Relay driving circuit, relay driving device and electronic equipment

Abstract

The utility model belongs to the technical field of circuits, and provides a relay driving circuit, a relay driving device and electronic equipment. The relay driving circuit is connected with the relay and used for controlling the working state of the relay, and the relay driving circuit comprises a relay holding circuit, a relay starting circuit and a relay control circuit. By setting the control signals of the relay to be different levels, a relatively large driving voltage can be provided for the relay at the initial starting stage of the relay, so that the relay can be normally started. After the relay is started to work, a relatively small driving voltage is provided for the relay, so that the relay can be kept started, the problem of relatively large driving loss of the relay can be solved, and the application cost can be reduced.

Description

Technical Field

[0001] The present application belongs to the field of circuit technology, and in particular relates to a relay drive circuit, a relay drive device and an electronic device. Background Art

[0002] As a control element in electrical control, relays are widely used. However, the driving current of relays is much larger than their working current. In fact, once the relay is closed, it can work reliably at about half of the rated voltage, but it often needs to use an unnecessary large power supply to power it, which greatly wastes electricity. This technical solution leads to large relay drive losses and increases application costs. Utility Model Content

[0003] The purpose of the present application is to provide a relay drive circuit, a relay drive device and an electronic device, aiming to solve the problem of large loss and increased application cost of existing relay drives.

[0004] A first aspect of an embodiment of the present application provides a relay drive circuit, the relay drive circuit being connected to a relay and used to control a working state of the relay, the relay drive circuit comprising:

[0005] A relay holding circuit, configured to receive a relay control signal and generate a relay start signal when the relay control signal is at a first level;

[0006] A relay start circuit, connected to the relay holding circuit, configured to receive the relay start signal, and be turned on according to the relay start signal to generate a first drive signal;

[0007] a relay control circuit connected to the relay start circuit and the relay, configured to receive the first drive signal and the relay control signal, and provide a first voltage to the relay according to the first drive signal and the relay control signal;

[0008] The relay holding circuit is also used to generate a relay holding signal when the relay control signal is at a second level. The relay starting circuit is also used to disconnect according to the relay holding signal and generate a second drive signal. The relay control circuit is also used to provide a second voltage to the relay according to the second drive signal and the relay control signal; wherein the first voltage is greater than the second voltage.

[0009] In one embodiment, the relay holding circuit comprises:

[0010] a charging unit, configured to receive the relay control signal, and charge according to the relay control signal to generate a charging signal;

[0011] The first switch unit is connected to the charging unit, and is used to receive the charging signal, and to be turned on or off according to the charging signal, so as to generate the relay start signal or the relay hold signal.

[0012] In one embodiment, the relay starting circuit comprises:

[0013] a second switch unit, connected to the relay holding circuit, configured to be turned on according to the relay start signal to generate the first drive signal, and turned off according to the relay holding signal to generate the second drive signal;

[0014] An isolation unit is provided between the second switch unit and the relay control circuit, and is used to isolate the second switch unit from the relay control circuit.

[0015] In one embodiment, the charging unit includes: a first capacitor, a first resistor and a second resistor; wherein,

[0016] The first end of the first resistor is used to connect to an external controller, the second end of the first resistor is connected to the first end of the second resistor and the first end of the first capacitor, the second end of the second resistor is grounded, the second end of the first capacitor is grounded, and the second end of the first resistor is also connected to the first switch unit.

[0017] In one embodiment, the first switch unit includes: a first switch tube, a control end of the first switch tube is connected to the charging unit, a first end of the first switch tube is grounded, and a second end of the first switch tube is connected to the relay starting circuit.

[0018] In one embodiment, the second switch unit includes: a third resistor, a fourth resistor, a second switch tube and a third switch tube; wherein,

[0019] The first end of the third resistor and the control end of the second switch tube are connected to the first switch unit, the second end of the third resistor and the first end of the third switch tube are connected to the first power supply, the first end of the second switch tube is grounded, the second end of the second switch tube is connected to the control end of the third switch tube after being connected in series with the fourth resistor, and the second end of the third switch tube is connected to the isolation unit.

[0020] In one embodiment, the isolation unit includes: a first diode and a second diode; wherein,

[0021] The first end of the first diode is connected to the second switch unit, the second end of the first diode and the second end of the second diode are connected to the relay control circuit, and the first end of the second diode is connected in series with the second power supply and then grounded.

