CN214959294U

CN214959294U - Power supply circuit and display device of start are waited to self-adaptation

Info

Publication number: CN214959294U
Application number: CN202023348187.4U
Authority: CN
Inventors: 陈波
Original assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Current assignee: Shenzhen Skyworth RGB Electronics Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2021-11-30
Anticipated expiration: 2030-12-31

Abstract

The utility model discloses a self-adaptation power supply circuit and display device of waiting to start, power supply circuit includes input rectifier circuit, main inverter circuit, output rectifier circuit and the feedback circuit that connects gradually, feedback circuit still is connected with the load, power supply circuit still includes PWM regulating circuit, PWM regulating circuit respectively with main inverter circuit with feedback circuit connects; the PWM adjusting circuit is used for entering a working mode when the load power is determined to be larger than a preset value according to the input current, or entering a standby mode when the load power is determined to be smaller than the preset value, so that the standby power control is effectively realized, the original standby circuit is saved, and the circuit structure is simplified.

Description

Power supply circuit and display device of start are waited to self-adaptation

Technical Field

The utility model relates to a power technical field, in particular to power supply circuit and TV set of start are treated to self-adaptation.

Background

At present, a driving power supply is needed for the liquid crystal television and other liquid crystal display devices, and the driving power supply converts the input 220V alternating current into direct current to supply power to a main board, a power amplifier and a backlight lamp bar of the liquid crystal television. As shown in fig. 1, after the system is turned on, clutter interference in the utility power is filtered by an anti-interference circuit, the filtered clutter interference is rectified and sent to a main circuit, the main circuit outputs 12V direct current voltage to a main board, and the main board starts initialization; after initialization is completed, the main board outputs high level of ON/OFF signals to the power supply and light bar control circuit, the power supply main circuit and the light bar control circuit start to work with load after receiving the signals, and the whole television starts to light and normally work by matching with glass controlled by T-COM.

After the television is used, a POWER button of a remote controller is generally pressed, the remote controller can give a control signal to a main board, the main board can send a low level of an ON/OFF signal to a POWER main circuit and a light bar control circuit after receiving the control signal, the television POWER supply outputs the low level and enters a standby mode, the light bar control circuit turns OFF current output, and a screen is turned OFF; when the television needs to be watched again, the POWER button is pressed again, after the television mainboard receives a signal, a high level of an ON/OFF control signal is sent to the main POWER circuit and the light bar control circuit, and the television enters a normal working mode from a standby mode.

Therefore, in the television starting process and the television standby process, the functions of starting, standby and the like of the television can be finished only by using an ON/OFF control circuit, namely a standby circuit, so that the complexity of the whole power circuit is increased, and the material cost is increased.

Thus, the prior art has yet to be improved and enhanced.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing prior art, an object of the present invention is to provide a power supply circuit and a display device that are adaptive to a standby power supply, which can simplify the structure of the power supply circuit and reduce the material cost.

In order to achieve the purpose, the utility model adopts the following technical proposal:

a self-adaptive power supply circuit to be started comprises an input rectifying circuit, a main conversion circuit, an output rectifying circuit and a feedback circuit which are sequentially connected, wherein the feedback circuit is also connected with a load; the PWM adjusting circuit is used for entering a working mode when the load power is determined to be larger than a preset value according to the input current, or entering a standby mode when the load power is determined to be smaller than the preset value.

The self-adaptive power supply circuit to be started comprises a PWM (pulse width modulation) chip and a current detection unit; the PWM chip is connected with the current detection unit; the current detection unit is used for outputting detection voltage to the PWM chip according to input current, and the PWM chip enters a working mode when determining that the load power is larger than a preset value according to the detection voltage or enters a standby mode when determining that the load power is smaller than the preset value.

The PWM adjusting circuit also comprises an auxiliary unit and a driving unit, and the auxiliary unit and the driving unit are both connected with the PWM chip; the driving unit is used for controlling the voltage output by the main conversion circuit according to the PWM signal output by the PWM chip, and the auxiliary unit is used for controlling the driving unit to immediately stop working when the PWM chip is switched from the standby mode to the normal mode and delays.

The PWM adjusting circuit further comprises a filtering unit, the filtering unit is connected with the current detection unit, and the filtering unit is used for filtering the input current.

In the self-adaptive power supply circuit to be started, the current detection unit comprises a first resistor, a second resistor, a third resistor and a first capacitor; one end of the first resistor and one end of the second resistor are both connected with an input current end, the other end of the first resistor and one end of the first capacitor are both connected with an IS signal end of the PWM chip, the other end of the second resistor IS grounded, one end of the third resistor IS connected with a CA signal end of the PWM chip, the other end of the third resistor IS grounded, and the other end of the first capacitor IS grounded.

