Switching circuit and electronic device

Abstract

The utility model provides a switching circuit and electronic equipment, the switching circuit comprises a relay, a first switch and a charging and discharging unit, the first end of the first switch is connected with the first end of a coil of the relay, the second end of the first switch is used for grounding, and the charging and discharging unit is connected with the second end of the coil and the control end of the first switch. The charging and discharging unit is configured to input a power supply voltage and a control signal. Wherein the charging and discharging unit is used for charging based on a power supply voltage when the control signal controls the first switch to be switched off, providing a first voltage for the second end of the coil at a first stage after the control signal controls the first switch to be switched on, and providing a second voltage for the second end of the coil at a second stage after the first switch is switched on, therefore, the purpose of triggering the relay can be achieved through the large first voltage, and the purpose of maintaining actuation of the relay can be achieved through the small second voltage, so that the loss of a relay coil is reduced.

Description

Technical Field

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

[0002] Electromagnetic relay is an electromechanical component that uses input signals (such as voltage or current) to generate electromagnetic force in the electromagnet core and attract the armature, thereby moving the contacts to achieve disconnection, closing or conversion control. Electromagnetic relays are widely used in aviation, industrial control, ships, home appliances and other fields. They mainly complete functions such as signal transmission, execution control, and system power distribution. They are one of the key electronic components in various systems.

[0003] The characteristic of the relay is that it requires a large current when it is triggered, which means that a large VCC voltage is required when it is triggered; but when the relay is triggered, the current required to keep it closed is very small, which means that only a low VCC voltage is required to keep it closed. Usually, the triggering and closing time of the relay is generally only about 5ms, so the relay coil remains in the closed state most of the time when it is working. At the same time, since the internal resistance of the relay coil is small, it will cause greater losses when it remains in the closed state for a long time. From the loss calculation formula, it can be seen that the higher the relay coil supply voltage VCC, the greater the relay coil loss. Utility Model Content

[0004] The embodiments of the present application provide a switching circuit and an electronic device to solve the problem that the maintenance voltage of the existing relay after triggering is too large, and the relay is in the attracted state most of the time when working, which leads to excessive loss of the relay coil.

[0005] In a first aspect, an embodiment of the present application provides a switch circuit, including:

[0006] Relay;

[0007] a first switch, wherein a first end of the first switch is connected to a first end of the coil of the relay, and a second end of the first switch is grounded;

[0008] A charge and discharge unit, the charge and discharge unit is connected to the second end of the coil and the control end of the first switch, the charge and discharge unit is configured to input a power supply voltage and a control signal, and the charge and discharge unit is used to:

[0009] When the control signal controls the first switch to be disconnected, the charge-discharge unit charges based on the power supply voltage, provides a first voltage to the second end of the coil in a first stage after the control signal controls the first switch to be closed, and provides a second voltage to the second end of the coil in a second stage after the first switch is closed;

[0010] The first voltage is greater than the power supply voltage, and the second voltage is equal to the power supply voltage.

[0011] In one embodiment, the charging and discharging unit includes:

[0012] a first capacitor, wherein a first end of the first capacitor is connected to a second end of the coil;

[0013] a first diode, wherein a cathode of the first diode is connected to a first end of the first capacitor;

[0014] a second capacitor, wherein a first end of the second capacitor is connected to the anode of the first diode and is configured to input a power supply voltage, and a second end of the second capacitor is grounded;

[0015] A switch control module, wherein the switch control module is connected to the second end of the first capacitor, the first end of the second capacitor, and the control end of the first switch, and the switch control module is used to:

[0016] Controlling the first switch to be disconnected according to the control signal, and conducting a path between the second end of the first capacitor and the ground; or

[0017] The first switch is controlled to be closed according to the control signal, and a path between the second end of the first capacitor and the first end of the second capacitor is turned on.

