KR20220120925A - Power apparatus and control method thereof - Google Patents

Abstract

In accordance with one embodiment of the present invention, a power apparatus includes: an input circuit including a driver integrated circuit (IC) performing switching; a transformer having a primary coil connected with the input circuit and a secondary coil interconnected with the primary coil; an output circuit connected with the secondary coil, and outputting DC power to an output terminal; and a control part controlling an output cutoff of the output circuit. The output circuit includes a sensing circuit connected in parallel with the output terminal, a power cutoff switch circuit connected in series between the output terminal and the secondary coil, and a control circuit outputting a control signal for controlling the opening/closing of the power cutoff switch circuit. The control part includes an input port receiving a signal for overload sensing from the sensing circuit, and an output port outputting a signal for overload protection to open the power cutoff switch when an overload is sensed based on the signal for overload sensing. The output port is connected with the control circuit. Therefore, the present invention can save costs for circuit composition.

Description

Power apparatus and control method thereof

An embodiment of the present specification relates to a power circuit and a control method thereof. More specifically, embodiments of the present specification relate to a control circuit and a control method capable of detecting an overcurrent of an output terminal in a power circuit and blocking the output terminal.

BACKGROUND ART An electric device such as a home appliance includes a modular power supply that supplies power by converting power supplied from the outside to be suitable for the operation of the corresponding electronic device.

Such a power supply is largely divided into a linear power supply and a switching mode power supply (SMPS), and in recent years, the use of the SMPS is increasing for the convenience of production and control.

A general control device uses an external power source as a power source for the operation of an internal circuit directly at the time of power supply start. Accordingly, the control device of the SMPS uses the external voltage supplied at the start of the operation as the operating voltage as it is, and converts the supplied external voltage to a voltage capable of operating the internal circuit by reducing the supplied external voltage inside the chip. Depending on the conversion, the output circuit can provide the desired output value. However, when power is supplied in this way, an overcurrent may occur at the output terminal, and an overcurrent blocking structure for blocking an abnormal current is required.

Prior literature: Republic of Korea Patent Publication No. 1583024

The prior literature discloses an SMPS circuit, and the SMPS circuit provides a DC output based on input power, which includes a first-circuit circuit to which power is input, a first-circuit circuit, and a second-block circuit connected through a transformer, , the second breaker circuit provides a DC output. In order to smoothly provide the DC output, the SMPS control unit of the primary circuit performs switching control. In such a circuit, it is impossible to effectively detect an overcurrent in the output of the secondary circuit, and even if the overcurrent is detected, the switching control is performed. The power supply of the entire SMPS is cut off through the control of the circuit, and accordingly, there is a problem that the power supply of the entire circuit is cut off.

Therefore, there is a need for a circuit structure that effectively detects the overcurrent and effectively blocks the output current when detected.

The embodiment of the present specification is proposed to solve the above-described problem, and by having a control circuit capable of checking the output terminal overcurrent in the power supply circuit and blocking the corresponding output terminal, an SMPS circuit capable of blocking only the output terminal circuit associated with an abnormal operation; and An object of the present invention is to provide a control method therefor.

Another embodiment of the present specification aims to provide a structure of various detection circuits capable of detecting an overcurrent of an output terminal in a power circuit and various blocking circuits capable of blocking an output terminal according to a detection result of the detection circuit.

In order to achieve the above object, a power supply device according to an embodiment of the present specification includes an input circuit including a driver integrated circuit (IC) for performing switching; a transformer connected to the input circuit and a primary side coil and including a secondary side coil interlocked with the primary side coil; an output circuit connected to the secondary side coil and outputting DC power to an output terminal; and a control unit for controlling an output cutoff of the output circuit, wherein the output circuit includes a sensing circuit connected in parallel to the output terminal, a power cutoff switch circuit connected in series between the output terminal and the secondary side coil, and the power and a control circuit outputting a control signal for controlling the opening and closing of the cut-off switch circuit, wherein the control unit detects an overload based on an input port for receiving a signal for overload detection from the detection circuit and a signal for overload detection , an output port for outputting a signal for overload protection for opening the power cut-off switch, wherein the output port is connected to the control circuit.

An input circuit according to another embodiment of the present specification, a transformer including a secondary side coil connected to the input circuit and the primary side coil and interlocked with the primary side coil, connected to the secondary side coil, and supplied with a DC power supply to an output terminal a sensing circuit connected in parallel to the output terminal, a power cut-off switch circuit connected in series between the output terminal and the secondary-side coil, and a control circuit for outputting a control signal for controlling opening and closing of the power cut-off switch circuit A control method of a power supply device including an output circuit comprising: receiving a signal for overload detection from the detection circuit; and generating a control signal for opening the power cut-off switch in response to the signal reception.

According to an embodiment of the present specification, an abnormal operation can be effectively prevented by effectively detecting an overcurrent of the output terminal in the power circuit and blocking the output terminal accordingly. In addition, by blocking only the output terminal through which the overcurrent flows, it is possible to prevent the entire output circuit from being blocked due to the overcurrent of one output terminal even when a plurality of output terminals are connected to one first blocking circuit.

