A multi-output short-circuit protection circuit

Abstract

The present invention discloses a multi-output short-circuit protection circuit. The multi-output short-circuit protection circuit includes a power supply module, an input winding, and multiple output windings. The power supply module is used to supply power to the input winding, and the output windings are used to couple the power supply signal transmitted by the input winding and output an isolated power supply signal to the corresponding load; multiple short-circuit detection circuits, which are used to adjust the output short-circuit control signal according to the isolated power supply signal output by the corresponding output winding; a short-circuit protection circuit, which is used to adjust the power supply control signal output to the power supply module according to the short-circuit control signals output by all the short-circuit detection circuits, so as to control the power supply state of the power supply module to the input winding. Through the technical solution of the present invention, while effectively reducing the cost of implementing multiple isolated power supplies output, short-circuit protection for each isolated power supply output branch is achieved, and the probability of components in the multiple isolated power supply signal output lines being burned out is reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of integrated circuit technology, and in particular, to a multi-output short-circuit protection circuit. Background Art

[0002] With the continuous development of electronic technology, the degree of integration of equipment in various industries is getting higher and higher. Sometimes, a single board or device needs to be supplied with electrical energy by different isolated power supplies, making the application of integrating multiple isolated power supplies in a single board or device more and more common.

[0003] At present, the way to realize multi-output isolated power supply signals is to use multiple off-the-shelf isolated power supply modules. However, the isolated power supply modules are expensive, which undoubtedly increases the technical cost of realizing multi-output isolated power supply signals. In addition, it is inevitable that the loads connected to different isolated power supply signal output branches are short-circuited. During the short-circuit process, a large mutant current is easily generated. The large short-circuit power consumption will cause the devices in the multi-output isolated power supply signal output line to burn out, affecting the normal operation of the device. Summary of the Invention

[0004] In view of this, the embodiments of the present invention provide a multi-output short-circuit protection circuit, which effectively reduces the cost of realizing multi-output isolated power supply while realizing short-circuit protection for each isolated power supply output branch, and reduces the probability of the devices in the multi-output isolated power supply signal output line being burned out.

[0005] The embodiments of the present invention provide a multi-output short-circuit protection circuit, including:

[0006] A power supply module, an input winding, and multiple output windings. The power supply module is used to supply power to the input winding, and the output windings are used to couple the power supply signal transmitted by the input winding and output isolated power supply signals to the corresponding loads;

[0007] Multiple short-circuit detection circuits, which are used to adjust the output short-circuit control signals according to the isolated power supply signals output by the corresponding output windings;

[0008] A short-circuit protection circuit, which is used to adjust the power supply control signal output to the power supply module according to the short-circuit control signals output by all the short-circuit detection circuits, so as to control the power supply state of the power supply module to the input winding.

[0009] Further, the short-circuit detection circuit includes:

[0010] A first switch circuit, which is used to adjust the output first switch control signal according to the received isolated power supply signal output by the corresponding output winding;

[0011] A second switch circuit, which is used to adjust the output short-circuit control signal according to the received first switch control signal.

[0012] Furthermore, the first switch circuit includes:

[0013] A first voltage divider device and a second voltage divider device. The first end of the first voltage divider device is connected to the isolated power supply signal. The second end of the first voltage divider device is electrically connected to the first end of the second voltage divider device. The second end of the second voltage divider device is connected to a first set power supply signal;

[0014] A first switch device. The control end of the first switch device is electrically connected to the second end of the first voltage divider device. The first end of the first switch device is connected to the first set power supply signal. The second end of the first switch device is used to output the first switch control signal;

[0015] The second switch circuit includes:

[0016] A light-emitting device. The first end of the light-emitting device is connected to a second set power supply signal. The second end of the light-emitting device is connected to the first switch control signal;

[0017] A photosensitive device. The first end of the photosensitive device is connected to the first set power supply signal. The second end of the photosensitive device is used to output the short-circuit control signal.

[0018] Furthermore, the short-circuit protection circuit includes:

[0019] A third switch circuit for adjusting the first power supply control signal output to the power supply module according to the received short-circuit control signal.

[0020] Furthermore, the third switch circuit includes:

[0021] A third switch device. The control end of the third switch device is connected to the short-circuit control signal. The first end of the third switch device is connected to the first set power supply signal. The second end of the third switch device is electrically connected to the first power supply control end of the power supply module and outputs the first power supply control signal.

