CN112671243B - Flyback switching power supply and control method and device thereof - Google Patents
Flyback switching power supply and control method and device thereof Download PDFInfo
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Abstract
The application discloses a flyback switching power supply and a control method and device thereof. Wherein, flyback switching power supply includes: the primary loop, the main loop unit and the first non-main loop unit are formed by connecting a primary coil, a switching tube and a power supply in series, wherein the first non-main loop unit comprises: a loop formed by the secondary coil, the output diode, the first relay and the load which are sequentially connected in series; the capacitor and the optocoupler are connected in parallel with the load; and the processor is used for collecting a conduction signal of the optocoupler secondary side triode, and controlling the first relay to be turned off when the conduction signal indicates that the optocoupler secondary side triode is conducted, wherein the optocoupler secondary side triode is conducted when the output diode is in short circuit. The application solves the technical problem that the polarity components and the back-end load on the non-main stable circuit of the flyback switching power supply are possibly damaged because the output diode is difficult to detect when short circuit fault occurs.
Description
Technical Field
The application relates to the technical field of switching power supplies, in particular to a flyback switching power supply, and a control method and a control device thereof.
Background
The flyback switching power supply has the advantages of simple structure, small volume and small number of devices, and is a switching power supply with wider application at present. The transformer of the flyback switching power supply can be provided with multiple paths of isolated voltage outputs, one path of voltage output with the largest load is generally taken as a main path voltage stabilizing loop, and other outputs with lighter loads (namely, non-main voltage stabilizing loops) can be taken as a power supply for isolating communication or a power supply for isolating a driving circuit or other power supplies needing isolation. In fig. 1, in a flyback switching power supply in the prior art, as shown in fig. 1, in three output paths of a transformer T, an output corresponding to a load 11 is a main circuit voltage stabilizing circuit, circuits corresponding to a load 12 and a load 13 are non-main circuit voltage stabilizing circuits, and since secondary side output diodes D1 and D2 of the transformer have no separate short circuit detection circuit, when one output diode D1 or D2 of the non-main circuit voltage stabilizing circuits has a short circuit fault, polar components such as an electrolytic capacitor and a back end load on the corresponding non-main circuit voltage stabilizing circuit may be damaged, and the whole switching power supply may not work normally. For example, D1 and D2 may be used as rectifying diodes to bear a high reverse voltage, if the type is not properly selected, or other special conditions may cause damage to D1 or D2 to cause short circuit, and if diode D1 or D2 is shorted, the corresponding electrolytic capacitor C1 or C2, load 13, and load 12 may be damaged.
Aiming at the technical problems that the polarity components and the back-end load on a non-main stabilizing circuit of a flyback switching power supply in the prior art are possibly damaged because the output diode is difficult to detect when short-circuit faults occur, no effective solution is proposed at present.
Disclosure of Invention
The embodiment of the application provides a flyback switching power supply, a control method, a control device, a storage medium and a processor thereof, which are used for at least solving the technical problem that the polarity components and the rear-end load on a non-main stable loop of the flyback switching power supply are possibly damaged because the output diode of the loop is difficult to detect when short circuit faults occur.
According to an aspect of an embodiment of the present application, there is provided a flyback switching power supply including: the primary loop, the main loop unit and the first non-main loop unit are formed by connecting a primary coil, a switching tube and a power supply in series, wherein the first non-main loop unit comprises: a loop formed by the secondary coil, the output diode, the first relay and the load which are sequentially connected in series; the capacitor and the optocoupler are connected in parallel with the load; and the processor is used for collecting a conduction signal of the optocoupler secondary side triode, and controlling the first relay to be turned off when the conduction signal indicates that the optocoupler secondary side triode is conducted, wherein the optocoupler secondary side triode is conducted when the output diode is in short circuit.
Further, the collector electrode of the optocoupler secondary side triode is connected to a preset power supply, the emitter electrode of the optocoupler secondary side triode is grounded, and the processor samples from the collector electrode of the optocoupler secondary side triode to obtain a conduction signal.
Further, the flyback switching power supply further includes: the load of the first non-main stable loop is connected to the second non-main stable loop unit through the second relay; the processor is further used for controlling the second relay to be conducted after the first relay is controlled to be turned off when the optocoupler secondary side triode is conducted, so that the load is connected to the second non-main stable loop unit.
Further, an isolated power chip is arranged between the first non-main loop and the second non-main loop.
Further, the processor is further used for controlling the display screen to display prompt information when the optocoupler secondary side triode is conducted, wherein the prompt information is used for indicating the output diode to be short-circuited.
According to another aspect of the embodiment of the present application, there is also provided a control method of a flyback switching power supply, including: the primary loop, the main steady loop unit and the first non-main steady loop unit, wherein, the first non-main steady loop unit includes: the control method of the flyback switching power supply comprises the following steps of: collecting a conduction signal of an optocoupler secondary side triode, wherein the conduction signal is used for indicating whether the optocoupler secondary side triode is conducted or not; when the optocoupler secondary side triode is conducted, the first relay is controlled to be turned off, and when the output diode is short-circuited, the optocoupler secondary side triode is conducted.
