Relay energy-saving driving circuit

Abstract

The utility model provides a relay energy-saving drive circuit, which relates to the technical field of relay drive control, and comprises a voltage transformation module, a switch module and a first rectifier module, the voltage transformation module comprises a primary winding and a first secondary winding; the first end of the primary winding is electrically connected with an external power supply, and the second end of the primary winding is electrically connected with the first end of the switch module; the first secondary winding is connected with the first rectifier module in parallel, and the first rectifier module is further electrically connected with a relay coil. The flyback switching power supply supplies power to the relay coil, the electric energy loss of the relay coil can be reduced by setting the leakage inductance of the first secondary winding and the capacity of the first capacitor, no extra control device needs to be added, and the control cost is reduced while the electric energy loss is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of relay drive control, in particular to a relay energy-saving drive circuit. Background Art

[0002] The relay has the characteristics of high closing action voltage, low closing holding voltage and constant relay coil impedance. In order to reduce the energy loss of the relay coil, the rated voltage can be provided to the relay coil during the closing action, and a lower closing holding voltage can be provided to the relay coil after the closing is stable.

[0003] The prior art uses the following methods to reduce the power loss of relay coils: (1) using two power supplies, one high and one low, to supply power to the relay coil, switching control is performed through a switch, and providing high and low voltages to the relay coil when the relay is closed and when the relay is closed; (2) using a chopper power supply to supply power to the relay coil, and adjusting the duty cycle of the power supply through a high-frequency on-off switch device, thereby achieving voltage regulation before and after the relay coil is closed; (3) connecting a buck step-down component in series with the relay coil winding, and designing the working characteristics of the buck step-down component to work at a large duty cycle when power is just supplied, outputting a high voltage to the relay coil, and reducing the duty cycle after a period of time to output a low voltage to the relay coil. These prior art methods require the addition of additional control devices, and the control cost is high. Utility Model Content

[0004] In view of this, the purpose of the utility model is to overcome the deficiencies in the prior art and provide a relay energy-saving drive circuit. The utility model provides the following technical solutions:

[0005] The utility model provides a relay energy-saving drive circuit, the circuit comprising: a transformer module, a switch module and a first rectifier module, the transformer module comprising a primary winding and a first secondary winding; the first end of the primary winding is electrically connected to an external power supply, and the second end of the primary winding is electrically connected to the first end of the switch module; the first secondary winding is connected in parallel with the first rectifier module, and the first rectifier module is also electrically connected to the relay coil;

[0006] The switch module is used to modulate the DC voltage obtained by the primary winding from the external power supply into an AC square wave voltage, so that the primary winding obtains the AC square wave voltage; the first secondary winding is used to output a first voltage when the primary winding obtains the AC square wave voltage; the first rectifier module is used to provide a power supply voltage to the relay coil when the first voltage is received, and the power supply voltage is determined by the first voltage and the leakage inductance voltage of the first secondary winding in the first stage, and is determined by the first voltage in the second stage. The power supply voltage in the first stage is greater than the power supply voltage in the second stage.

[0007] In one embodiment, the first rectifier module includes a first diode and a first capacitor; the first end of the first diode is electrically connected to the first end of the first secondary winding, and the second end of the first diode is electrically connected to the first end of the first capacitor and the relay coil respectively; the second end of the first capacitor is electrically connected to the second end of the first secondary winding, and the second end of the first capacitor is also grounded;

[0008] The inductance of the first secondary winding satisfies the following conditions:

[0009]

[0010] Among them, V N1 Indicates the first voltage, L N1 represents the leakage inductance of the first secondary winding, V out1 Indicates the rated voltage of the relay, Indicates the rate of change of current in the first secondary winding;

[0011] The capacity of the first capacitor satisfies the following conditions:

[0012]

[0013] Among them, C 1 represents the capacity of the first capacitor, t represents the maximum closing time of the relay, V out2 Indicates the minimum closing voltage of the relay, L K Indicates the impedance of the relay coil.

