CN219420288U - Protection circuit for preventing relay misoperation caused by signal abnormality - Google Patents
Protection circuit for preventing relay misoperation caused by signal abnormality Download PDFInfo
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- CN219420288U CN219420288U CN202320799783.9U CN202320799783U CN219420288U CN 219420288 U CN219420288 U CN 219420288U CN 202320799783 U CN202320799783 U CN 202320799783U CN 219420288 U CN219420288 U CN 219420288U
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Abstract
The utility model provides a protection circuit for preventing misoperation of a relay caused by signal abnormality, which comprises the relay and a control module, wherein the control module sends a first control signal and a second control signal to enable the relay to be turned on or turned off; the protection circuit has at least three states, when the protection circuit is in a first state, the first control signal is a low-level signal, and the relay is disconnected; when the relay is in the second state, the first control signal is a high-level signal, the second control signal is a low-level signal, and the relay is conducted; when the relay is in the third state, the first control signal is a high-level signal, the second control signal is a high-level signal, and the relay is disconnected; the relay is controlled to be opened and closed by the two control signals, and the relay is conducted only when the two control signals are in a normal state, otherwise, the relay is disconnected, an external power supply cannot be connected into a next-stage circuit through the relay, and misoperation caused by abnormal conditions of the mixed signals and the control module in an initial starting stage or the relay is avoided.
Description
Technical Field
The utility model relates to the technical field of relays, in particular to a protection circuit for preventing misoperation of a relay caused by signal abnormality.
Background
In the current industrial field, such as injection molding grinding tool heating, screen assembling and disassembling, industrial incubator and the like, temperature measurement and monitoring are needed, a control module usually adopts a signal to control on or off of a switch in a traditional temperature control circuit in a large-current control system so as to control the on/off of heating/refrigerating equipment, and because the large-current system often has a mixed signal, when the control module is in an initial starting stage or the control signal is abnormal, misoperation of a relay is easy to occur, which can cause immeasurable serious consequences in industrial application.
Disclosure of Invention
The utility model aims to provide a protection circuit for preventing misoperation of a relay caused by signal abnormality, which has high safety.
In order to achieve the above purpose, the present utility model provides the following technical solutions:
a protection circuit for preventing misoperation of a relay caused by signal abnormality comprises the relay and a control module, wherein the control module sends a first control signal and a second control signal to enable the relay to be turned on or turned off;
the protection circuit has at least three states, when the protection circuit is in a first state, the first control signal is a low-level signal, and the relay is disconnected; when the relay is in the second state, the first control signal is a high-level signal, the second control signal is a low-level signal, and the relay is conducted; when the relay is in the third state, the first control signal is a high level signal, the second control signal is a high level signal, and the relay is opened.
Further, the relay is provided with a movable contact connected with a lower-stage power utilization circuit, a first fixed contact and a second fixed contact connected with an external power supply;
the protection circuit comprises a first transistor and a second transistor, wherein the grid electrode of the first transistor is electrically connected with a first control signal, and the drain electrode of the first transistor is electrically connected with a second stationary contact; the grid electrode of the second transistor is electrically connected with the second control signal, and the drain electrode of the second transistor is electrically connected with the grid electrode of the first transistor;
when the protection circuit is in the second state, the movable contact is contacted with the first static contact and the second static contact, and the relay is conducted so that the external power supply provides working voltage for the lower-stage circuit.
Further, the protection circuit comprises a pull-down resistor, one end of the pull-down resistor is electrically connected with the grid electrode of the first transistor, and the other end of the pull-down resistor is grounded.
Further, the protection circuit is also provided with a first signal input end which is electrically connected with the control module and used for accessing a first control signal and a second signal input end which is electrically connected with a second control signal, wherein the first signal input end is electrically connected with the grid electrode of the first transistor, and the second signal input end is electrically connected with the grid electrode of the second transistor; current limiting resistors are arranged between the first signal input end and the grid electrode of the first transistor and between the second signal input end and the grid electrode of the second transistor.