[0022] Furthermore, the third switch circuit further includes:

[0023] A first capacitive reactance device. The first end of the first capacitive reactance device is connected to the first set power supply signal. The second end of the first capacitive reactance device is electrically connected to the control end of the third switch device.

[0024] Furthermore, the short-circuit protection circuit further includes:

[0025] A fourth switch circuit for adjusting the second power supply control signal output to the power supply module according to the received first power supply control signal.

[0026] Further, the fourth switching circuit includes:

[0027] A fourth switching device, a control end of the fourth switching device is connected to the first power supply control signal, and a first end of the fourth switching device is connected to a first set power supply signal;

[0028] A fifth switching device, a control end of the fifth switching device is electrically connected to a second end of the fourth switching device, a first end of the fifth switching device is electrically connected to a power-on end of the power supply module, and a second end of the fifth switching device is electrically connected to a second power supply control end of the power supply module and outputs the second power supply control signal.

[0029] Further, the power supply module is configured to output a power-on signal through the power-on end when detecting that a voltage of the second power supply control signal received by the second power supply control end changes to a set voltage;

[0030] The short-circuit protection circuit further includes:

[0031] A power-on circuit, configured to power on the second power supply control end of the power supply module according to the received power-on signal.

[0032] Further, the power-on circuit includes:

[0033] A third voltage divider device, a first end of the third voltage divider device is connected to the power-on signal, and a second end of the third voltage divider device is electrically connected to a control end of the fourth switching device;

[0034] A second capacitive reactance device, a first end of the second capacitive reactance device is electrically connected to a control end of the fourth switching device, and a second end of the second capacitive reactance device is connected to the first set power supply signal.

[0035] An embodiment of the present invention provides a multi-output short-circuit protection circuit. The multi-output short-circuit protection circuit is provided with a power supply module, an input winding, and multiple output windings. The power supply module is used to supply power to the input winding, and the output windings are used to couple the power supply signal transmitted by the input winding and output an isolated power supply signal to the corresponding load. That is, a transformer structure is formed by the input winding and the output windings, which effectively reduces the cost of implementing multiple isolated power supplies compared to directly using multiple isolated power supply modules to drive different loads. Moreover, the multi-output short-circuit protection circuit is provided with multiple short-circuit detection circuits and a short-circuit protection circuit. The multiple short-circuit detection circuits are used to adjust the output short-circuit control signal according to the isolated power supply signal output by the corresponding output winding, and the short-circuit protection circuit is used to adjust the power supply control signal output to the power supply module according to the short-circuit control signals output by all the short-circuit detection circuits to control the power supply state of the power supply module to the input winding. When there is a short-circuit in the load connected to the output winding, the short-circuit detection circuit can accurately detect whether there is a short-circuit in the load electrically connected to each output winding. Furthermore, when there is a short-circuit in the load electrically connected to any one of the output windings, the short-circuit protection circuit controls the power supply module to stop supplying power to the input winding, that is, cuts off the power supply line of the power supply module, realizing short-circuit protection for each isolated power supply output branch and reducing the probability of components in the multi-isolated power supply signal output line being burned out. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the background art, the following will briefly introduce the drawings required for the description of the embodiments or the background art. Obviously, the drawings in the following description are schematic diagrams of some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0037] Figure 1 FIG. is a schematic structural diagram of a multi-output short-circuit protection circuit provided by an embodiment of the present invention;

[0038] Figure 2 FIG. is a schematic specific circuit structure diagram of a short-circuit detection circuit provided by an embodiment of the present invention;

