Power adapter adopting low control voltage to carry out boost control

Abstract

The utility model discloses a power adapter using low control voltage to carry out boost control, which relates to the technical field of gamepads, and comprises an input rectification filter unit, a transformer T1, a boost circuit, a control IC U1 and a voltage regulating circuit, the boost circuit comprises a capacitor C2, a resistor R7, a diode D21, an mos tube Q1, a resistor R11 and a resistor RS1; the voltage regulating circuit at least comprises a triode Q4, the control IC U1 is used for conducting / cutting off control on the voltage regulating circuit with low conducting control voltage, the voltage regulating circuit amplifies voltage transmitted from the input rectifying and filtering unit in the conducting state and then outputs a high-voltage signal to a grid electrode of the mos tube Q1, so that conducting / cutting off of the mos tube Q1 can be controlled, and in the process, the voltage of the mos tube Q1 is controlled to be larger than that of the triode Q4. Under the condition that the mos tube Q1 is controlled to be conducted / cut off, the control IC U1 only needs to control and output low control voltage used for controlling the triode Q4 to be conducted; the limitation during the model selection of the control IC can be effectively weakened, and the low-cost model selection of the control IC is facilitated.

Description

Technical Field

[0001] The utility model relates to the technical field of power adapters, in particular to a power adapter which adopts a low control voltage to perform boost control. Background Art

[0002] In a power adapter, a boost circuit is required for voltage control, such as Boost control. It is usually equipped with an energy storage capacitor and a MOSFET. The control terminal of the control IC controls the on / off state of the MOSFET, allowing the energy storage capacitor to store energy and release energy for the power adapter's transformer. The output voltage of the transformer is controlled by controlling the percentage of time the MOSFET is on. Since the output voltage of the transformer can be controlled to be greater than the input voltage of the power adapter, it is called boost control. A common circuit connection method is the MOSFET Q1 and capacitor C3 provided in the Chinese utility model "An Energy-Saving Power Supply Adapter" with announcement number CN217563537U. The driver U1 controls the on / off state of the MOSFET Q1, thereby boosting the input voltage of the transformer W2.

[0003] However, when the MOS switch is directly controlled by the control IC, the control IC needs to be able to output a relatively high control voltage, which directly leads to relatively higher requirements for the selection of the control IC and does not take advantage of the cost control of the power adapter. Utility Model Content

[0004] In order to overcome the above-mentioned shortcomings, the present invention aims to provide a technical solution that can solve the above-mentioned problems.

[0005] To achieve the above object, the present invention provides the following technical solution: a power adapter that uses a low control voltage for boost control, comprising

[0006] The input rectifier and filter unit and the input end of the input rectifier and filter unit are used to connect to an external power supply;

[0007] Transformer T1;

[0008] The boost circuit includes capacitor C2, resistor R7, diode D21, MOSFET Q1, resistor R11, and resistor RS1;

[0009] Control IC U1;

[0010] A voltage regulating circuit includes at least a transistor Q4, the voltage regulating circuit having a control terminal connected to the base of the transistor Q4, an input terminal connected to the collector of the transistor Q4, and a high voltage output terminal connected to the emitter of the transistor Q4;

[0011] Among them, the input end of the voltage regulating circuit is connected to the first output end of the input rectifier and filter unit, the input end of the voltage regulating circuit is connected to the control end GATE of the control IC U1, and the output end of the voltage regulating circuit is connected to the gate of the MOSFET Q1; one end of the primary winding of the transformer T1 is connected to the second output end of the input rectifier and filter unit, and the other end of the primary winding of the transformer T1 is connected to the source of the MOSFET Q1; one end of the capacitor C2 is connected to one end of the primary winding of the transformer T1, and the other end of the capacitor C2 is connected to the cathode of the diode D21 through the resistor R7, and the anode of the diode D21 is connected to the other end of the primary winding of the transformer T1; the gate of the MOSFET Q1 is grounded through the resistor R11, and the drain of the MOSFET Q1 is grounded through the resistor RS1.

[0012] As a further solution of the present invention: the voltage regulating circuit also includes a resistor R12, a resistor R10 and a diode D3; the emitter of the transistor Q4 is connected to the cathode of the diode D3 through the resistor R12, the anode of the diode D3 is connected to the gate of the MOS tube Q1, and the two ends of the resistor R10 are respectively connected to the cathode of the transistor D3 and the anode of the transistor D3.

[0013] As a further solution of the present invention: the voltage regulating circuit also includes a transistor Q3, a resistor R13 and a resistor R19; the base of the transistor Q4 is connected to the control terminal GATE of the control IC U1 through the resistor R19; the base of the transistor Q3 is connected to the base of the transistor Q4, the emitter of the transistor Q3 is connected to the emitter of the transistor Q4, and the collector of the transistor Q3 is grounded; the two ends of the resistor R13 are respectively connected to the base of the transistor Q4 and the emitter of the transistor Q4.

