] In light of the problems mentioned above, we propose a power input circuit for a vehicle-mounted flip screen. Utility Model Content

[0004] The purpose of this invention is to provide a power input circuit for a vehicle-mounted rotating screen to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] The power input circuit for the vehicle-mounted flip screen includes:

[0007] The input protection unit includes: a bidirectional Zener diode DZ1 connected in parallel between IN+ and IN− and connected to the power input terminals IN+ and IN−; and a fuse F1 connected in series with the power input line.

[0008] A switch control unit, comprising: a MOSFET Q1, and a control sub-circuit for controlling the on / off state of Q1, the control sub-circuit comprising an operational amplifier U1, a transistor Q2, and a transistor Q3, the output terminal of the operational amplifier U1 being connected to the base of the transistor Q2 via a resistor R1, the collector of the transistor Q2 being connected to the cathode of a Zener diode DZ2 via a resistor R2, the anode of the Zener diode DZ2 being grounded, and the Zener diode DZ2 being connected in parallel with a resistor R3 between the output side of Q1 and ground;

[0009] The non-inverting input of operational amplifier U1 is connected to a voltage divider branch consisting of resistors R4 and R5 and diode D1 via resistor R6. The inverting input is connected to a reference adjustment circuit consisting of resistors R9, R10, R11, capacitors C7 and C8, and resistor R12. The collector of transistor Q3 is connected to the non-inverting input of operational amplifier U1, the emitter is grounded, and the base is connected to the reference adjustment circuit via resistor R9.

[0010] The output filtering unit includes an inductor L1 connected in series on the output side of Q1, and a capacitor C3 and an electrolytic capacitor C4 connected in parallel between the output terminal of L1 and ground.

[0011] Preferably, the switch control unit further includes: a resistor R7 connected to the gate of Q1, and a capacitor C1 connected to the source of Q1, with the other end of the capacitor C1 grounded.

[0012] Preferably, the inverting input terminal of the operational amplifier U1 is further connected to a capacitor C6 and a resistor R8 in parallel, and the other end of the capacitor C6 and the resistor R8 is grounded.

[0013] Preferably, the resistor R4 and capacitor C5 are connected in series and then in parallel between the source of Q1 and ground.

[0014] Compared with the prior art, the beneficial effects of this utility model are:

[0015] The input protection unit of this utility model achieves dual protection against overvoltage and overcurrent through a bidirectional voltage regulator and a fuse, effectively dealing with instantaneous fluctuations and faults in the vehicle power supply.

[0016] The switching control unit of this utility model works in conjunction with the voltage regulation feedback unit to form a closed-loop control, dynamically adjusting the on / off state of the MOSFET to maintain a stable output voltage;

[0017] The LC structure of the output filter unit of this invention significantly filters out high-frequency interference, making the power supply cleaner; the RC filter and phase compensation circuit in the switch control unit also improve the anti-interference capability.

[0018] The overall circuit adapts to the complex power environment of the vehicle, providing a stable and reliable power supply for the vehicle-mounted rotating screen, ensuring its working performance and service life. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] like Figure 1 As shown, the power input circuit of the vehicle-mounted flip screen includes:

[0022] The input protection unit includes: a bidirectional Zener diode DZ1 connected in parallel between IN+ and IN−, and a fuse F1 connected in series with the power input line; the bidirectional Zener diode DZ1, connected in parallel between IN+ and IN−, can suppress instantaneous positive and negative overvoltages of the input voltage, clamp the voltage within a safe range, and protect the downstream circuit; the fuse F1, connected in series with the power input line, will blow to cut off the power supply when an overcurrent fault (such as a short circuit) occurs in the circuit, thus preventing damage to downstream components.

[0023] The switch control unit includes a MOSFET Q1 and a control sub-circuit for controlling the on / off state of Q1. The control sub-circuit includes an operational amplifier U1, a transistor Q2, and a transistor Q3. The output terminal of the operational amplifier U1 is connected to the base of the transistor Q2 via a resistor R1. The collector of the transistor Q2 is connected to the cathode of the Zener diode DZ2 via a resistor R2. The anode of the Zener diode DZ2 is grounded, and the Zener diode DZ2 is connected in parallel with a resistor R3 between the output side of Q1 and ground.

[0024] The switch control unit also includes a resistor R7 connected to the gate of Q1 and a capacitor C1 connected to the source of Q1, with the other end of capacitor C1 grounded.

[0025] The switching control unit uses MOSFET Q1 as its core, and works in conjunction with a control sub-circuit consisting of operational amplifier U1, transistor Q2, transistor Q3, etc., to achieve dynamic adjustment of power supply on / off state.

[0026] The MOSFET Q1 serves as the main switching element. Its gate is grounded through resistor R7 (R7 limits the gate current), its source is connected to the input power supply side (after F1 and DZ1), and its drain is connected to the subsequent circuit. A capacitor C1 is also connected in parallel to the source (to filter out source interference signals).

[0027] Operational amplifier U1 is the core of the comparator / amplifier: the output terminal controls the base of transistor Q2 via resistor R1; the non-inverting input terminal is connected to the voltage divider branch composed of resistors R4, R5 and diode D1 via resistor R6 (to sample the source voltage of Q1); the inverting input terminal is connected to the reference adjustment circuit composed of resistors R9, R10, R11, capacitors C7 and C8 and resistor R12, and capacitor C6 and resistor R8 are connected in parallel at the inverting input terminal (for filtering, phase compensation, and to prevent operational amplifier oscillation).