Further, the flyback switching power supply further includes: the load of the first non-main loop stabilizing unit is connected to the second non-main loop stabilizing unit through a second relay, and when the optocoupler secondary side triode is conducted, the method further comprises the following steps: and controlling the second relay to be conducted so as to enable the load to be connected into the second non-main loop stabilizing unit.
According to another aspect of the embodiment of the present application, there is also provided a control device for a flyback switching power supply, including: the primary loop, the main steady loop unit and the first non-main steady loop unit, wherein, the first non-main steady loop unit includes: the control device of the flyback switching power supply comprises a loop formed by a secondary coil, an output diode, a first relay and a load which are sequentially connected in series, and a capacitor and an optocoupler which are connected with the load in parallel, wherein the control device comprises: the collecting module is used for collecting a conduction signal of the optocoupler secondary side triode, wherein the conduction signal is used for indicating whether the optocoupler secondary side triode is conducted or not; and the control module is used for controlling the first relay to be turned off when the optocoupler secondary side triode is turned on, wherein the optocoupler secondary side triode is turned on when the output diode is short-circuited.
According to another aspect of the embodiment of the present application, there is further provided a storage medium including a stored program, where the device where the storage medium is controlled to execute the control method of the flyback switching power supply when the program runs.
According to another aspect of the embodiment of the present application, a processor is further provided for running a program, where the control method of the flyback switching power supply is executed when the program runs.
In the embodiment of the application, the relay and the optocoupler are added in the non-main stable loop of the flyback switching power supply, whether the output diode in the non-main stable loop is short-circuited is detected through the on-off state of the light-emitting diode of the optocoupler, and a conducting signal is sent to the processor when the output diode of the non-main stable loop is short-circuited, and the processor correspondingly controls the relay to be disconnected so as to cut off the secondary side output of the power supply with faults, so that the technical problem that the output diode of the non-main stable loop of the flyback switching power supply is difficult to detect in the prior art is solved, and the rear load is protected and the damage of the rear load is avoided by cutting off the output path of one power supply with faults.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute a limitation on the application. In the drawings:
FIG. 1 is a schematic diagram of a flyback switching power supply topology according to the prior art;
FIG. 2 is a schematic diagram of a flyback switching power supply according to an embodiment of the present application;
FIG. 3 is a schematic diagram of an alternative flyback switching power supply according to an embodiment of the present application;
FIG. 4 is a flow chart of an alternative control method of a flyback switching power supply according to an embodiment of the present application;
FIG. 5 is a flow chart of a control method of a flyback switching power supply according to an embodiment of the present application;
fig. 6 is a schematic diagram of a control device of a flyback switching power supply according to an embodiment of the application.
Detailed Description
In order that those skilled in the art will better understand the present application, a technical solution in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present application without making any inventive effort, shall fall within the scope of the present application.
It should be noted that the terms "first," "second," and the like in the description and the claims of the present application and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.
Example 1
According to an embodiment of the present application, there is provided an embodiment of a flyback switching power supply, as shown in fig. 2, including: the primary loop, the main loop unit 22 and the first non-main loop unit, which are formed by connecting the primary coil L1, the switching tube Q and the power supply DC in series, wherein the first non-main loop unit comprises: secondary coil L connected in series in turn Auxiliary pair A loop formed by the output diode D, the first relay K and the load 21; capacitance deviceC and the optical coupler U are connected in parallel with the load 21; the processor 23 collects the conduction signal of the secondary side triode of the optocoupler U, and when the conduction signal indicates the conduction of the secondary side triode of the optocoupler, the first relay K is controlled to be turned off, wherein when the output diode D is short-circuited, the secondary side triode of the optocoupler is turned on.
The power supply DC may be a direct current source, or a direct current input formed by a rectifier bridge and a filter capacitor of alternating current output from an alternating current power supply. The switching tube Q can be a field effect tube MOSFET or a thyristor IGBT, and is switched on or off under the control of a control signal, so that the secondary side of the transformer T generates voltage output, and optionally, the control signal of the switching tube Q is provided by a control chip of a switching power supply, and the control signal is a pulse signal with set frequency, so that the switching tube Q is controlled to be switched on or off.
The processor may be a control chip, such as an MCU (Micro Controller Unit, micro control unit), or an integrated analog control chip.