[0039] Figure 3 FIG. is a schematic specific circuit structure diagram of a short-circuit protection circuit provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0040] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the sake of description, only parts related to the present invention rather than all structures are shown in the accompanying drawings. Throughout this specification, the same or similar reference numerals represent the same or similar structures, elements or processes. It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0041] Figure 1 It is a schematic structural diagram of a multi-output short-circuit protection circuit provided by an embodiment of the present invention. As Figure 1 shown, the multi-output short-circuit protection circuit includes a power supply module 1, an input winding 2, and a plurality of output windings 3. The power supply module 1 is used to supply power to the input winding 2, and the output winding 3 is used to couple the power supply signal transmitted by the input winding 2 and output an isolated power supply signal to the corresponding load ( Figure 1 not shown in the figure). The multi-output short-circuit protection circuit further includes a plurality of short-circuit detection circuits 4 and a short-circuit protection circuit 5. Figure 1 Exemplarily, it is shown that the multi-output short-circuit protection circuit includes three output windings 3, and correspondingly, the multi-output short-circuit protection circuit includes three short-circuit detection circuits 4. The short-circuit detection circuit 4 is used to adjust the output short-circuit control signal according to the isolated power supply signal output by the corresponding output winding 3, and the short-circuit protection circuit 5 is used to adjust the power supply control signal output to the power supply module 1 according to the short-circuit control signals output by all the short-circuit detection circuits 4, so as to control the power supply state of the power supply module 1 to the input winding 2.

[0042] Specifically, the power supply module 1 is used to supply power to the input winding 2. The power supply module 1 can be a power supply chip. The power supply module 1 inputs a power supply signal to the input winding 2. The output winding 3 couples the power supply signal transmitted by the input winding 2 and outputs an isolated power supply signal to the corresponding load. It can be set that the input winding 2 and the output winding 3 form a transformer structure. In this way, compared with directly using a plurality of isolated power supply modules to drive different loads, there is no need to additionally use an isolated power supply module, effectively reducing the cost of realizing multiple isolated power supplies output.

[0043] In addition, each output winding 3 is provided with a corresponding short-circuit detection circuit 4. If a short-circuit problem occurs in the load electrically connected to any one of the output windings 3, the voltage of the isolated power supply signal output by the corresponding output winding 3 will change. The port B of the short-circuit detection circuit 4 is connected to the isolated power supply signal output by the corresponding output winding 3. When the short-circuit detection circuit 4 detects a change in the voltage of the corresponding isolated power supply signal, it adjusts the voltage of the output short-circuit control signal. The ports A of all the short-circuit detection circuits 4 for outputting the short-circuit control signal are short-circuited and then connected to the short-circuit protection circuit 5. In this way, any change in the voltage of the short-circuit control signal can be detected by the short-circuit protection circuit 5. Furthermore, when the short-circuit protection circuit 5 confirms the existence of a short-circuit situation, it adjusts the output power supply control signal to control the power supply module 1 to stop supplying power to the input winding 2, realizing short-circuit protection for each isolated power supply output branch, and thus reducing the probability of components being burned out in the multi-path isolated power supply signal output line.

[0044] Figure 2 FIG. is a schematic diagram of the specific circuit structure of a short-circuit detection circuit provided by an embodiment of the present invention. Combining Figure 1 and Figure 2 , the short-circuit detection circuit 4 includes a first switch circuit 41 and a second switch circuit 42. The first switch circuit 41 is configured to adjust the output first switch control signal according to the received isolated power supply signal output by the corresponding output winding 3. The second switch circuit 42 is configured to adjust the output short-circuit control signal according to the received first switch control signal.

[0045] Specifically, taking the first short-circuit detection circuit 4 as an example, the first switch circuit 41 in the short-circuit detection circuit 4 receives the isolated power supply signal output by the first output winding 3. When a short circuit occurs in the load electrically connected to the first output winding 3, the voltage of the isolated power supply signal received by the first switch circuit 41 from port B changes, resulting in a change in the switching state of the first switch circuit 41. The level of the first switch control signal output by the first switch circuit 41 changes, and further causes a change in the switching state of the second switch circuit 42. The level of the short-circuit control signal output by the second switch circuit 42 changes. When the short-circuit protection circuit 5 detects the change in the level of the short-circuit control signal, it can control the power supply module 1 to stop supplying power to the input winding 2, realizing short-circuit protection.

[0046] Optionally, combining Figure 1 and Figure 2, the first switch circuit 41 includes a first voltage divider component R1, a second voltage divider component R2, and a first switch device K1. The first end of the first voltage divider component R1 is connected to an isolated power supply signal. The second end of the first voltage divider component R1 is electrically connected to the first end of the second voltage divider component R2. The second end of the second voltage divider component R2 is connected to a first set power supply signal. The first set power supply signal can be, for example, a ground signal. The first voltage divider component R1 and the second voltage divider component R2 can be, for example, resistor elements to achieve voltage division of the input isolated power supply signal. When the voltage of the isolated power supply signal changes, the voltage of the voltage division signal output at the voltage division node also changes.