In addition, according to the embodiment of the present specification, an overcurrent can be detected and effectively blocked through a simple circuit structure without the need for a complicated circuit such as a comparator for detecting the overcurrent, thereby reducing the cost for circuit configuration.

1 is a conceptual diagram of an SMPS circuit according to an embodiment of the present specification.
2 is another conceptual diagram of an SMPS circuit according to an embodiment of the present specification.
3 is a circuit diagram of an SMPS circuit according to an embodiment of the present specification.
4 is a diagram illustrating an output circuit of an SMPS circuit according to an embodiment of the present specification.
5 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.
6 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.
7 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.
8 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.
9 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.
10 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.
11 is a flowchart illustrating a method of controlling an SMPS circuit according to an embodiment of the present specification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the art to which the present invention pertains. It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible for the instructions stored in the flowchart block(s) to produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in the blocks to occur out of order. For example, it is possible that two blocks shown in succession are actually performed substantially simultaneously, or that the blocks are sometimes performed in the reverse order according to the corresponding function.

At this time, the term '~ unit' used in this embodiment means software or hardware components such as FPGA or ASIC, and '~ unit' performs certain roles. However, '-part' is not limited to software or hardware. '~unit' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Thus, as an example, '~' denotes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card.

1 is a conceptual diagram of an SMPS circuit according to an embodiment of the present specification.

Referring to FIG. 1, an SMPS circuit according to an embodiment of the specification is shown.

The SMPS circuit of the embodiment may include a switching circuit 110 and a first output circuit 120 and a second output circuit 125 interlocked with a transformer (T). In an embodiment, the winding ratio of the transformer T may be adjusted according to an output value of each output circuit. Also, in an embodiment, the output circuits may include a diode for rectification and an RC circuit connected in parallel. In an embodiment, the switching circuit 110 may include at least one switch, and may include an SMPS driver integrated circuit (IC). The SMPS driver IC may provide input power to the transformer T through switching, receive feedback information from at least one of the output circuits, and generate an output based thereon.

The switching circuit 110 may control the power supplied to the output circuits linked to the transformer T through the switching operation of the switch Q with respect to the input voltage Vi. In an embodiment, the operation of the switch Q may be adjusted according to a feedback operation of at least some of the output circuits, and accordingly, a change in at least one of an output current and an output voltage of at least some of the output circuits is changed in the switching circuit 110 . can be fed back to control the operation of the circuit. Also, in the embodiment, when the current of at least one of the output circuits exceeds the threshold value, a feedback operation for circuit protection may be performed, and the feedback operation according to the current may be performed on the switch Q.

The output voltage of the first output circuit 120 is Vo1 and the output voltage of the second output circuit 125 is Vo2. In an embodiment, the values of Vo1 and Vo2 may be determined according to the transformer winding ratio on the switching circuit side and the winding ratio of each output circuit.

At least one of the first output circuit 120 and the second output circuit 125 may provide feedback information to the switching circuit 110 , and the operation of the switch Q may be controlled according to the feedback information .

Through this operation, two different outputs may be provided based on one switching circuit, and the state of at least one of the output circuits may be fed back to the switching circuit to improve the reliability of the circuit.

2 is another conceptual diagram of an SMPS circuit according to an embodiment of the present specification.

Referring to FIG. 2, an SMPS circuit according to an embodiment of the present specification is shown.

The SMPS driver circuit 210 may be connected to a main power supply and control power delivered to the transformer 220 through switching. In addition, it may be connected to at least one of the output circuits to receive feedback information to control switching.

The transformer 220 may include at least one coil, and the at least one coil may include a primary side coil and at least one secondary side coil interacting with the primary side coil. The primary side coil may be connected to the SMPS driver circuit 210 , and the secondary side coil may be connected to at least one of the first output circuit 230 and the second output circuit 240 . The secondary side coil may include at least one sub-coil, and each of the at least one sub-coil may receive power through interaction with the primary side coil. In an embodiment, the secondary side coil may include a first sub-coil connected to the first output circuit 230 and a second sub-coil connected to the second output circuit 240 . The turns ratio of the sub-coils included in the first sub-coil and the second sub-coil may be adjusted based on the output voltage of each output circuit. By adjusting the turns ratio in this way, a plurality of output circuits connected to one SMPS driver circuit may provide different output voltages.

