CN219513968U - Power supply circuit and power supply adapter - Google Patents
Power supply circuit and power supply adapter Download PDFInfo
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- CN219513968U CN219513968U CN202320047591.2U CN202320047591U CN219513968U CN 219513968 U CN219513968 U CN 219513968U CN 202320047591 U CN202320047591 U CN 202320047591U CN 219513968 U CN219513968 U CN 219513968U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
- Y02B70/10—Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
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Abstract
The embodiment of the utility model relates to a power circuit and a power adapter. The power supply circuit comprises a transformer, a switch control module, a first power supply output end, a second power supply output end and a synchronous rectification module; the synchronous rectification module comprises a rectification unit and a rectification control unit, the rectification control unit comprises a voltage detection end and a first control end, the voltage detection end is connected with the second power output end, and the first control end is connected with the first controlled end of the rectification unit; the voltage detection end of the rectification control unit receives the output voltage signal, and outputs a rectification driving signal to the first controlled end of the rectification unit through the first control end to drive the rectification unit to be conducted so as to realize synchronous rectification. The output end of the power supply circuit adopts the synchronous rectification module with lower power consumption to carry out output rectification, thereby effectively reducing the power loss on the rectification element, being beneficial to reducing the overall power consumption of the switching power supply and improving the power supply conversion efficiency.
Description
Technical Field
The present utility model relates to the field of power circuits, and in particular, to a power circuit and a power adapter.
Background
The Power adapter (Power adapter) is a Power supply conversion device for small portable electronic equipment and electronic appliances, and is generally composed of components such as a shell, a transformer, an inductor, a capacitor, a control chip, a circuit board and the like, can convert alternating current input into direct current output to provide direct current Power for a rear-end load, and can be widely applied to various electronic equipment.
In a general power adapter, a rectifying diode is generally adopted at a power output end to realize output rectification. Under the condition of partial low-voltage and high-current output, if a rectifier diode is adopted for output rectification of the switching power supply, the power loss is very large due to higher conduction voltage drop of the rectifier diode, so that the overall power consumption of the switching power supply is not reduced, and the power conversion efficiency is lower.
Disclosure of Invention
Based on the above, the utility model provides a power supply circuit and a power supply adapter. The output end of the power supply circuit adopts the synchronous rectification module with lower power consumption to carry out output rectification, thereby effectively preventing excessive power consumption on the rectification element, being beneficial to reducing the overall power consumption of the switching power supply and improving the power supply conversion efficiency.
According to a first aspect of the present utility model, there is provided a power supply circuit comprising a transformer, a switch control module, a first power supply output, a second power supply output and a synchronous rectification module;
a first end of a primary coil of the transformer is connected to an external power supply, and a second end of the primary coil of the transformer is connected to a power supply reference ground through the switch control module to form a switch energizing loop;
the first power output end and the second power output end are respectively connected to two ends of a secondary coil of the transformer and are used for being connected with a rear-end power utilization load, and the first end of the secondary coil of the transformer, the first power output end, the rear-end power utilization load, the second power output end and the second end of the secondary coil of the transformer are mutually connected to form an output power supply loop;
the synchronous rectification module comprises a rectification unit and a rectification control unit, wherein the rectification unit comprises a first signal end, a second signal end and a first controlled end, the first signal end is connected with the second power output end, and the second signal end is connected with the second end of the secondary coil of the transformer; the rectification control unit comprises a voltage detection end and a first control end, the voltage detection end is connected with the second power supply output end, and the first control end is connected with a first controlled end of the rectification unit; the voltage detection end of the rectification control unit receives the output voltage signal, generates a rectification driving signal, and outputs the rectification driving signal to the first controlled end of the rectification unit through the first control end to drive the rectification unit to synchronously rectify.
Optionally, the rectifying unit is an N-channel MOS transistor, the first signal end of the rectifying unit is a source electrode of the N-channel MOS transistor, the second signal end of the rectifying unit is a drain electrode of the N-channel MOS transistor, and the first controlled end of the rectifying unit is a gate electrode of the N-channel MOS transistor.