As shown in fig. 2, the cathode of the light emitting diode in the optocoupler U is connected to the cathode of the output diode D, and in a state where the circuit is normally operated (i.e., the output diode D on the secondary side of the transformer T is not shorted), the first relay K is in a closed state. Under the action of a control signal, a primary side switch tube Q of the transformer is conducted, a primary side coil inductor L1 of the transformer is excited, an electromotive force with positive upper and negative lower is induced by a primary winding of the transformer, and a secondary side coil L of the corresponding flyback transformer Auxiliary pair The coupling induces an electromotive force of positive negative up and positive down, so that the output diode D is not turned on, the light emitting diode in the optocoupler U is also not turned on, and the load 21 supplies current from the electric energy stored in the capacitor C. When the primary side switching tube Q of the transformer is controlled to be turned off, energy accumulated by the primary side inductance L1 of the transformer is transferred to the secondary side, at the moment, the primary side of the transformer generates electromotive force with positive upper and negative lower, the secondary side of the transformer generates electromotive force with positive upper and negative lower according to the characteristics of a flyback power supply, the diode D is conducted, and the secondary side winding of the transformer and the capacitor C supply power to the load 21 at the same time.
When the output diode D in the first non-main loop unit is short-circuited, the primary side switch tube Q of the transformer is conducted under the action of the control signal, and the primary side inductance of the transformerL1 excitation, the primary winding of the transformer induces electromotive force with positive upper and negative lower, and the corresponding flyback transformer secondary coil L Auxiliary pair Induces an electromotive force of positive upper, negative and positive lower, and the LED of the optocoupler U is turned on due to the short circuit of the output diode D (the LED of the optocoupler U, the first relay K, the output diode D and the secondary coil L of the transformer in FIG. 2) Auxiliary pair Forms a loop), correspondingly, the secondary triode of the optical coupler U is conducted and sends a conduction signal to the processor 23, and the processor 23 controls the first relay K to be disconnected after receiving the conduction signal, so that the light emitting diode, the first relay K, the output diode D and the secondary coil L of the transformer of the optical coupler U Auxiliary pair The formed loop is disconnected, and correspondingly, the first non-main loop stabilizing unit is disconnected.
The application adds the relay and the optocoupler in the non-main stable loop of the flyback switching power supply, detects whether the output diode in the non-main stable loop is short-circuited or not through the on-off state of the light emitting diode of the optocoupler, and sends a conducting signal to the processor when the output diode of the non-main stable loop is short-circuited, and the processor correspondingly controls the relay to be disconnected so as to cut off the secondary side output of the power supply with faults, thereby solving the technical problem that the output diode of the non-main stable loop of the flyback switching power supply is difficult to detect when the output diode of the non-main stable loop of the flyback switching power supply has short-circuited faults in the prior art, and protecting the back-end load and avoiding the damage of the back-end load by cutting off the output path of one-path power supply with faults.
As an alternative embodiment, the collector of the optocoupler secondary side triode is connected to a preset power supply, the emitter of the optocoupler secondary side triode is grounded, and the processor samples from the collector of the optocoupler secondary side triode to obtain a conduction signal.
The voltage value of the preset power supply can be 5V or 12V, and can be selected according to the model of the processor, and the preset power supply can be powered by an external power supply independent of the flyback switching power supply in the embodiment.
Taking the non-main loop 1 in fig. 3 as an example, the collector electrode of the secondary side triode of the optocoupler U1 is connected to a preset power supply VCC, the emitter electrode of the secondary side triode of the optocoupler is grounded GND, and the processor MCU samples from the collector electrode of the secondary side triode of the optocoupler U1 to obtain a conducting signal. The signal 1 input port of the processor MCU is connected to the collector electrode of the secondary triode of the optical coupler U1, when the non-main stable circuit 1 works normally, the collector electrode and the emitter electrode of the secondary triode of the optical coupler U1 are not conducted, the sampling voltage of the signal 1 input port is close to the voltage value of a preset power supply VCC, and the signal 1 input port of the processor MCU is equivalent to a high-level signal. When the output diode D1 in the loop is short-circuited, the collector and the emitter of the secondary triode of the optical coupler U1 are conducted, so that the sampling voltage of the input port of the signal 1 is close to the power ground GND, and the input port of the signal 1 corresponding to the processor MCU is a low-level signal, namely a conducting signal acquired by the MCU.
As an alternative embodiment, the flyback switching power supply further includes: the load of the first non-main stable loop is connected to the second non-main stable loop unit through the second relay; the processor is further used for controlling the second relay to be conducted after the first relay is controlled to be turned off when the optocoupler secondary side triode is conducted, so that the load is connected to the second non-main stable loop unit.
