Direct-current relay for realizing reverse connection protection

Abstract

The utility model relates to the technical field of direct-current relays, in particular to a direct-current relay for realizing reverse connection protection, which comprises a relay coil, a positive terminal, a negative terminal, a control switch, a normally closed switch and a normally open switch. The control switch comprises a switch part and a control part; the positive terminal is connected with the positive electrode of the control part; the cathode of the control part is connected with the cathode binding post through the normally closed switch; the negative terminal is connected with one end of a relay coil; the other end of the relay coil is connected with the positive terminal through the switch part; and the other end of the relay coil is connected with the positive terminal through a normally open switch. According to the utility model, the control switch, the normally closed switch and the normally open switch are arranged, so that when the relay is positively connected with a power supply, a relay coil forms a self-locking loop and can work normally; and when the relay is reversely connected with the power supply, the relay coil cannot form a conductive loop, so that the relay can be effectively protected.

Description

Technical Field

[0001] The utility model relates to the technical field of DC relays, and particularly relates to a DC relay for realizing reverse connection protection. Background Art

[0002] As one of the main electrical components in modern industrial automation control, the DC relay is widely and indispensably applied in various electrical circuits, and can be said to play a crucial role in the electrical weak current control loop. However, due to the specific circuit principle inside the DC relay, in actual applications, the DC relay usually has specified requirements for the positive and negative polarity wiring of its coil and cannot be reversely connected. Once the reverse connection occurs, it may directly cause the internal components of the DC relay to burn out or the materials to be scrapped, thus affecting the normal use of the entire electrical circuit. Content of the Utility Model

[0003] The purpose of the utility model is to provide a DC relay for realizing reverse connection protection aiming at the above deficiencies in the prior art.

[0004] The purpose of the utility model is achieved through the following technical solutions: A DC relay for realizing reverse connection protection includes a relay coil, a positive terminal, a negative terminal, a control switch, a normally closed switch cooperating with the relay coil, and a normally open switch cooperating with the relay coil;

[0005] The control switch includes a switch part and a control part;

[0006] The positive terminal is connected to the positive pole of the control part; the negative pole of the control part is connected to the negative terminal through the normally closed switch; the negative terminal is connected to one end of the relay coil; the other end of the relay coil is connected to the positive terminal through the switch part; the other end of the relay coil is connected to the positive terminal through the normally open switch.

[0007] The utility model is further provided that the control switch is an optocoupler.

[0008] The utility model is further provided that a first resistor is provided between the negative pole of the control part and the normally closed switch.

[0009] The utility model is further provided that the DC relay for realizing reverse connection protection further includes a first light-emitting LED; the positive pole of the first light-emitting LED is connected to the other end of the relay coil; the negative pole of the first light-emitting LED is connected to the negative terminal.

[0010] The utility model is further provided that a second resistor is provided between the negative pole of the first light-emitting LED and the negative terminal.

[0011] The present utility model is further configured such that the DC relay for reverse connection protection further includes a freewheeling diode; the freewheeling diode is connected in parallel with the relay coil; the positive electrode of the freewheeling diode is connected to one end of the relay coil; the negative electrode of the freewheeling diode is connected to the other end of the relay coil.

[0012] The present utility model is further configured such that the DC relay for reverse connection protection further includes a second light-emitting LED; the positive electrode of the second light-emitting LED is connected to the negative terminal; the negative electrode of the second light-emitting LED is connected to the positive terminal.

[0013] The present utility model is further configured such that a third resistor is provided between the negative electrode of the second light-emitting LED and the positive terminal.

[0014] The beneficial effects of the present utility model: By providing a control switch, a normally closed switch, and a normally open switch, when the present utility model is correctly connected to the power supply, the relay coil forms a self-locking circuit and can operate normally; when it is reversely connected to the power supply, the relay coil cannot form a conductive circuit, effectively protecting the relay. Description of the Drawings

[0015] The present utility model will be further described with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation to the present utility model. For those of ordinary skill in the art, other drawings can also be obtained based on the following drawings without creative efforts.

[0016] Figure 1 is the circuit schematic diagram of the present utility model;

[0017] Figure 2 is the circuit schematic diagram when the present utility model is correctly connected;

[0018] Figure 3 is the circuit schematic diagram when the present utility model is reversely connected;

[0019] Wherein: 1. Relay coil; 21. Positive terminal; 22. Negative terminal; 31. Normally closed switch; 32. Normally open switch; 41. Switch part; 42. Control part; 51. First resistor; 52. Second resistor; 53. Third resistor; 61. First light-emitting LED; 62. Second light-emitting LED; 7. Freewheeling diode. Detailed Embodiments

[0020] The present utility model will be further described in conjunction with the following embodiments.