Optionally, the transformer further comprises an auxiliary coil, and the switch control module comprises a switch unit and a power management unit;
the switch unit comprises a third signal end, a fourth signal end and a second controlled end, wherein the third signal end is connected with the second end of the primary coil of the transformer, and the fourth signal end is connected with a power supply reference ground;
the power management unit comprises a zero-crossing detection end and a second control end, the zero-crossing detection end is connected with the first end of the auxiliary coil of the transformer, the zero-crossing detection end of the power management unit receives a zero-crossing voltage signal, a switch driving signal is generated and is output to the second controlled end of the switch unit through the second control end to drive the switch unit to be conducted, and the third signal end and the fourth signal end are connected to form a switch energizing loop.
Optionally, the power supply circuit further comprises a current limiting module and an overcurrent detection unit; the current limiting module is connected between a fourth signal end of the switch unit and a power supply reference ground, and an overcurrent detection node is formed at the joint of the current limiting module and the fourth signal end;
the power management unit further comprises an overcurrent detection end, the overcurrent detection end is connected to the overcurrent detection node through the overcurrent detection unit, the overcurrent detection end of the power management unit receives an overcurrent signal, and a current-limiting signal is generated and output to a second controlled end of the switch unit through a second control end to drive the switch unit to be turned on or turned off.
Optionally, the power management unit further includes a feedback signal detection end, and the power circuit further includes an output feedback module, where the output feedback module includes a first current limiting resistor, a second current limiting resistor, and an optocoupler; the first end of the light emitting component of the optical coupler is connected to the first power supply output end, the second end of the light emitting component is grounded, the first end of the light receiving component of the optical coupler is connected to the feedback signal detection end, and the second end of the light receiving component is grounded.
Optionally, the output feedback module further comprises a controllable precise voltage stabilizing source, a first voltage stabilizing resistor and a second voltage stabilizing resistor;
the cathode of the controllable precise voltage stabilizing source is connected to the second end of the light emitting component of the optocoupler, the anode of the controllable precise voltage stabilizing source is grounded, and the reference electrode of the controllable precise voltage stabilizing source is connected to the first power output end through the first voltage stabilizing resistor and is grounded through the second voltage stabilizing resistor.
Optionally, the power circuit further comprises a full-wave rectifying module, and two ends of the primary coil of the transformer are connected to an external power supply through the full-wave rectifying module.
Optionally, the power supply circuit further comprises an anti-surge protection module, wherein the anti-surge protection module comprises a first fuse, a piezoresistor and a thermistor;
the first input end of the full-wave rectifying module is connected to the live wire input end of the external power supply through the first fuse, the second input end of the full-wave rectifying module is connected to the zero line input end of the external power supply through the thermistor, and the piezoresistor is connected between the live wire input end and the zero line input end of the external power supply in parallel.
Optionally, the anti-surge protection module further includes a second fuse, a first end of the second fuse is connected with a live wire input end of the external power supply, and a second end of the second fuse is connected with the first fuse and the piezoresistor.
According to a second aspect of the present utility model, there is provided a power adapter comprising a power circuit according to any one of the embodiments described above.
By applying the technical scheme in the embodiment of the utility model, the special synchronous rectification module is arranged in the power supply circuit to synchronously rectify the output power supply of the power supply circuit, and the synchronous rectification module consumes lower power, so that the problem of high power consumption caused by adopting the rectification diode as the output rectification in the general power supply adapter can be solved, the overall power consumption of the switching power supply can be reduced, and the power supply conversion efficiency can be improved.
For a better understanding and implementation, the technical solution of the present utility model is described in detail below with reference to the accompanying drawings.
Drawings
FIG. 1 is a schematic block diagram of a power supply circuit according to an embodiment of the present utility model;
FIG. 2 is a schematic circuit diagram of a synchronous rectification module according to an embodiment of the present utility model;
FIG. 3 is a schematic connection diagram of a switch control module according to an embodiment of the present utility model;
FIG. 4 is a schematic connection diagram of an output feedback module according to an embodiment of the present utility model;
fig. 5 is a schematic connection diagram of a full-wave rectifying module and an anti-surge protection module according to an embodiment of the present utility model.
Reference numerals in the drawings: 11. a full wave rectification module; 12. a transformer; 13. a switch control module; 131. a switching unit; 132. a power management unit; 141. a rectifying unit; 142. and a rectification control unit.
Detailed Description
The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting thereof. It should be further noted that, for convenience of description, only some, but not all of the matters related to the present utility model are shown in the accompanying drawings.
It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.