Further, the protection circuit is provided with a voltage input end electrically connected with the control module, a grid electrode of the second transistor is electrically connected with the voltage input end, and a pull-up resistor is arranged between the grid electrode of the second transistor and the voltage input end.
Further, the protection circuit further comprises a diode for preventing the first transistor from being broken down, one end of the diode is electrically connected between the external power supply and the first static contact, and the other end of the diode is electrically connected between the drain electrode of the first transistor and the second static contact.
Further, the source of the first transistor is grounded, and the source of the second transistor is grounded.
The utility model has the beneficial effects that: the relay is controlled to be opened and closed by the two control signals, and the relay is conducted only when the two control signals are in a normal state, otherwise, the relay is disconnected, an external power supply cannot be connected into a next-stage circuit through the relay, and misoperation such as abnormal actuation of the relay caused by abnormal signals, the control module in an initial starting stage or single signal is avoided.
The foregoing description is only an overview of the present utility model, and is intended to provide a better understanding of the present utility model, as it is embodied in the following description, with reference to the preferred embodiments of the present utility model and the accompanying drawings.
Drawings
Fig. 1 is a schematic diagram of a protection circuit for preventing malfunction of a relay due to signal abnormality according to an embodiment of the present utility model.
Detailed Description
The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model. In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.
Examples
Referring to fig. 1, a protection circuit for preventing malfunction of a relay caused by signal abnormality in this embodiment includes a relay K, a control module, a first transistor Q1 and a second transistor Q2. The control module sends a first control signal and a second control signal to enable the relay K to be conducted or closed, and voltage is connected into a lower-stage power utilization circuit only when the relay K is conducted.
Specifically, the relay K has a movable contact K1 connected to the lower-stage power consumption circuit, a first stationary contact K2 and a second stationary contact K3 connected to the external power source VIN. When the protection circuit is connected in the temperature control circuit, the lower-stage power utilization circuit is heating/refrigerating equipment.
The protection circuit is provided with a first signal input end in1, a second signal input end in2 and a voltage input end in3, wherein the first signal input end in1 is electrically connected with the control module, the second signal input end in2 is electrically connected with the second control signal, the grid electrode of the first transistor Q1 is electrically connected with the first signal input end in1, the drain electrode of the first transistor Q1 is electrically connected with the second fixed contact K3, and the source electrode of the first transistor Q is grounded. The gate of the first transistor Q1 is further electrically connected to a pull-down resistor R1, and one end of the pull-down resistor R1, which is far away from the gate of the first transistor Q1, is grounded.
The second signal input end in and the voltage input end in3 are electrically connected with the grid electrode of the second transistor Q2, and a pull-up resistor R3 is arranged between the grid electrode of the second transistor Q2 and the voltage input end in 3. The drain electrode of the second transistor Q2 is electrically connected to the gate electrode of the first transistor Q1, and the source electrode is grounded.
A current limiting resistor R2 is disposed between the first signal input terminal and the gate of the first transistor Q1, and between the second signal input terminal and the gate of the second transistor Q2, and is used for limiting the current to prevent the transistor from being burned out.
The protection circuit further includes a diode D for preventing the first transistor Q1 from being broken down, one end of the diode D is electrically connected between the external power source VIN and the first stationary contact K, and the other end of the diode is electrically connected between the drain of the first transistor Q1 and the second stationary contact.
The working principle of the protection circuit of the embodiment is as follows:
the first transistor Q1 and the second transistor Q2 are used as switching transistors, and the first control signal and the second control signal are respectively used for controlling on and off of the first transistor Q1 and the second transistor Q2.
The protection circuit has at least three states, when the protection circuit is in the first state, the first control signal is a low level signal, the first transistor Q1 is turned off, the relay K is turned off, and on the basis, no matter the second control signal is in a high level or a low level, namely, no matter the second transistor Q2 is turned on or off, the relay K can not be turned on.
When the protection circuit is in the second state, the first control signal is a high level signal and the second control signal is a low level signal, the first transistor Q1 is turned on, the second transistor Q2 is turned off, the movable contact K1 is contacted with the first fixed contact K2 and the second fixed contact K3, the relay K is conducted, and the external power supply VIN is connected to the lower-level power utilization circuit.