[0014] In one embodiment, the transformer module also includes a second secondary winding, and the circuit also includes: a second rectifier module; the second secondary winding is connected in parallel with the second rectifier module, and the second rectifier module is also electrically connected to the second end of the switch module; the second secondary winding is used to output a second voltage when the primary winding obtains the AC square wave voltage; the second rectifier module is used to output a modulation signal to the switch module when receiving the second voltage.

[0015] In one embodiment, the second rectifier module includes a second diode and a second capacitor; the first end of the second diode is electrically connected to the first end of the second secondary winding, and the second end of the second diode is electrically connected to the second capacitor and the second end of the switch module respectively; the second end of the second capacitor is electrically connected to the second end of the second secondary winding, and the second end of the second capacitor is also grounded.

[0016] In one embodiment, the switching module includes a PWM controller and a first switch; the PWM controller is electrically connected to the second end of the second diode, and the PWM controller is also grounded; the input end of the first switch is electrically connected to the second end of the primary winding, and the output end of the first switch is grounded; the PWM controller is used to adjust the duty cycle of the AC square wave voltage according to the modulation signal.

[0017] In one implementation, the switch module further includes: a first resistor, wherein the first resistor is connected in series between the PWM controller and a control end of the first switch.

[0018] In one embodiment, the circuit further includes a control module, a first end of the control module is electrically connected to the relay coil, and a second end of the control module is grounded; the control module is used to control the relay coil to be energized or de-energized.

[0019] In one embodiment, the control module includes a second switch and a start switch; the first end of the start switch is electrically connected to the control end of the second switch, and the second end of the start switch is grounded; the input end of the second switch is electrically connected to the relay coil, and the output end of the second switch is grounded; the start switch is used to control the second switch to be turned on when a start signal is obtained; the second switch is used to energize the relay coil when it is turned on.

[0020] In one embodiment, the control module further includes a second resistor, and the second resistor is connected in series between the start switch and a control end of the second switch.

[0021] In one embodiment, the control module further includes a third resistor, and the third resistor is connected in series between the control end and the output end of the second switch.

[0022] The relay energy-saving drive circuit provided by the utility model modulates the DC voltage obtained by the primary winding from the external power supply into an AC square wave voltage through the switch module, so that the primary winding obtains the AC square wave voltage; when the primary winding obtains the AC square wave voltage, the first secondary winding outputs a first voltage; when the first voltage is received, the first rectifier module provides a power supply voltage to the relay coil, and the power supply voltage is determined by the first voltage and the leakage inductance voltage of the first secondary winding in the first stage, and by the first voltage in the second stage, and the power supply voltage in the first stage is greater than the power supply voltage in the second stage. The present application uses a flyback switching power supply to power the relay coil, and by setting the leakage inductance size of the first secondary winding and the capacity of the first capacitor, it is possible to reduce the power loss of the relay coil without adding additional control devices, thereby reducing the power loss and the control cost.

[0023] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A schematic diagram of a structure of a relay energy-saving drive circuit provided by an embodiment of the utility model is shown;

[0026] Figure 2 Another structural schematic diagram of the relay energy-saving drive circuit provided by an embodiment of the utility model is shown;

[0027] Figure 3 Another structural schematic diagram of the relay energy-saving drive circuit provided by the embodiment of the utility model is shown;

[0028] Figure 4 1 is a circuit schematic diagram showing a relay energy-saving drive circuit provided in an embodiment of the utility model.

