Drive circuit and electromagnetic relay

Abstract

The utility model discloses a driving circuit and an electromagnetic relay, the driving circuit comprises a voltage source, a switch tube, an inductor and a controller, the positive electrode of the voltage source is connected with the drain electrode of the switch tube, the source electrode of the switch tube is connected with one end of the inductor, the other end of the inductor is connected with a third pin of the relay, and the negative electrode of the voltage source is grounded; the negative electrode of the voltage source is also connected with the fourth pin of the relay; the output end of the controller is connected with the grid electrode of the switching tube; and the output end of the controller outputs a PWM control signal.

Description

Technical Field

[0001] The utility model relates to the field of electronics, in particular to a drive circuit and an electromagnetic relay. Background Art

[0002] Electromagnetic relays are common devices used in the power electronics industry. Their operating principle is as follows: an electromagnet is a device that uses electric current to generate a magnetic field. When current flows through the coil of an electromagnet, a magnetic field is generated within the coil. This magnetic field attracts or repels ferromagnetic materials, thereby attracting or repelling objects. The strength of the electromagnet's magnetic field is proportional to the current in the coil; the higher the current, the stronger the magnetic field. The contact system, the core component of an electromagnetic relay, consists of a set of movable contacts and a set of fixed contacts. When the electromagnet generates a magnetic field, the movable contacts are attracted to the fixed contacts, completing the circuit. When the electromagnet loses its magnetic field, the movable contacts are pulled back by a spring, disconnecting the circuit. The spring is a crucial component of an electromagnetic relay, ensuring that the movable contacts return quickly to their original position when the electromagnet loses its magnetic field. The spring's elastic force is proportional to its degree of deformation; the greater the deformation, the greater the elastic force.

[0003] Existing electromagnetic drivers have large driving losses and low efficiency. Utility Model Content

[0004] The embodiments of the present utility model provide a driving circuit and an electromagnetic relay, which have the advantages of reducing driving loss and improving efficiency.

[0005] In a first aspect, a drive circuit is provided, comprising: a voltage source, a switch tube, an inductor, and a controller, wherein a positive electrode of the voltage source is connected to a drain electrode of the switch tube, a source electrode of the switch tube is connected to one end of the inductor, the other end of the inductor is connected to a third pin of a relay, a negative electrode of the voltage source is grounded, and the negative electrode of the voltage source is also connected to a fourth pin of the relay, and an output end of the controller is connected to a gate electrode of the switch tube;

[0006] The output end of the controller outputs a PWM control signal.

[0007] Optional,

[0008] The switch tube is MOS or TFT.

[0009] Optional,

[0010] The duty cycle of the PWM control signal is 0, 1 or 0.6.

[0011] Optional,

[0012] The driving circuit further includes a diode, wherein the anode of the diode is grounded and the cathode of the diode is connected to one end of the inductor.

[0013] Optional,

[0014] The driving circuit further includes a capacitor, with two ends of the capacitor connected to the third pin and the fourth pin respectively.

[0015] In a second aspect, an electromagnetic relay is provided, comprising: a relay and a drive circuit, wherein the relay comprises: a control coil R, a switch K, and four pins; wherein the two ends of the control coil R are respectively connected to a third pin and a fourth pin, and the two ends of the switch K are respectively connected to a first pin and a second pin, wherein the switch K and the control coil R are in a magnetically coupled structure; and the drive circuit comprises:

[0016] A voltage source, a switching tube, an inductor, and a controller, wherein the positive electrode of the voltage source is connected to the drain of the switching tube, the source of the switching tube is connected to one end of the inductor, the other end of the inductor is connected to the third pin of the relay, the negative electrode of the voltage source is grounded, and the negative electrode of the voltage source is also connected to the fourth pin of the relay, and the output end of the controller is connected to the gate of the switching tube;

[0017] The output end of the controller outputs a PWM control signal.

[0018] Optional,

[0019] The switch tube is MOS or TFT.

[0020] Optional,

[0021] The duty cycle of the PWM control signal is 0, 1 or 0.6.

