Energy-saving control circuit of single-coil relay

Abstract

The utility model discloses an energy-saving control circuit of a single-coil relay, which comprises a voltage conversion unit, a delay switch unit and a voltage output feedback unit, and is characterized in that the input end of the voltage conversion unit is connected with a power supply input, the output end of the voltage conversion unit is connected with a relay coil, and the voltage input by the power supply is converted into a first control voltage or a second control voltage; a first input end of the delay switch unit is connected with power input, a second input end of the delay switch unit is connected with an output end of the voltage conversion unit, and the delay switch unit is used for outputting a first control signal and outputting a second control signal after delaying a preset time; the first input end of the voltage output feedback unit is connected with the output end of the voltage conversion unit, the second input end is connected with the output end of the delay switch unit, and the output end is connected with the feedback end of the voltage conversion unit; the voltage output feedback unit controls the voltage conversion unit to output corresponding first control voltage or second control voltage according to the first control signal or the second control signal; the circuit is simple in structure and low in cost.

Description

Technical Field

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

[0002] In the related art, energy-saving relays are usually driven by two groups of coils, one group of coils is used for starting excitation, and the other group of coils is used for holding; in order to save costs, there are also single-coil relays. In order to save energy, the existing single-coil relays need to additionally control the coil conduction duty cycle through the MCU's PWM, and then adjust the starting excitation, holding and disconnection of the control relay. When holding, the coil conduction duty cycle is reduced to achieve energy saving, or the two power supply circuits are switched separately to achieve the starting excitation, holding and disconnection of the relay, and a lower voltage power supply circuit is used when holding to achieve energy saving. However, the above two solutions are not only complex to implement, but also costly. Utility Model Content

[0003] The utility model aims to solve at least one of the technical problems in the above-mentioned technology to a certain extent. To this end, the purpose of the utility model is to propose an energy-saving control circuit of a single-coil relay, which affects the voltage output by adjusting different voltage feedbacks, and uses a delay switch unit to control the start excitation time, and switches to holding after the excitation ends, with a simple circuit structure and low cost.

[0004] In order to achieve the above-mentioned purpose, the utility model proposes an energy-saving control circuit of a single-coil relay, comprising: a voltage conversion unit, the input end of the voltage conversion unit is connected to the power input, the output end of the voltage conversion unit is connected to the relay coil, and the voltage conversion unit is used to convert the voltage of the power input into a first control voltage or a second control voltage of the power output so as to control the normal operation of the relay; a delay switch unit, the first input end of the delay switch unit is connected to the power input, the second input end of the delay switch unit is connected to the output end of the voltage conversion unit, and the delay switch unit is used to output a first control signal and output a first control signal after a preset delay. a voltage output feedback unit, wherein the first input terminal of the voltage output feedback unit is connected to the output terminal of the voltage conversion unit, the second input terminal of the voltage output feedback unit is connected to the output terminal of the delay switch unit, the output terminal of the voltage output feedback unit is connected to the feedback terminal of the voltage conversion unit, and the voltage output feedback unit generates a first feedback signal according to the first control signal so that the voltage conversion unit outputs a first control voltage according to the first feedback signal, or generates a second feedback signal according to the second control signal so that the voltage conversion unit outputs a second control voltage according to the second feedback signal.

[0005] The energy-saving control circuit of the single-coil relay proposed by the utility model includes a voltage conversion unit, a delay switch unit and a voltage output feedback unit. The input end of the voltage conversion unit is connected to the power input, and the output end of the voltage conversion unit is connected to the relay coil. The voltage conversion unit is used to convert the voltage of the power input into a first control voltage or a second control voltage of the power output so as to control the normal operation of the relay; the first input end of the delay switch unit is connected to the power input, and the second input end of the delay switch unit is connected to the output end of the voltage conversion unit. The delay switch unit is used to output a first control signal and output a second control signal after a preset delay time; the first input end of the voltage output feedback unit is connected to the power input, and the second input end of the delay switch unit is connected to the output end of the voltage conversion unit. An input end is connected to the output end of the voltage conversion unit, a second input end of the voltage output feedback unit is connected to the output end of the delay switch unit, the output end of the voltage output feedback unit is connected to the feedback end of the voltage conversion unit, the voltage output feedback unit generates a first feedback signal according to a first control signal, so that the voltage conversion unit outputs a first control voltage according to the first feedback signal, or generates a second feedback signal according to a second control signal, so that the voltage conversion unit outputs a second control voltage according to the second feedback signal; thereby, the voltage output is affected by adjusting different voltage feedbacks, and the delay switch unit is used to control the start excitation time, and the excitation is switched to hold after the end, the circuit structure is simple and the cost is low.