[0014] As a further solution of the present invention: the input rectifier and filter unit includes a common-mode inductor LF1 and a rectifier bridge BD1; the first output end of the input rectifier and filter unit is formed between the common-mode inductor LF1 and the input end of the rectifier bridge BD1, and the second output end of the input rectifier and filter unit is formed at the output end of the rectifier bridge BD1.

[0015] Compared with the prior art, the beneficial effects of the present technical solution are as follows: the control IC U1 is used to control the on / off of the voltage regulating circuit with a low conduction control voltage, and when the voltage regulating circuit is controlled by the control IC U1 to make its transistor Q4 in the on state, the voltage regulating circuit amplifies the voltage transmitted from the input rectifier and filter unit, and outputs a high voltage signal to the gate of the MOSFET Q1 after the voltage amplification, thereby controlling the on / off of the MOSFET Q1. In this process, when the on / off control of the MOSFET Q1 is satisfied, the control IC U1 only needs to control the output of a low control voltage for controlling the conduction of the transistor Q4. The limitation of the control voltage suffered when selecting the control IC can be effectively eliminated or weakened, which is more conducive to the low-cost selection of the control IC.

[0016] Additional aspects and advantages of the present invention will be given in part in the following description and will become apparent from the following description or learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 It is a circuit principle diagram of the utility model;

[0019] Figure 2 It is a current principle diagram of the voltage regulating circuit in the utility model. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] See also Figure 1-2 A power adapter that uses a low control voltage for boost control includes an input rectifier and filter unit 100, a transformer T1, a boost circuit, a control IC U1 and a voltage regulation circuit 200.

[0022] The input end of the input rectifier filter unit 100 is used to connect to an external power supply. The boost circuit includes a capacitor C2, a resistor R7, a diode D21, a MOSFET Q1, a resistor R11 and a resistor RS1.

[0023] The voltage regulator circuit includes at least a transistor Q4. The voltage regulator circuit has a control terminal connected to the base of the transistor Q4, an input terminal connected to the collector of the transistor Q4, and a high-voltage output terminal connected to the emitter of the transistor Q4. The input terminal of the voltage regulator circuit is connected to the first output terminal of the input rectifier and filter unit, the input terminal of the voltage regulator circuit is connected to the control terminal GATE of the control ICU1, and the output terminal of the voltage regulator circuit is connected to the gate of the MOSFET Q1.

[0024] One end of the primary winding of the transformer T1 is connected to the second output end of the input rectifier and filter unit, and the other end of the primary winding of the transformer T1 is connected to the source of the MOSFET Q1.

[0025] One end of capacitor C2 is connected to one end of the primary winding of transformer T1, and the other end of capacitor C2 is connected to the cathode of diode D21 through resistor R7. The anode of diode D21 is connected to the other end of the primary winding of transformer T1. The gate of MOSFET Q1 is grounded through resistor R11, and the drain of MOSFET Q1 is grounded through resistor RS1.

[0026] The control IC U1 is used to control the on / off state of the voltage regulating circuit with a low conduction control voltage. When the voltage regulating circuit is controlled by the control IC U1 to make the transistor Q4 in the on state, the voltage regulating circuit amplifies the voltage sent from the input rectifier and filter unit, and outputs a high voltage signal to the gate of the MOSFET Q1 after the voltage amplification, thereby controlling the on / off state of the MOSFET Q1. In this process, when the on / off control of the MOSFET Q1 is satisfied, the control IC U1 only needs to control the output of the low control voltage for controlling the conduction of the transistor Q4. The limitation of the control voltage suffered when selecting the control IC can be effectively eliminated or weakened, which is more conducive to the low-cost selection of the control IC.

[0027] Preferably, the voltage regulating circuit further includes a resistor R12, a resistor R10 and a diode D3; the emitter of the transistor Q4 is connected to the cathode of the diode D3 through the resistor R12, the anode of the diode D3 is connected to the gate of the MOSFET Q1, and the two ends of the resistor R10 are respectively connected to the cathode and anode of the transistor D3.

[0028] Preferably, the voltage regulating circuit further includes a transistor Q3, a resistor R13 and a resistor R19; the base of the transistor Q4 is connected to the control terminal GATE of the control IC U1 through the resistor R19; the base of the transistor Q3 is connected to the base of the transistor Q4, the emitter of the transistor Q3 is connected to the emitter of the transistor Q4, and the collector of the transistor Q3 is grounded; the two ends of the resistor R13 are respectively connected to the base of the transistor Q4 and the emitter of the transistor Q4.

[0029] In some embodiments, the input rectifier and filter unit includes a common-mode inductor LF1 and a rectifier bridge BD1; the first output end of the input rectifier and filter unit is formed between the common-mode inductor LF1 and the input end of the rectifier bridge BD1, and the second output end of the input rectifier and filter unit is formed at the output end of the rectifier bridge BD1.