[0047] The control end of the first switch device K1, that is Figure 2 the right port of K1 in is electrically connected to the second end of the first voltage divider component R1. The first end of the first switch device K1 is connected to a first set power supply signal, such as a ground signal. The second end of the first switch device K1 is used to output a first switch control signal. The first switch device K1 can be, for example, an insulated-gate field-effect transistor, that is, a MOS transistor, or a bipolar junction transistor, that is, a BJT transistor. The first switch device K1 can also be as Figure 2 shown as a diode with a control function. The diode conducts or cuts off according to the voltage division signal input at the right control end to achieve adjustment of the high level of the first switch control signal output by the first switch circuit 41.

[0048] The second switch circuit 42 includes a light-emitting device D1 and a photosensitive device T1. The first end of the light-emitting device D1 is connected to a second set power supply signal, such as a VDD signal. The second end of the light-emitting device D1 is connected to the first switch control signal, that is, electrically connected to the second end of the first switch device K1. The first end of the photosensitive device T1 is connected to a first set power supply signal, such as a ground signal. The second end of the photosensitive device T1 is used to output a short-circuit control signal. The light-emitting device D1 can be, for example, a light-emitting diode. The photosensitive device T1 can be, for example, a photosensitive transistor. The light-emitting device D1 controls its own conduction or turn-off according to the first switch control signal output by the first switch circuit 41. When the light-emitting device D1 conducts, it emits light. The photosensitive device T1 conducts when it senses light. It can be set that the first set power supply signal connected to the first end of the photosensitive device T1 is a ground signal, then the short-circuit control signal output by the second end of the photosensitive device T1 is a low-level signal. On the contrary, if the light-emitting device D1 is turned off and does not emit light, the short-circuit control signal output by the second end of the photosensitive device T1 is a high-level signal. The short-circuit protection circuit 5 detects the change in the level of the short-circuit control signal and can control the power supply module 1 to stop supplying power to the input winding 2 to achieve short-circuit protection.

[0049] Figure 3 is a schematic diagram of the specific circuit structure of a short-circuit protection circuit provided by an embodiment of the present invention. Combining Figures 1 to 3, the short - circuit protection circuit 5 includes a third switch circuit 51. The third switch circuit 51 is used to adjust the first power supply control signal output to the power supply module 1 according to the received short - circuit control signal, that is, the short - circuit control signal input at port A, namely the first power supply control signal output through the first power supply control terminal COM. The port A of the third switch circuit 51 is electrically connected to the short - circuit port A of all short - circuit detection circuits 4. The third switch circuit 51 can adjust the level of the first power supply control signal output to the power supply module 1 according to the level of the short - circuit control signal received at port A. The power supply module 1 controls whether to supply power to the input winding 2 when the levels of the received first power supply control signals are different.

[0050] Optionally, combined with Figures 1 to 3 , the third switch circuit 51 includes a third switching device K3. The control terminal of the third switching device K3 is connected to the short - circuit control signal. The first terminal of the third switching device K3 is connected to the first set power signal, such as a ground signal. The second terminal of the third switching device K3 is electrically connected to the first power supply control terminal COM of the power supply module 1 and outputs the first power supply control signal.

[0051] Specifically, the third switching device K3 can be an insulated - gate field - effect transistor, that is, a MOS transistor, or a bipolar junction transistor, that is, a BJT transistor. The control terminal of the third switching device K3 controls whether its first terminal and second terminal are connected according to the received short - circuit control signal. The first set power signal connected to the first terminal of the third switching device K3 can be, for example, a ground signal. If the third switching device K3 is turned on, the first power supply control signal output from the second terminal of the third switching device K3 to the first power supply control terminal COM of the power supply module 1 is a low - level signal. If the third switching device K3 is turned off, the first power supply control signal output from the second terminal of the third switching device K3 to the first power supply control terminal COM of the power supply module 1 is a high - level signal. It can be set that the levels of the short - circuit control signals output by the short - circuit detection circuits 4 corresponding to whether there is a short - circuit in the load are different, thereby controlling the switching states of the third switching device K3 differently. When the first power supply control terminal COM of the power supply module 1 receives a short - circuit valid signal (high - level signal or low - level signal), it no longer supplies power to the input wire group, realizing short - circuit protection.