Several specific examples are given below to describe the technical solution of the present utility model in detail. The following embodiments may be combined with each other, and some embodiments may not be repeated for the same or similar concepts or processes.
The embodiment of the utility model provides a power circuit and a power adapter. The output end of the power supply circuit adopts the synchronous rectification module with lower self-power consumption to carry out output rectification, thereby effectively preventing excessive power consumption on the rectification element, being beneficial to reducing the overall power consumption of the switching power supply and improving the power supply conversion efficiency.
The power supply circuit and the power supply adapter in the embodiment of the utility model are described below with reference to the drawings.
Referring to fig. 1 and 2, fig. 1 is a schematic block diagram of a power supply circuit according to an embodiment of the utility model; fig. 2 is a schematic circuit diagram of a synchronous rectification module according to an embodiment of the present utility model.
As shown in fig. 1, the power supply circuit includes a full-wave rectification module 11, a transformer 12, a switch control module 13, a first power supply output terminal v+, a second power supply output terminal V-, and synchronous rectification modules (141 and 142). The first end of the primary coil of the transformer 12 is connected to an external power source through a full-wave rectification module 11 to obtain an ac power source of 100V-240V. The signal end of the switch control module 13 is connected to the first end of the primary coil of the transformer 12 (the 4 th pin of the transformer T1), the ground end of the switch control module 13 is connected to the power supply reference PGND, that is, the second end of the primary coil of the transformer 12 is connected to the power supply reference PGND through the switch control module, and when the transformer 12 works, the input current flows through the first end and the second end of the primary coil and flows to the power supply reference ground through the switch control module to form a switch energizing circuit.
The first power output terminal v+ and the second power output terminal V-are respectively connected to two ends of the secondary winding of the transformer 12 (the 6 th and 7 th pins of the transformer T1) and are used for connecting a back-end power consumption load, the first end of the secondary winding of the transformer 12 (the 6 th pin of the transformer T1), the first power output terminal v+, the back-end power consumption load (not shown), the second power output terminal V-, and the second end of the secondary winding of the transformer 12 (the 7 th pin of the transformer T1) are connected to each other to form an output power supply loop.
The switch control module 13 is used for power conversion management, the full-wave rectifying module 11 is used for converting an ac power supply into a dc power supply, the transformer 12 is used for reducing the voltage of the full-wave rectified dc power supply so as to output a low-voltage dc power supply with the voltage matched with the voltage to the electric load at the rear end, for example, a low-voltage dc power supply with the output voltage of 12V and the current of 3A.
The synchronous rectification module is connected to the output power supply circuit and used for synchronously rectifying the low-voltage direct-current power supply at the output end. The synchronous rectification module comprises a rectification unit 141 and a rectification control unit 142, wherein the rectification unit 141 comprises a first signal end, a second signal end and a first controlled end, the first signal end is connected with the second power output end V-, and the second signal end is connected with a second end (a 7 th pin of a transformer T1) of the secondary coil of the transformer 12; the rectifying control unit 142 includes a voltage detection end RT and a first control end GATE, the voltage detection end RT is connected to the second power output end V-, and the first control end GATE is connected to the first controlled end of the rectifying unit 141; the voltage detection terminal RT of the rectification control unit 142 receives the output voltage signal, which indicates that the power circuit starts to operate, and at this time, a rectification driving signal may be generated and output to the first controlled terminal of the rectification unit 141 through the first control terminal GATE, so as to drive the rectification unit 141 to conduct and realize synchronous rectification for the output low-voltage dc power supply.
Compared with the prior art that the rectifier diode with larger power consumption is adopted to realize output rectification, the synchronous rectifier module in the embodiment has lower power consumption, and effectively prevents the excessive power consumed by the rectifier element during working, so that the problem of large power consumption caused by adopting the rectifier diode as output rectification in a general power adapter can be solved, the overall power consumption of the switching power supply can be reduced, and the power conversion efficiency can be improved.
In an alternative embodiment, as shown in fig. 2, the rectifying unit 141 may be an N-channel MOS transistor Q2, the first signal end of the rectifying unit 141 is a source S of the N-channel MOS transistor Q2, the second signal end of the rectifying unit 141 is a drain D of the N-channel MOS transistor Q2, and the first controlled end of the rectifying unit 141 is a gate G of the N-channel MOS transistor Q2. The rectification control unit 142 may be a rectification control chip U2, and the specific model thereof is not limited.