[0006] In addition, the energy-saving control circuit of the single-coil relay proposed in the utility model may also have the following additional technical features:

[0007] Optionally, when the voltage conversion unit outputs the first control voltage, the relay is in an energized state, and when the voltage conversion unit outputs the second control voltage, the relay is in a held state, wherein the first control voltage is greater than the second control voltage.

[0008] Optionally, the energy-saving control circuit of the single-coil relay also includes: a start-shutdown unit, a first output end of the start-shutdown unit is connected to the power input, a second output end of the start-shutdown unit is connected to the output end of the voltage conversion unit, and the output end of the start-shutdown unit is connected to the enable end of the voltage conversion unit, and the start-shutdown unit is used to control the minimum input voltage output by the voltage conversion unit and shut down the maximum input voltage output by the voltage conversion unit.

[0009] Specifically, the voltage conversion unit includes a DCDC chip.

[0010] Specifically, the start-shutdown unit includes: a first resistor, one end of the first resistor is connected to the voltage input; a second resistor, one end of the second resistor is connected to the other end of the first resistor, and the other end of the second resistor is grounded; a third resistor, one end of the third resistor is connected to the power supply output; a first diode, the positive electrode of the first diode is connected to the other end of the third resistor, and the negative electrode of the first diode is connected to the enable pin of the DCDC chip.

[0011] Specifically, the voltage output feedback unit includes: a fourth resistor, one end of the fourth resistor is connected to the power supply output; a fifth resistor, one end of the fifth resistor is connected to the other end of the fourth resistor, and the other end of the fifth resistor is grounded; a sixth resistor, one end of the sixth resistor is connected to the feedback pin of the DCDC chip; a MOS tube, the drain of the MOS tube is connected to the other end of the sixth resistor, the source of the MOS tube is grounded, and the gate of the MOS tube is connected to the delay switch unit.

[0012] Specifically, the delay switch unit includes: a seventh resistor, one end of the seventh resistor is connected to the power supply output; a second diode, the cathode of the second diode is connected to the other end of the seventh resistor; a first capacitor, one end of the first capacitor is connected to the anode of the second diode and has a first node, and the other end of the first capacitor is grounded; an eighth resistor, one end of the eighth resistor is connected to the first node, and the other end of the eighth resistor is grounded; a ninth resistor, one end of the ninth resistor is connected to the power supply output, and the other end of the ninth resistor is connected to the first node; a transistor, the base of the transistor is connected to the first node, the emitter of the transistor is grounded, and the collector of the transistor is connected to the gate of the MOS tube; a tenth resistor, one end of the tenth resistor is connected to the power supply input, the other end of the tenth resistor is connected to the collector of the transistor, and has a second node; an eleventh resistor, one end of the eleventh resistor is connected to the second node, and the other end of the eleventh resistor is grounded. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 1 is a circuit block diagram of an energy-saving control circuit of a single-coil relay according to an embodiment of the utility model;

[0014] Figure 2 The figure is a circuit schematic diagram of an energy-saving control circuit of a single-coil relay according to an embodiment of the utility model. DETAILED DESCRIPTION

[0015] 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 intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0016] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0017] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0018] refer to Figure 1 As shown, the energy-saving control circuit of the single-coil relay proposed in the embodiment of the utility model includes a voltage conversion unit 10, a delay switch unit 20 and a voltage output feedback unit 30.