The first output circuit 230 and the second output circuit 240 may be interlocked with the SMPS driver circuit 210 through the transformer 220, respectively, and may be respectively connected to a load to supply power. Each of the first output circuit 230 and the second output circuit 240 may provide an output within a range set for the load, and when the current flowing through each output circuit increases, the output voltage may relatively decrease. Meanwhile, the first output circuit 230 and the second output circuit 240 may include blocking circuits 232 and 242 and sensing circuits 234 and 244 connected to the output terminals, respectively, and a control unit 270 for controlling them. . The control unit 270 may be a part of a microcomputer connected to the entire SMPS circuit, and may include a process for a separate blocking operation. The detection circuits 234 and 244 may detect an output terminal overload of each of the output circuits 230 and 240 , and may transmit information about this to the control unit 270 . The control unit may block the output terminals of each of the output circuits 230 and 240 by operating the blocking circuits 232 and 242 when the overload is detected. By having such a blocking circuit, by blocking the output terminals of each of the output circuits 230 and 240 in which the overload is detected, only the output circuit in which the overload has occurred and the operation of the other circuits are maintained, thereby plural connected to one SMPS driver circuit 210 Among the output terminals, the output circuit that is not overloaded can operate normally. Meanwhile, in an embodiment, the control unit 270 may provide an output to a blocking circuit corresponding to the circuit in which the overload detection signal is sensed, thereby blocking the output of the corresponding output circuit.

The feedback circuit 250 may transmit information according to the operation of the first output circuit 230 to the SMPS driver circuit 210 . For example, information according to the operation of the first output circuit 230 may be transmitted to the SMPS driver circuit 210 through the feedback circuit 250 . Such a feedback circuit 250 may include a photo coupler to limit the electrical connection between the SMPS driver circuit 210 and each output circuit 230 and effectively transmit information. Power supplied through the transformer 220 may be controlled by transmitting feedback information to the SMPS driver circuit according to the operation of the first output circuit 230 through the photocoupler. Also, when the current output from the first output circuit 230 is equal to or greater than a predetermined value, feedback information may be provided to the SMPS driver circuit 210 through the feedback circuit 250 for circuit protection, and the SMPS driver circuit according to the feedback information. 210 may perform a circuit protection operation.

The interlocking circuit 260 may transmit information according to the operation of the second output circuit 240 to the first output circuit 230 . More specifically, when it is detected that the output current of the second output circuit 240 is equal to or greater than the set current, the sensed information may be transmitted to the first output circuit 230 through the interlocking circuit 260 . As described above, the first output circuit 230 that has received the information through the interlocking circuit 260 may transmit the feedback information to the SMPS driver circuit 210 through the feedback circuit 250 to perform a circuit protection operation.

According to the circuit configuration of this embodiment, even when only a feedback circuit connected to one output circuit is provided, feedback information for initiating a circuit protection operation may be provided to the SMPS driver circuit, and accordingly, abnormal operation in each of the plurality of output circuits Even when this occurs, the operation of the SMPS driver circuit can be controlled through one feedback circuit.

Meanwhile, in an embodiment, at least one of the feedback circuit 250 and the interlocking circuit 260 may be selectively provided.

3 is a circuit diagram of an SMPS circuit according to an embodiment of the present specification.

Referring to FIG. 3 , the rectifier circuit 310 , the SMPS driver circuit 320 , the transformer 330 , the output circuits 340 and 350 , the second output circuits 360 and 370 and the interlocking circuit according to the embodiment of the specification ( 380) is shown.

The rectifier circuit 310 includes a bridge diode BD1 and a capacitor C1, and may rectify AC power input from the outside. The power rectified in the rectifier circuit 310 is applied to the primary coil of the transformer 330, and the transformer 330 may induce a voltage in the secondary coil by the interaction between the primary coil and the secondary coil. . Also, the SMPS driver circuit 320 may control the voltage induced in the secondary coil of the transformer 330 by intermitting power applied to the primary side of the transformer 330 . Meanwhile, in an embodiment, the ground portion of the rectifier circuit 320 and the ground portion of the SMPS driver circuit 320 may be connected to each other. In addition, the power applied to the output circuits 340 and 350 by the transformer 330 is rectified and smoothed through the rectification and smoothing circuit 340 , so that a DC voltage of V1 may be output. In addition, in an embodiment, a plurality of output circuits interlocked with the transformer 330 may be provided.

The PWM IC of the SMPS driver circuit 320 may be an IC in which an amplifier, a comparator, an oscillator, a PWM comparator, and a transistor are integrated into one module, and is connected to one end of the primary side coil of the transformer 330, on/off ( ON/OFF) By intermitting the current flowing through the transformer 330 by switching, the ON/OFF of the voltage induced in the secondary coil can be controlled.

The photocoupler switch of the feedback terminal 322 of the PWM IC 323 may be controlled in conjunction with the photocoupler light emitting diode 354 of the output circuits 340 and 350, and according to the current supplied to the light emitting diode 354 The photocoupler switch 324 may be controlled, and when the light emitting diode 354 is operated, the current of the feedback terminal 322 flows through the photocoupler switch 324, so that the voltage charged in the C3 capacitor 326 is low. can get When the voltage charged in the C3 capacitor 326 exceeds a certain level, a circuit protection operation of the PWM IC may be performed. According to the interlocking of the photocoupler switch 324 and the light emitting diode 354 , the operation of the PWM IC may be controlled according to at least one of the output current and voltage of the output circuits 340 and 350 . More specifically, the feedback terminal 322 of the PWM IC provides an output current, and when the photocoupler switch 324 operates, current flows through the photocoupler switch 324 to limit the voltage applied to the C3 capacitor 326 . A feedback operation for the operation of the output circuit can be performed by controlling the operation of the PWM IC based on the limited voltage, and when the photocoupler switch 324 is opened, the voltage on the C3 capacitor 326 is is applied, and when the reference voltage of the feedback terminal 322 is greater than or equal to the reference voltage, a circuit protection operation may be performed.