[0018] In one embodiment, a second switch, wherein a first end of the second switch is connected to a second end of the first capacitor, a second end of the second switch is grounded, and a control end of the second switch is configured to input a control signal;

[0019] a third switch, wherein a first end of the third switch is connected to the second end of the first capacitor, and a second end of the third switch is connected to the first end of the second capacitor;

[0020] a first resistor, wherein a first end of the first resistor is connected to the control end of the third switch, and a second end of the first resistor is connected to the first end of the second capacitor;

[0021] A second resistor, wherein a first end of the second resistor is connected to the control end of the third switch, and a second end of the second resistor is connected to the first end of the first switch.

[0022] In one embodiment, a third resistor, wherein a first end of the third resistor is connected to a first end of the second switch, and a second end of the third resistor is connected to a second end of the first capacitor;

[0023] A fourth resistor, wherein a first end of the fourth resistor is connected to the control end of the second switch, and a second end of the fourth resistor is connected to the first end of the second switch.

[0024] In one embodiment, a fifth resistor, wherein a first end of the fifth resistor is connected to the control end of the second switch, and a second end of the fifth resistor is grounded;

[0025] a sixth resistor, wherein a first end of the sixth resistor is connected to the control end of the second switch, and a second end of the sixth resistor is connected to the control end of the first switch;

[0026] A seventh resistor, wherein a first end of the seventh resistor is connected to the control end of the first switch, and a second end of the seventh resistor is grounded.

[0027] In one embodiment, the first switch is an NPN transistor, the control end, the first end, and the second end of the first switch are respectively a base, a collector, and an emitter; the second switch is a PNP transistor, the control end, the first end, and the second end of the second switch are respectively a base, an emitter, and a collector; the third switch is a PNP transistor, the control end, the first end, and the second end of the third switch are respectively a base, a collector, and an emitter.

[0028] In one embodiment, the capacitance values ​​of the first capacitor and the second capacitor are equal.

[0029] In one embodiment, the switch circuit further includes a second diode, an anode of the second diode is connected to the first end of the coil, and a cathode of the second diode is connected to the second end of the coil.

[0030] In one embodiment, the switching circuit further includes a load, a first end of the load is configured to input a first reference voltage, a second end of the load is connected to a first end of a secondary switch of the relay, and a second end of the secondary switch is configured to input a second reference voltage.

[0031] In a second aspect, an embodiment of the present application further provides an electronic device, comprising a switching circuit as in any of the above embodiments.

[0032] The switching circuit provided in the embodiment of the present application includes a relay, a first switch and a charge and discharge unit, wherein the first end of the first switch is connected to the first end of the coil of the relay, and the second end of the first switch is used for grounding. At the same time, the charge and discharge unit is connected to the second end of the coil and the control end of the first switch, and the charge and discharge unit is configured to input a power supply voltage and a control signal.

[0033] Among them, the charging and discharging unit is used to charge based on the power supply voltage when the control signal controls the first switch to be disconnected, and to provide a first voltage to the second end of the coil in the first stage after the control signal controls the first switch to be closed, and to provide a second voltage to the second end of the coil in the second stage after the first switch is closed.

[0034] It can be understood that in the switching circuit provided in the embodiment of the present application, since the first voltage is greater than the power supply voltage, in the first stage after the control signal controls the first switch to close (that is, the relay is in the waiting state to be triggered), a larger first voltage can be used to achieve the purpose of triggering the relay; at the same time, since the second voltage is equal to the power supply voltage, in the second stage after the control signal controls the first switch to close (that is, after the relay is in the triggered state), a smaller second voltage can be used to maintain the relay closure, thereby ensuring that the maintenance voltage after the relay is triggered and closure is small, so as to reduce the loss of the relay coil and save the electric energy required for the operation of the switching circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0036] Figure 1 A schematic diagram of the structure of a switch circuit provided in one embodiment of the present application.

[0037] Figure 2 A schematic diagram of the structure of a switch circuit provided in another embodiment of the present application.