In the self-adaptive power supply circuit to be started, the auxiliary unit comprises a fourth resistor, a fifth resistor, a second capacitor, a third capacitor and a fourth capacitor; one end of the fourth resistor, one end of the fifth resistor and one end of the second capacitor are connected with a VW signal end of the PWM chip, the other end of the fourth resistor is connected with a VCC signal end of the PWM chip, and the other end of the fifth resistor, the other end of the second capacitor, one end of the third capacitor and one end of the fourth capacitor are all grounded.

The driving unit of the self-adaptive power supply circuit to be started comprises a first MOS tube and a second MOS tube; the drain electrode of the first MOS tube is connected with the power supply, the grid electrode of the first MOS tube is connected with the HO signal end of the PWM chip, the source electrode of the first MOS tube is connected with the VS signal end of the PWM chip, the drain electrode of the second MOS tube and the main conversion circuit, the grid electrode of the second MOS tube is connected with the LO signal end of the PWM chip, and the source electrode of the second MOS tube is grounded.

The filtering unit comprises a fifth capacitor, one end of the fifth capacitor is connected with a CA signal end of the PWM chip, and the other end of the fifth capacitor is grounded.

A display device comprises the self-adaptive power supply circuit to be started.

Compared with the prior art, the utility model provides a pair of power supply circuit and display device that waits to start by self-adaptation, power supply circuit includes input rectifier circuit, main inverter circuit, output rectifier circuit and the feedback circuit that connects gradually, feedback circuit still is connected with the load, power supply circuit still includes PWM regulating circuit, PWM regulating circuit respectively with main inverter circuit with feedback circuit connects; the PWM adjusting circuit is used for entering a working mode when the load power is determined to be larger than a preset value according to the input current, or entering a standby mode when the load power is determined to be smaller than the preset value, so that the standby power control is effectively realized, the original standby circuit is saved, and the circuit structure is simplified.

Drawings

Fig. 1 is a block diagram of a conventional power supply circuit;

fig. 2 is a block diagram of a power supply circuit provided by the present invention;

fig. 3 is a block diagram of a PWM adjusting circuit in the power circuit provided by the present invention;

fig. 4 and fig. 5 are schematic diagrams of a PWM adjusting circuit in a power circuit according to the present invention.

Detailed Description

The utility model provides a power supply circuit and display device of start are treated to self-adaptation can simplify power supply circuit's structure, reduces material cost.

In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the following description of the present invention will refer to the accompanying drawings and illustrate embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

Referring to fig. 2 and fig. 3 together, the power supply circuit for self-adaptive standby power on according to the present invention includes an EMI filter circuit 10, an input rectifier circuit 20, a main converter circuit 30, an output rectifier circuit 40 and a feedback circuit 50, which are connected in sequence, wherein the feedback circuit 50 is further connected to a load 70, the power supply circuit further includes a PWM adjusting circuit 60, and the PWM adjusting circuit 60 is connected to the main converter circuit 30 and the feedback circuit 50, respectively; the PWM adjusting circuit 60 is configured to enter an operating mode when it is determined that the load 70 is greater than a preset value according to the input current, or enter a standby mode when it is determined that the load 70 is less than the preset value; it should be noted that the EMI filter circuit 10, the input rectifier circuit 20, the main converter circuit 30, the output rectifier circuit 40, and the feedback circuit 50 are all in the prior art, and the structure thereof is not described herein again. Compared with the existing power supply circuit, the power supply circuit of the embodiment omits a circuit to be started, and the control to be started is directly carried out through the PWM adjusting circuit 60 according to the load 70, so that the structure of the main circuit of the power supply is simplified, and the material cost is saved.

Further, the PWM adjusting circuit 60 includes a PWM chip 61 and a current detecting unit 62; the PWM chip 61 is connected to the current detection unit 62; the current detection unit 62 is configured to output a detection voltage to the PWM chip 61 according to an input current, and the PWM chip 61 enters a working mode when determining that the load 70 is greater than a preset value according to the detection voltage, or enters a standby mode when determining that the load 70 is less than the preset value; in this embodiment, the model of the PWM chip 61 is FA6B 20N-N6-L3. Specifically, the IS signal terminal and the CA signal terminal in the PWM chip 61 and the current detection unit 62 detect a current through the current detection unit 62, and at the same time, a voltage proportional to the input current IS output to the CA signal terminal, so that the PWM chip 61 determines a change of the load 70 according to the voltage of the CA signal terminal, specifically, when the PWM chip 61 determines that the voltage of the CA signal terminal IS greater than a preset voltage, it indicates that the load 70 IS greater than the preset value, the PWM chip 61 switches to the standby mode, and when it determines that the voltage of the CA signal terminal IS less than the preset voltage, it indicates that the load 70 IS less than the preset value, the PWM chip 61 switches to the normal operating mode.