The output circuits 340 and 350 may output an output voltage according to a turns ratio between the primary side coil and each secondary side coil of the transformer 330 . The feedback operation may be performed by interworking between the output circuits 340 and 350 and the SMPS driver circuit 320 , and such interlocking is performed by the photocouplers 354 and 324 .

The output control circuit 350 may include a comparison switch element 352 and a photocoupler diode 354 . The switch element 352 may have an open or short-circuit characteristic based on the voltage applied to the resistor R3, and in an embodiment, a short circuit when the voltage applied to the resistor R3 is greater than or equal to the reference voltage, and an open characteristic when less than the voltage applied to the resistor R3 will have Meanwhile, according to the value of V1 set in the embodiment, the resistance ratio of the resistors R2 and R3 may be determined, and the corresponding resistance ratio may be set in consideration of the reference voltage of the switch element 352 .

When the switch element 352 is a short circuit, a feedback operation may be performed according to the interlocking of the photocoupler diode 354 and the photocoupler switch 324 , and when the switch element 352 is open, the photocoupler diode 354 . is not operated, the photocoupler switch 324 is opened, so that a circuit protection operation may be performed in the SMPS driver circuit 320 .

In addition, a sensing circuit 360 , a blocking circuit 370 , and a control unit 380 may be further provided at the output terminals of the output circuits 340 and 350 .

Meanwhile, in an embodiment, the control input for determining the switching of the switching element may be provided as a voltage value, the switching of the switching element may be determined according to the voltage value, and the reference value at which the switching is determined is set differently depending on the switching element can be

In addition, the reference voltage value at which the operation for circuit protection is performed at the feedback terminal of the PWM IC may also be set to a value different from the reference value of the switching element, but may be set to the same value according to the circuit configuration.

In addition, in an embodiment, at least a part of the output control circuit 350 may be omitted, and even in this case, overload control may be performed according to the operations of the sensing circuit 360 , the blocking circuit 370 , and the control unit 380 . . On the other hand, even in this case, a part of the feedback operation can be performed by providing a configuration of a part of the control circuit 350 .

4 is a diagram illustrating an output circuit of an SMPS circuit according to an embodiment of the present specification.

Referring to FIG. 4 , an output circuit of an SMPS circuit according to an embodiment is shown.

In order to describe the output circuit of the SMPS circuit throughout the embodiment, the illustration of the circuit structure of the first stage interlocked with the transformer 402 is omitted.

A plurality of output circuits may be connected to the second blocking circuit interlocked with the transformer 402 , and in the embodiment, one output circuit will be described as a reference, and the sensing circuit 410 and the blocking circuit 420 connected to the smoothing circuit 404 . ) configuration and operation will be described.

The second blocking circuit interlocked with the transformer 402 may provide a rectified and smoothed output through a smoothing circuit. The output terminal 406 is described based on 12V, but is not limited thereto.

The sensing circuit 410 may be connected to the output terminal 406 . The detection circuit 410 may perform overload detection according to the current flowing through the output terminal 406 .

When a large amount of current flows in the output terminal 406 , a relatively low voltage is input to the overload detection signal input, and the overload can be detected by detecting such a drop in voltage.

The switch of the control switch circuit 440 is opened according to the overload detection, and accordingly, the switch of the power switch circuit 450 is opened and the output power may be cut off. The trigger circuit 430 that provides an input for opening the switch of the control switch circuit 440 may operate according to the overload protection signal output of the control unit. Meanwhile, in the embodiment, the auxiliary power source 408 may be connected in relation to the operation of the trigger circuit, and in the embodiment, the auxiliary power source 408 is described as 5V, but is not limited thereto. can

An alternative configuration of circuits included in the sensing circuit 410 and the trigger circuit 430 in the following embodiment will be described.

In this embodiment, the sensing circuit 410 may include two resistors connected in parallel with the output terminal 406, the two resistors are connected in series with each other, and the overload detection signal input port of the control unit is connected between the two resistors. Thus, it is possible to detect an overload of the output terminal 406 .

In addition, according to the overload detection, the output of the overload protection signal of the control unit is changed from low to high, and accordingly, the switch of the trigger circuit 430 may be closed. Accordingly, the switch of the control switch circuit 440 is opened, and accordingly, the switch of the power switch circuit 450 is opened and the output power may be cut off.

By performing the control operation through the circuit configuration as described above, the cost for the circuit configuration can be reduced by performing overload blocking using the sensing circuit 410 and the trigger circuit 430 having a resistor and a transistor switch.

5 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.

Referring to FIG. 5 , an output circuit of an SMPS circuit according to an embodiment is shown.

A plurality of output circuits may be connected to the second blocking circuit interlocked with the transformer 502 , and in the embodiment, one output circuit among the plurality of output circuits will be described as a reference, and the sensing circuit 510 connected to the smoothing circuit 504 . ) and the configuration and operation of the blocking circuit 520 will be described.

