Bleeding circuit applied to electromagnetic relay

Abstract

The utility model provides a bleeder circuit applied to an electromagnetic relay. The bleeder circuit applied to the electromagnetic relay comprises an NPN-type triode Q1 and a bleeder unit, a base electrode of the NPN-type triode Q1 is used for receiving external control signals, an emitter electrode of the NPN-type triode Q1 is grounded, a collector electrode of the NPN-type triode Q1 is connected with a first end of a magnet exciting coil of an electromagnetic relay K1, and a second end of the magnet exciting coil of the electromagnetic relay K1 is connected with the bleeder unit. The second end of the excitation coil of the electromagnetic relay K1 is connected with the power supply, the first end of the discharge unit is connected with the first end of the excitation coil of the electromagnetic relay K1, and the second end of the discharge unit is connected with the power supply or grounded. The bleeder circuit applied to the electromagnetic relay can adapt to the inductance energy discharge of the electromagnetic relay with different requirements, and the suitability is greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electromagnetic relays, in particular to a discharge circuit applied to electromagnetic relays. Background Art

[0002] Electromagnetic relays are electronic control devices commonly used in automatic control circuits. They act as an "automatic switch" that uses a smaller current and lower voltage to control a larger current and higher voltage. Consequently, they are widely used in industrial control. However, if the inductive energy in the excitation coil is not discharged promptly when the electromagnetic relay is disconnected, the disconnection time of the electromagnetic relay will be prolonged, causing the electromagnetic relay's arcing time to increase, affecting system performance and the life of the electromagnetic relay.

[0003] Existing technologies typically discharge the inductive energy in the excitation coil by connecting a freewheeling diode in parallel with the excitation coil. However, this solution is only suitable for low-power electromagnetic relays and is not suitable for high-power electromagnetic relays or relays with strict shutdown time requirements. This is because in existing applications of high-power electromagnetic relays and relays with strict shutdown time requirements, the freewheeling diode will continue to supply magnetizing current to the excitation coil of the electromagnetic relay during the inductive energy discharge process. The magnetizing current will not disappear until the inductive energy is discharged, which in turn increases the shutdown time of the electromagnetic relay. Utility Model Content

[0004] The purpose of the utility model is to provide a discharge circuit applied to an electromagnetic relay, so as to solve the technical problem of insufficient adaptability of the discharge circuit in the prior art.

[0005] The technical solution of the present utility model is as follows, which provides a discharge circuit applied to an electromagnetic relay, including an NPN transistor Q1 and a discharge unit 10, wherein the base of the NPN transistor Q1 is used to receive an external control signal, the emitter of the NPN transistor Q1 is grounded, the collector of the NPN transistor Q1 is connected to the first end of the excitation coil of the electromagnetic relay K1, the second end of the excitation coil of the electromagnetic relay K1 is connected to the power supply, the first end of the discharge unit 10 is connected to the first end of the excitation coil of the electromagnetic relay K1, and the second end of the discharge unit 10 is connected to the power supply or ground.

[0006] Preferably, the discharge unit 10 includes a fast recovery diode D2 and a Zener diode D1, the first end of the fast recovery diode D2 is connected to the first end of the Zener diode D1, the second end of the fast recovery diode D2 is connected to the first end of the excitation coil of the electromagnetic relay K1, and the second end of the Zener diode D1 is connected to the power supply.

[0007] Preferably, the avalanche voltage of the Zener diode D1 is greater than the voltage VCC of the power supply.

[0008] Preferably, the discharge unit 10 includes a fast recovery diode D2 and a Zener diode D1, the first end of the fast recovery diode D2 is connected to the first end of the Zener diode D1, the second end of the fast recovery diode D2 is connected to the first end of the excitation coil of the electromagnetic relay K1, and the second end of the Zener diode D1 is grounded.

[0009] Preferably, the discharge unit 10 includes a TVS tube TVS1 , a first end of the TVS tube TVS1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the TVS tube TVS1 is connected to a power supply.

[0010] Preferably, the avalanche voltage of the TVS tube TVS1 is greater than the voltage VCC of the power supply.