When the protection circuit is in the third state, the first control signal is a high level signal and the second control signal is a high level signal, at this time, the second transistor Q2 is turned on, and the gate of the first transistor Q1 is pulled down, which corresponds to the first transistor Q1 being turned off, so that the relay K is turned off.
The protection circuit of this embodiment utilizes two signals to jointly control the switching of relay K to prevent that control module is in when the power on is initially, control module input output is wrong, single control signal is disturbed the unusual actuation of relay K that causes of waiting, and then prevents to take place the accident, stability and security are higher.
The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.
Claims (7)
1. The protection circuit is characterized by comprising a relay and a control module, wherein the control module sends a first control signal and a second control signal to enable the relay to be turned on or turned off;
the protection circuit has at least three states, when the protection circuit is in a first state, the first control signal is a low-level signal, and the relay is disconnected; when the relay is in the second state, the first control signal is a high-level signal and the second control signal is a low-level signal, and the relay is conducted; when the relay is in the third state, the first control signal is a high level signal and the second control signal is a high level signal, and the relay is opened.
2. The protection circuit for preventing malfunction of a relay due to signal abnormality according to claim 1, wherein the relay has a movable contact connected to a lower-stage power circuit, a first stationary contact connected to an external power source, and a second stationary contact;
the protection circuit comprises a first transistor and a second transistor, wherein the grid electrode of the first transistor is electrically connected with a first control signal, and the drain electrode of the first transistor is electrically connected with a second static contact; the grid electrode of the second transistor is electrically connected with a second control signal, and the drain electrode of the second transistor is electrically connected with the grid electrode of the first transistor;
when the protection circuit is in a second state, the movable contact is contacted with the first static contact and the second static contact, and the relay is conducted so that an external power supply provides working voltage for a lower-stage circuit.
3. The protection circuit for preventing malfunction of a relay due to signal abnormality according to claim 2, wherein the protection circuit comprises a pull-down resistor, one end of the pull-down resistor is electrically connected to the gate of the first transistor, and the other end is grounded.
4. The protection circuit for preventing malfunction of a relay due to signal abnormality according to claim 2, further comprising a first signal input terminal for accessing a first control signal and a second signal input terminal for accessing a second control signal, which are electrically connected to the control module, the first signal input terminal being electrically connected to the gate of the first transistor, the second signal input terminal being electrically connected to the gate of the second transistor; and current limiting resistors are arranged between the first signal input end and the grid electrode of the first transistor and between the second signal input end and the grid electrode of the second transistor.
5. The protection circuit according to claim 4, wherein the protection circuit has a voltage input terminal electrically connected to the control module, a gate of the second transistor is electrically connected to the voltage input terminal, and a pull-up resistor is disposed between the gate of the second transistor and the voltage input terminal.
6. The protection circuit for preventing malfunction of a relay due to signal abnormality according to claim 2, further comprising a diode for preventing breakdown of the first transistor, one end of the diode being electrically connected between the external power supply and the first stationary contact, and the other end of the diode being electrically connected between the drain of the first transistor and the second stationary contact.
7. The protection circuit for preventing malfunction of a relay due to signal abnormality according to claim 2, wherein a source of the first transistor is grounded and a source of the second transistor is grounded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320799783.9U CN219420288U (en) | 2023-04-12 | 2023-04-12 | Protection circuit for preventing relay misoperation caused by signal abnormality |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202320799783.9U CN219420288U (en) | 2023-04-12 | 2023-04-12 | Protection circuit for preventing relay misoperation caused by signal abnormality |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN219420288U true CN219420288U (en) | 2023-07-25 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202320799783.9U Active CN219420288U (en) | 2023-04-12 | 2023-04-12 | Protection circuit for preventing relay misoperation caused by signal abnormality |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN219420288U (en) |
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2023
- 2023-04-12 CN CN202320799783.9U patent/CN219420288U/en active Active
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