The second blocking circuit interlocked with the transformer 502 may provide a rectified and smoothed output through a smoothing circuit. The output terminal 506 is described based on 12V, but is not limited thereto.

A sensing circuit 510 may be connected to the output terminal 506 . The detection circuit 510 may perform overload detection according to the current flowing through the output terminal 506 .

The switch of the control switch circuit 540 is opened according to the overload detection, and accordingly, the switch of the power switch circuit 550 is opened and the output power may be cut off. The trigger circuit 530 that provides an input for opening the switch of the control switch circuit 540 may operate according to an overload protection signal output of the control unit. Meanwhile, in the embodiment, the auxiliary power 508 may be connected in relation to the operation of the trigger circuit, and in the embodiment, the auxiliary power 508 is described as 5V, but is not limited thereto, and the auxiliary power receives power from the primary circuit. can

In this embodiment, the sensing circuit 510 may include two circuits connected in parallel to the output terminal 506, respectively, and the two circuits may include two resistor circuits connected in series and a resistor and a sensing switch. .

The control input of the detection switch 512 is connected between the two resistors connected in series, and when the voltage sensed at the control input falls due to the overload of the output terminal 506, the switch is connected to the ground, so the overload detection signal of the control unit A low input corresponding to ground may be provided to the input port. According to the provision of such an input, the control unit may detect an overload.

As the control unit detects the overload, the overload protection signal output of the control unit is changed from low to high, and accordingly, the switch of the trigger circuit 530 may be closed. Accordingly, the switch of the control switch circuit 540 is opened, and accordingly, the switch of the power switch circuit 550 is opened and the output power may be cut off.

By performing a control operation through such a circuit configuration, overload blocking is performed using the sensing circuit 510 and the trigger circuit 530 having a resistor and a transistor switch, thereby reducing the cost for the circuit configuration. In addition, according to such a configuration, when the detection circuit 510 detects an overload, the change in the input value provided to the overload detection signal input port of the control unit increases, and accordingly, it is possible to easily determine whether the overload occurs.

6 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.

Referring to FIG. 6 , an output circuit of an SMPS circuit according to an embodiment is shown.

A plurality of output circuits may be connected to the second blocking circuit interlocked with the transformer 602 , and in the embodiment, one output circuit among the plurality of output circuits will be described as a reference, and the sensing circuit 610 connected to the smoothing circuit 604 . ) and the configuration and operation of the blocking circuit 620 will be described.

The second blocking circuit interlocked with the transformer 602 may provide a rectified and smoothed output through a smoothing circuit. The output terminal 606 is described based on 12V, but is not limited thereto.

The sensing circuit 610 may be connected to the output terminal 606 . The detection circuit 610 may perform overload detection according to the current flowing through the output terminal 606 .

The switch of the control switch circuit 640 is opened according to the overload detection, and accordingly, the switch of the power switch circuit 650 is opened and the output power may be cut off. The trigger circuit 630 providing an input for opening the switch of the control switch circuit 640 may operate according to an overload protection signal output of the control unit. Meanwhile, in the embodiment, the auxiliary power 608 may be connected in relation to the operation of the trigger circuit, and in the embodiment, the auxiliary power 608 is described as 5V, but is not limited thereto. can

In this embodiment, the sensing circuit 610 may include a resistor and a Zener diode 612 connected in parallel with the output terminal 606 .

An overload detection signal input port of the controller may be connected between the series-connected resistor and the Zener diode 612 . In general, when the voltage of the output terminal 606 is maintained, a value of 0.6 to 1V applied to the Zener diode 612 is input to the overload detection signal input port of the controller. When the voltage of the output terminal 606 falls below the breakdown voltage, the Zener diode 612 is cut off so that an input corresponding to high is provided to the overload detection signal input port of the control unit. In an embodiment, the voltage of the output terminal 610 for overload detection may be set by adjusting the breakdown voltage of the Zener diode 612 and the magnitude of the connected resistor. According to the provision of such an input, the control unit may detect an overload.

As the control unit detects an overload, the overload protection signal output of the control unit is changed from low to high, and accordingly, the switch of the trigger circuit 630 may be closed. Accordingly, the switch of the control switch circuit 640 is opened, and accordingly, the switch of the power switch circuit 650 is opened and the output power may be cut off.

By performing a control operation through such a circuit configuration, overload blocking is performed using the sensing circuit 610 and the trigger circuit 630 having a resistor and a transistor switch, so that the cost for the circuit configuration can be relatively reduced. In addition, by adjusting the resistance of the sensing circuit and the characteristics of the Zener diode 612 according to this configuration, overload can be effectively sensed, and when the control unit detects the overload, it can be less affected by noise.

7 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.

Referring to FIG. 7 , an output circuit of an SMPS circuit according to an embodiment is shown.

A plurality of output circuits may be connected to the second blocking circuit interlocked with the transformer 702 . In the embodiment, one output circuit among the plurality of output circuits will be described as a reference, and the sensing circuit 710 connected to the smoothing circuit 704 . ) and the configuration and operation of the blocking circuit 720 will be described.