[0052] Optionally, combined with Figures 1 to 3 , the third switch circuit 51 further includes a first capacitive reactance device C1. The first terminal of the first capacitive reactance device C1 is connected to the first set power signal, such as a ground signal. The second terminal of the first capacitive reactance device C1 is electrically connected to the control terminal of the third switching device K3.

[0053] Specifically, the first capacitive reactance device C1 can be a capacitive element. The first capacitive reactance device C1 connects the ground signal GND to the control end of the third switching device K3. The second end of the photosensitive device T1 in the short-circuit detection circuit 4 for outputting the short-circuit control signal can also be connected to the second power supply control end POW1 of the power supply module 1, that is, the power supply end of the power supply module. It can be set that when there is a short circuit in the load connected to the output winding 3, the corresponding voltage-dividing signal output to the first switching device K1 is a low-level signal, the first switching device K1 is turned off, the light-emitting device D1 in the optocoupler does not emit light, and the first end and the second end of the photosensitive device T1 are disconnected. When power is established, that is, when the power supply module 1 just starts to supply power to the input winding 2, since the voltage of the isolated power supply signal output by the output winding 3 is close to 0V, according to the description of the corresponding short-circuit situation above, there is no short-circuit situation when power is established, but the short-circuit protection will still be triggered erroneously.

[0054] In the embodiment of the present invention, by setting that the third switching circuit 51 further includes a first capacitive reactance device C1, the first end of the first capacitive reactance device C1 is connected to a first set power signal, and the second end of the first capacitive reactance device C1 is electrically connected to the control end of the third switching device K3, so that the potential of the control end of the third switching device K3 rises slowly, and the short-circuit protection will not be directly triggered when power is established, thereby avoiding the problem of erroneous triggering of the short-circuit protection caused by power establishment.

[0055] Optionally, in combination with Figures 1 to 3 , the short-circuit protection circuit 5 further includes a fourth switching circuit 52. The fourth switching circuit 52 is used to adjust the second power supply control signal output to the power supply module 1 according to the received first power supply control signal, that is, the signal output to the first power supply control end COM. When there is a short circuit in the load electrically connected to the output winding 3, while controlling the power supply module 1 to stop supplying power through the first power supply control signal, that is, the enable signal of the power supply module, the second power supply control signal output by the fourth switching device K4, that is, the signal output to the second power supply control end POW1 of the power supply module 1, can also control the power supply module 1 to stop supplying power, and the double short-circuit protection mechanism is used to improve the accuracy of the short-circuit protection function of the circuit.

[0056] Optionally, in combination with Figures 1 to 3 , the fourth switching circuit 52 includes a fourth switching device K4 and a fifth switching device K5. The control end of the fourth switching device K4 is connected to the first power supply control signal, the first end of the fourth switching device K4 is connected to the first set power signal, the control end of the fifth switching device K5 is electrically connected to the second end of the fourth switching device K4, the first end of the fifth switching device K5 is electrically connected to the power-on end POW of the power supply module 1, and the second end of the fifth switching device K5 is electrically connected to the second power supply control end POW1 of the power supply module 1 and outputs the second power supply control signal.

[0057] Specifically, the fourth switching device K4 and the fifth switching device K5 can be insulated gate field effect transistors, i.e., MOS transistors, or bipolar junction transistors, i.e., BJT transistors. When the level of the first power supply control signal connected to the fourth switching device K4 is different corresponding to whether there is a short circuit in the load, the switching state of the fourth switching device K4 is different, which makes the level of the switching control signal connected to the control terminal of the fifth switching device K5 also different. The switching state of the fifth switching device K5 is different, and it can control the fifth switching device K5 to turn off when there is a short circuit. The power-on terminal POW of the power supply module 1 is disconnected from the second power supply control terminal POW1, and the second power supply control signal at the second power supply control terminal POW1 is a low-level signal, and the power supply module 1 stops supplying power.