[0028] The collector of transistor Q3 is connected to the non-inverting input of operational amplifier U1, the emitter is grounded, and the base is connected to the reference adjustment circuit via resistor R9. This circuit is used to adjust the non-inverting input signal according to the reference voltage and participate in feedback control.

[0029] Resistor R4 and capacitor C5 are connected in series and then in parallel between the source of Q1 and ground (forming an RC filter to stabilize the sampling signal).

[0030] The non-inverting input of operational amplifier U1 is connected to a voltage divider branch consisting of resistors R4 and R5 and diode D1 via resistor R6. The inverting input is connected to a reference adjustment circuit consisting of resistors R9, R10, R11, capacitors C7 and C8, and resistor R12. The collector of transistor Q3 is connected to the non-inverting input of operational amplifier U1, the emitter is grounded, and the base is connected to the reference adjustment circuit via resistor R9.

[0031] The inverting input of operational amplifier U1 is also connected to a parallel capacitor C6 and a resistor R8, with the other ends of capacitor C6 and resistor R8 grounded.

[0032] The voltage regulation feedback unit consists of Zener diode DZ2, resistors R2 and R3: Zener diode DZ2 operates in reverse breakdown state, providing a stable reference voltage; resistors R2 and R3 divide the output voltage on the drain side of Q1, and the feedback signal is introduced into the collector of transistor Q2. The on / off duty cycle of Q1 is adjusted by the control sub-circuit to achieve output voltage stability.

[0033] The output filtering unit includes: an inductor L1 connected in series on the output side of Q1, and a capacitor C3 and an electrolytic capacitor C4 connected in parallel between the output terminal of L1 and ground. A resistor R4 and a capacitor C5 are connected in series and then in parallel between the source of Q1 and ground.

[0034] The output filter unit consists of an LC filter circuit composed of an inductor L1, a capacitor C3, and an electrolytic capacitor C4: the inductor L1 is connected in series at the drain output terminal of Q1 (to impede sudden current changes), and the capacitors C3 and C4 are connected in parallel between the output terminal of L1 and ground (to store charge). Together, they filter out high-frequency ripple and interference in the power supply, making the output voltage smooth and stable.

[0035] like Figure 1 As shown, the working process of the power input circuit of the vehicle-mounted flip screen of this utility model is as follows:

[0036] Power supply connection and initial protection: After the input power is connected to IN+ and IN-, the bidirectional Zener diode DZ1 suppresses overvoltage and the fuse F1 prevents overcurrent, thus providing initial protection for the power supply.

[0037] Switching and feedback regulation: Operational amplifier U1 compares the "sampled voltage at the non-inverting input" with the "reference voltage at the inverting input". The output signal controls the conduction level of transistor Q2 through resistor R1, thereby adjusting the gate voltage of MOSFET Q1 and changing the on / off state of Q1. The voltage regulation feedback unit samples the output voltage in real time through DZ2, R2, and R3, and introduces the feedback signal into the control sub-circuit to form a closed loop, ensuring the stability of the output voltage.

[0038] Filtered output: The voltage regulated by the switch enters the output filtering unit. The LC filter circuit composed of inductor L1 and capacitors C3 and C4 filters out high-frequency interference and finally outputs a clean and stable power supply to power the vehicle-mounted flip screen.

[0039] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. The power input circuit for a vehicle-mounted flip screen, characterized in that, include: The input protection unit includes: a bidirectional Zener diode DZ1 connected in parallel between IN+ and IN− and connected to the power input terminals IN+ and IN−; and a fuse F1 connected in series with the power input line. A switch control unit, comprising: a MOSFET Q1, and a control sub-circuit for controlling the on / off state of Q1, the control sub-circuit comprising an operational amplifier U1, a transistor Q2, and a transistor Q3, the output terminal of the operational amplifier U1 being connected to the base of the transistor Q2 via a resistor R1, the collector of the transistor Q2 being connected to the cathode of a Zener diode DZ2 via a resistor R2, the anode of the Zener diode DZ2 being grounded, and the Zener diode DZ2 being connected in parallel with a resistor R3 between the output side of Q1 and ground; The non-inverting input of operational amplifier U1 is connected to a voltage divider branch consisting of resistors R4 and R5 and diode D1 via resistor R6. The inverting input is connected to a reference adjustment circuit consisting of resistors R9, R10, R11, capacitors C7 and C8, and resistor R12. The collector of transistor Q3 is connected to the non-inverting input of operational amplifier U1, the emitter is grounded, and the base is connected to the reference adjustment circuit via resistor R9. The output filtering unit includes an inductor L1 connected in series on the output side of Q1, and a capacitor C3 and an electrolytic capacitor C4 connected in parallel between the output terminal of L1 and ground.

2. The power input circuit of the vehicle-mounted flip screen according to claim 1, characterized in that, The switch control unit further includes: a resistor R7 connected to the gate of Q1, and a capacitor C1 connected to the source of Q1, with the other end of capacitor C1 grounded.

3. The power input circuit of the vehicle-mounted flip screen according to claim 1, characterized in that, The inverting input terminal of the operational amplifier U1 is also connected to a parallel capacitor C6 and a resistor R8, with the other ends of capacitor C6 and resistor R8 grounded.

4. The power input circuit of the vehicle-mounted flip screen according to claim 1, characterized in that, The resistor R4 and capacitor C5 are connected in series and then in parallel between the source of Q1 and ground.

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