[0022] In one embodiment, the relay control circuit includes: a second capacitor, a fifth resistor, a sixth resistor and a fourth switch tube; wherein,

[0023] The first end of the second capacitor and the first end of the fifth resistor are connected to the isolation unit, the second end of the second capacitor is grounded, the first end of the fifth resistor is connected to the first end of the fourth switch tube, the second end of the fourth switch tube is grounded, and the control end of the fourth switch tube is connected in series with the sixth resistor and then connected to an external controller.

[0024] An embodiment of the present application further provides a relay driving device, wherein the relay driving device includes the relay driving circuit as described in any one of the above items.

[0025] An embodiment of the present application further provides an electronic device, which includes the relay drive circuit described in any one of the above items.

[0026] Compared with the prior art, the embodiments of the present application have the following beneficial effects: by setting the relay control signal to different levels, a larger driving voltage can be provided to the relay at the initial stage of relay startup, so that the relay can be started normally. After the relay is started, a relatively small driving voltage is provided to the relay, so that the relay can remain started, which can solve the problem of large relay drive loss and reduce application costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic diagram of a relay drive circuit according to an embodiment of the present invention Figure 1 ;

[0028] Figure 2 A schematic diagram of a relay drive circuit according to an embodiment of the present invention Figure 2 ;

[0029] Figure 3 A specific circuit diagram of a relay drive circuit provided by an embodiment of the present application;

[0030] Figure 4 A simulation schematic diagram of a relay drive circuit provided in accordance with an embodiment of the present application. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do 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 should not be understood as a limitation on the present application.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] As a control element in electrical control, relays are widely used. However, the driving current of relays is much larger than their working current. In fact, once the relay is closed, it can work reliably at about half of the rated voltage, but it often needs to use an unnecessary large power supply to power it, which greatly wastes electricity. This technical solution leads to large relay drive losses and increases application costs.

[0036] In order to solve the above technical problems, refer to Figure 1 As shown, an embodiment of the present application provides a relay driving circuit, which is connected to a relay 100 and is used to control the working state of the relay 100. The relay driving circuit includes: a relay holding circuit 10, a relay starting circuit 20 and a relay control circuit 30.

[0037] Specifically, the relay holding circuit 10 is used to receive the relay control signal, and when the relay control signal is at a first level, generate a relay start signal. The relay start circuit 20 is connected to the relay holding circuit 10, and the relay start circuit 20 is used to receive the relay start signal, and is turned on according to the relay start signal to generate a first drive signal. The relay control circuit 30 is connected to the relay start circuit 20 and the relay 100, and the relay control circuit 30 is used to receive the first drive signal and the relay control signal, and provide the first voltage to the relay 100 according to the first drive signal and the relay control signal. The relay holding circuit 10 is also used to generate a relay holding signal when the relay control signal is at a second level, and the relay start circuit 20 is also used to disconnect according to the relay holding signal and generate a second drive signal, and the relay control circuit 30 is also used to provide the relay 100 with a second voltage according to the second drive signal and the relay control signal; wherein the first voltage is greater than the second voltage.

[0038] In this embodiment, the relay control signal is sent by an external control signal, wherein the relay control signal can be a high level or a low level. For example, when the relay control signal is at a first level, it can indicate that the relay control signal is at a low level; when the relay control signal is at a second level, it can indicate that the relay control signal is at a high level. By setting the relay control signal to a high level or a low level, the relay drive circuit can provide different voltages for the relay 100 to solve the problem of large drive loss of the relay 100, and can reduce the application cost.

[0039] In this embodiment, at the initial stage of starting the relay 100, the relay control signal can be set to the first level. At this time, when the relay holding circuit 10 receives the relay control signal as the first level, a relay start signal is generated, the relay start circuit 20 is turned on according to the relay start signal, and a first drive signal is generated. The relay control circuit 30 provides a first voltage to the relay 100 according to the first drive signal and the relay control signal. The first voltage is used to control the relay 100 to close and start the work.

[0040] In this embodiment, after the relay 100 is started, that is, when the relay 100 is working normally, the relay control signal can be set to the second level. At this time, when the relay holding circuit 10 receives the relay control signal as the second level, a relay holding signal is generated; the relay starting circuit 20 is also used to disconnect according to the relay holding signal and generate a second drive signal; the relay control circuit 30 is also used to provide a second voltage to the relay 100 according to the second drive signal and the relay control signal; wherein the first voltage is greater than the second voltage.

