AC-DC constant multipath output voltage control circuit for TV power supply

Abstract

The utility model discloses an AC-to-DC constant multipath output voltage control circuit used for a TV power supply, comprising a control chip U1 and a driving chip U2, one end of the driving chip is electrically connected with a grid electrode of an MOS tube Q1, a drain electrode of the MOS tube Q1 is grounded, a source electrode of the MOS tube Q1 is electrically connected to a P2 end of an inductor T1, a P1 end of the inductor T1 is electrically connected to an input HV, and a P2 end of the inductor T1 is electrically connected to an output HV. The A end of the inductor T1 is electrically connected to the diode D1, the other end of the diode is electrically connected to the output CV3, and the B end, the C end and the D end of the inductor T1 are electrically connected to the drain electrodes of the MOS transistor Q2, the MOS transistor Q3 and the MOS transistor Q4 respectively; and an SR1 pin, an SR2 pin and an SR3 pin of the control chip U1 are electrically connected to grid electrodes of the MOS tube Q2, the MOS tube Q3 and the MOS tube Q4 respectively. According to the utility model, a DC-DC secondary circuit is not needed, the standby power consumption of TV application is reduced by using the primary conversion circuit, and the functions of small size and high efficiency are realized.

Description

Technical Field

[0001] The utility model relates to the field of power supplies, in particular to an AC-to-DC constant multi-channel output voltage control circuit for a TV power supply. Background Art

[0002] Despite the diversification of current electronic products, TVs remain a must-have in every household. Existing TV power supplies cannot achieve constant multi-voltage outputs in the primary circuit, requiring the addition of a DC-DC circuit. This results in low conversion efficiency, increased size, and weight. The standby power consumption of the secondary DC-DC circuit also increases the standby power consumption of the entire device, resulting in high power consumption. Therefore, a technology that eliminates the need for a secondary DC-DC circuit is urgently needed, making the overall solution simpler, more efficient, smaller, more energy-efficient, and enhancing the consumer experience. Utility Model Content

[0003] In view of the above problems, the present invention aims to provide an AC-to-DC constant multi-channel output voltage control circuit for a TV power supply.

[0004] To achieve this technical purpose, the present invention provides a solution: an AC-DC constant multi-channel output voltage control circuit for a TV power supply, comprising a control chip U1 and a driver chip U2, wherein one end of the driver chip is electrically connected to the gate of a MOS transistor Q1, the drain of the MOS transistor Q1 is grounded, the source of the MOS transistor Q1 is electrically connected to the P2 end of an inductor T1, the P1 end of the inductor T1 is electrically connected to an input HV, the A end of the inductor T1 is electrically connected to a diode D1, the other end of the diode is electrically connected to an output CV3, the B end, the C end, and the D end of the inductor T1 are electrically connected to the drains of the MOS transistors Q2, Q3, and Q4, respectively; the SR1 pin, SR2 pin, and SR3 pin of the control chip U ... The MOS transistors Q2, Q3, and Q4 are electrically connected to the gates thereof; the source of the MOS transistor Q2 is grounded, and the sources of the MOS transistors Q3 and Q4 are electrically connected to the outputs CV1 and CV2, respectively; the VO1 pin, VO2 pin, and VO3 pin of the control chip U1 are electrically connected to the outputs CV1, CV2, and CV3, respectively; a voltage dividing resistor is also electrically connected between the control chip U1 and the outputs CV1, CV2, and CV3; an electrolytic capacitor EC1 is connected in parallel between the MOS transistors Q2 and Q3, an electrolytic capacitor EC2 is connected in parallel between the MOS transistors Q2 and Q4, and an electrolytic capacitor EC3 is connected in parallel between the MOS transistor Q2 and the diode D1.

[0005] Preferably, the voltage-dividing resistors include resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, and resistor R6; the FB1 pin of the control chip U1 is electrically connected to the output CV1 after voltage division by resistor R1, and the FB1 pin of the control chip U1 is grounded via resistor R2; the FB2 pin of the control chip U1 is electrically connected to the output CV2 after voltage division by resistor R3, and the FB2 pin of the control chip U1 is grounded via resistor R4; the FB3 pin of the control chip U1 is electrically connected to the output CV3 after voltage division by resistor R5, and the FB3 pin of the control chip U1 is grounded via resistor R6.