Further, the PWM adjusting circuit 60 further includes an auxiliary unit 63 and a driving unit 64, and both the auxiliary unit 63 and the driving unit 64 are connected to the PWM chip 61; the driving unit 64 is configured to control the voltage output by the main converting circuit 30 according to the PWM signal output by the PWM chip 61, and the auxiliary unit 63 is configured to control the driving unit 64 to immediately stop working when the PWM chip 61 is delayed when switching from the standby mode to the normal mode; during the automatic standby, there is a delay in switching the PWM chip 61 from the low standby operation mode to the normal operation mode, and during the delay, the auxiliary unit 63 forcibly turns off the operation of the driving unit 64, thereby preventing the output of the main converter circuit 30 from falling.

Further, the PWM adjusting circuit 60 further includes a filtering unit 65, the filtering unit 65 is connected to the current detecting unit 62, the filtering unit 65 is configured to perform filtering processing on the input current, and in this embodiment, the filtering unit 65 is configured to perform smoothing processing on the detected input current, so as to ensure stability and reliability of the input current.

Further, referring to fig. 4, the current detecting unit 62 includes a first resistor R1, a second resistor R2, a third resistor R3 and a first capacitor C1; one end of the first resistor R1 and one end of the second resistor R2 are both connected to an input current end, the other end of the first resistor R1 and one end of the first capacitor C1 are both connected to an IS signal end of the PWM chip 61, the other end of the second resistor R2 IS grounded, one end of the third resistor R3 IS connected to a CA signal end of the PWM chip 61, the other end of the third resistor R3 IS grounded, and the other end of the first capacitor C1 IS grounded; the voltage of the CA signal terminal in the PWM chip 61 is decreased based on the decrease of the load 70; when the load 70 is reduced, the voltage at the CA signal end will drop to a preset voltage, and after a delay of 108ms, the PWM chip 61 will switch from the operating mode to the standby mode, and stop outputting the PWM signal, so as to make the entire power circuit enter the standby mode; when the load 70 is raised and the voltage of the corresponding CA signal terminal is raised to the preset voltage, the PWM signal is detected and then switched from the standby mode to the normal operation mode, during which no external switching signal is required, thereby reducing the number of external components, simplifying the circuit structure, and further saving the material cost.

Further, referring to fig. 5, the auxiliary unit 63 includes a fourth resistor R4, a fifth resistor R5, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4; one end of the fourth resistor R4, one end of the fifth resistor R5 and one end of the second capacitor C2 are connected to the VW signal terminal of the PWM chip 61, the other end of the fourth resistor R4 is connected to the VCC signal terminal of the PWM chip 61, and the other end of the fifth resistor R5, the other end of the second capacitor C2, one end of the third capacitor C3 and one end of the fourth capacitor C4 are all grounded; in the automatic standby device, a delay of 600us occurs when the PWM chip 61 is switched from the standby mode to the normal operation mode, and during the delay, the control switch is forcibly turned off by the VM signal terminal to prevent the output voltage of the main inverter circuit 30 from dropping.

Further, the driving unit 64 includes a first MOS transistor Q1 and a second MOS transistor Q2; the drain of the first MOS transistor Q1 is connected to power, the gate of the first MOS transistor Q1 is connected to the HO signal end of the PWM chip 61, the source of the first MOS transistor Q1 is connected to the VS signal end of the PWM chip 61, the drain of the second MOS transistor Q2 and the main converter circuit 30, the gate of the second MOS transistor Q2 is connected to the LO signal end of the PWM chip 61, the source of the second MOS transistor Q2 is grounded, the PWM chip 61 provides PWM signals for the first MOS transistor Q1 and the second MOS transistor Q2, and the first MOS transistor Q1 and the second MOS transistor Q2 are controlled to be switched on or off, so that the main converter circuit 30 outputs a required voltage.

Further, with reference to fig. 4, the filtering unit 65 includes a fifth capacitor C5, one end of the fifth capacitor C5 is connected to the CA signal terminal of the PWM chip 61, and the other end of the fifth capacitor C5 is grounded; the fifth capacitor C5 smoothes the input current, thereby ensuring the stability and reliability of the input current.