[0041] Exemplarily, the first voltage may be 7.7V, and the second voltage may be 14.7V.

[0042] In this embodiment, by setting the relay control signal to different levels, a larger driving voltage can be provided to the relay 100 at the initial start-up of the relay 100, so that the relay 100 can be normally started. After the relay 100 is started, a relatively small driving voltage is provided to the relay 100, so that the relay 100 can remain started, which can solve the problem of large driving loss of the relay 100 and reduce the application cost.

[0043] In one embodiment, reference Figure 2 As shown, the relay holding circuit 10 includes: a charging unit 11 and a first switch unit 12 .

[0044] Specifically, the charging unit 11 is used to receive a relay control signal, and to charge according to the relay control signal, and to generate a charging signal. The first switch unit 12 is connected to the charging unit 11, and the first switch unit 12 is used to receive a charging signal, and to conduct or cut off according to the charging signal, and to generate a relay start signal or a relay hold signal.

[0045] In this embodiment, when the relay control signal is at the first level, the charging unit 11 charges according to the relay control signal, the first switch unit 12 is turned off according to the charging signal, and a relay start signal is generated. When the relay control signal is at the second level, the charging unit 11 charges according to the relay control signal, the first switch unit 12 is turned on according to the charging signal, and a relay hold signal is generated.

[0046] In one embodiment, reference Figure 2 As shown, the relay starting circuit 20 includes: a second switch unit 21 and an isolation unit 22 .

[0047] Specifically, the second switch unit 21 is connected to the relay holding circuit 10, and the second switch unit 21 is used to turn on according to the relay start signal to generate a first drive signal, and to turn off according to the relay holding signal to generate a second drive signal. The isolation unit 22 is provided between the second switch unit 21 and the relay control circuit 30, and the isolation unit 22 is used to isolate the second switch unit 21 from the relay control circuit 30.

[0048] In this embodiment, the second switch unit 21 is used to turn on according to the relay start signal to generate a first drive signal, and to turn off according to the relay hold signal to generate a second drive signal. The relay control circuit 30 provides a first voltage to the relay 100 according to the first drive signal and the relay control signal, and the first voltage is used to control the relay 100 to close and start working. The relay control circuit 30 is also used to provide a second voltage to the relay 100 according to the second drive signal and the relay control signal to control the relay 100 to keep working.

[0049] In this embodiment, the isolation unit 22 is used to isolate the second switch unit 21 and the relay control circuit 30 to prevent the second switch unit 21 and the relay control circuit 30 from interfering with each other.

[0050] In one embodiment, reference Figure 3 As shown, the charging unit 11 includes: a first capacitor C1, a first resistor R1 and a second resistor R2.

[0051] Specifically, the first end of the first resistor R1 is used to connect to an external controller, the second end of the first resistor R1 is connected to the first end of the second resistor R2 and the first end of the first capacitor C1, the second end of the second resistor R2 is grounded, the second end of the first capacitor C1 is grounded, and the second end of the first resistor R1 is also connected to the first switching unit 12.

[0052] In this embodiment, the first resistor R1 is a current limiting resistor, and the first capacitor C1 is a charging capacitor.

[0053] In one embodiment, reference Figure 3 As shown, the first switch unit 12 includes: a first switch tube Q1, a control end of the first switch tube Q1 is connected to the charging unit 11, a first end of the first switch tube Q1 is grounded, and a second end of the first switch tube Q1 is connected to the relay start circuit 20. In this embodiment, the first switch tube Q1 is used to be turned off when the relay control signal is at the first level, and turned on when the relay control signal is at the second level.

[0054] In one embodiment, reference Figure 3 As shown, the second switch unit 21 includes: a third resistor R3, a fourth resistor R4, a second switch tube Q2 and a third switch tube Q3.

[0055] Specifically, the first end of the third resistor R3 and the control end of the second switch tube Q2 are connected to the first switch unit 12, the second end of the third resistor R3 and the first end of the third switch tube Q3 are connected to the first power supply, the first end of the second switch tube Q2 is grounded, the second end of the second switch tube Q2 is connected in series with the fourth resistor R4 and then connected to the control end of the third switch tube Q3, and the second end of the third switch tube Q3 is connected to the isolation unit 22.