Taking the flyback switching power supply shown in fig. 3 as an example, unless the main stabilizing circuit 1 also comprises an non-main stabilizing circuit 2, a load 31 of the non-main stabilizing circuit 1 can be connected into the non-main stabilizing circuit 2 through a relay K4. The two ends of the relay K4 are connected with the output positive electrode of the non-main stable circuit 1 and the output positive electrode of the non-main stable circuit 2, and correspondingly, the output negative electrode of the non-main stable circuit 1 is connected with the output negative electrode of the non-main stable circuit 2. When the output diode D1 of the non-main stable loop 1 is short-circuited, the signal 1 input end of the MCU obtains a low-level conduction signal, and correspondingly, the MCU controls the signal 3 output end and the signal 6 thereof to output corresponding control signals according to the obtained conduction signal, so that the relay K1 is opened and the relay K4 is closed and conducted, so that the load 31 is switched from the non-main stable loop 1 to the non-main stable loop 2, and at the moment, the load 31 and the load 32 are simultaneously used as the loads of the non-main stable loop 2.
In an alternative embodiment, the relays K1 and K4 are normally open relays, as shown in fig. 3, contacts of the relay K4 are respectively connected to an emitter of the transistor Q4 and to the power ground GND through the resistor R4, a collector of the transistor Q4 is connected to the preset power VCC, and a base of the transistor Q4 is connected to the signal 6 output end of the MCU. The contact of the relay K1 is respectively connected with the emitter of the transistor Q1 and the power ground GND through the resistor R1, the collector of the transistor Q1 is connected with the preset power VCC, and the base of the transistor Q1 is connected with the signal 3 output end of the MCU. When the output diode D1 of the non-main stable loop 1 is short-circuited, the signal 1 input end of the MCU acquires a low-level conduction signal, correspondingly, the MCU controls the signal 3 output end of the MCU to output a low-level signal and the control signal 6 output end to output a high-level signal according to the acquired conduction signal, the base electrode of the transistor Q1 receives the low level output by the signal 3 output end, so that the collector electrode and the emitter electrode of the transistor Q1 are not conducted, and the relay K1 is disconnected; the base of the transistor Q4 receives a high level output by the output end of the signal 6, so that the collector and the emitter of the transistor Q4 are conducted, and the relay K4 is conducted under the voltage difference between VCC and GND, so that the load 31 is connected in parallel to the non-main loop 2.
It should be noted that, the relay may be selected to be in a normally open (i.e. closed and turned on after power-on, and opened when power-off) state or a normally closed (i.e. opened after power-on, and closed after power-off) state according to actual use, and the high/low level of the control signal triggering its operation is selected to match the type thereof. For example, in the above embodiment, K1 may be a normally closed relay, and when D1 is shorted, the signal 3 of the MCU is output to a high level, so that K1 is energized and turned off.
In the implementation, the processor can acquire the conducting signal fed back by the optocoupler, correspondingly disconnect the load from the fault loop and connect the load into the output loop in other normal states, so that the load of the loop is prevented from being damaged due to the short circuit of the output diode of the fault loop, the safety coefficient of the circuit is improved, the load of the loop can still work normally through loop switching, the normal operation of the circuit is ensured, and the reliability of the circuit is improved.
As an alternative embodiment, an isolated power supply chip is arranged between the first non-main loop and the second non-main loop unit.
It should be noted that, the isolated power chip is divided into an anode and a cathode, the cathode of the isolated power chip is connected to the first non-main loop stabilizing unit (i.e. the fault loop), and the anode of the isolated power chip can be connected to the second non-main loop stabilizing unit (i.e. the loop working normally). Through setting up isolation power chip for be in the isolation state between first non-main steady return circuit and the second non-main steady return circuit, reduce the interference between the return circuit, prevent to take place to cross talk, improve circuit reliability.
As an alternative embodiment, the processor is further configured to control the display screen to display a prompt message when the photo-coupler secondary transistor is turned on, where the prompt message is used to indicate that the output diode is shorted.
The processor can be connected with a display screen, such as a nixie tube, a liquid crystal display and the like, when the processor receives the conduction signals sent by the optocoupler, the processor triggers corresponding prompt information, and the source of the conduction signals is judged according to different input ports of the processor.
For example, as shown in fig. 3, when the output diode D1 of the non-main loop 1 is shorted, the secondary transistor of the corresponding optocoupler U1 is turned on and outputs a low-level on signal to the signal 1 input end of the processor MCU, and the MCU controls the nixie tube or the liquid crystal display to prompt a fault according to the received on signal, and may display "D1 shorted" on the display screen. Correspondingly, when the output diode D2 of the non-main loop 2 is short-circuited, the secondary-side tertiary tube of the optocoupler U2 is conducted and transmits a conducting signal to the input end of the signal 2 of the processor, and the processor correspondingly displays 'D2 short-circuited' on a display screen.
In the embodiment, whether the secondary side output diode of the flyback switching power supply is short-circuited or not can be detected, and the fault position can be accurately displayed when the secondary side output diode is short-circuited, so that the follow-up maintenance is facilitated.