[0029] Description of main component symbols:

[0030] 100-relay energy-saving drive circuit; 110-transformer module; N0-primary winding; N1-first secondary winding; N2-second secondary winding; 120-switch module; 130-first rectifier module; 140-second rectifier module; 200-external power supply; K-relay coil; 150-control module. DETAILED DESCRIPTION

[0031] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] 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. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of the template herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] Example 1

[0035] The utility model embodiment provides a relay energy-saving drive circuit, for details, see Figure 1 The relay energy-saving driving circuit 100 includes: a transformer module 110, a switch module 120 and a first rectifier module 130, and the transformer module 110 includes a primary winding N0 and a first secondary winding N1;

[0036] The first end of the primary winding N0 is electrically connected to the external power supply 200, and the second end of the primary winding N0 is electrically connected to the first end of the switch module 120; the first secondary winding N1 is connected in parallel with the first rectifier module 130, and the first rectifier module 130 is also electrically connected to the relay coil K;

[0037] The switch module 120 is used to modulate the DC voltage obtained by the primary winding N0 from the external power supply 200 into an AC square wave voltage, so that the primary winding N0 obtains the AC square wave voltage; the first secondary winding N1 is used to output a first voltage when the primary winding N0 obtains the AC square wave voltage; the first rectifier module 130 is used to provide a power supply voltage to the relay coil K when the first voltage is received, and the power supply voltage is determined by the first voltage and the leakage inductance voltage of the first secondary winding N1 in the first stage, and is determined by the first voltage in the second stage. The power supply voltage in the first stage is greater than the power supply voltage in the second stage.

[0038] In this embodiment, a flyback switching power supply, i.e., the relay energy-saving drive circuit described in the embodiment of the present application, is used to power the relay coil K, so that the relay coil K obtains a higher power supply voltage in the first stage after being powered on, i.e., before closing, and obtains a lower power supply voltage in the second stage after being powered on, i.e., when the closure is maintained, thereby reducing the power loss of the relay coil K.

[0039] Specifically, the DC voltage input from the external power supply 200 is modulated into an AC square wave voltage through the switch module 120. When the primary winding N0 obtains the AC square wave voltage, the magnetic field of the primary winding N0 changes, thereby affecting the change of the magnetic field of the first secondary winding N1, so that the first secondary winding N1 generates current and outputs the first voltage. It should be understood that when the first secondary winding N1 is unloaded, that is, when the relay coil K is not powered, due to the existence of the leakage inductance of the first secondary winding N1, the power supply voltage output by the first rectifier module 130 is actually the sum of the first voltage and the leakage inductance voltage of the first secondary winding N1; after the first secondary winding N1 is loaded, that is, after the relay coil K is powered, the leakage inductance of the first secondary winding N1 gradually tends to saturation, at which time the leakage inductance voltage of the first secondary winding N1 will approach zero, and the power supply voltage output by the first rectifier module 130 will eventually be equal to the first voltage. That is, when the relay coil K is just energized, the voltage obtained is the sum of the first voltage and the leakage inductance voltage of the first secondary winding N1. Afterwards, as the leakage inductance voltage decreases, the voltage obtained by the relay coil K gradually decreases to the first voltage, thereby reducing the power loss of the relay coil K.

[0040] It should be noted that since the voltage obtained by the primary winding N0 is an AC square wave voltage, that is, a voltage that repeatedly alternates between positive and negative directions, the first voltage output by the first secondary winding N1 is actually an AC square wave voltage of the same frequency. In order to ensure that the voltage input to the relay coil K is direct current, it is necessary to connect the first rectifier module 130 in parallel at both ends of the first secondary winding N1 to convert the voltage at both ends of the first secondary winding N1 into direct current and then supply power to the relay coil K. Figure 1The middle dotted line indicates that the primary winding N0 is coupled to the first secondary winding N1 , and the ratio of the number of turns of the primary winding N0 to the first secondary winding N1 is equal to the ratio of the voltage obtained by the primary winding N0 to the first voltage.

[0041] In one embodiment, see Figure 2 , the transformer module 110 further includes a second secondary winding N2, and the relay energy-saving drive circuit 100 further includes: a second rectifier module 140; the second secondary winding N2 is connected in parallel with the second rectifier module 140, and the second rectifier module 140 is also electrically connected to the second end of the switch module 120;

[0042] The second secondary winding N2 is used to output a second voltage when the primary winding N0 obtains the AC square wave voltage; the second rectifier module 140 is used to output a modulation signal to the switch module 120 when receiving the second voltage.