When the N-channel field effect transistor Q2 is triggered by high level and the grid G of the N-channel field effect transistor Q2 receives a high level rectification driving 5 signal, voltage drop exists between the drain electrode D and the source electrode S of the N-channel field effect transistor and the N-channel field effect transistor is conducted, so that a power supply loop is formed and is an input
The low-voltage direct current power supply performs synchronous rectification, and has very low power consumption, so that the overall power consumption of the power supply circuit is reduced.
In this embodiment, the rectifying unit 141 uses a power N-channel MOS transistor with an extremely low on-state resistance to replace a rectifying diode to reduce rectifying loss, greatly improve the efficiency of the DC/DC converter, and has no dead voltage caused by schottky barrier voltage. The N-channel MOS tube belongs to a voltage control type device, the volt-ampere characteristic is in a linear relation when the N-channel MOS tube is conducted, and when the N-channel MOS tube is used as a rectifier, the grid voltage and the phase of the rectified voltage are kept synchronous to realize the synchronous rectification function.
In other embodiments, the rectifying unit 141 may be a P-channel MOS transistor, where the P-channel MOS transistor and the rectifying control chip U2 are connected to each other and matched to form a synchronous rectifying module, and perform synchronous rectification on the low-voltage dc output by the power circuit, and the connection mode of the P-channel MOS transistor may be adaptively improved.
Referring to fig. 3, fig. 3 is a schematic circuit diagram of a switch control module according to an embodiment of the utility model.
The switch control module 13 includes a switch unit 131 and a power management unit 132. In a switching power supply circuit, power
The loss of the switching tube can also have a great influence on the conversion efficiency of the power supply circuit. In order to further improve the conversion efficiency of the power supply circuit, in this embodiment, the switch control module 13 is designed to implement zero-crossing detection, that is, when the switch unit 131 of the switch control module 13 oscillates to the valley, the switch unit 131 is turned on, so that the loss of the switch unit 131 itself can be reduced, thereby reducing the overall power consumption of the power supply circuit and improving the power supply conversion efficiency.
The transformer 12 further comprises an auxiliary winding, which is a secondary winding of the transformer 12, which, when the transformer 12 is in operation,
a voltage will be present at the first end of the auxiliary winding (pin 5 of the transformer). When the waveform of the power supply circuit is switched to the valley, the transformer 12 is not operated and no voltage is present at the first end of the auxiliary winding (pin 5 of the transformer).
The switch unit 131 includes a third signal terminal, a fourth signal terminal, and a second controlled terminal, where the third signal terminal is connected with the second controlled terminal
The second terminal of the primary winding of the transformer 12 (the 4 th pin of the transformer) is connected, and the fourth signal terminal is connected to the power supply reference ground 5 PGND. The power management unit 132 includes a zero-crossing detection terminal FB and a second control terminal OUT
The terminal FB is connected to a first terminal of the auxiliary winding of said transformer 12 (pin 5 of the transformer). The power input from the input terminal of the full-wave rectifying module is an ac power, and the full-wave rectifying module 11 is in a state of switching between the peaks and the troughs when rectifying the ac power. When the waveform oscillates to the valley, the zero-crossing detection terminal FB of the power management unit 132 receives the zero-crossing voltage signal
At this time, a switch driving signal may be generated to be outputted to a second 0 controlled terminal of the switching unit 131 through the second control terminal OUT to drive the switching unit 131 to be turned on, so that a third signal terminal and a fourth signal terminal are connected to form a switch-on loop,
thereby realizing the valley conduction, the power consumption of the switch unit 131 at this time is the lowest, which is helpful to improve the conversion efficiency of the power supply circuit.
Optionally, the switch unit 131 may be an N-channel MOS transistor Q1, the third signal end of the switch unit 131 is a drain D of the N-channel MOS transistor Q1, the fourth signal end of the switch unit 131 is a source S of the N-channel MOS transistor Q1, and the second controlled end of the switch unit 131 is a gate G of the N-channel MOS transistor Q1. In other embodiments, the switching unit 131 may also employ other power switching devices.