Fig. 3 is a circuit diagram of an alternative flyback switching power supply according to an embodiment of the present application, and as shown in fig. 3, a flyback switching power supply 300 includes: the primary loop is formed by connecting a primary coil L1, a switching tube Q5 and a power supply DC in series; the switching power supply chip controls the on-off of the switching tube Q5 and receives the voltage feedback signal outputted from the main stability. The secondary coil L4 of the transformer outputs a diode D3, the main stabilizing load forms a main stabilizing loop, the capacitor C3 is connected in parallel before the main stabilizing load, and the capacitor C3 is used for stabilizing and stabilizing the voltage output by the main loop. A non-primary loop 1 and a non-primary loop 2, wherein the non-primary loop 1 comprises: a loop formed by a secondary coil L2, an output diode D1, a relay K1 and a load 31 which are sequentially connected in series, wherein a capacitor C1 and an optocoupler U1 are connected in parallel with the load 31; the non-main loop 2 includes: the secondary coil L3, the output diode D2, the relay K2 and the load 32 form a loop, and the capacitor C2 and the optocoupler U2 are connected in parallel with the load 32. The non-main stable loop 1 and the non-main stable loop 2 are connected by a relay K3, a relay K4 and an isolated power supply chip.
The processor MCU has 2 signal inputs: the input end of the signal 1 is connected with the collector electrode of the secondary triode of the optical coupler U1, the input end of the signal 2 is connected with the collector electrode of the secondary triode of the optical coupler U2 and is respectively used for acquiring the conduction signal of the secondary triode of the optical coupler U1 and the conduction signal of the secondary triode of the optical coupler U2 so as to detect whether the output diode D1 of the non-main stable circuit 1 and the output diode D2 of the non-main stable circuit 2 are in short circuit or not. The processor MCU has 4 signal output terminals: the output end of the signal 3 is connected with the relay K1 and is used for controlling the turn-off of the first relay K1, so that when the output diode D1 is short-circuited, the load 31 is disconnected from the non-main stable loop 1; the output end of the signal 4 is connected with the relay K2 and is used for controlling the turn-off of the relay K2, so that when the output diode D2 of the non-main stable loop 2 is short-circuited, the load 32 is disconnected from the non-main stable loop 2; the output end of the signal 5 is connected with the relay K3 and used for controlling the closing of the relay K3, so that when the output diode D2 of the non-main stable loop 2 is short-circuited, the load 32 is switched to the non-main stable loop 1; the output end of the signal 6 is connected with the relay K4 and used for controlling the closing of the relay K4, so that when the output diode D1 of the non-main stable loop 1 is short-circuited, the load 31 is switched to the non-main stable loop 2.
In addition, the flyback switching power supply of fig. 3 further includes three transistors Q1, Q2, Q3, Q4, which are respectively connected with the relays K1, K2, K3, K4, and bases of the Q1, Q2, Q3, Q4 are respectively connected with the signals 3, 4, 5 and 6 of the processor MCU, so as to control on/off of the corresponding relays according to the high/low level of the corresponding processor signals. For example, the contacts of the relay K1 are respectively connected with the emitter of the transistor Q1 and the power ground GND through the resistor R1, the collector of the transistor Q1 is connected with the preset power VCC, and if the relay K1 is a normally open relay, when the input of the base of the transistor Q1 is low, the reverse bias between the collector and the emitter of the transistor Q1 is cut off, and the preset power VCC is not switched on by the relay K1, and is in an off state. The connection modes of the corresponding K2, K3 and K4 are the same, and are not repeated here.
The following describes the working flow of the flyback switching power supply in the embodiment of fig. 3 when the circuit works normally, taking the normally open relays as K1-K4. The current is electrified for the first time, the main chip MCU is reset, the signal 3 and the signal 4 sent by the MCU are both in high level, the signal 5 and the signal 6 are in low level, and the received signal 1 and the signal 2 are both in high level. The primary side switching tube Q5 of the transformer is turned on, the primary side inductance L1 of the transformer is excited, the primary winding induces electromotive force which is positive from top to bottom, the corresponding secondary side coils L2, L3 and L4 of the flyback transformer induce electromotive force which is negative from top to bottom due to coupling, at the moment, the diodes D1, D2 and D3 are not conducted, the light emitting diodes in the photocouplers U1 and U2 are also not conducted, and each load is supplied with current by electricity stored in the capacitor. When the primary side switching tube Q5 is turned off, energy accumulated by the primary side inductance L1 of the transformer is transferred to the secondary side, the primary side generates electromotive force with the upper negative and the lower positive, the secondary side generates electromotive force with the upper positive and the lower negative, the diodes D1, D2 and D3 are in a conducting state, and the load is simultaneously supplied by the secondary side winding and the capacitor of the transformer.
Fig. 4 is a flowchart of the operation of the flyback switching power supply of fig. 3 in the event of a circuit abnormality, as shown in fig. 4:
in step S401, the main chip MCU is powered on for reset, and the MCU sends out two continuous high level signals 3 and 4, sends out two continuous low level signals 5 and 6, and receives two continuous high level signals 1 and 2. When the secondary side output diode D1 of the non-primary loop 1 is shorted, the step S405 is entered; when the secondary side output diode D2 of the non-main loop 2 is short-circuited, the process proceeds to step S402.
