Electronic switching circuit with large current protection on airplane

Abstract

The utility model discloses an electronic switch circuit with heavy current protection on an airplane, which comprises an electronic switch and a control circuit matched with the electronic switch, the input end of the electronic switch is electrically connected with an external power supply, the output end of the electronic switch is connected with a load, and the control circuit is connected with the output end of the load. An MOS (Metal Oxide Semiconductor) tube is arranged on a connecting path of the control circuit and the output end of the load; the load input end is electrically connected with an external circuit, and a shunt resistor is arranged on a connection path of the load input end and the external circuit, so that a selective electronic switching circuit is formed. According to the utility model, through the shunt resistor connected to the access from the power supply to the load, when the current in the circuit is too large at the moment that the external power supply is conducted with the internal circuit, the shunt resistor can play a role in limiting the current, so that other elements in the circuit are prevented from being damaged by the too large current.

Description

Technical Field

[0001] The utility model relates to the technical field of power electronics, and more specifically, to an electronic switch circuit with high current protection on an aircraft. Background Art

[0002] Circuit boards are important electronic components, supporting electronic components and carriers for electrical interconnection of electronic components. The main material of circuit boards is copper clad laminate (copper clad laminate), which is composed of substrate, copper foil and adhesive. The substrate is an insulating layer composed of polymer synthetic resin and reinforcing material.

[0003] The electronic switch in the related art directly welds or mounts the input and output wires or terminals on the circuit board, and all the current between the input and output is borne by the copper foil on the circuit board. However, the copper foil on the circuit board is only a few microns thick, and even if it can bear the current passing through, it will have a large temperature rise and a large resistance. The higher the temperature rise, the greater the resistance, and the greater the resistance, the higher the temperature rise, and this vicious cycle will eventually burn out.

[0004] For example, the switching circuit and electronic device disclosed in Patent No. CN202022537299.8, when the circuit is connected to the input end of the power supply, the current in the internal circuit has not yet stabilized, and the current is too large, which can easily break down the MOS tube in the circuit. The MOS tube needs to be replaced frequently, which increases costs and reduces work efficiency. Utility Model Content

[0005] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages to be described below.

[0006] In order to achieve these purposes and other advantages according to the utility model, an electronic switch circuit with high current protection on an aircraft is provided, including an electronic switch and a control circuit matched therewith, the input end of the electronic switch is electrically connected to an external power supply, the output end of the electronic switch is connected to a load, the control circuit is connected to the output end of the load, and a MOS tube is arranged on the connection path between the control circuit and the output end of the load; the load input end is electrically connected to an external circuit, and a shunt resistor is arranged on the connection path between the load input end and the external circuit to form a selective electronic switch circuit.

[0007] Preferably, the control circuit includes: a single chip microcomputer, a triode;

[0008] Among them, the PA14 pin of the single-chip microcomputer is electrically connected to the electronic switch, and a transistor is arranged on the connection path between the PA14 pin of the single-chip microcomputer and the electronic switch, and the PA9 pin of the single-chip microcomputer is connected to the MOS tube.

[0009] Preferably, it further comprises: a current sensing resistor arranged in the path between the load and the MOS tube;

[0010] A current detection chip is arranged at both ends of the current detection resistor;

[0011] Wherein, the output pin of the current detection chip is connected to the PA4 pin of the single chip microcomputer.

[0012] The utility model at least includes the following beneficial effects: the utility model connects a shunt resistor on the path from the power supply to the load, and when the external power supply and the internal circuit are turned on at the moment, the current in the circuit is too large, the shunt resistor will play a current limiting role to prevent the excessive current from damaging other components in the circuit.

[0013] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a circuit diagram of the utility model.

[0015] Markings in the figure: 1. Microcontroller, 2. Electronic switch, 3. External power supply, 4. Shunt resistor, 5. Load, 6. Current sensing resistor, 7. Current detection chip, 8. MOS tube, 9. Transistor. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0017] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0018] It should be noted that in the description of the present invention, the orientation or position relationship indicated by the term is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0019] In the description of the present utility model, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "sleeved / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0020] In addition, in the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0021] Figure 1 The utility model shows an electronic switch circuit with high current protection on an aircraft, including an electronic switch 2 and a control circuit matched therewith, wherein the input end of the electronic switch 2 is electrically connected to an external power supply 3, the output end of the electronic switch 2 is connected to a load 5, the control circuit is connected to the output end of the load 5, and a MOS tube 8 is provided on the connection path between the control circuit and the output end of the load 5; the input end of the load 5 is electrically connected to an external circuit, and a shunt resistor 4 is provided on the connection path between the input end of the load 5 and the external circuit, so as to form a selective electronic switch circuit.