[0011] Preferably, the discharge unit 10 includes a TVS tube TVS1 , a first end of the TVS tube TVS1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the TVS tube TVS1 is grounded.

[0012] Preferably, the discharge unit 10 includes a varistor MOV1 , a first end of the varistor MOV1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the varistor MOV1 is connected to a power supply.

[0013] Preferably, the avalanche voltage of the varistor MOV1 is greater than the voltage VCC of the power supply.

[0014] Preferably, the discharge unit 10 includes a varistor MOV1 , a first end of the varistor MOV1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the varistor MOV1 is grounded.

[0015] The beneficial effect of the present invention is that the discharge unit 10 is used to quickly discharge the inductive energy remaining in the excitation coil of the electromagnetic relay to the power supply or the ground when the power supply no longer provides current to the excitation coil of the electromagnetic relay K1. While discharging the inductive energy, it will not have a secondary impact on the excitation coil, so that the discharge circuit applied to the electromagnetic relay can adapt to the inductive energy discharge of the electromagnetic relay with different requirements, greatly improving the adaptability of the discharge circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural block diagram of the discharge circuit applied to the electromagnetic relay of the utility model.

[0017] Figure 2This is a first circuit principle diagram of a discharge circuit applied to an electromagnetic relay according to the present invention.

[0018] Figure 3 This is a second circuit principle diagram of the discharge circuit applied to the electromagnetic relay of the utility model.

[0019] Figure 4 This is a third circuit principle diagram of the discharge circuit applied to the electromagnetic relay of the present utility model.

[0020] Figure 5 This is a fourth circuit principle diagram of the discharge circuit applied to the electromagnetic relay of the present invention.

[0021] Figure 6 This is a fifth circuit principle diagram of the discharge circuit applied to the electromagnetic relay of the present utility model.

[0022] Figure 7 This is the sixth circuit principle diagram of the discharge circuit applied to the electromagnetic relay of the utility model. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0024] References to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] Figure 1 This is a block diagram of the discharge circuit of the electromagnetic relay according to the embodiment of the present invention. It should be noted that if there is substantially the same result, the present invention is not based on Figure 1 The structure shown is limited. Figure 1As shown, the discharge circuit applied to the electromagnetic relay includes an NPN transistor Q1 and a discharge unit 10, wherein the base of the NPN transistor Q1 is used to receive an external control signal, the emitter of the NPN transistor Q1 is grounded, the collector of the NPN transistor Q1 is connected to the first end of the excitation coil of the electromagnetic relay K1, the second end of the excitation coil of the electromagnetic relay K1 is connected to the power supply, the first end of the discharge unit 10 is connected to the first end of the excitation coil of the electromagnetic relay K1, and the second end of the discharge unit 10 is connected to the power supply or ground.

[0026] In this embodiment, an NPN transistor Q1 receives an external control signal through its base to control the on / off state between its emitter and collector, thereby controlling the on / off state of the bleeder circuit for the electromagnetic relay. Specifically, when the base of the NPN transistor Q1 receives a high-level signal, the NPN transistor Q1 turns on, allowing current to flow from its collector to its emitter. Current from the power supply normally flows through the excitation coil of the electromagnetic relay K1, causing the electromagnetic relay K1 to close. Subsequently, when the base of the NPN transistor receives a low-level signal or no input, the transistor turns off, and the power supply no longer supplies current to the excitation coil of the electromagnetic relay K1. At this point, the residual inductive energy in the excitation coil of the electromagnetic relay K1 is discharged to the power supply or ground through the bleeder circuit. This discharge of inductive energy does not cause any secondary effects on the excitation coil. This allows the bleeder circuit for the electromagnetic relay to adapt to different requirements for inductive energy discharge in electromagnetic relays, significantly improving adaptability.

[0027] In some embodiments, Figure 2 FIG. 1 is a first circuit schematic diagram of a discharge circuit applied to an electromagnetic relay, such as Figure 2 As shown, the discharge unit 10 includes a fast recovery diode D2 and a Zener diode D1, the first end of the fast recovery diode D2 is connected to the first end of the Zener diode D1, the second end of the fast recovery diode D2 is connected to the first end of the excitation coil of the electromagnetic relay K1, and the second end of the Zener diode D1 is connected to the power supply.