When the grid electrode G of the N-channel field effect tube Q1 receives a high-level switch driving signal, voltage drop exists between the drain electrode D and the source electrode S of the N-channel field effect tube Q1 and the N-channel field effect tube Q1 is conducted, so that a switch energizing loop is formed. Because the N-channel field effect transistor Q1 is conducted when the waveform of the power supply oscillates to the valley, the power consumption of the N-channel field effect transistor Q1 is very small, so that the overall power consumption of the power supply circuit is reduced, and the conversion efficiency of the power supply circuit is improved.
Optionally, the gate G of the N-channel MOS transistor Q1 is further connected to the second control terminal OUT of the power management unit 132 through a current limiting resistor R13, a current limiting resistor R14, and a diode D3. The diode D3 plays an isolating protection role for the power management unit 132.
In an alternative embodiment, to implement over-current protection for the power circuit, the power circuit further includes a current limiting module and an over-current detection unit; the current limiting module is connected between the fourth signal end of the switch unit 131 and the power reference ground PGND, and the junction between the current limiting module and the fourth signal end forms an overcurrent detection node.
The current limiting module may be formed by combining a current limiting resistor R17A, a current limiting resistor R17B, a current limiting resistor R17C and a current limiting resistor R17D, so as to prevent the current in the switch energizing circuit from being too large. The over-current detection unit may be a sampling resistor R16.
In this embodiment, the resistance values of each current limiting resistor and each sampling resistor are not limited to specific values.
The power management unit 132 further includes an overcurrent detection end CS, where the overcurrent detection end CS is connected to the overcurrent detection node through the overcurrent detection unit R16, and the overcurrent detection end CS of the power management unit 132 receives an overcurrent signal, generates a current-limiting signal, and outputs the current-limiting signal to the second controlled end of the switch unit 131 through the second control end OUT to drive the switch unit 131 to be turned on or off, so as to implement overcurrent protection.
In an alternative embodiment, to better implement the regulation of the output voltage, the power management unit 132 further includes a feedback signal detection terminal COMP.
Referring to fig. 4, fig. 4 is a schematic connection diagram of an output feedback module according to an embodiment of the utility model.
The power supply circuit further comprises an output feedback module, wherein the output feedback module comprises a first current limiting resistor R25, a second current limiting resistor R26 and optocouplers (PC 1A and PC 1B); the first end of the light emitting component PC1A of the optocoupler is connected to the first power output end V+, the second end of the light emitting component PC1A is grounded, and the first end of the light receiving component PC1B of the optocoupler is connected to the feedback signal detection end COMP, and the second end of the light receiving component PC1B is grounded.
When the first power output end v+ outputs a low-voltage direct current power supply, the light emitting component PC1A of the optocoupler is turned on, and the light receiving component PC1B of the optocoupler receives the light and is adaptively turned on along with the light intensity, so that the feedback signal detection end COMP can collect a certain voltage signal. The power management unit 132 controls the second control terminal thereof to correspondingly output a switch driving signal to drive the switch unit Q1 to be turned on or off according to the voltage signal of the feedback signal detection terminal COMP, thereby realizing voltage stabilizing output.
Optionally, the output feedback module further includes a controllable precision voltage stabilizing source U3, a first voltage stabilizing resistor R27 and a second voltage stabilizing resistor R30; the cathode K of the controllable precise voltage stabilizing source U3 is connected to the second end of the light emitting component PC1A of the optocoupler, the anode A of the controllable precise voltage stabilizing source U3 is grounded, the reference electrode R of the controllable precise voltage stabilizing source U is connected to the first power output end V+ through the first voltage stabilizing resistor R27, and the reference electrode R of the controllable precise voltage stabilizing source U is grounded through the second voltage stabilizing resistor R30. Under the coordination adjustment of the first voltage stabilizing resistor R27 and the second voltage stabilizing resistor R30, the controllable precise voltage stabilizing source U3 can output a corresponding voltage stabilizing reference signal, so that the adjustment of the on voltage of the light emitting component PC1A of the optocoupler is realized, and the adjustment of the voltage of the output end of the power circuit is realized through the power management unit 132.
Referring to fig. 5, fig. 5 is a schematic connection diagram of a full-wave rectifying module and an anti-surge protection module according to an embodiment of the utility model.