[0006] Preferably, the MOS transistor Q1 , MOS transistor Q2 , MOS transistor Q3 , and MOS transistor Q4 are all enhancement-mode MOS transistors.

[0007] Preferably, the control chip U1 is communicatively connected to the driver chip U2 via a Link cable.

[0008] The beneficial effects of the present invention are as follows: since no DC-DC secondary circuit is required, the overall components are reduced and the production cost is lowered; the use of a primary conversion circuit reduces the standby power consumption of TV applications and reduces the size, saving consumers' overall indoor space; it is highly efficient, environmentally friendly and energy-saving; the overall solution achieves the functions of small size and high efficiency, greatly improving the consumer experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 This is the circuit diagram of the utility model; DETAILED DESCRIPTION

[0010] The utility model of this application is further described in detail below with reference to the accompanying drawings and specific embodiments. In order to clearly and completely describe the technical solution, the following embodiments are selected for illustration; other embodiments obtained based on the content recorded in this application without creative work are all within the scope of protection of this utility model.

[0011] In the following embodiments, it should be noted that the terms "up", "down", "left", "right", "inside", "outside", "top / bottom" and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of clearly describing the present embodiment, and do not indicate or imply that the device or element referred to must have a specific orientation. Therefore, they cannot be understood as limitations on this application.

[0012] like Figure 1As shown, the specific embodiment of the present invention is an AC-DC constant multi-channel output voltage control circuit for a TV power supply, including a control chip U1 and a driver chip U2. One end of the driver chip is electrically connected to the gate of the MOS transistor Q1, the drain of the MOS transistor Q1 is grounded, the source of the MOS transistor Q1 is electrically connected to the P2 end of the inductor T1, the P1 end of the inductor T1 is electrically connected to the input HV, the A end of the inductor T1 is electrically connected to the diode D1, the other end of the diode is electrically connected to the output CV3, the B end of the inductor T1 is electrically connected to the drain of the MOS transistor Q2, the C end of the inductor T1 is electrically connected to the drain of the MOS transistor Q3, and the D end of the inductor T1 is electrically connected to the drain of the MOS transistor Q4; the SR1 pin of the control chip U1 is electrically connected to the gate of the MOS transistor Q2, and the SR2 pin of the control chip U1 is electrically connected The gate of the MOS transistor Q3 is connected to the SR3 pin of the control chip U1, and the gate of the MOS transistor Q4 is electrically connected to the SR3 pin of the control chip U1. The source of the MOS transistor Q2 is grounded, the source of the MOS transistor Q3 is electrically connected to the output CV1, and the source of the MOS transistor Q4 is electrically connected to the output CV2. The VO1 pin of the control chip U1 is electrically connected to the output CV1, the VO2 pin of the control chip U1 is electrically connected to the output CV2, and the VO3 pin of the control chip U1 is electrically connected to the output CV3. A voltage divider resistor is also electrically connected between the control chip U1 and the outputs CV1, CV2, and CV3. An electrolytic capacitor EC1 is connected in parallel between the MOS transistors Q2 and Q3, an electrolytic capacitor EC2 is connected in parallel between the MOS transistors Q2 and Q4, and an electrolytic capacitor EC3 is connected in parallel between the MOS transistor Q2 and the diode D1.

[0013] In order to ensure the accuracy of the feedback signal and the stability of the system, a voltage divider resistor including resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, and resistor R6 are set; the FB1 pin of the control chip U1 is electrically connected to the output CV1 after voltage division by resistor R1, and the FB1 pin of the control chip U1 is grounded via resistor R2; the FB2 pin of the control chip U1 is electrically connected to the output CV2 after voltage division by resistor R3, and the FB2 pin of the control chip U1 is grounded via resistor R4; the FB3 pin of the control chip U1 is electrically connected to the output CV3 after voltage division by resistor R5, and the FB3 pin of the control chip U1 is grounded via resistor R6. In this way, the output voltage can be accurately controlled, and the FB pin helps to improve the efficiency and stability of power management. This solution of FB pin connection and layout can reduce the noise and fluctuation of the output voltage and improve the reliability of the system.