[0021] By Figures 1 to 3It can be known that a DC relay for realizing reverse connection protection according to this embodiment includes a relay coil 1, a positive terminal 21, a negative terminal 22, a control switch, a normally closed switch 31 cooperating with the relay coil 1, and a normally open switch 32 cooperating with the relay coil 1;

[0022] The control switch includes a switch part 41 and a control part 42;

[0023] The positive terminal 21 is connected to the positive pole of the control part 42; the negative pole of the control part 42 is connected to the negative terminal 22 through the normally closed switch 31; the negative terminal 22 is connected to one end of the relay coil 1; the other end of the relay coil 1 is connected to the positive terminal 21 through the switch part 41; the other end of the relay coil 1 is connected to the positive terminal 21 through the normally open switch 32.

[0024] Specifically, for the DC relay for realizing reverse connection protection according to this embodiment, as Figure 2 shown, when the relay coil 1 is correctly connected, that is, when the positive terminal 21 is connected to the positive pole of the power supply and the negative terminal 22 is connected to the negative pole of the power supply, since the normally closed switch 31 is in a closed state at the moment of power-on, the branch of the control part 42 of the control switch is conducting, so that the switch part 41 of the control switch is also conducting, then the relay coil 1 is conducting and powered on. At this time, due to the electromagnetic force, the normally closed switch 31 is disconnected, and at the same time the normally open switch 32 is closed, so that a loop is formed among the relay coil 1, the normally open switch 32, the positive terminal 21 and the negative terminal 22. This makes the relay coil 1 loop actually self-lock. Therefore, even if the normally closed switch 31 is disconnected at this time and the control switch stops operating, as long as the positive terminal 21 and the negative terminal 22 are still in a powered-on state, the relay coil 1 will always be in a powered-on state; in addition, the disconnection of the normally closed switch 31 can also avoid additional power consumption caused by the continuous operation of the control switch.

[0025] As Figure 3 shown, when the relay coil 1 is reversely connected, that is, when the positive terminal 21 is connected to the negative pole of the power supply and the negative terminal 22 is connected to the positive pole of the power supply, at this time the control part 42 of the control switch cannot conduct, so that the switch part 41 of the control switch is always in an open state, and the normally open switch 32 is also always in an open state because the relay coil 1 is not powered on. Therefore, a loop can never be formed among the relay coil 1, the positive terminal 21 and the negative terminal 22. Thus, the relay coil 1 never works, which can prevent damage to the relay coil 1 after reverse connection.

[0026] For the DC relay for realizing reverse connection protection according to this embodiment, the control switch is an optocoupler. Through the above settings, the overall structure is stable and reliable.

[0027] A DC relay for implementing reverse connection protection according to this embodiment, a first resistor 51 is provided between the negative electrode of the control unit 42 and the normally closed switch 31. Through the above arrangement, it is possible to prevent a short - circuit situation from occurring in the branch where the control unit 42 and the normally closed switch 31 are located.

[0028] A DC relay for implementing reverse connection protection according to this embodiment, the DC relay for implementing reverse connection protection further includes a first light - emitting LED61; the positive electrode of the first light - emitting LED61 is connected to the other end of the relay coil 1; the negative electrode of the first light - emitting LED61 is connected to the negative terminal 22.

[0029] Specifically, as Figure 2 shown, when the relay coil 1 is connected correctly, that is, when the positive terminal 21 is connected to the positive electrode of the power supply and the negative terminal 22 is connected to the negative electrode of the power supply, since the normally open switch 32 is closed, a loop is formed among the first light - emitting LED61, the normally open switch 32, the positive terminal 21, and the negative terminal 22, causing the first light - emitting LED61 to emit light, reminding the user that the relay coil 1 is in the correct connection state at this time.

[0030] A DC relay for implementing reverse connection protection according to this embodiment, a second resistor 52 is provided between the negative electrode of the first light - emitting LED61 and the negative terminal 22. Through the above arrangement, it is possible to prevent a short - circuit situation from occurring in the branch where the first light - emitting LED61 is located.