On the basis of the above embodiment, the full-wave rectification module 11 may include the first filter inductance LF1, the rectification bridge BD1, and the filter capacitance EC1. The rectifier bridge BD1 has two rectifier inputs and two rectifier outputs, wherein the two rectifier inputs are connected to an external ac power source through the first filter inductor LF1, the two rectifier outputs are connected to two ends of the primary coil of the transformer 12 (1 st pin and 4 th pin of the transformer), and a filter capacitor is further connected in parallel between the two rectifier outputs.
On the basis of the embodiment, in order to realize the safety protection of the power circuit, the power circuit further comprises an anti-surge protection module. The anti-surge protection module comprises a first fuse F2, a piezoresistor MOV1 and a thermistor NTC1; the first input end of the full-wave rectifying module 11 is connected to the live wire input end of the external power supply through the first fuse F2, the second input end of the full-wave rectifying module 11 is connected to the zero line input end of the external power supply through the thermistor NTC1, and the piezoresistor MOV1 is connected in parallel between the live wire input end and the zero line input end of the external power supply. If the power adapter itself fails, the first fuse F2 may be disconnected, thereby ensuring the safety of the power adapter. Optionally, the specification of the first fuse F2 may be 3.15A/250V, and if the current flowing through the first fuse F2 exceeds 3.15A, the first fuse F2 will be automatically disconnected, so as to realize heavy current surge protection for the power circuit.
The varistor MOV1 is a voltage limiting type protection device. By utilizing the nonlinear characteristic of the piezoresistor MOV1, overvoltage appears between two poles of the piezoresistor MOV1, the piezoresistor MOV1 can clamp the voltage to a relatively fixed voltage value, so that the protection of a subsequent circuit is realized.
Optionally, in order to realize lightning-proof surge protection of the power circuit, the surge-proof protection module further includes a second fuse F1. The first end of the second fuse F1 is connected with the live wire input end of an external power supply, and the second end of the second fuse F1 is connected with the first fuse F2 and the piezoresistor MOV 1. When the power supply circuit encounters a lightning stroke in thunderstorm weather, the second fuse F1 can be disconnected, so that the lightning stroke-resistant surge protection can be realized. Alternatively, the specification of the second fuse F1 may be 6.3A/250V, and if the current flowing through the second fuse F1 exceeds 6.3A, the second fuse F1 will be automatically opened, so as to realize lightning protection.
In addition, the power circuit is also provided with a plurality of filtering elements and an EMI suppression element, so that the power circuit has a low-voltage direct-current power supply output with better quality.
By applying the technical scheme in the embodiment of the utility model, the special synchronous rectification module is arranged in the power supply circuit to synchronously rectify the output power supply of the power supply circuit, the self-consumption power of the synchronous rectification module is lower, the problem of high power consumption caused by adopting the rectification diode as the output rectification in the general power supply adapter can be solved, the overall power consumption of the switching power supply can be reduced, and the power conversion efficiency can be improved. Meanwhile, lightning surge protection and power supply safety protection are realized through the design of double insurance.
According to a second aspect of the present embodiment, there is provided a power adapter comprising a power circuit as described in any one of the embodiments above.
By applying the technical scheme in the embodiment of the utility model, the special synchronous rectification module is arranged in the power adapter to synchronously rectify the output power of the power circuit, the synchronous rectification module consumes lower power, the problem of high power consumption caused by adopting the rectification diode as the output rectification in the general power adapter can be solved, the overall power consumption of the switching power supply can be reduced, and the power conversion efficiency can be improved.
The foregoing examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model.
Claims (10)
1. The power supply circuit is characterized by comprising a transformer, a switch control module, a first power supply output end, a second power supply output end and a synchronous rectification module;
a first end of a primary coil of the transformer is connected to an external power supply, and a second end of the primary coil of the transformer is connected to a power supply reference ground through the switch control module to form a switch energizing loop;
the first power output end and the second power output end are respectively connected to two ends of a secondary coil of the transformer and are used for being connected with a rear-end power utilization load, and the first end of the secondary coil of the transformer, the first power output end, the rear-end power utilization load, the second power output end and the second end of the secondary coil of the transformer are mutually connected to form an output power supply loop;
the synchronous rectification module comprises a rectification unit and a rectification control unit, wherein the rectification unit comprises a first signal end, a second signal end and a first controlled end, the first signal end is connected with the second power output end, and the second signal end is connected with the second end of the secondary coil of the transformer; the rectification control unit comprises a voltage detection end and a first control end, the voltage detection end is connected with the second power supply output end, and the first control end is connected with a first controlled end of the rectification unit; the voltage detection end of the rectification control unit receives the output voltage signal, generates a rectification driving signal, outputs the rectification driving signal to the first controlled end of the rectification unit through the first control end, drives the rectification unit to conduct and synchronously rectifies.