In step S405, the primary chip receives the signal 1 from high to low, and determines that the secondary output diode D1 is shorted.
In step S406, the main chip sends a continuous low level signal 3 (changing signal 3 from high to low), relay K1 is opened, and sends a continuous high level signal 6 (changing signal 6 from low to high), relay K4 is closed, and load 31 of non-main loop 1 is incorporated into non-main loop 2.
In step S407, the main chip sends out a fault signal to cause the nixie tube or the lcd to display D1 short circuit.
In step S402, the primary chip receives the signal 2 from high to low, and determines that the secondary output diode D2 is shorted.
In step S403, the master chip sends a continuous low level signal 4 (changing signal 4 from high to low), relay K2 is opened, and sends a continuous high level signal 5 (changing signal 5 from low to high), relay K3 is closed, and the load 32 of the non-master loop 2 is incorporated into the non-master loop 1.
In step S407, the main chip sends out a fault signal to cause the nixie tube or the lcd to display D2 short circuit.
Through the steps, when the flyback switching power supply circuit detects the short-circuit signal of the diode D1 or the diode D2, the load of the short-circuit loop can be disconnected in time, damage caused by the fact that the load at the rear end bears reverse voltage is avoided, the safety coefficient of the circuit is improved, meanwhile, the disconnected load is connected into other normal output loops, normal operation of the load is guaranteed, and the reliability of the circuit is improved. In addition, the position and the reason of the fault can be displayed through the display screen, so that the accurate positioning of the fault in the process of multiplexing output is realized, and the maintenance time and the cost are saved.
Example 2
According to an embodiment of the present application, there is provided a control method embodiment of a flyback switching power supply, it should be noted that the steps shown in the flowchart of the drawings may be performed in a computer system such as a set of computer executable instructions, and that although a logic sequence is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown or described herein.
Fig. 5 is a control method of a flyback switching power supply according to an embodiment of the present application, as shown in fig. 5, the flyback switching power supply includes: the primary loop, the main steady loop unit and the first non-main steady loop unit, wherein, the first non-main steady loop unit includes: the method comprises the following steps of:
step S501, collecting a conduction signal of an optocoupler secondary side triode, wherein the conduction signal is used for indicating whether the optocoupler secondary side triode is conducted or not;
and step S502, when the optocoupler secondary side triode is conducted, the first relay is controlled to be turned off, wherein when the output diode is short-circuited, the optocoupler secondary side triode is conducted.
The above steps will be described using the flyback switching power supply configuration of fig. 2 as an example. As shown in fig. 2, the cathode of the light emitting diode in the optocoupler U is connected to the cathode of the output diode D, and in a state where the circuit is normally operated (i.e., the output diode D on the secondary side of the transformer T is not shorted), the first relay K is in a closed state. Under the action of a control signal, a primary side switch tube Q of the transformer is conducted, a primary side coil inductor L1 of the transformer is excited, an electromotive force with positive upper and negative lower is induced by a primary winding of the transformer, and a secondary side coil L of the corresponding flyback transformer Auxiliary pair The coupling induces an electromotive force of positive negative up and positive down, so that the output diode D is not turned on, the light emitting diode in the optocoupler U is also not turned on, and the load 21 supplies current from the electric energy stored in the capacitor C. When the primary side switching tube Q of the transformer is controlled to be turned off, energy accumulated by the primary side inductance L1 of the transformer is transferred to the secondary side, at the moment, the primary side of the transformer generates electromotive force with positive upper and negative lower, the secondary side of the transformer generates electromotive force with positive upper and negative lower according to the characteristics of a flyback power supply, the diode D is conducted, and the secondary side winding of the transformer and the capacitor C supply power to the load 21 at the same time.
When the output diode D in the first non-main loop unit is short-circuited, under the action of a control signal, the primary side switching tube Q of the transformer is conducted, the primary side inductance L1 of the transformer is excited, the primary winding of the transformer induces electromotive force with positive upper and negative lower, and the secondary side coil L of the corresponding flyback transformer Auxiliary pair Induces an electromotive force of positive upper, negative and positive lower, and the LED of the optocoupler U is turned on due to the short circuit of the output diode D (the LED of the optocoupler U, the first relay K, the output diode D and the secondary coil L of the transformer in FIG. 2) Auxiliary pair Forms a loop), and correspondingly, the secondary side of the optical coupler U has three polesThe tube is conducted and sends a conducting signal to the processor 23, and the processor 23 controls the first relay K to be disconnected after receiving the conducting signal, so that the light emitting diode, the first relay K, the output diode D and the secondary coil L of the transformer of the optocoupler U Auxiliary pair The formed loop is disconnected, and correspondingly, the first non-main loop stabilizing unit is disconnected.