[0031] A DC relay for implementing reverse connection protection according to this embodiment, the DC relay for implementing reverse connection protection further includes a free - wheeling diode 7; the free - wheeling diode 7 is connected to the relay coil 1; the positive electrode of the free - wheeling diode 7 is connected to one end of the relay coil 1; the negative electrode of the free - wheeling diode 7 is connected to the other end of the relay coil 1.

[0032] Specifically, when the relay coil 1 is connected correctly, that is, when the positive terminal 21 is connected to the positive electrode of the power supply and the negative terminal 22 is connected to the negative electrode of the power supply, the relay coil 1 circuit actually locks itself. Therefore, even if the normally closed switch 31 is disconnected at this time and the control switch stops operating, as long as the positive terminal 21 and the negative terminal 22 are still powered on, the relay coil 1 will always be powered on; when there is a sudden power - off between the positive terminal 21 and the negative terminal 22, because the free - wheeling diode 7 is connected in parallel with the relay coil 1, the high electromotive force generated by the sudden voltage change of the relay coil 1 can also be consumed in the free - wheeling diode 7, avoiding impact damage to sensitive components inside or outside the relay.

[0033] A DC relay for implementing reverse connection protection according to this embodiment, the DC relay for implementing reverse connection protection further includes a second light-emitting LED62; the positive pole of the second light-emitting LED62 is connected to the negative terminal 22; the negative pole of the second light-emitting LED62 is connected to the positive terminal 21. Specifically, as Figure 3 shown, when the relay coil 1 is reversely connected, that is, when the positive terminal 21 is connected to the negative pole of the power supply and the negative terminal 22 is connected to the positive pole of the power supply, a loop is formed among the second light-emitting LED62, the positive terminal 21, and the negative terminal 22, causing the second light-emitting LED62 to emit light, reminding the user that the relay coil 1 is in a reversely connected state at this time.

[0034] A DC relay for implementing reverse connection protection according to this embodiment, a third resistor 53 is provided between the negative pole of the second light-emitting LED62 and the positive terminal 21. Through the above setting, the situation of short circuit in the branch where the second light-emitting LED62 is located can be prevented.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A DC relay for implementing reverse connection protection, characterized in that: It includes a relay coil (1), a positive terminal (21), a negative terminal (22), a control switch, a normally closed switch (31) cooperating with the relay coil (1), and a normally open switch (32) cooperating with the relay coil (1); The control switch includes a switch part (41) and a control part (42); The positive terminal (21) is connected to the positive pole of the control part (42); the negative pole of the control part (42) is connected to the negative terminal (22) through the normally closed switch (31); the negative terminal (22) is connected to one end of the relay coil (1); the other end of the relay coil (1) is connected to the positive terminal (21) through the switch part (41); the other end of the relay coil (1) is connected to the positive terminal (21) through the normally open switch (32).

2. The DC relay for implementing reverse connection protection according to claim 1, wherein: The control switch is an optocoupler.

3. A DC relay for implementing reverse connection protection according to claim 1, characterized in that: A first resistor (51) is provided between the negative pole of the control part (42) and the normally closed switch (31).

4. A DC relay for implementing reverse connection protection according to claim 1, characterized in that: The DC relay for realizing reverse connection protection further includes a first light-emitting LED (61); the positive pole of the first light-emitting LED (61) is connected to the other end of the relay coil (1); the negative pole of the first light-emitting LED (61) is connected to the negative terminal (22).

5. A DC relay for implementing reverse connection protection according to claim 4, characterized in that: A second resistor (52) is provided between the negative pole of the first light-emitting LED (61) and the negative terminal (22).

6. A DC relay for implementing reverse connection protection according to claim 1, characterized in that: The DC relay for realizing reverse connection protection further includes a freewheeling diode (7); the freewheeling diode (7) is connected in parallel with the relay coil (1); the positive pole of the freewheeling diode (7) is connected to one end of the relay coil (1); the negative pole of the freewheeling diode (7) is connected to the other end of the relay coil (1).

7. A DC relay for implementing reverse connection protection according to claim 1, characterized in that: The DC relay for realizing reverse connection protection further includes a second light-emitting LED (62); the positive pole of the second light-emitting LED (62) is connected to the negative terminal (22); the negative pole of the second light-emitting LED (62) is connected to the positive terminal (21).

8. A DC relay for implementing reverse connection protection according to claim 7, characterized in that: A third resistor (53) is provided between the negative pole of the second light-emitting LED (62) and the positive terminal (21).

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