[0030] Preferably, the input rectification and filtering unit further includes a resistor R2, a resistor R2A, a resistor R1, a resistor R1A, a common-mode inductor LF2, a capacitor CX1, and a resistor R9.

[0031] One end of the first group of coils of the common-mode inductor LF1 is connected in series to the live wire of the adapter interface through the fuse F2 and the fuse F1. The other end of the first group of coils of the common-mode inductor LF1 is connected to one end of the first group of coils of the common-mode inductor LF2. The other end of the first group of coils of the common-mode inductor LF2 is connected to the first input end of the rectifier bridge BD1.

[0032] One end of the second group of coils of the common-mode inductor LF1 is connected to the neutral line of the adapter interface through the fuse HT1, the other end of the second group of coils of the common-mode inductor LF1 is connected to one end of the second group of coils of the common-mode inductor LF2, and the other end of the second group of coils of the common-mode inductor LF2 is connected to the second input end of the rectifier bridge BD1.

[0033] One end of the resistor R2 is connected to the other end of the first coil of the common-mode inductor LF1 , the other end of the resistor R2 is connected to one end of the resistor R1 , and the other end of the resistor R1 is connected to the other end of the second coil of the common-mode inductor LF1 .

[0034] One end of the resistor R2A is connected to one end of the first group of coils of the common-mode inductor LF2, the other end of the resistor R2A is connected to the other end of the resistor R2, one end of the resistor R1A is connected to the other end of the resistor R2, and the other end of the resistor R1A is connected to one end of the second group of coils of the common-mode inductor LF2.

[0035] Two ends of the capacitor CX1 are connected to the other end of the first coil of the common-mode inductor LF1 and the other end of the second coil of the common-mode inductor LF1 respectively.

[0036] One end of the resistor R9 is connected to the other end of the resistor R2A, and the other end of the resistor R9 is connected to the collector of the transistor Q4.

[0037] When power is connected through the adapter interface, the input end of the regulating circuit can always obtain voltage input by setting the resistor R2, the resistor R2A, the resistor R1, the resistor R1A and the resistor R9.

[0038] In some embodiments, a secondary output circuit connected to the secondary winding of the transformer T1 is further included to sense the input voltage of the primary winding of the transformer T1 to supply power to a subsequent circuit.

[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be encompassed within the present invention. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A power adapter that uses a low control voltage for boost control, characterized in that: include The input rectifier and filter unit and the input end of the input rectifier and filter unit are used to connect to an external power supply; Transformer T1; The boost circuit includes capacitor C2, resistor R7, diode D21, MOSFET Q1, resistor R11, and resistor RS1; Control IC U1; A voltage regulating circuit includes at least a transistor Q4, the voltage regulating circuit having a control terminal connected to the base of the transistor Q4, an input terminal connected to the collector of the transistor Q4, and a high voltage output terminal connected to the emitter of the transistor Q4; The input end of the voltage regulating circuit is connected to the first output end of the input rectifier and filter unit, the input end of the voltage regulating circuit is connected to the control end GATE of the control IC U1, and the output end of the voltage regulating circuit is connected to the gate of the MOSFET Q1; One end of the primary winding of the transformer T1 is connected to the second output end of the input rectifier filter unit, and the other end of the primary winding of the transformer T1 is connected to the source of the MOSFET Q1; One end of the capacitor C2 is connected to one end of the primary winding of the transformer T1, the other end of the capacitor C2 is connected to the cathode of the diode D21 through the resistor R7, and the anode of the diode D21 is connected to the other end of the primary winding of the transformer T1; The gate of the MOSFET Q1 is grounded through the resistor R11 , and the drain of the MOSFET Q1 is grounded through the resistor RS1 .

2. The power adapter according to claim 1, wherein: The voltage regulating circuit also includes a resistor R12, a resistor R10 and a diode D3; The emitter of transistor Q4 is connected to the cathode of diode D3 through resistor R12. The anode of diode D3 is connected to the gate of MOSFET Q1. The two ends of resistor R10 are connected to the cathode and anode of transistor D3 respectively.

3. The power adapter according to claim 1 or 2, characterized in that: The voltage regulating circuit also includes transistor Q3, resistor R13 and resistor R19; The base of transistor Q4 is connected to the control terminal GATE of control IC U1 through resistor R19; The base of the transistor Q3 is connected to the base of the transistor Q4, the emitter of the transistor Q3 is connected to the emitter of the transistor Q4, and the collector of the transistor Q3 is grounded; Two ends of the resistor R13 are connected to the base of the transistor Q4 and the emitter of the transistor Q4 respectively.

4. The power adapter according to claim 1, wherein: The input rectifier filter unit includes a common-mode inductor LF1 and a rectifier bridge BD1; A first output terminal of the input rectifying and filtering unit is formed between the common mode inductor LF1 and the input terminal of the rectifier bridge BD1 , and a second output terminal of the input rectifying and filtering unit is formed at the output terminal of the rectifier bridge BD1 .

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