[0043] In this embodiment, Figure 2 The dotted line portion in indicates that the primary winding N0 is coupled with the first secondary winding N1 and the second secondary winding N2, respectively, wherein the ratio of the number of turns of the primary winding N0 to the number of turns of the second secondary winding N2 is equal to the ratio of the voltage obtained by the primary winding N0 to the second voltage. The second voltage output by the second secondary winding N2 is an AC square wave voltage, and its frequency is the same as the voltage frequency obtained by the primary winding N0. The second rectifier module 140 is used to convert the second voltage into a corresponding direct current, and output the direct current as a control signal to the switch module 120. The switch module 120 controls the duty cycle of the AC square wave voltage, so that the voltage of the second secondary winding N2 is stabilized at a certain voltage value, so that the first voltage output by the first secondary winding is also stabilized at a certain voltage value.

[0044] In one embodiment, see Figure 3 The relay energy-saving driving circuit 100 also includes a control module 150, a first end of the control module 150 is electrically connected to the relay coil K, and a second end of the control module 150 is grounded; the control module 150 is used to control the relay coil K to be energized or de-energized.

[0045] In this embodiment, when the control module 150 receives a start signal, it is turned on, and at this time the relay coil K obtains a power supply voltage from the second rectifier module 140, that is, the relay coil K is energized; when the control module 150 receives a shutdown signal, it is disconnected, and at this time the relay coil K loses power.

[0046] It should be noted that after the relay coil K is powered, in the first stage, the first rectifier module 130 provides a higher power supply voltage for the relay coil K, and in the second stage, the second rectifier module 140 provides a lower power supply voltage for the relay coil K.

[0047] In one embodiment, see Figure 4 , the first rectifier module 130 includes a first diode D1 and a first capacitor C1; the first end of the first diode D1 is electrically connected to the first end of the first secondary winding N1, and the second end of the first diode D1 is electrically connected to the first end of the first capacitor C1 and the relay coil K respectively; the second end of the first capacitor C1 is electrically connected to the second end of the first secondary winding N1, and the second end of the first capacitor C1 is also grounded;

[0048] The inductance of the first secondary winding N1 satisfies the following conditions:

[0049]

[0050] Among them, V N1 Indicates the first voltage, L N1 Represents the leakage inductance of the first secondary winding N1, V out1 Indicates the rated voltage of the relay, Indicates the current change rate of the first secondary winding N1;

[0051] The capacity of the first capacitor C1 satisfies the following conditions:

[0052]

[0053] Among them, C 1 represents the capacity of the first capacitor, t represents the maximum closing time of the relay, V out2 Indicates the minimum closing voltage of the relay, L K Represents the impedance of relay coil K.

[0054] To ensure that the relay closes smoothly, the supply voltage obtained by the relay coil K in the first stage after being energized must meet the following conditions: (1) the supply voltage must be greater than the minimum closing voltage of the relay; (2) the time that the supply voltage is greater than the minimum closing voltage of the relay should be greater than the closing time of the relay.