The utility model discloses utilize the PWM chip directly to realize waiting to start management function, simplified the main circuit design, saved one and waited to start the circuit, strengthened whole power supply circuit's stability and reliability.

The utility model discloses still the correspondence provides a display device, display device includes that the power supply circuit of start is treated to above-mentioned self-adaptation, because the above has carried out detailed description to the power supply circuit that this self-adaptation was treated to the start, and it is no longer repeated here.

To sum up, the utility model provides a pair of power supply circuit and display device that waits to start by self-adaptation, power supply circuit includes input rectifier circuit, main inverter circuit, output rectifier circuit and the feedback circuit that connects gradually, feedback circuit still is connected with the load, power supply circuit still includes PWM regulating circuit, PWM regulating circuit respectively with main inverter circuit with feedback circuit connects; the PWM adjusting circuit is used for entering a working mode when the load power is determined to be larger than a preset value according to the input current, or entering a standby mode when the load power is determined to be smaller than the preset value, so that the standby power control is effectively realized, the original standby circuit is saved, and the circuit structure is simplified.

It should be understood that equivalent alterations and modifications can be made by those skilled in the art according to the technical solution of the present invention and the inventive concept thereof, and all such alterations and modifications should fall within the scope of the appended claims.

Claims

1. A self-adaptive power supply circuit to be started comprises an input rectifying circuit, a main conversion circuit, an output rectifying circuit and a feedback circuit which are sequentially connected, wherein the feedback circuit is also connected with a load; the PWM adjusting circuit is used for entering a working mode when the load power is determined to be larger than a preset value according to the input current, or entering a standby mode when the load power is determined to be smaller than the preset value.

2. The adaptive power supply circuit to be started according to claim 1, wherein the PWM adjusting circuit comprises a PWM chip and a current detecting unit; the PWM chip is connected with the current detection unit; the current detection unit is used for outputting detection voltage to the PWM chip according to input current, and the PWM chip enters a working mode when determining that the load power is larger than a preset value according to the detection voltage or enters a standby mode when determining that the load power is smaller than the preset value.

3. The adaptive power supply circuit to be started according to claim 2, wherein the PWM regulating circuit further comprises an auxiliary unit and a driving unit, both of which are connected to the PWM chip; the driving unit is used for controlling the voltage output by the main conversion circuit according to the PWM signal output by the PWM chip, and the auxiliary unit is used for controlling the driving unit to immediately stop working when the PWM chip is switched from the standby mode to the normal mode and delays.

4. The adaptive power supply circuit to be started according to claim 2, wherein the PWM adjusting circuit further comprises a filtering unit, the filtering unit is connected to the current detecting unit, and the filtering unit is configured to filter the input current.

5. The adaptive standby power supply circuit according to claim 2, wherein the current detection unit comprises a first resistor, a second resistor, a third resistor and a first capacitor; one end of the first resistor and one end of the second resistor are both connected with an input current end, the other end of the first resistor and one end of the first capacitor are both connected with an IS signal end of the PWM chip, the other end of the second resistor IS grounded, one end of the third resistor IS connected with a CA signal end of the PWM chip, the other end of the third resistor IS grounded, and the other end of the first capacitor IS grounded.

6. The adaptive standby power supply circuit according to claim 3, wherein the auxiliary unit comprises a fourth resistor, a fifth resistor, a second capacitor, a third capacitor and a fourth capacitor; one end of the fourth resistor, one end of the fifth resistor and one end of the second capacitor are connected with a VW signal end of the PWM chip, the other end of the fourth resistor is connected with a VCC signal end of the PWM chip, and the other end of the fifth resistor, the other end of the second capacitor, one end of the third capacitor and one end of the fourth capacitor are all grounded.

7. The adaptive power supply circuit to be started according to claim 3, wherein the driving unit comprises a first MOS transistor and a second MOS transistor; the drain electrode of the first MOS tube is connected with the power supply, the grid electrode of the first MOS tube is connected with the HO signal end of the PWM chip, the source electrode of the first MOS tube is connected with the VS signal end of the PWM chip, the drain electrode of the second MOS tube and the main conversion circuit, the grid electrode of the second MOS tube is connected with the LO signal end of the PWM chip, and the source electrode of the second MOS tube is grounded.

8. The adaptive power supply circuit to be started according to claim 4, wherein the filtering unit comprises a fifth capacitor, one end of the fifth capacitor is connected to the CA signal end of the PWM chip, and the other end of the fifth capacitor is grounded.

9. A display device comprising the adaptive standby power supply circuit of any one of claims 1-8.