The second blocking circuit interlocked with the transformer 702 may provide a rectified and smoothed output through a smoothing circuit. The output terminal 706 is described based on 12V, but is not limited thereto.

The sensing circuit 710 may be connected to the output terminal 706 . The detection circuit 710 may perform overload detection according to the current flowing through the output terminal 706 .

The switch of the control switch circuit 740 is opened according to the overload detection, and accordingly, the switch of the power switch circuit 750 is opened and the output power may be cut off. The trigger circuit 730 that provides an input for opening the switch of the control switch circuit 740 may operate according to the overload protection signal output of the control unit. On the other hand, in the embodiment, the auxiliary power 708 may be connected in relation to the operation of the trigger circuit, and in the embodiment, the auxiliary power 708 is described as 5V, but is not limited thereto. can

In this embodiment, the sensing circuit 710 may include a Zener diode 712 and a resistor circuit connected in parallel to the output terminal 706 , and a resistor and a switching transistor 714 circuit.

A switching transistor 714 may be connected between the series-connected resistor and the Zener diode 712, and in a normal situation, the switching transistor 714 maintains a close state, and the voltage of the output terminal 706 falls due to overload, When the voltage falls below the breakdown voltage of the Zener diode 712 , the switching transistor 714 is opened and an input corresponding to high is provided to the overload detection signal input port of the control unit. In an embodiment, the voltage of the output terminal 710 for overload detection may be set by adjusting the breakdown voltage of the Zener diode 712 and the magnitude of the connected resistor. According to the provision of such an input, the control unit may detect an overload.

As the control unit detects an overload, the overload protection signal output of the control unit is changed from low to high, and accordingly, the switch of the trigger circuit 730 may be closed. Accordingly, the switch of the control switch circuit 740 is opened, and accordingly, the switch of the power switch circuit 750 is opened and the output power may be cut off.

By performing a control operation through such a circuit configuration, overload blocking is performed using the sensing circuit 710 and the trigger circuit 730 having a resistor and a transistor switch, and thus the cost for the circuit configuration can be relatively reduced. In addition, by adjusting the resistance of the sensing circuit and the characteristics of the Zener diode 712 according to this configuration, overload can be effectively detected, and the control unit can perform overload detection stably through a switching operation.

8 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.

Referring to FIG. 8 , an output circuit of an SMPS circuit according to an embodiment is shown.

A plurality of output circuits may be connected to the second blocking circuit interlocked with the transformer 802 . In the embodiment, one output circuit among the plurality of output circuits will be described as a reference, and the sensing circuit 810 connected to the smoothing circuit 804 . ) and the configuration and operation of the blocking circuit 820 will be described.

The second blocking circuit interlocked with the transformer 802 may provide a rectified and smoothed output through a smoothing circuit. The output terminal 806 is described based on 12V, but is not limited thereto.

The sensing circuit 810 may be connected to the output terminal 806 . The detection circuit 810 may perform overload detection according to the current flowing through the output terminal 806 .

The switch of the control switch circuit 840 is opened according to the overload detection, and accordingly, the switch of the power switch circuit 850 is opened and the output power may be cut off. The trigger circuit 830 that provides an input for opening the switch of the control switch circuit 840 may operate according to an overload protection signal output of the control unit. On the other hand, in the embodiment, the auxiliary power 808 may be connected in relation to the operation of the trigger circuit, and in the embodiment, the auxiliary power 808 is described as 5V, but is not limited thereto. can

In this embodiment, the sensing circuit 810 may include a resistor circuit, a switch 812 circuit, and a transistor switch 814 circuit connected in parallel with the output terminal 806, respectively.

When a normal output voltage is maintained at the output terminal 806, the transistor switch 814 can remain open, and when an overload is detected, the switch 812 closes, providing a high input to the transistor switch 814 Accordingly, an input corresponding to low is provided to the overload detection signal input of the control unit.

As the control unit detects an overload, the overload protection signal output of the control unit is changed from low to high, and accordingly, the switch of the trigger circuit 830 may be closed. Accordingly, the switch of the control switch circuit 840 is opened, and accordingly, the switch of the power switch circuit 850 is opened and the output power may be cut off.

By performing the control operation through the circuit configuration as described above, overload blocking is performed using the sensing circuit 810 and the trigger circuit 830 having a resistor and a transistor switch, thereby reducing the cost for the circuit configuration. In addition, according to this configuration, it is possible to effectively reduce the malfunction of the transistor switch 814 due to noise.

9 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.

Referring to FIG. 9 , an output circuit of an SMPS circuit according to an embodiment is shown.

A plurality of output circuits may be connected to the second blocking circuit interlocked with the transformer 902 , and in the embodiment, one output circuit among the plurality of output circuits will be described as a reference, and the sensing circuit 910 connected to the smoothing circuit 904 . ) and the configuration and operation of the blocking circuit 920 will be described.

The second blocking circuit interlocked with the transformer 902 may provide a rectified and smoothed output through a smoothing circuit. The output terminal 906 is described based on 12V, but is not limited thereto.