[0028] In this embodiment, the first end of the fast recovery diode D2 is a cathode, the second end of the fast recovery diode D2 is an anode, the first end of the Zener diode D1 is a cathode, and the second end of the Zener diode D1 is an anode. When the electromagnetic relay K1 is no longer energized, the second end of the fast recovery diode D2 attracts the residual current in the excitation coil of the electromagnetic relay K1 and quickly discharges the residual current to the power supply.

[0029] In some embodiments, the avalanche voltage of the Zener diode D1 is greater than the voltage VCC of the power supply.

[0030] In this embodiment, the avalanche voltage of the Zener diode D1 is greater than the voltage VCC of the power supply, which prevents the Zener diode D1 from avalanching when the electromagnetic relay K1 is working normally, thereby preventing the normal operation of the electromagnetic relay K1 from being affected, thereby ensuring the stability of the discharge circuit applied to the electromagnetic relay of the present invention.

[0031] In some embodiments, Figure 3 The second circuit schematic diagram of the discharge circuit applied to the electromagnetic relay is as follows: Figure 3 As shown, the discharge unit 10 includes a fast recovery diode D2 and a Zener diode D1, the first end of the fast recovery diode D2 is connected to the first end of the Zener diode D1, the second end of the fast recovery diode D2 is connected to the first end of the excitation coil of the electromagnetic relay K1, and the second end of the Zener diode D1 is grounded.

[0032] In this embodiment, the first end of the fast recovery diode D2 is a cathode, and the second end of the fast recovery diode D2 is an anode. The first end of the Zener diode D1 is a cathode, and the second end of the Zener diode D1 is an anode. When the electromagnetic relay K1 is no longer energized, the second end of the fast recovery diode D2 absorbs the residual inductive energy in the excitation coil of the electromagnetic relay K1 and quickly discharges this residual inductive energy to the ground.

[0033] In some embodiments, Figure 4 The third circuit schematic diagram of the discharge circuit applied to the electromagnetic relay is shown in FIG. Figure 4 As shown, the discharge unit 10 includes a TVS tube TVS1 , a first end of the TVS tube TVS1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the TVS tube TVS1 is connected to a power supply.

[0034] In this embodiment, the TVS diode is a bidirectional TVS diode. When the electromagnetic relay K1 is no longer energized, the TVS diode can absorb the residual inductive energy in the excitation coil of the electromagnetic relay K1 and quickly discharge the residual inductive energy to the power supply.

[0035] In some embodiments, the avalanche voltage of the TVS tube TVS1 is greater than the voltage VCC of the power supply.

[0036] In this embodiment, the avalanche voltage of the TVS tube TVS1 is greater than the power supply voltage VCC of the power supply, thereby preventing the Zener diode D1 from avalanching when the electromagnetic relay K1 is working normally, thereby affecting the normal operation of the electromagnetic relay K1, thereby ensuring the stability of the discharge circuit applied to the electromagnetic relay of the utility model.

[0037] In some embodiments, Figure 5FIG4 is a fourth circuit schematic diagram of a discharge circuit applied to an electromagnetic relay, such as Figure 5 As shown, the discharge unit 10 includes a TVS tube TVS1 , a first end of the TVS tube TVS1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the TVS tube TVS1 is grounded.

[0038] In this embodiment, when the electromagnetic relay K1 is powered on, the TVS diode can absorb the residual inductive energy in the excitation coil of the electromagnetic relay K1 and quickly discharge the residual inductive energy to the ground.

[0039] In some embodiments, Figure 6 The fifth circuit schematic diagram of the discharge circuit applied to the electromagnetic relay is shown in FIG. Figure 6 As shown, the discharge unit 10 includes a varistor MOV1 , a first end of the varistor MOV1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the varistor MOV1 is connected to a power supply.

[0040] In this embodiment, when the electromagnetic relay K1 is powered on, the varistor MOV1 can absorb the residual inductive energy in the excitation coil of the electromagnetic relay K1 and quickly discharge the residual inductive energy to the power supply.