[0022] Optional,

[0023] The driving circuit further includes a diode, wherein the anode of the diode is grounded and the cathode of the diode is connected to one end of the inductor.

[0024] Optional,

[0025] The driving circuit further includes a capacitor, with two ends of the capacitor connected to the third pin and the fourth pin respectively.

[0026] The implementation of the present invention has the following beneficial effects:

[0027] The technical solution of the present application is that when K is disconnected, Drive = 0, that is, V (the voltage between PIN3 and PIN4) = 0, and the PWM duty cycle is equal to 0. When Drive = 1, V (the voltage between PIN3 and PIN4) = D, that is, K is closed, and the PWM duty cycle is equal to 1. After a period of time, for example, after 1 second, K is continuously closed, and the PWM duty cycle is equal to 0.6, that is, V = 0.6D, thus reducing power consumption. Through the above circuit and control strategy, a single drive signal can control the hierarchical power supply of the relay, while reducing drive loss and improving efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 It is a circuit diagram of an electromagnetic relay;

[0030] Figure 2 This is a schematic diagram of the structure of an electromagnetic relay provided by this application;

[0031] Figure 3 This is a schematic diagram of the PWM duty cycle provided by this application. DETAILED DESCRIPTION

[0032] 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 part of the embodiments of the present invention, not all of them. 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.

[0033] The terms "first," "second," "third," and "fourth," etc., in the specification, claims, and accompanying drawings of the present invention are used to distinguish between different items, not to describe a specific order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements, but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0034] References to "embodiments" herein mean that a particular feature, result, or characteristic described in connection with the embodiment 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.

[0035] See Figure 1 , Figure 1 A circuit diagram of an electromagnetic relay is shown in FIG. Figure 1 The circuit shown includes: a current source DC, a driving winding R, and a switch K, wherein:

[0036] Pins 3 (PIN3) and 4 (PIN4) are internally connected to a relay drive winding (impedance R), which controls the on / off state of power pins PIN1 and PIN2. When a voltage of VA (typically 12V) is applied to PIN3 and PIN4, relay K is energized (connecting PIN1 and PIN2). When a voltage of 0V is applied to PIN3 and PIN4, K is disconnected (disconnecting PIN1 and PIN2). When a voltage of VA is applied to relay pins PIN3 and PIN4, K energizes. To ensure continued energization, a holding voltage VB must be applied to PIN3 and PIN4 (typically 0.6*VA ≤ VB ≤ VA).

[0037] When voltage is applied to PIN3 and PIN4, the loss of the driving winding P = V2 / R. In order to reduce the loss, VB is generally set to 0.6*VA.

[0038] See Figure 2 , Figure 2 A schematic diagram of the structure of an electromagnetic relay is provided for this application. Figure 2 As shown, the electromagnetic relay comprises: a relay 10 and a drive circuit 20; Figure 2 As shown,

[0039] The relay 10 comprises a control coil R, a switch K and four pins (PIN); wherein,

[0040] The two ends of the control coil R are connected to the third pin PIN3 and the fourth pin PIN4 respectively, and the two ends of the switch K are connected to the first pin PIN1 and the second pin PIN2 respectively. The switch K and the control coil R have a magnetic attraction matching structure. That is, the magnetic field generated when the control coil R is energized will attract the switch K and make the switch K closed. Conversely, when the control coil R is de-energized, the magnetic field disappears and the switch K will return to being open.

[0041] The driving circuit 20 includes a voltage source VA, a switch Q, an inductor L, and a controller. The positive electrode of the voltage source VA is connected to the drain of the switch Q, the source of the switch Q is connected to one end of the inductor L, the other end of the inductor L is connected to the third pin PIN3 of the relay 10, the negative electrode of the voltage source VA is grounded, and the negative electrode of the voltage source VA is also connected to the fourth pin PIN4. The output end of the controller is connected to the gate of the switch Q.

[0042] The output end of the controller outputs a PWM control signal.

[0043] For example, the switch tube Q may be a MOS tube or a TFT (thin film transistor).