A sensing circuit 910 may be connected to the output terminal 906 . The detection circuit 910 may perform overload detection according to the current flowing through the output terminal 906 .

The switch of the control switch circuit 940 is opened according to the overload detection, and accordingly, the switch of the power switch circuit 950 is opened and the output power may be cut off. The trigger circuit 930 that provides an input for opening the switch of the control switch circuit 940 may operate according to the overload protection signal output of the control unit. Meanwhile, in the embodiment, the auxiliary power 908 may be connected in relation to the operation of the trigger circuit, and in the embodiment, the auxiliary power 908 is described as 5V, but is not limited thereto. can

In this embodiment, a sensing circuit corresponding to the sensing circuit described with reference to FIG. 4 may be provided, through which the control unit may perform overload detection.

Meanwhile, in this embodiment, the overload protection signal output of the control unit may be set to change from high to low as the control unit detects an overload, and as the overload protection signal output is changed to low, the first switch ( 922 may be opened, and thus the second switch 922 may be closed. Thereafter, the switch of the control switch circuit 940 is opened, and accordingly, the switch of the power switch circuit 950 is opened and the output power may be cut off.

Through such a circuit configuration, it is possible to improve the reliability of the circuit for blocking overload.

10 is a diagram illustrating an output circuit of an SMPS circuit according to another embodiment of the present specification.

Referring to FIG. 10 , an output circuit of an SMPS circuit according to an embodiment is shown.

A plurality of output circuits may be connected to the second blocking circuit interlocked with the transformer 1002 . In the embodiment, one output circuit among the plurality of output circuits will be described as a reference, and the sensing circuit 1010 connected to the smoothing circuit 1004 . ) and the configuration and operation of the blocking circuit 1020 will be described.

The second blocking circuit interlocked with the transformer 1002 may provide a rectified and smoothed output through a smoothing circuit. The output terminal 1006 is described based on 12V, but is not limited thereto.

The sensing circuit 1010 may be connected to the output terminal 1006 . The detection circuit 1010 may perform overload detection according to the current flowing through the output terminal 1006 .

The switch of the control switch circuit 1040 is opened according to the overload detection, and accordingly, the switch of the power switch circuit 1050 is opened and the output power may be cut off. The trigger circuit 1030 that provides an input for opening the switch of the control switch circuit 1040 may operate according to an overload protection signal output of the control unit. Meanwhile, in the embodiment, one or more auxiliary power sources 1008 may be connected in relation to the operation of the trigger circuit and the sensing circuit, and in the embodiment, the auxiliary power source 1008 is described as 5V, but is not limited thereto, and the auxiliary power is a first-block circuit You can get power supply from

In this embodiment, the sensing circuit 1010 may include a resistor circuit in parallel with the output terminal 1006, and the comparator 1012 is connected between the two resistors of the resistor circuit so that the output voltage falls below the reference voltage. A high input is provided to the overload detection signal input of the control unit, and accordingly, the control unit detects the overload.

is changed to high, and accordingly, the switch of the trigger circuit 1030 may be closed. Accordingly, the switch of the control switch circuit 1040 is opened, and accordingly, the switch of the power switch circuit 1050 is opened and the output power may be cut off.

By performing a control operation through such a circuit configuration, overload can be detected more precisely, and a voltage value for overload detection can be effectively adjusted by setting comparator-related circuit elements.

11 is a flowchart illustrating a method of controlling an SMPS circuit according to an embodiment of the present specification.

Referring to FIG. 11 , a control method of an SMPS circuit is illustrated.

In step 1105, the SMPS circuit may operate. As described in the embodiment, in the SMPS circuit, the first breaking circuit and at least one second breaking circuit may be interlocked through a transformer, and at least a part of the second breaking circuit is a detection circuit for performing overload detection and an output stage blocking according to the occurrence of overload A blocking circuit is provided to perform the

In step 1110, the controller may determine whether an abnormal signal is detected by the detection circuit. The abnormal signal in the detection circuit may be an output value preset in the detection signal according to the occurrence of overload, which may be provided to a specific input port of the control unit to detect whether overload occurs. If not detected, the SMPS circuit operation may be performed while continuously performing overload detection.

When an overload is detected, the controller may provide a signal output for circuit protection in step 1115 . A signal for circuit protection may be output as a preset value among a high value or a low value in relation to the operation of the blocking circuit, and a specific voltage or current value may be output according to the circuit configuration.

In step 1120, the blocking circuit operates according to the output of the circuit protection signal, and the output of the second blocking circuit in which the overload is detected may be blocked.

Meanwhile, the potential values corresponding to the high and low values may be different values, and may vary according to circuit settings. Therefore, the reference values corresponding to each of high and low may be set differently depending on the embodiment, which may be interpreted as having relatively high and low values according to the elements of the circuit and the operation of the circuit.

In this way, it is possible to perform effective control by monitoring the overload of each of the plurality of second-blocking outputs and blocking the output terminal of the second-blocking circuit in which the overload is detected.