[0058] Optionally, in combination with Figures 1 to 3 , the power supply module 1 is configured to output a power-on signal through the power-on terminal POW when it detects that the voltage of the second power supply control signal received at the second power supply control terminal POW1 changes to a set voltage. The short-circuit protection circuit 5 further includes a power-on circuit 53, which is configured to power on the second power supply control terminal POW1 of the power supply module 1 according to the received power-on signal. It can be set that the power-on circuit 53 includes a third voltage divider device R3 and a second capacitive reactance device C2. The first end of the third voltage divider device R3 is connected to the power-on signal, the second end of the third voltage divider device R3 is electrically connected to the control terminal of the fourth switching device K4, the first end of the second capacitive reactance device C2 is electrically connected to the control terminal of the fourth switching device K4, and the second end of the second capacitive reactance device C2 is connected to a first set power supply signal, such as a ground signal.

[0059] Specifically, since the pin corresponding to the second power supply control terminal POW1 of the power supply module 1 has a certain capacitance, when the voltage of the second power supply control signal received at the second power supply control terminal POW1 drops to 0V after a short circuit occurs, the short-circuit protection process will end. The power supply module 1 outputs a power-on signal through the power-on terminal POW when it detects that the voltage of the second power supply control signal received at the second power supply control terminal POW1 changes to a set voltage, such as 0V, that is, powers on the power supply module 1 again. The power-on signal output by the power-on terminal POW passes through the third voltage divider device R3 and the second capacitive reactance device C2, making the fourth switching device K4 that is turned off during short-circuit protection conduct again, and then making the fifth switching device K5 conduct. The power-on terminal POW of the power supply module 1 is connected to the second power supply control terminal POW1 of the power supply module 1, and the second power supply control terminal POW1 receives a high-level second power supply control signal again, and the power supply module 1 can continue to supply power to the input winding 2. That is, the entire circuit can perform short-circuit protection when a short circuit occurs to disconnect the power supply line between the power supply module 1 and the input winding 2, and after power-off, it can automatically power on the power supply module 1 using the feedback mechanism inside the power supply module 1 to achieve hiccup short-circuit protection.

[0060] Next, in combination withFigures 1 to 3 A general description of the working principle of the multi-output short-circuit protection circuit is as follows:

[0061] The relationship between all short-circuit detection circuits 4 is an "OR" relationship, that is, when any short-circuit detection branch detects a short circuit in the corresponding load, a short-circuit control signal for controlling the short-circuit protection circuit 5 to perform short-circuit protection is output.

[0062] The short-circuit detection circuit 4 first detects the change in the voltage of the isolated power supply signal connected through a voltage divider device. If the load is short-circuited, the voltage of the isolated power supply signal will drop. When the voltage of the isolated power supply signal drops to less than or equal to the set detection voltage, the first switching device K1 can be controlled to turn off, and then the light-emitting device D1 is controlled not to emit light. The photosensitive device T1 outputs a high level, and then the third switching device is controlled to conduct. The first power supply control terminal COM of the power supply module receives a low-level first power supply control signal. At the same time, the fourth switching device K4 is turned off under the action of the low-level first power supply control signal, and the fifth switching device K5 is turned off. POW1 receives a low-level second power supply control signal, and thus short-circuit protection is achieved by using a dual short-circuit protection mechanism.

[0063] In addition, overcurrent protection can also be achieved by using the above multi-output short-circuit protection circuit. For example, when the current value of the isolated power supply signal output by the output winding 3 is too large, the voltage division voltages of the first voltage divider device R1 and the second voltage divider device R2 can also be reduced, and overcurrent protection is achieved by using the above short-circuit protection principle.

[0064] It should be noted that the embodiments of the present invention do not limit whether the switch in the multi-output short-circuit protection circuit is controlled to conduct by a high level or a low level, and the corresponding switch effective signal can be set to a high-level signal or a low-level signal according to the function of realizing short-circuit protection.

[0065] The embodiments of the present invention form a transformer structure by using the input winding and the output winding, which effectively reduces the cost of realizing multiple output isolated power supplies compared with directly using multiple isolated power supply modules to drive different loads. When there is a short circuit in the load connected to the output winding, the short-circuit detection circuit can accurately detect whether there is a short circuit in the load electrically connected to each output winding. Then, when there is a short circuit in the load electrically connected to any output winding, the short-circuit protection circuit controls the power supply module to stop supplying power to the input winding, that is, cuts off the power supply line of the power supply module, realizes short-circuit protection for each isolated power supply output branch, and reduces the probability of the components in the multiple isolated power supply signal output lines being burned out.