[0055] In this embodiment, at the moment when the relay coil K is energized, the power supply voltage provided by the first rectifier module 130 to the relay coil K is determined by the first voltage and the leakage inductance voltage of the first secondary winding N1. To ensure that the relay is closed smoothly and safely, it is necessary to ensure that at the moment when the relay coil K is energized, the power supply voltage obtained is equal to the rated voltage of the relay coil, that is, the sum of the first voltage and the leakage inductance voltage of the first secondary winding N1 is equal to the rated voltage of the relay, that is, It should be noted that the rated voltage of the relay coil is greater than the minimum pick-up voltage of the relay. After the relay coil K is energized, as the leakage inductance of the first secondary winding N1 gradually decreases, the power supply voltage obtained by the relay coil K also gradually decreases, and its decreasing trend is Where V out2 It represents the supply voltage at any time after the relay coil K is energized. To ensure the smooth closing of the relay, the supply voltage obtained by the relay coil K should always be greater than the minimum closing voltage within the closing time t of the closed relay. Based on this, the minimum capacity value of the first capacitor C1 can be determined. The minimum capacity value of the first capacitor C1 can ensure that when the maximum closing time is reached, the supply voltage is exactly equal to the minimum closing voltage of the relay. Among them, the rated voltage, maximum closing time, minimum closing voltage of the relay and the impedance of the relay coil can all be obtained by referring to the manual of the corresponding model of the relay.

[0056] It should be noted that the first voltage output by the first secondary winding N1 is an AC square wave voltage with the same frequency as the primary winding N0. In order to ensure that the relay coil K obtains stable direct current, the first voltage is adjusted to direct current through the first diode D1 and the first capacitor C1. Specifically, when the direction of the first voltage is in the first direction, the first end of the first diode D1 obtains a forward voltage and is turned on to supply power to the relay coil K, while the first capacitor C1 is charged; when the direction of the first voltage is in the second direction, the first end of the first diode D1 obtains a negative voltage. Due to the unidirectional conduction property of the first diode D1, the first diode D1 is turned off at this time, and the first capacitor C1 is discharged to ensure continuous power supply to the relay coil K, thereby achieving stable output of direct current. The calculation formula for the current change rate of the first secondary winding N1 is as follows: Among them, k is the current ripple coefficient; Irms is the average output current of the first secondary winding N1, which can be calculated based on the current on the primary winding N0; f is the preset switching frequency of the switch module; D is the duty cycle of the primary PWM, and its size will be automatically adjusted as the primary input voltage and current change. It is generally best to preset it between 0.2-0.45. In this embodiment, the maximum duty cycle of 0.45 is taken for calculation.

[0057] In one embodiment, see again Figure 4 The second rectifier module 140 includes a second diode D2 and a second capacitor C2; the first end of the second diode D2 is electrically connected to the first end of the second secondary winding N2, and the second end of the second diode D2 is electrically connected to the second capacitor C2 and the second end of the switch module 120 respectively; the second end of the second capacitor C2 is electrically connected to the second end of the second secondary winding N2, and the second end of the second capacitor C2 is also grounded.

[0058] In this embodiment, the second voltage output by the second secondary winding N2 is an alternating current with the same frequency as the alternating square wave voltage obtained by the primary winding N0. When the direction of the second voltage is the first direction, the first end of the second diode D2 obtains a forward voltage and is turned on, outputting current to the switch module 120, and charging the second capacitor C2 at the same time; when the direction of the second voltage is the second direction, the first end of the second diode D2 obtains a negative voltage. Due to the unidirectional conduction property of the second diode D2, the second diode D2 is turned off at this time, and the second capacitor C2 is discharged, thereby achieving a stable output of direct current to the switch module 120 to modulate the duty cycle of the alternating square wave voltage through the switch module 120.

[0059] In one embodiment, see again Figure 4 The switch module 120 includes a PWM controller and a first switch Q1; the PWM controller is electrically connected to the second end of the second diode D2, and the PWM controller is also grounded; the input end of the first switch Q1 is electrically connected to the second end of the primary winding N0, and the output end of the first switch Q1 is grounded; the PWM controller is used to adjust the duty cycle of the AC square wave voltage according to the modulation signal.

[0060] In this embodiment, the PWM controller outputs a square wave current and controls the first switch Q1 to be turned on or off, so that the direct current obtained by the primary winding N0 is converted into an alternating square wave voltage.