[0038] Figure 3 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0039] Description of reference numerals:

[0040] 100, switch circuit; 110, relay; 120, charge and discharge unit; 130, switch control module; 140, load; 200, electronic device; Q1, first switch; C1, first capacitor; D1, first diode; C2, second capacitor; Q2, second switch; Q3, third switch; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; R6, sixth resistor; R7, seventh resistor; D2, second diode. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0042] Electromagnetic relay is an electromechanical component that uses input signals (such as voltage or current) to generate electromagnetic force in the electromagnet core and attract the armature, thereby moving the contacts to achieve disconnection, closing or conversion control. Electromagnetic relays are widely used in aviation, industrial control, ships, home appliances and other fields. They mainly complete functions such as signal transmission, execution control, and system power distribution. They are one of the key electronic components in various systems.

[0043] The characteristic of the relay is that it requires a large current when it is triggered, which means that a large VCC voltage is required when it is triggered; but when the relay is triggered, the current required to keep it closed is very small, which means that only a low VCC voltage is required to keep it closed. Usually, the triggering and closing time of the relay is generally only about 5ms, so the relay coil remains in the closed state most of the time when it is working. At the same time, since the internal resistance of the relay coil is small, it will cause greater losses when it remains in the closed state for a long time. From the loss calculation formula, it can be seen that the higher the relay coil supply voltage VCC, the greater the relay coil loss.

[0044] Based on the above technical problems, the present application embodiment provides a switch circuit 100. Figure 1 , Figure 1 A schematic diagram of the structure of a switch circuit provided in one embodiment of the present application.

[0045] In this embodiment, if Figure 1 As shown, the switch circuit 100 includes a relay 110, a first switch Q1 and a charge and discharge unit 120, wherein a first end of the first switch Q1 is connected to a first end of a coil of the relay 110, and a second end of the first switch Q1 is grounded. Meanwhile, the charge and discharge unit 120 is connected to a second end of the coil and a control end of the first switch Q1, and the charge and discharge unit 120 is configured to input a power supply voltage VCC and a control signal Drive.

[0046] Among them, the charge and discharge unit 120 is used to charge based on the power supply voltage VCC when the control signal Drive controls the first switch Q1 to be disconnected, and to provide a first voltage to the second end of the coil in the first stage after the control signal Drive controls the first switch Q1 to be closed, and to provide a second voltage to the second end of the coil in the second stage after the first switch Q1 is closed.

[0047] It can be understood that in the switching circuit 100 provided in the embodiment of the present application, since the first voltage is greater than the power supply voltage VCC, in the first stage after the control signal Drive controls the first switch Q1 to be closed (that is, the relay 110 is in the to-be-triggered state), a larger first voltage can be used to achieve the purpose of triggering the relay 110; at the same time, since the second voltage is equal to the power supply voltage VCC, in the second stage after the control signal Drive controls the first switch Q1 to be closed (that is, after the relay 110 is in the triggered state), a smaller second voltage can be used to achieve the purpose of maintaining the relay 110 closed, ensuring that the maintenance voltage of the relay 110 after the triggering is small, so as to reduce the loss of the relay 110 coil and save the electric energy required for the operation of the switching circuit 100.

[0048] See also Figure 2 , Figure 2 FIG. 1 is a schematic diagram of a switch circuit provided in another embodiment of the present application. Figure 2 As shown, the charge and discharge unit 120 may include a first capacitor C1, a first diode D1, a second capacitor C2 and a switch control module 130, wherein the first end of the first capacitor C1 is connected to the second end of the coil, the cathode of the first diode D1 is connected to the first end of the first capacitor C1, the first end of the second capacitor C2 is connected to the anode of the first diode D1 and is configured to input a power supply voltage VCC, and the second end of the second capacitor C2 is grounded.