[0022] Working principle:

[0023] When the power is on, the battery voltage forms a loop through the shunt resistor 4 and the load 5. At this time, the current in the circuit is relatively small due to the existence of the shunt resistor 4. This prevents the MOS tube from being impacted by a sudden large current. However, the shunt resistor 4 is an energy-consuming component. Therefore, when the circuit is started, we need to short-circuit the shunt resistor 4 through the electronic switch 2. This makes the voltage drop on the shunt resistor 4 0, thereby reducing the power consumption of the circuit.

[0024] At the output end of the load 5, it is connected to one end of the MOS tube 8. The MOS tube 8 plays the role of signal conversion and circuit on-off control. The other end of the MOS tube 8 is connected to the control circuit, and the control circuit controls the MOS tube 8. The control circuit sends a corresponding control signal to the MOS tube 8, thereby realizing the control of the load 5 circuit.

[0025] In the above scheme, the control circuit includes: a single chip computer 1, a transistor 9;

[0026] Among them, the PA14 pin of the single-chip computer 1 is electrically connected to the electronic switch 2, and a transistor 9 is provided on the connection path between the PA14 pin of the single-chip computer 1 and the electronic switch 2, and the PA9 pin of the single-chip computer 1 is connected to the MOS tube 8. With this technical method, the PA14 pin of the single-chip computer 1 is electrically connected to the electronic switch 2, and the single-chip computer 1 directly controls the opening and closing of the electronic switch 2 by sending a control signal through the PA14 pin. A transistor 9 is provided on the connection path between the PA14 pin of the single-chip computer 1 and the electronic switch 2 to amplify and convert the control signal. Its base receives the control signal from the single-chip computer 1, and controls the on-off state between its collector and emitter according to the change of the signal. When the single-chip computer 1 sends a control signal to turn on the transistor 9, the electronic switch 2 can receive the control signal and make a corresponding action; when the transistor 9 is turned off, the electronic switch 2 cannot receive the control signal and maintains its original state. The PA9 pin of the single chip computer 1 is connected to the MOS tube 8, and the single chip controls the MOS tube 8 through the PA9 pin.

[0027] The above scheme also includes: a current-sensing resistor 6 set on the path between the load 5 and the MOS tube 8; a current detection chip 7 set at both ends of the current-sensing resistor 6; wherein the output pin of the current detection chip 7 is connected to the PA4 pin of the single-chip computer 1. Using this technical method, the current-sensing resistor 6 is set between the load 5 and the path between the MOS tube 8, and its two ends are respectively connected to the two positive and negative input pins of the current detection chip 7. When the current flows through the current-sensing resistor 6, according to Ohm's law, a voltage drop proportional to the current will be generated on the current-sensing resistor 6. This voltage drop is captured by the two input pins of the current detection chip 7, and is converted into a measurable voltage signal after being processed by the internal circuit.

[0028] The output pin of the current detection chip 7 is connected to the PA4 pin of the single chip microcomputer 1, so that the voltage signal output by the current detection chip 7 can be read by the single chip microcomputer 1. The single chip microcomputer 1 receives this voltage signal through the PA4 pin, and the single chip microcomputer 1 can obtain the current value of the internal circuit, and judge whether the current in the internal circuit is stable according to the current values ​​measured multiple times. After the internal current is stable, the single chip microcomputer 1 controls the electronic switch 2 to close through communication, and the external power supply 3 is connected to the load 5 through the electronic switch 2 path to avoid the loss of the input current on the shunt resistor 4.

[0029] Although the implementation scheme of the utility model has been disclosed as above, it is not limited to the applications listed in the specification and implementation modes. It can be fully applied to various fields suitable for the utility model. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the utility model is not limited to the specific details and the illustrations shown and described herein.

Claims

1. An electronic switch circuit with high current protection on an aircraft, comprising an electronic switch and a control circuit matched therewith, wherein the input end of the electronic switch is electrically connected to an external power supply, the output end of the electronic switch is connected to a load, the control circuit is connected to the output end of the load, and a MOS tube is arranged on the connection path between the control circuit and the output end of the load; characterized in that: The load input terminal is electrically connected to an external circuit, and a shunt resistor is provided on a connection path between the load input terminal and the external circuit to form a selective electronic switch circuit.

2. The electronic switch circuit with high current protection on an aircraft according to claim 1, characterized in that: The control circuit comprises: a single chip microcomputer and a triode; Among them, the PA14 pin of the single-chip microcomputer is electrically connected to the electronic switch, and a transistor is arranged on the connection path between the PA14 pin of the single-chip microcomputer and the electronic switch, and the PA9 pin of the single-chip microcomputer is connected to the MOS tube.

3. The electronic switch circuit with high current protection on an aircraft according to claim 1, characterized in that: Also includes: A current sensing resistor is set in the path between the load and the MOS tube; A current detection chip is arranged at both ends of the current detection resistor; Wherein, the output pin of the current detection chip is connected to the PA4 pin of the single chip microcomputer.

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