On the other hand, in the present specification and drawings, preferred embodiments of the present invention have been disclosed, and although specific terms are used, these are only used in a general sense to easily explain the technical contents of the present invention and help the understanding of the present invention, It is not intended to limit the scope of the invention. It will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented in addition to the embodiments disclosed herein.

110: switching circuit
120: first output circuit
130: second output circuit

Claims (10)

A power supply device comprising:
an input circuit including a driver integrated circuit (IC) that performs switching;
a transformer connected to the input circuit and a primary side coil and including a secondary side coil interlocked with the primary side coil;
an output circuit connected to the secondary side coil and outputting DC power to an output terminal; and
A control unit for controlling the output cutoff of the output circuit,
The output circuit is
A sensing circuit connected in parallel to the output terminal, a power cut-off switch circuit connected in series between the output terminal and the secondary coil, and a control circuit for outputting a control signal for controlling opening and closing of the power cut-off switch circuit,
the control unit
An input port for receiving a signal for overload detection from the detection circuit and an output port for outputting a signal for overload protection for opening the power cut-off switch when an overload is detected based on the signal for overload detection ,
The output port is a power supply connected to the control circuit. According to claim 1,
The control circuit is
a trigger circuit having one side connected to a DC power source and a first transistor connected to the output port and a base; and
and a control switch circuit connected to the DC power source and the base and including a second transistor having one side connected to the power cutoff switch circuit. According to claim 1,
The sensing circuit includes a first resistor and a second resistor connected in series with the first resistor,
The input port is connected between the first resistor and the second resistor,
the control unit
Power supply device, characterized in that outputting the signal for the overload protection when the potential of the input port is less than a reference value. According to claim 1,
The sensing circuit is
a first sub sensing circuit including a third resistor and a fourth resistor connected in series with the third resistor;
a second sub-sensing circuit connected in parallel with the first sub-sensing circuit and including a fifth resistor and a sensing switch having one end connected in series with the fifth resistor and the other end connected to the ground;
A control input of the sensing switch is connected between the third resistor and the fourth resistor,
The sensing switch is closed when the potential of the control input is less than or equal to the first reference value,
The input port is connected between the fifth resistor and the sensing switch,
the control unit
When the potential of the input port is less than or equal to a second reference value, the power supply device, characterized in that for outputting the signal for the overload protection. According to claim 1,
The sensing circuit includes a sixth resistor and a Zener diode connected to a reverse voltage in series with the sixth resistor,
The input port is connected between the sixth resistor and the Zener diode,
the control unit
Power supply device, characterized in that outputting the signal for the overload protection when the potential of the input port is less than a reference value. According to claim 1,
The sensing circuit is
a third sub sensing circuit including a Zener diode connected to apply a reverse voltage and a seventh resistor connected in series with the Zener diode;
a third resistor connected in parallel with the third sub sensing circuit, one end connected in series with an eighth resistor and the eighth resistor, the other end connected to the ground, and a base connected between the Zener diode and the seventh resistor A fourth sub-sensing circuit including a transistor;
The input port is connected between the eighth resistor and the third transistor,
the control unit
When the potential of the input port is greater than or equal to a third reference value, the power supply device, characterized in that outputting a signal for the overload protection. According to claim 1,
The sensing circuit is
a fifth sub sensing circuit including a ninth resistor connected to the output terminal;
a sixth sub sensing circuit connected in parallel with the fifth sub sensing circuit, the sixth sub sensing circuit including a sensing switch and a tenth resistor connected in series with the sensing switch; and
A seventh sub sensing circuit including a fourth transistor connected in parallel with a sixth sub sensing circuit, connected in series with an eleventh resistor and the eleventh resistor, and having a base connected between the sensing switch and the tenth resistor including;
The ninth resistor and the control input of the sensing switch are connected,
The input port is connected between the eleventh resistor and the fourth transistor,
the control unit
When the potential of the input port is less than or equal to a fourth reference value, the power supply device, characterized in that outputting the signal for the overload protection. According to claim 1,
The control circuit is
A trigger circuit including a fifth transistor having one end connected to a first DC power supply, a fifth transistor connected to the output port and a base, and a sixth transistor connected to a second DC power source and one end connected to the first DC power source and a base ; and
and a control switch circuit including a seventh transistor connected to the second DC power source and a base, and one end connected to the power cutoff switch circuit. According to claim 1,
The sensing circuit includes a first resistor, a second resistor connected in series with the first resistor, and a comparator with one input connected between the first resistor and the second resistor and an output connected with the input port,
the control unit
Power supply device, characterized in that outputting the signal for the overload protection when the potential of the input port is greater than or equal to a reference value. an input circuit, a transformer to which the input circuit and the primary side coil are connected, and a transformer including a secondary side coil interlocked with the primary side coil, is connected to the secondary side coil, outputs a DC power to an output terminal, and is parallel to the output terminal A power source comprising an output circuit having a sensing circuit connected to A method for controlling a device, comprising:
receiving a signal for overload detection from the detection circuit; and
and generating a control signal for opening the power cut-off switch in response to the signal reception.

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