[0049] At the same time, the switch control module 130 is connected to the second end of the first capacitor C1, the first end of the second capacitor C2, and the control end of the first switch Q1, wherein the switch control module 130 is used to control the first switch Q1 to be disconnected according to the control signal Drive, and to conduct the path between the second end of the first capacitor C1 and the ground; at the same time, the switch control module 130 can also control the first switch Q1 to be closed according to the control signal Drive, and to conduct the path between the second end of the first capacitor C1 and the first end of the second capacitor C2.

[0050] Specifically, the switch control module 130 controls the first switch Q1 to be disconnected, and turns on the path between the second end of the first capacitor C1 and the ground, thereby forming two charging loops: power supply voltage VCC-first diode D1-first capacitor C1-ground GND; and power supply voltage VCC-second capacitor C2-ground GND, so that the power supply voltage VCC can charge the first capacitor C1 and the second capacitor C2, thereby making the voltage of the first end (right end) of the first capacitor C1 and the voltage of the first end (upper end) of the second capacitor C2 equal to the power supply voltage VCC.

[0051] Specifically, the switch control module 130 controls the first switch Q1 to close and turns on the path between the second end of the first capacitor C1 and the first end of the second capacitor C2, so that the power supply voltage VCC is suddenly applied to the second end (left end) of the first capacitor C1. Due to the characteristic that the voltage difference across the capacitor will not change suddenly and the unidirectional conductivity of the first diode D1, the voltage of the first end (right end) of the first capacitor C1 will be raised to twice the power supply voltage VCC (i.e., 2VCC). Therefore, a voltage of 2VCC will be provided to the relay 110, that is, the first voltage will be provided to the second end of the coil.

[0052] Subsequently, due to the continuous discharge of the first capacitor C1, after reaching a steady state, the second capacitor C2 provides the power supply voltage VCC to the relay 110, that is, provides the second voltage to the second end of the coil.

[0053] In some embodiments, please refer to Figure 2 The switch control module 130 may include a second switch Q2 and a third switch Q3, wherein a first end (upper end) of the second switch Q2 is connected to a second end (left end) of the first capacitor C1, a second end (lower end) of the second switch Q2 is grounded, and a control end of the second switch Q2 is configured to input a control signal Drive, thereby forming a charging loop: power supply voltage VCC-first diode D1-first capacitor C1-second switch Q2-ground GND; meanwhile, a first end (left end) of the third switch Q3 is connected to a second end (left end) of the first capacitor C1, and a second end (right end) of the third switch Q3 is connected to a first end (upper end) of the second capacitor C2, thereby forming a charging loop: power supply voltage VCC-third switch Q3-first capacitor C1.

[0054] It can be understood that, in this embodiment, the first switch Q1 is an NPN transistor, the second switch Q2 is a PNP transistor, and the third switch Q3 is a PNP transistor. In other embodiments, the first switch Q1, the second switch Q2, and the third switch Q3 can also be other types of transistors, MOS tubes, or semiconductor devices with switching functions.

[0055] It can be understood that when the relay 110 needs to be triggered, the second switch Q2 can be disconnected under the action of the control signal Drive, and the first switch Q1 and the third switch Q3 are turned on. When the second switch Q2 is disconnected and the third switch Q3 is turned on, the path between the second end of the first capacitor C1 and the first end of the second capacitor C2 can be turned on, so that the power supply voltage VCC is suddenly applied to the second end (left end) of the first capacitor C1. Due to the characteristic that the voltage difference across the capacitor will not change suddenly and the unidirectional conductivity of the first diode D1, the voltage of the first end (right end) of the first capacitor C1 will be raised to twice the power supply voltage VCC (i.e., 2VCC). Therefore, a voltage of 2VCC will be provided to the relay 110, that is, the first voltage will be provided to the second end of the coil. At the same time, since the first voltage is higher than the minimum triggering voltage of the relay 110, the large current required for triggering is met, thereby ensuring reliable triggering of the relay 110.