[0041] In some embodiments, the avalanche voltage of the varistor MOV1 is greater than the voltage VCC of the power supply.

[0042] In this embodiment, the avalanche voltage of the varistor MOV1 is greater than the power supply voltage VCC of the power supply, which prevents the varistor MOV1 from avalanching when the electromagnetic relay K1 is working normally, thereby preventing the normal operation of the electromagnetic relay K1 from being affected, thereby ensuring the stability of the discharge circuit applied to the electromagnetic relay of the utility model.

[0043] In some embodiments, Figure 7 The sixth circuit schematic diagram of the discharge circuit applied to the electromagnetic relay is shown in FIG. Figure 7 As shown, the discharge unit 10 includes a varistor MOV1 , a first end of the varistor MOV1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the varistor MOV1 is grounded.

[0044] When the electromagnetic relay K1 is no longer energized, the varistor MOV1 can absorb the residual inductive energy in the excitation coil of the electromagnetic relay K1 and quickly discharge the residual inductive energy to the ground.

[0045] The above is only an embodiment of the present invention. It should be pointed out that those skilled in the art can make improvements without departing from the inventive concept of the present invention, but these improvements are all within the scope of protection of the present invention.

Claims

1. A discharge circuit applied to an electromagnetic relay, characterized in that: It includes an NPN transistor Q1 and a discharge unit, wherein the base of the NPN transistor Q1 is used to receive an external control signal, the emitter of the NPN transistor Q1 is grounded, the collector of the NPN transistor Q1 is connected to the first end of the excitation coil of the electromagnetic relay K1, the second end of the excitation coil of the electromagnetic relay K1 is connected to the power supply, the first end of the discharge unit is connected to the first end of the excitation coil of the electromagnetic relay K1, and the second end of the discharge unit is connected to the power supply or ground.

2. The discharge circuit for electromagnetic relay according to claim 1, characterized in that: The discharge unit includes a fast recovery diode D2 and a Zener diode D1, a first end of the fast recovery diode D2 is connected to the first end of the Zener diode D1, a second end of the fast recovery diode D2 is connected to the first end of the excitation coil of the electromagnetic relay K1, and a second end of the Zener diode D1 is connected to a power supply.

3. The discharge circuit for electromagnetic relay according to claim 2, characterized in that: The avalanche voltage of the Zener diode D1 is greater than the voltage VCC of the power supply.

4. The discharge circuit for electromagnetic relay according to claim 1, characterized in that: The discharge unit includes a fast recovery diode D2 and a Zener diode D1. The first end of the fast recovery diode D2 is connected to the first end of the Zener diode D1. The second end of the fast recovery diode D2 is connected to the first end of the excitation coil of the electromagnetic relay K1. The second end of the Zener diode D1 is grounded.

5. The discharge circuit for electromagnetic relay according to claim 1, characterized in that: The discharge unit includes a TVS tube TVS1 , a first end of the TVS tube TVS1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the TVS tube TVS1 is connected to a power supply.

6. The discharge circuit for electromagnetic relay according to claim 5, characterized in that: The avalanche voltage of the TVS tube TVS1 is greater than the voltage VCC of the power supply.

7. The discharge circuit for electromagnetic relay according to claim 1, characterized in that: The discharge unit includes a TVS tube TVS1 , a first end of the TVS tube TVS1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the TVS tube TVS1 is grounded.

8. The discharge circuit for electromagnetic relay according to claim 1, characterized in that: The discharge unit includes a varistor MOV1 , a first end of the varistor MOV1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the varistor MOV1 is connected to a power supply.

9. The discharge circuit for electromagnetic relay according to claim 8, characterized in that: The avalanche voltage of the varistor MOV1 is greater than the voltage VCC of the power supply.

10. The discharge circuit for electromagnetic relay according to claim 1, characterized in that: The discharge unit includes a varistor MOV1 , a first end of the varistor MOV1 is connected to a first end of the excitation coil of the electromagnetic relay K1 , and a second end of the varistor MOV1 is grounded.

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