[0056] In this embodiment, the third resistor R3 is a current limiting resistor, the fourth resistor R4 is a current limiting resistor, the first switch tube Q1 is used to be turned off when the relay control signal is at the first level, the second switch tube Q2 and the third switch tube Q3 are turned on, and the first switch tube Q1 is turned on when the relay control signal is at the second level, and the second switch tube Q2 and the third switch tube Q3 are turned off.

[0057] In one embodiment, the first power source is 15V.

[0058] In one embodiment, reference Figure 3 As shown, the isolation unit 22 includes: a first diode D1 and a second diode D2; wherein the first end of the first diode D1 is connected to the second switch unit 21, the second end of the first diode D1 and the second end of the second diode D2 are connected to the relay control circuit 30, and the first end of the second diode D2 is connected in series with the second power supply and then grounded. Since the first diode D1 and the second diode D2 have unidirectional conduction characteristics, the first diode D1 and the second diode D2 can isolate the second switch unit 21 and the relay control circuit 30.

[0059] In one embodiment, reference Figure 3 As shown, the relay control circuit 30 includes: a second capacitor C2, a fifth resistor R5, a sixth resistor R6 and a fourth switch tube Q4.

[0060] Specifically, the first end of the second capacitor C2 and the first end of the fifth resistor R5 are connected to the isolation unit 22, the second end of the second capacitor C2 is grounded, the first end of the fifth resistor R5 is connected to the first end of the fourth switch tube Q4, the second end of the fourth switch tube Q4 is grounded, and the control end of the fourth switch tube Q4 is connected in series with the sixth resistor R6 and then connected to the external controller. In this embodiment, the second capacitor C2 is a charging capacitor, and the fifth resistor R5 and the sixth resistor R6 are current limiting resistors.

[0061] In one embodiment, the second power supply is 8V.

[0062] In one embodiment, when the relay control signal Drive is at a low level, the first switch tube Q1 and the fourth switch tube Q4 are in the off state, the second switch tube Q2 is in the on state, and the third switch tube Q3 is in the on state, so the +15V power supply is added to both ends of the second capacitor C2 through the third switch tube Q3 and the first diode D1, and the voltage on the second capacitor C2 is about +14.7V (+15 minus the voltage drop of the first diode D1, and the first diode D1 adopts a Schottky diode), so the first voltage is +14.7V.

[0063] When the relay control signal Drive changes from a low level to a high level, the fourth switch tube Q4 changes from off to on, and a +14.7V voltage is applied to both ends of the fifth resistor R5. After a period of time (when the voltage on the first capacitor C1 is charged by Drive through the first resistor R1 and is higher than 0.6V), the first switch tube Q1 starts to turn on, and the base voltage of the second switch tube Q2 is pulled down, so the second switch tube Q2 turns to the off state, and the third switch tube Q3 also turns to the off state, the +15V power supply is cut off, and the voltage on the second capacitor C2 turns to about +7.7V (+8V minus the voltage drop of the second diode D2).

[0064] From the working principle of the above circuit, it can be known that when the relay 100 is just turned on, the voltage across the relay 100 is +14.7V (a high voltage can accelerate the turning on of the relay 100). After being turned on for a period of time, the voltage across the relay 100 changes from +14.7V to 7.7V (a low voltage can keep the relay 100 closed and reduce the loss of the relay 100), which meets the actual needs.

[0065] The conversion time from +14.7V to 7.7V is determined by the first resistor R1 and the first capacitor C1. The voltage rise time of the first capacitor C1 is the integral of the driving signal charging the first capacitor C1 through the first resistor R1.

[0066] In one embodiment, the circuit simulation results are as follows: Figure 4 As shown, V1 is a +15V power supply, V2 is a voltage on the second capacitor C2 (i.e., a voltage provided to the relay 100), V3 is a relay drive, and V4 is a base voltage of the first switch tube Q1. When the relay drive changes from a low level to a high level 24ms later, the voltage on the second capacitor C2 changes from +14.7V to 7.7V. When the relay 100 starts to close, the voltage on the coil is +14.7V and changes to 7.7V after 24ms.

[0067] An embodiment of the present application further provides a relay driving device, which includes a relay driving circuit as provided in any of the above embodiments.

[0068] By setting the above-mentioned relay driving circuit in the relay driving device, for a period of time when the relay 100 is just turned on, the voltage across the relay 100 is +14.7V (a high voltage can accelerate the turning on of the relay 100). After being turned on for a period of time, the voltage across the relay 100 changes from +14.7V to 7.7V (a low voltage can keep the relay 100 closed while reducing the loss of the relay 100), which meets actual needs.