[0056] When the relay 110 is triggered, the second switch Q2 is disconnected and no longer charges the first capacitor C1, so the voltage on the first capacitor C1 gradually decreases to 0V. When the relay 110 reaches a steady state, the second capacitor C2 provides the power supply voltage VCC to the relay 110, that is, provides the second voltage to the second end of the coil. Since the coil of the relay 110 has been triggered and attracted, even if the voltage of the coil of the relay 110 is lower than 2 times the power supply voltage VCC, the relay 110 can still maintain the attracted state, thereby reducing the loss of the coil of the relay 110 and saving the power required for the operation of the switch circuit 100.

[0057] Meanwhile, in the above embodiments, if Figure 2 As shown, the switch control module 130 may further include a first resistor R1 and a second resistor R2, wherein a first end of the first resistor R1 is connected to a control end of the third switch Q3, and a second end of the first resistor R1 is connected to a first end of a second capacitor C2, so as to improve the anti-interference capability of the third switch Q3; a first end of the second resistor R2 is connected to a control end of the third switch Q3, and a second end of the second resistor R2 is connected to a first end of the first switch Q1, so as to limit a base current passing through the third switch Q3.

[0058] In some embodiments, Figure 2 As shown, the switch control module 130 may further include a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7. The first end of the third resistor R3 is connected to the first end of the second switch Q2, and the second end of the third resistor R3 is connected to the second end of the first capacitor C1, thereby limiting the charging current flowing through the first capacitor C1 to prevent the first capacitor C1 from being damaged by excessive current.

[0059] Meanwhile, a first end of the fourth resistor R4 is connected to the control end of the second switch Q2 , and a second end of the fourth resistor R4 is connected to the first end of the second switch Q2 , thereby improving the anti-interference capability of the second switch Q2 .

[0060] At the same time, the first end of the fifth resistor R5 is connected to the control end of the second switch Q2, and the second end of the fifth resistor R5 is grounded, thereby preventing the base voltage of the second switch Q2 from being too high when the control signal Drive end is in a floating state, thereby preventing the base voltage of the first switch Q1 from being too high and causing mis-conduction.

[0061] Meanwhile, a first end of the sixth resistor R6 is connected to the control end of the second switch Q2 , and a second end of the sixth resistor R6 is connected to the control end of the first switch Q1 , thereby further limiting the base current flowing through the first switch Q1 .

[0062] Meanwhile, a first end of the seventh resistor R7 is connected to the control end of the first switch Q1 , and a second end of the seventh resistor R7 is grounded, thereby further improving the anti-interference capability of the first switch Q1 .

[0063] In some embodiments, the first switch Q1 is an NPN transistor, the control end, the first end and the second end of the first switch Q1 are the base, the collector and the emitter respectively, the second switch Q2 is a PNP transistor, the control end, the first end and the second end of the second switch Q2 are the base, the emitter and the collector respectively, and the third switch Q3 is a PNP transistor, the control end, the first end and the second end of the third switch Q3 are the base, the collector and the emitter respectively.

[0064] In some embodiments, Figure 2 As shown, the switch circuit 100 may further include a second diode D2, the anode of the second diode D2 is connected to the first end of the coil, and the cathode of the second diode D2 is connected to the second end of the coil, which plays a protective role for the relay 110. Figure 2 The switch circuit 100 may further include a load 140, a first end of the load 140 being configured to input a first reference voltage, a second end of the load 140 being connected to a first end of a secondary switch of the relay 110, and a second end of the secondary switch being configured to input a second reference voltage.

[0065] The present application also provides an electronic device 200. Figure 3 , Figure 3 Schematic diagram of the structure of the electronic device 200 provided in the embodiment of the present application. Figure 3 As shown, in this embodiment, the electronic device 200 may include the switch circuit 100 mentioned in any of the above embodiments.

[0066] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0067] In the description of this application, 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 technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features.