[0044] For example, the duty cycle of the PWM control signal is 0, 1 or 0.6.

[0045] Figure 3 The schematic diagram of the PWM duty cycle provided for this application is as follows: Figure 3 As shown, when K is disconnected, Drive = 0 (as Figure 3 The voltage shown is L), that is, at this time V (voltage between PIN3 and PIN4) = 0, the PWM duty cycle is equal to 0, at this time Drive = 1, at this time V (voltage between PIN3 and PIN4) = D (such as Figure 3 The voltage shown is H), meaning K is closed at this time, and the PWM duty cycle is 1. After a period of time, for example, one second, K remains closed, and the PWM duty cycle is 0.6, meaning V = (T1 / T2)*D = 0.6D, thus reducing power consumption. With the above circuit and control strategy, a single drive signal can control the relay's hierarchical power supply, while reducing drive losses and improving efficiency.

[0046] For example, the driving circuit further includes a diode D, wherein the anode of the diode D is grounded and the cathode is connected to one end of the inductor L. The purpose of configuring the diode D is to prevent current backflow, that is, to prevent current backflow caused by the voltage of PIN4 being higher than PIN3, thereby improving the safety and reliability of the circuit.

[0047] For example, the driving circuit further includes a capacitor C, with both ends of the capacitor C connected to the third pin PIN3 and the fourth pin PIN4 respectively. The capacitor C is provided to maintain the stability of the circuit and avoid current instability.

[0048] In the several embodiments provided in this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0049] The above is a detailed introduction to the embodiments of the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A driving circuit, characterized in that: The driving circuit includes: a voltage source, a switch tube, an inductor, and a controller, wherein the positive electrode of the voltage source is connected to the drain of the switch tube, the source of the switch tube is connected to one end of the inductor, the other end of the inductor is connected to the third pin of the relay, the negative electrode of the voltage source is grounded, and the negative electrode of the voltage source is also connected to the fourth pin of the relay, and the output end of the controller is connected to the gate of the switch tube; The output end of the controller outputs a PWM control signal.

2. The driving circuit according to claim 1, wherein: The switch tube is MOS or TFT.

3. The driving circuit according to claim 1 or 2, characterized in that: The duty cycle of the PWM control signal is 0, 1 or 0.

6.

4. The driving circuit according to claim 1 or 2, characterized in that: The driving circuit further includes a diode, wherein the anode of the diode is grounded and the cathode of the diode is connected to one end of the inductor.

5. The driving circuit according to claim 1 or 2, characterized in that: The driving circuit further includes a capacitor, with two ends of the capacitor connected to the third pin and the fourth pin respectively.

6. An electromagnetic relay, comprising: A relay and a drive circuit, wherein the relay comprises: a control coil R, a switch K, and four pins; wherein the two ends of the control coil R are connected to the third pin and the fourth pin, respectively, and the two ends of the switch K are connected to the first pin and the second pin, respectively; wherein the switch K and the control coil R are in a magnetically coupled structure; wherein the drive circuit comprises: A voltage source, a switching tube, an inductor, and a controller, wherein the positive electrode of the voltage source is connected to the drain of the switching tube, the source of the switching tube is connected to one end of the inductor, the other end of the inductor is connected to the third pin of the relay, the negative electrode of the voltage source is grounded, and the negative electrode of the voltage source is also connected to the fourth pin of the relay, and the output end of the controller is connected to the gate of the switching tube; The output end of the controller outputs a PWM control signal.

7. The electromagnetic relay according to claim 6, characterized in that: The switch tube is MOS or TFT.

8. The electromagnetic relay according to claim 6 or 7, characterized in that: The duty cycle of the PWM control signal is 0, 1 or 0.

6.

9. The electromagnetic relay according to claim 6 or 7, characterized in that: The driving circuit further includes a diode, wherein the anode of the diode is grounded and the cathode of the diode is connected to one end of the inductor.

10. The electromagnetic relay according to claim 6 or 7, characterized in that: The driving circuit further includes a capacitor, with two ends of the capacitor connected to the third pin and the fourth pin respectively.

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