Through the steps, the relay and the optocoupler are added in the non-main stable loop of the flyback switching power supply, whether the output diode in the non-main stable loop is short-circuited is detected through the on-off state of the secondary side tertiary tube (consistent with the on-off state of the light emitting diode) of the optocoupler, and a conducting signal is sent to the processor when the output diode of the non-main stable loop is short-circuited, the processor correspondingly controls the relay to be disconnected so as to cut off the secondary side output of the power supply with faults, the technical problem that the output diode of the non-main stable loop of the flyback switching power supply is difficult to detect when the output diode of the non-main stable loop of the flyback switching power supply has short-circuit faults in the prior art is solved, and the back load is protected by cutting off the output path of one power supply with faults, so that the back load is prevented from being damaged.
As an alternative embodiment, the flyback switching power supply further includes: the load of the first non-main loop stabilizing unit is connected to the second non-main loop stabilizing unit through a second relay, and when the optocoupler secondary side triode is conducted, the method further comprises the following steps: and controlling the second relay to be conducted so as to enable the load to be connected into the second non-main loop stabilizing unit.
The flyback switching power supply comprises a first non-main stable loop unit and a second non-main stable loop unit, wherein two ends of the first relay are connected with an output positive electrode of the first non-main stable loop unit and an output positive electrode of the second non-main stable loop unit, and correspondingly, an output negative electrode of the first non-main stable loop unit is connected with an output negative electrode of the second non-main stable loop unit. When the output diode of the first non-main stable loop unit is short-circuited, the processor acquires a conduction signal of the secondary side transistor of the optocoupler, and correspondingly, the processor controls the first relay to be opened and the second relay to be closed and turned on according to the acquired conduction signal, so that the load of the first non-main stable loop unit is switched from the first non-main stable loop unit to the second non-main stable loop unit, and at the moment, the second non-main stable loop unit supplies power to the load of the first non-main stable loop unit.
Through the steps, the processor can acquire the conducting signals fed back by the optocoupler, correspondingly disconnect the load from the fault loop and connect the load into the output loop in other normal states, so that the load of the loop is prevented from being damaged due to the short circuit of the output diode of the fault loop, the safety coefficient of the circuit is improved, the load of the loop can still work normally through loop switching, the normal operation of the circuit is ensured, and the reliability of the circuit is improved.
Example 3
According to an embodiment of the present application, there is provided a control device embodiment of a flyback switching power supply, including: the primary loop, the main steady loop unit and the first non-main steady loop unit, wherein, the first non-main steady loop unit includes: the control device of the flyback switching power supply, as shown in fig. 6, includes: the collecting module 61 is configured to collect a conduction signal of the optocoupler secondary side triode, where the conduction signal is used to indicate whether the optocoupler secondary side triode is turned on; the control module 62 is configured to control the first relay to be turned off when the optocoupler secondary transistor is turned on, wherein the optocoupler secondary transistor is turned on when the output diode is shorted.
The apparatus described above also includes modules that perform the other method steps of examples 1 and 2.
Example 4
According to an embodiment of the present application, there is provided an embodiment of a storage medium, including a stored program, where when the program runs, a device where the storage medium is controlled to execute the control method of the flyback switching power supply.
According to an embodiment of the present application, an embodiment of a processor is provided for running a program, where the program executes the control method of the flyback switching power supply.
The foregoing embodiment numbers of the present application are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.
In the foregoing embodiments of the present application, the descriptions of the embodiments are emphasized, and for a portion of this disclosure that is not described in detail in this embodiment, reference is made to the related descriptions of other embodiments.
In the several embodiments provided in the present application, it should be understood that the disclosed technology may be implemented in other manners. The above-described embodiments of the apparatus are merely exemplary, and the division of the units, for example, may be a logic function division, and may be implemented in another manner, for example, a plurality of units or components may be combined or may be integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interfaces, units or modules, or may be in electrical or other forms.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a removable hard disk, a magnetic disk, or an optical disk, or other various media capable of storing program codes.
The foregoing is merely a preferred embodiment of the present application and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present application, which are intended to be comprehended within the scope of the present application.
Claims (9)
1. A flyback switching power supply, the flyback switching power supply comprising: the primary loop, the main loop unit and the first non-main loop unit which are formed by connecting a primary coil, a switching tube and a power supply in series, wherein the first non-main loop unit comprises:
a loop formed by the secondary coil, the output diode, the first relay and the load which are sequentially connected in series;
the capacitor and the optocoupler are connected with the load in parallel;
the processor is used for collecting a conduction signal of the optocoupler secondary side triode, controlling the first relay to be turned off when the conduction signal indicates that the optocoupler secondary side triode is conducted, wherein the optocoupler secondary side triode is conducted when the output diode is in short circuit, a collector electrode of the optocoupler secondary side triode is connected with a preset power supply, an emitter electrode of the optocoupler secondary side triode is grounded, and the processor is used for sampling from the collector electrode of the optocoupler secondary side triode to obtain the conduction signal.