[0068] The switching circuit and electronic device provided in the embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A switching circuit, characterized in that: The switch circuit comprises: Relay; a first switch, wherein a first end of the first switch is connected to a first end of the coil of the relay, and a second end of the first switch is grounded; A charge and discharge unit, the charge and discharge unit is connected to the second end of the coil and the control end of the first switch, the charge and discharge unit is configured to input a power supply voltage and a control signal, and the charge and discharge unit is used to: When the control signal controls the first switch to be disconnected, the charge-discharge unit charges based on the power supply voltage, provides a first voltage to the second end of the coil in a first stage after the control signal controls the first switch to be closed, and provides a second voltage to the second end of the coil in a second stage after the first switch is closed; The first voltage is greater than the power supply voltage, and the second voltage is equal to the power supply voltage.

2. The switch circuit according to claim 1, characterized in that: The charging and discharging unit comprises: a first capacitor, wherein a first end of the first capacitor is connected to a second end of the coil; a first diode, wherein a cathode of the first diode is connected to a first end of the first capacitor; a second capacitor, wherein a first end of the second capacitor is connected to the anode of the first diode and is configured to input a power supply voltage, and a second end of the second capacitor is grounded; A switch control module, wherein the switch control module is connected to the second end of the first capacitor, the first end of the second capacitor, and the control end of the first switch, and the switch control module is used to: Controlling the first switch to be disconnected according to the control signal, and conducting a path between the second end of the first capacitor and the ground; or The first switch is controlled to be closed according to the control signal, and a path between the second end of the first capacitor and the first end of the second capacitor is turned on.

3. The switch circuit according to claim 2, characterized in that: The switch control module comprises: a second switch, wherein a first end of the second switch is connected to the second end of the first capacitor, a second end of the second switch is grounded, and a control end of the second switch is configured to input a control signal; a third switch, wherein a first end of the third switch is connected to the second end of the first capacitor, and a second end of the third switch is connected to the first end of the second capacitor; a first resistor, wherein a first end of the first resistor is connected to the control end of the third switch, and a second end of the first resistor is connected to the first end of the second capacitor; A second resistor, wherein a first end of the second resistor is connected to the control end of the third switch, and a second end of the second resistor is connected to the first end of the first switch.

4. The switch circuit according to claim 3, characterized in that: The switch control module further includes: a third resistor, wherein a first end of the third resistor is connected to the first end of the second switch, and a second end of the third resistor is connected to the second end of the first capacitor; A fourth resistor, wherein a first end of the fourth resistor is connected to the control end of the second switch, and a second end of the fourth resistor is connected to the first end of the second switch.

5. The switch circuit according to claim 3, characterized in that: The switch control module further includes: a fifth resistor, wherein a first end of the fifth resistor is connected to the control end of the second switch, and a second end of the fifth resistor is grounded; a sixth resistor, wherein a first end of the sixth resistor is connected to the control end of the second switch, and a second end of the sixth resistor is connected to the control end of the first switch; A seventh resistor, wherein a first end of the seventh resistor is connected to the control end of the first switch, and a second end of the seventh resistor is grounded.

6. The switch circuit according to claim 3, characterized in that: The first switch is an NPN transistor, the control end, the first end and the second end of the first switch are the base, the collector and the emitter respectively; the second switch is a PNP transistor, the control end, the first end and the second end of the second switch are the base, the emitter and the collector respectively; the third switch is a PNP transistor, the control end, the first end and the second end of the third switch are the base, the collector and the emitter respectively.

7. The switch circuit according to claim 2, characterized in that: The first capacitor and the second capacitor have the same capacitance value.

8. The switch circuit according to claim 1, characterized in that: The switch circuit further includes a second diode, an anode of the second diode is connected to the first end of the coil, and a cathode of the second diode is connected to the second end of the coil.

9. The switch circuit according to claim 1, characterized in that: The switch circuit also includes a load, a first end of the load is configured to input a first reference voltage, a second end of the load is connected to a first end of a secondary switch of the relay, and a second end of the secondary switch is configured to input a second reference voltage.

10. An electronic device, characterized in that: The electronic device comprises the switching circuit according to any one of claims 1 to 9.

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