[0069] An embodiment of the present application further provides an electronic device, which includes the relay drive circuit provided in any of the above embodiments.

[0070] By setting the above relay driving circuit in an electronic device, for a period of time when the relay 100 is just turned on, the voltage across the relay 100 is +14.7V (a high voltage can accelerate the turning on of the relay 100). After a period of time, the voltage across the relay 100 changes from +14.7V to 7.7V (a low voltage can keep the relay 100 closed while reducing the loss of the relay 100), which meets actual needs.

[0071] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0072] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0073] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0074] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A relay drive circuit, characterized in that: The relay driving circuit is connected to the relay and is used to control the working state of the relay. The relay driving circuit includes: A relay holding circuit, configured to receive a relay control signal and generate a relay start signal when the relay control signal is at a first level; A relay start circuit, connected to the relay holding circuit, configured to receive the relay start signal, and be turned on according to the relay start signal to generate a first drive signal; a relay control circuit connected to the relay start circuit and the relay, configured to receive the first drive signal and the relay control signal, and provide a first voltage to the relay according to the first drive signal and the relay control signal; The relay holding circuit is also used to generate a relay holding signal when the relay control signal is at a second level. The relay starting circuit is also used to disconnect according to the relay holding signal and generate a second drive signal. The relay control circuit is also used to provide a second voltage to the relay according to the second drive signal and the relay control signal; wherein the first voltage is greater than the second voltage.

2. The relay drive circuit according to claim 1, characterized in that: The relay holding circuit comprises: a charging unit, configured to receive the relay control signal, and charge according to the relay control signal to generate a charging signal; The first switch unit is connected to the charging unit, and is used to receive the charging signal, and to be turned on or off according to the charging signal, so as to generate the relay start signal or the relay hold signal.

3. The relay driving circuit according to claim 2, characterized in that: The relay starting circuit comprises: a second switch unit, connected to the relay holding circuit, configured to be turned on according to the relay start signal to generate the first drive signal, and turned off according to the relay holding signal to generate the second drive signal; An isolation unit is provided between the second switch unit and the relay control circuit, and is used to isolate the second switch unit from the relay control circuit.

4. The relay driving circuit according to claim 2, characterized in that: The charging unit includes: a first capacitor, a first resistor and a second resistor; wherein, The first end of the first resistor is used to connect to an external controller, the second end of the first resistor is connected to the first end of the second resistor and the first end of the first capacitor, the second end of the second resistor is grounded, the second end of the first capacitor is grounded, and the second end of the first resistor is also connected to the first switch unit.

5. The relay driving circuit according to claim 4, characterized in that: The first switch unit includes: a first switch tube, a control end of the first switch tube is connected to the charging unit, a first end of the first switch tube is grounded, and a second end of the first switch tube is connected to the relay starting circuit.

6. The relay driving circuit according to claim 3, characterized in that: The second switch unit includes: a third resistor, a fourth resistor, a second switch tube and a third switch tube; wherein, The first end of the third resistor and the control end of the second switch tube are connected to the first switch unit, the second end of the third resistor and the first end of the third switch tube are connected to the first power supply, the first end of the second switch tube is grounded, the second end of the second switch tube is connected to the control end of the third switch tube after being connected in series with the fourth resistor, and the second end of the third switch tube is connected to the isolation unit.

7. The relay driving circuit according to claim 3, characterized in that: The isolation unit includes: a first diode and a second diode; wherein, The first end of the first diode is connected to the second switch unit, the second end of the first diode and the second end of the second diode are connected to the relay control circuit, and the first end of the second diode is connected in series with the second power supply and then grounded.

8. The relay driving circuit according to claim 7, characterized in that: The relay control circuit includes: a second capacitor, a fifth resistor, a sixth resistor and a fourth switch tube; wherein, The first end of the second capacitor and the first end of the fifth resistor are connected to the isolation unit, the second end of the second capacitor is grounded, the first end of the fifth resistor is connected to the first end of the fourth switch tube, the second end of the fourth switch tube is grounded, and the control end of the fourth switch tube is connected in series with the sixth resistor and then connected to an external controller.

9. A relay driving device, characterized in that: The relay driving device comprises the relay driving circuit as claimed in any one of claims 1 to 8.

10. An electronic device, characterized in that: The electronic device comprises the relay drive circuit as claimed in any one of claims 1 to 8.

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