2. The power supply circuit of claim 1, wherein the rectifying unit is an N-channel MOS transistor, the first signal terminal of the rectifying unit is a source of the N-channel MOS transistor, the second signal terminal of the rectifying unit is a drain of the N-channel MOS transistor, and the first controlled terminal of the rectifying unit is a gate of the N-channel MOS transistor.
3. The power supply circuit of claim 1, wherein the transformer further comprises an auxiliary coil, and the switch control module comprises a switch unit and a power management unit;
the switch unit comprises a third signal end, a fourth signal end and a second controlled end, wherein the third signal end is connected with the second end of the primary coil of the transformer, and the fourth signal end is connected with a power supply reference ground;
the power management unit comprises a zero-crossing detection end and a second control end, the zero-crossing detection end is connected with the first end of the auxiliary coil of the transformer, the zero-crossing detection end of the power management unit receives a zero-crossing voltage signal, a switch driving signal is generated and is output to the second controlled end of the switch unit through the second control end to drive the switch unit to be conducted, and the third signal end and the fourth signal end are connected to form a switch energizing loop.
4. The power supply circuit of claim 3, further comprising a current limiting module and an over-current detection unit; the current limiting module is connected between a fourth signal end of the switch unit and a power supply reference ground, and an overcurrent detection node is formed at the joint of the current limiting module and the fourth signal end;
the power management unit further comprises an overcurrent detection end, the overcurrent detection end is connected to the overcurrent detection node through the overcurrent detection unit, the overcurrent detection end of the power management unit receives an overcurrent signal, and a current-limiting signal is generated and output to a second controlled end of the switch unit through a second control end to drive the switch unit to be turned on or turned off.
5. The power supply circuit of claim 3, wherein the power management unit further comprises a feedback signal detection terminal, the power supply circuit further comprising an output feedback module comprising a first current limiting resistor, a second current limiting resistor, and an optocoupler; the first end of the light emitting component of the optical coupler is connected to the first power supply output end, the second end of the light emitting component is grounded, the first end of the light receiving component of the optical coupler is connected to the feedback signal detection end, and the second end of the light receiving component is grounded.
6. The power circuit of claim 5, wherein the output feedback module further comprises a controllable precision voltage regulator source, a first voltage regulator resistor, and a second voltage regulator resistor;
the cathode of the controllable precise voltage stabilizing source is connected to the second end of the light emitting component of the optocoupler, the anode of the controllable precise voltage stabilizing source is grounded, and the reference electrode of the controllable precise voltage stabilizing source is connected to the first power output end through the first voltage stabilizing resistor and is grounded through the second voltage stabilizing resistor.
7. The power supply circuit according to any one of claims 1 to 6, further comprising a full-wave rectification module through which both ends of the primary coil of the transformer are connected to an external power supply.
8. The power circuit of claim 7, further comprising an anti-surge protection module comprising a first fuse, a varistor, and a thermistor;
the first input end of the full-wave rectifying module is connected to the live wire input end of the external power supply through the first fuse, the second input end of the full-wave rectifying module is connected to the zero line input end of the external power supply through the thermistor, and the piezoresistor is connected between the live wire input end and the zero line input end of the external power supply in parallel.
9. The power circuit of claim 8, wherein the anti-surge protection module further comprises a second fuse having a first end connected to a live input of an external power source and a second end connected to the first fuse and the varistor.
10. A power supply adapter comprising a power supply circuit as claimed in any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320047591.2U CN219513968U (en) | 2023-01-06 | 2023-01-06 | Power supply circuit and power supply adapter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320047591.2U CN219513968U (en) | 2023-01-06 | 2023-01-06 | Power supply circuit and power supply adapter |
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| Publication Number | Publication Date |
|---|---|
| CN219513968U true CN219513968U (en) | 2023-08-11 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320047591.2U Active CN219513968U (en) | 2023-01-06 | 2023-01-06 | Power supply circuit and power supply adapter |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219513968U (en) |
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2023
- 2023-01-06 CN CN202320047591.2U patent/CN219513968U/en active Active
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