[0061] It should be noted that since the magnitude and direction of the direct current do not change, when the primary winding N0 obtains direct current, the magnetic field of the primary winding N0 will not change, thereby not affecting the change in the magnetic field of the secondary winding, and thus the secondary winding will not generate voltage. By controlling the on or off of the first switch Q1, the direct current input by the external power supply can be modulated into an alternating square wave voltage.

[0062] In one implementation, the switch module 120 further includes: a first resistor R1 , wherein the first resistor R1 is connected in series between the PWM controller and a control terminal of the first switch Q1 .

[0063] In this embodiment, the first resistor R1 is used to limit the current input to the control terminal of the first switch Q1. The first switch Q1 is a MOS tube.

[0064] In one embodiment, the control module 150 includes a second switch Q2 and a start switch Q3; a first end of the start switch Q3 is electrically connected to a control end of the second switch Q2, and a second end of the start switch Q2 is grounded; an input end of the second switch Q2 is electrically connected to the relay coil K, and an output end of the second switch Q2 is grounded;

[0065] The starting switch Q3 is used to control the second switch Q2 to be turned on when a starting signal is obtained; the second switch Q2 is used to energize the relay coil K when it is turned on.

[0066] In this embodiment, the start switch Q3 can be, for example, a button. When pressed, the start switch Q3 obtains a start signal and outputs a high level to the control end of the second switch Q2 to control the second switch Q2 to be turned on, thereby energizing the relay coil K.

[0067] In one embodiment, the control module 150 further includes a second resistor R2 , and the second resistor R2 is connected in series between the start-up switch Q3 and a control terminal of the second switch Q2 .

[0068] In this embodiment, the second resistor R2 plays a current limiting role, limiting the current input to the control end of the second switch Q2. The second switch Q2 is a triode.

[0069] In one embodiment, the control module 150 further includes a third resistor R3 , and the third resistor R3 is connected in series between the control terminal and the output terminal of the second switch Q2 .

[0070] In this embodiment, the third resistor R3 is used to keep the output end of the second switch Q2 at a high level when the output end of the second switch Q2 reaches a high level, thereby controlling the second switch Q2 to be continuously turned on, until the start switch Q3 receives a shutdown signal and outputs a low level to the output end of the second switch Q2, thereby controlling the second switch Q2 to be turned off.

[0071] The relay energy-saving drive circuit provided by the embodiment of the utility model comprises: a transformer module, a switch module and a first rectifier module, the transformer module comprises a primary winding and a first secondary winding; the first end of the primary winding is electrically connected to an external power supply, and the second end of the primary winding is electrically connected to the first end of the switch module; the first secondary winding is connected in parallel with the first rectifier module, and the first rectifier module is also electrically connected to the relay coil; the switch module is used to modulate the DC voltage obtained by the primary winding from the external power supply into an AC square wave voltage, so that the primary winding obtains the AC square wave voltage; the first secondary winding is used to output a first voltage when the primary winding obtains the AC square wave voltage; the first rectifier module is used to provide a power supply voltage to the relay coil when receiving the first voltage, and the power supply voltage is determined by the first voltage and the leakage inductance voltage of the first secondary winding in the first stage, and is determined by the first voltage in the second stage, and the power supply voltage in the first stage is greater than the power supply voltage in the second stage. The present application uses a flyback switching power supply to power the relay coil. By setting the leakage inductance of the first secondary winding and the capacity of the first capacitor, the energy loss of the relay coil can be reduced without adding additional control components. While reducing the energy loss, the control cost is also reduced.

[0072] In all examples shown and described herein, any specific values ​​should be interpreted as merely exemplary and not as limiting, and thus other examples of the exemplary embodiments may have different values.