[0014] In order to reduce input current and lower power consumption, MOS transistors Q1, Q2, Q3 and Q4 are all configured as enhancement-type MOS transistors.

[0015] In order to provide a high transmission rate and keep the high-speed transmission performance more stable, the control chip U1 is connected to the driver chip U2 via a Link cable.

[0016] During operation, the primary MOS transistor conducts, and the primary coil transfers the excitation energy to the secondary. When CV1, CV2, and CV3 all require energy, CV1's energy supply is prioritized, maintaining the CV1 voltage at the voltage set by the voltage-divider resistors R1 and R2. At this point, the gate switch Q4 is turned off. When CV1 has no energy demand but CV2 requires energy from the primary, the gate switch Q4 opens, transferring the stored excitation energy to CV2. When neither CV1 nor CV2 requires energy, but CV3 does, the remaining excitation energy is transferred to CV3, maintaining the CV3 voltage at the set value. If none of CV1, CV2, or CV3 require energy, chip U1 sends a signal to U2 via the link to reduce the operating frequency or pulse width, thereby reducing energy generation and transmission.

[0017] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any minor modifications, equivalent replacements and improvements made to the above embodiments based on the technical essence of the present invention should be included in the scope of protection of the technical solution of the present invention.

Claims

1. An AC-to-DC constant multi-channel output voltage control circuit for TV power supply, characterized by: The invention comprises a control chip U1 and a driver chip U2, wherein one end of the driver chip is electrically connected to the gate of the MOS transistor Q1, the drain of the MOS transistor Q1 is grounded, the source of the MOS transistor Q1 is electrically connected to the P2 end of the inductor T1, the P1 end of the inductor T1 is electrically connected to the input HV, the A end of the inductor T1 is electrically connected to the diode D1, the other end of the diode is electrically connected to the output CV3, the B end, the C end, and the D end of the inductor T1 are electrically connected to the drains of the MOS transistors Q2, Q3, and Q4, respectively; the SR1 pin, SR2 pin, and SR3 pin of the control chip U1 are electrically connected to the MOS transistors Q2, Q3, and Q4, respectively. The gate of Q4; the source of the MOS transistor Q2 is grounded, and the sources of the MOS transistors Q3 and Q4 are electrically connected to the output CV1 and the output CV2, respectively; the VO1 pin, VO2 pin, and VO3 pin of the control chip U1 are electrically connected to the output CV1, the output CV2, and the output CV3, respectively; a voltage dividing resistor is also electrically connected between the control chip U1 and the output CV1, the output CV2, and the output CV3; an electrolytic capacitor EC1 is connected in parallel between the MOS transistors Q2 and Q3, an electrolytic capacitor EC2 is connected in parallel between the MOS transistor Q2 and the MOS transistor Q4, and an electrolytic capacitor EC3 is connected in parallel between the MOS transistor Q2 and the diode D1.

2. The AC-to-DC constant multi-channel output voltage control circuit for a TV power supply according to claim 1, characterized in that: The voltage-dividing resistors include resistor R1, resistor R2, resistor R3, resistor R4, resistor R5, and resistor R6; the FB1 pin of the control chip U1 is electrically connected to the output CV1 after voltage division by resistor R1, and the FB1 pin of the control chip U1 is grounded via resistor R2; the FB2 pin of the control chip U1 is electrically connected to the output CV2 after voltage division by resistor R3, and the FB2 pin of the control chip U1 is grounded via resistor R4; the FB3 pin of the control chip U1 is electrically connected to the output CV3 after voltage division by resistor R5, and the FB3 pin of the control chip U1 is grounded via resistor R6.

3. The AC-to-DC constant multi-channel output voltage control circuit for a TV power supply according to claim 1, characterized in that: The MOS transistor Q1 , MOS transistor Q2 , MOS transistor Q3 , and MOS transistor Q4 are all enhancement-type MOS transistors.

4. The AC-to-DC constant multi-channel output voltage control circuit for a TV power supply according to claim 1, characterized in that: The control chip U1 is communicatively connected to the driver chip U2 via a Link cable.

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