2. The flyback switching power supply of claim 1 further comprising:
the load of the first non-main stable loop unit is connected into the second non-main stable loop unit through a second relay; wherein,,
and the processor is also used for controlling the second relay to be conducted after controlling the first relay to be turned off when the optocoupler secondary side triode is conducted so as to enable the load to be connected into the second non-main stable loop unit.
3. The flyback switching power supply of claim 2 wherein an isolated power supply chip is disposed between the first non-main loop-stabilizing unit and the second non-main loop-stabilizing unit.
4. The flyback switching power supply of claim 1 wherein the processor is further configured to control a display screen to display a prompt message when the optocoupler secondary transistor is on, wherein the prompt message is configured to indicate that the output diode is shorted.
5. The control method of the flyback switching power supply is characterized in that the flyback switching power supply comprises the following steps: the primary loop, the main steady loop unit and the first non-main steady loop unit, wherein, the first non-main steady loop unit includes: the control method of the flyback switching power supply comprises the following steps of:
collecting a conduction signal of the optocoupler secondary side triode, wherein the conduction signal is used for indicating whether the optocoupler secondary side triode is conducted or not;
and when the optocoupler secondary side triode is conducted, the first relay is controlled to be turned off, and when the output diode is short-circuited, the optocoupler secondary side triode is conducted.
6. The control method of claim 5, wherein the flyback switching power supply further comprises: the load of the first non-main stable loop unit is connected to the second non-main stable loop unit through a second relay, wherein when the optocoupler secondary side triode is conducted, the method further comprises:
and controlling the second relay to be conducted so as to enable the load to be connected into the second non-main loop stabilizing unit.
7. A control device for a flyback switching power supply, wherein the flyback switching power supply comprises: the primary loop, the main steady loop unit and the first non-main steady loop unit, wherein, the first non-main steady loop unit includes: the control device of the flyback switching power supply comprises a loop formed by a secondary coil, an output diode, a first relay and a load which are sequentially connected in series, and a capacitor and an optocoupler which are connected with the load in parallel, wherein the control device comprises:
the collecting module is used for collecting a conduction signal of the optocoupler secondary side triode, wherein the conduction signal is used for indicating whether the optocoupler secondary side triode is conducted or not, a collector electrode of the optocoupler secondary side triode is connected with a preset power supply, an emitting electrode of the optocoupler secondary side triode is grounded, and the collecting module samples from the collector electrode of the optocoupler secondary side triode to obtain the conduction signal;
and the control module is used for controlling the first relay to be turned off when the optocoupler secondary side triode is turned on, wherein the optocoupler secondary side triode is turned on when the output diode is short-circuited.
8. A storage medium comprising a stored program, wherein the program, when run, controls a device in which the storage medium is located to perform the control method of the flyback switching power supply of claim 5 or 6.
9. A processor, wherein the processor is configured to run a program, and wherein the program, when run, performs the method of controlling a flyback switching power supply according to claim 5 or 6.
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| CN202011323896.9A CN112671243B (en) | 2020-11-23 | 2020-11-23 | Flyback switching power supply and control method and device thereof |
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| JP2000148265A (en) * | 1998-11-13 | 2000-05-26 | Fuji Electric Co Ltd | Switching power source |
| WO2016037511A1 (en) * | 2014-09-10 | 2016-03-17 | 广州金升阳科技有限公司 | Power supply protection and control method |
| CN105680697A (en) * | 2014-12-08 | 2016-06-15 | 戴洛格半导体公司 | Adaptive reference voltage for switching power converters |
| CN108365756A (en) * | 2018-03-23 | 2018-08-03 | 佛山德仁照明科技有限公司 | A kind of Switching Power Supply |
| CN111865059A (en) * | 2020-07-16 | 2020-10-30 | 珠海格力电器股份有限公司 | Output power self-adaptive adjusting circuit and control method thereof and flyback switching power supply |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JP2000148265A (en) * | 1998-11-13 | 2000-05-26 | Fuji Electric Co Ltd | Switching power source |
| WO2016037511A1 (en) * | 2014-09-10 | 2016-03-17 | 广州金升阳科技有限公司 | Power supply protection and control method |
| CN105680697A (en) * | 2014-12-08 | 2016-06-15 | 戴洛格半导体公司 | Adaptive reference voltage for switching power converters |
| CN108365756A (en) * | 2018-03-23 | 2018-08-03 | 佛山德仁照明科技有限公司 | A kind of Switching Power Supply |
| CN111865059A (en) * | 2020-07-16 | 2020-10-30 | 珠海格力电器股份有限公司 | Output power self-adaptive adjusting circuit and control method thereof and flyback switching power supply |
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