[0066] Note that the above is only a preferred embodiment of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments here, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A multi-output short-circuit protection circuit, characterized in that, Comprising: A power supply module, an input winding, and a plurality of output windings. The power supply module is used to supply power to the input winding, and the output windings are used to couple the power signal transmitted by the input winding and output an isolated power signal to the corresponding load; A plurality of short - circuit detection circuits, which are used to adjust the output short - circuit control signal according to the isolated power signal output by the corresponding output winding; A short - circuit protection circuit, which is used to adjust the power supply control signal output to the power supply module according to the short - circuit control signals output by all the short - circuit detection circuits, so as to control the power supply state of the power supply module to the input winding; The short - circuit protection circuit includes: A third switch circuit, which is used to adjust the first power supply control signal output to the power supply module according to the received short - circuit control signal; A fourth switch circuit, which is used to adjust the second power supply control signal output to the power supply module according to the received first power supply control signal; The fourth switch circuit includes: A fourth switch device, the control end of the fourth switch device accesses the first power supply control signal, and the first end of the fourth switch device accesses a first set power signal; A fifth switch device, the control end of the fifth switch device is electrically connected to the second end of the fourth switch device, the first end of the fifth switch device is electrically connected to the power - on end of the power supply module, and the second end of the fifth switch device is electrically connected to the second power supply control end of the power supply module and outputs the second power supply control signal; The power supply module is used to output a power - on signal through the power - on end when detecting that the voltage of the second power supply control signal received by the second power supply control end changes to a set voltage; The short - circuit protection circuit further includes: A power - on circuit, which is used to power on the second power supply control end of the power supply module according to the received power - on signal; When a short - circuit occurs, the multi - output short - circuit protection circuit can perform short - circuit protection to disconnect the power supply line between the power supply module and the input winding, and after power - off, it can automatically power on the power supply module by using the feedback mechanism inside the power supply module.

2. The multi-output short-circuit protection circuit according to claim 1, wherein The short - circuit detection circuit includes: A first switch circuit, which is used to adjust the output first switch control signal according to the isolated power signal output by the corresponding output winding received; A second switch circuit, which is used to adjust the output short - circuit control signal according to the received first switch control signal.

3. The multi-output short-circuit protection circuit according to claim 2, characterized in that, The first switch circuit includes: A first voltage - dividing device and a second voltage - dividing device. The first end of the first voltage - dividing device accesses the isolated power signal, the second end of the first voltage - dividing device is electrically connected to the first end of the second voltage - dividing device, and the second end of the second voltage - dividing device accesses a first set power signal; A first switch device, the control end of the first switch device is electrically connected to the second end of the first voltage - dividing device, the first end of the first switch device accesses the first set power signal, and the second end of the first switch device is used to output the first switch control signal; The second switch circuit includes: A light-emitting device, a first end of the light-emitting device is connected to a second set power signal, and a second end of the light-emitting device is connected to the first switch control signal; A photosensitive device, a first end of the photosensitive device is connected to the first set power signal, and a second end of the photosensitive device is used to output the short-circuit control signal.

4. The multi-output short-circuit protection circuit according to claim 1, characterized in that, The third switch circuit includes: A third switch device, a control end of the third switch device is connected to the short-circuit control signal, a first end of the third switch device is connected to the first set power signal, and a second end of the third switch device is electrically connected to a first power supply control end of the power supply module and outputs the first power supply control signal.

5. The multi-output short-circuit protection circuit according to claim 4, characterized in that The third switch circuit further includes: A first capacitive reactance device, a first end of the first capacitive reactance device is connected to the first set power signal, and a second end of the first capacitive reactance device is electrically connected to the control end of the third switch device.

6. The multi-output short-circuit protection circuit according to claim 1, wherein The power-on circuit includes: A third voltage divider device, a first end of the third voltage divider device is connected to the power-on signal, and a second end of the third voltage divider device is electrically connected to the control end of the fourth switch device; A second capacitive reactance device, a first end of the second capacitive reactance device is electrically connected to the control end of the fourth switch device, and a second end of the second capacitive reactance device is connected to the first set power signal.

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