[0073] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0074] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A relay energy-saving drive circuit, characterized in that: The circuit comprises: a transformer module, a switch module and a first rectifier module, wherein the transformer module comprises a primary winding and a first secondary winding; The first end of the primary winding is electrically connected to an external power supply, and the second end of the primary winding is electrically connected to the first end of the switch module; The first secondary winding is connected in parallel with the first rectifier module, and the first rectifier module is also electrically connected to the relay coil; The switch module is used to modulate the DC voltage obtained by the primary winding from the external power supply into an AC square wave voltage, so that the primary winding obtains the AC square wave voltage; The first secondary winding is used to output a first voltage when the primary winding obtains the AC square wave voltage; The first rectifier module is used to provide a power supply voltage to the relay coil when receiving the first voltage. The power supply voltage is determined by the first voltage and the leakage inductance voltage of the first secondary winding in the first stage, and is determined by the first voltage in the second stage. The power supply voltage in the first stage is greater than the power supply voltage in the second stage.

2. The relay energy-saving driving circuit according to claim 1, characterized in that: The first rectifier module includes a first diode and a first capacitor; The first end of the first diode is electrically connected to the first end of the first secondary winding, and the second end of the first diode is electrically connected to the first end of the first capacitor and the relay coil respectively; The second end of the first capacitor is electrically connected to the second end of the first secondary winding, and the second end of the first capacitor is also grounded; The inductance of the first secondary winding satisfies the following conditions: Among them, V N1 Indicates the first voltage, L N1 represents the leakage inductance of the first secondary winding, V out1 Indicates the rated voltage of the relay, Indicates the rate of change of current in the first secondary winding; The capacity of the first capacitor satisfies the following conditions: Where C1 represents the capacity of the first capacitor, t represents the maximum closing time of the relay, V out2 Indicates the minimum closing voltage of the relay, L K Indicates the impedance of the relay coil.

3. The relay energy-saving driving circuit according to claim 2, characterized in that: The transformer module further includes a second secondary winding, and the circuit further includes: a second rectifier module; The second secondary winding is connected in parallel with the second rectifier module, and the second rectifier module is also electrically connected to the second end of the switch module; The second secondary winding is used to output a second voltage when the primary winding obtains the AC square wave voltage; The second rectifier module is used to output a modulation signal to the switch module when receiving the second voltage.

4. The relay energy-saving driving circuit according to claim 3, characterized in that: The second rectifier module includes a second diode and a second capacitor; A first end of the second diode is electrically connected to a first end of the second secondary winding, and a second end of the second diode is electrically connected to the second capacitor and a second end of the switch module respectively; The second end of the second capacitor is electrically connected to the second end of the second secondary winding, and the second end of the second capacitor is also grounded.

5. The relay energy-saving driving circuit according to claim 4, characterized in that: The switch module includes a PWM controller and a first switch; The PWM controller is electrically connected to the second end of the second diode, and the PWM controller is also grounded; The input end of the first switch is electrically connected to the second end of the primary winding, and the output end of the first switch is grounded; The PWM controller is used to adjust the duty cycle of the AC square wave voltage according to the modulation signal.

6. The relay energy-saving driving circuit according to claim 5, characterized in that: The switch module further includes: a first resistor, which is connected in series between the PWM controller and a control end of the first switch.

7. The relay energy-saving driving circuit according to any one of claims 1 to 6, characterized in that: The circuit also includes a control module, a first end of the control module is electrically connected to the relay coil, and a second end of the control module is grounded; the control module is used to control the relay coil to be energized or de-energized.

8. The relay energy-saving driving circuit according to claim 7, characterized in that: The control module includes a second switch and a start switch; The first end of the start switch is electrically connected to the control end of the second switch, and the second end of the start switch is grounded; The input end of the second switch is electrically connected to the relay coil, and the output end of the second switch is grounded; The start switch is used to control the second switch to be turned on when a start signal is obtained; The second switch is used to energize the relay coil when it is turned on.

9. The relay energy-saving driving circuit according to claim 8, characterized in that: The control module further includes a second resistor, which is connected in series between the start switch and a control end of the second switch.

10. The relay energy-saving driving circuit according to claim 9, characterized in that: The control module further includes a third resistor, which is connected in series between the control end and the output end of the second switch.

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