[0019] Among them, the input end of the voltage conversion unit 10 is connected to the power input, the output end of the voltage conversion unit 10 is connected to the relay coil, and the voltage conversion unit 10 is used to convert the voltage of the power input into a first control voltage or a second control voltage of the power output, so as to control the normal operation of the relay; the first input end of the delay switch unit 20 is connected to the power input, and the second input end of the delay switch unit 20 is connected to the output end of the voltage conversion unit 10, and the delay switch unit 20 is used to output a first control signal and output a second control signal after a preset delay time; the first input end of the voltage output feedback unit 30 is connected to the output end of the voltage conversion unit 10, the second input end of the voltage output feedback unit 30 is connected to the output end of the delay switch unit 20, and the output end of the voltage output feedback unit 30 is connected to the feedback end of the voltage conversion unit 10, and the voltage output feedback unit 30 generates a first feedback signal according to the first control signal, so that the voltage conversion unit 10 outputs the first control voltage according to the first feedback signal, or generates a second feedback signal according to the second control signal, so that the voltage conversion unit 10 outputs the second control voltage according to the second feedback signal.

[0020] That is to say, the voltage conversion unit 10 is responsible for converting the input power supply into the first control voltage or the second control voltage output that needs to be set, and supplies it to the coil of the relay, so as to realize the switching of the excitation state or the holding state, wherein the switching between the first control voltage and the second control voltage is completed by the voltage output feedback unit 30, and the time for switching the excitation state to the holding state is completed by the delay switch unit 20; that is, by adjusting different voltage feedbacks to affect the voltage output, the start-up excitation and maintenance of the single-coil relay are realized, and the solution is simple and low-cost.

[0021] As an embodiment, when the voltage conversion unit 10 outputs a first control voltage, the relay is in an energized state, and when the voltage conversion unit 10 outputs a second control voltage, the relay is in a held state, wherein the first control voltage is greater than the second control voltage.

[0022] That is, when the relay is in the energized state, it needs to be set to a higher voltage output than in the held state, and when the relay is in the held state, it needs to be set to a lower voltage output than in the energized state.

[0023] As an embodiment, the energy-saving control circuit of the single-coil relay also includes a start-stop unit 40, a first output end of the start-stop unit 40 is connected to the power input, a second output end of the start-stop unit 40 is connected to the output end of the voltage conversion unit 10, and an output end of the start-stop unit 40 is connected to the enable end of the voltage conversion unit 10. The start-stop unit 40 is used to control the minimum input voltage output by the voltage conversion unit 10 and shut down the maximum input voltage output by the voltage conversion unit 10.

[0024] It should be noted that the start-shutdown unit 40 sets the minimum input voltage of the power supply output and the maximum input voltage of the power supply output, so as to set the minimum starting voltage of the relay coil and shut down the power supply output when it is lower than the release voltage, so as to achieve the function of normal operation even when the voltage rises or falls slowly. In addition, when the power supply input is enabled with DCDC, when the voltage input is less than or equal to the set voltage output, the output voltage is approximately the input voltage, and when the voltage input is greater than the set voltage output, the output voltage is the set value, which serves to limit the maximum excitation current.

[0025] That is to say, by combining the enable pin characteristics of the DCDC chip of the voltage conversion unit 10, adding a start-stop unit 40, and adjusting the start-up and shutdown voltages of the DCDC chip, the start-up excitation, maintenance and disconnection of the single-coil relay are realized, and the voltage ramp-up and ramp-down functions and the maximum excitation current limiting functions are provided. The solution is simple and the cost is low.

[0026] As a specific example, Figure 2 As shown, the voltage conversion unit 10 includes a DCDC chip.

[0027] That is to say, the voltage conversion unit 10 forms a power supply circuit through a DCDC chip with an enable EN detection function, for example, a DCDC chip of model SCT2620MRER.

[0028] In addition, the start-up / shutdown unit 40 includes a first resistor R1, a second resistor R8, a third resistor R3 and a first diode D2.

[0029] Among them, one end of the first resistor R1 is connected to the voltage input; one end of the second resistor R8 is connected to the other end of the first resistor R1, and the other end of the second resistor R8 is grounded GND; one end of the third resistor R3 is connected to the power output; the anode of the first diode D2 is connected to the other end of the third resistor R3, and the cathode of the first diode D2 is connected to the enable pin EN of the DCDC chip.

[0030] It should be noted that, since the minimum input voltage of the power output of the DCDC chip is set to be enabled and the maximum input voltage range of the power output is turned off are relatively close, the requirements of the relay start-up and release relay voltage cannot be met; therefore, a hysteresis mechanism is formed by the first resistor R1, the second resistor R8, the third resistor R3 and the first diode D2. When the input voltage VIN rises from 0 to a high voltage, the enabling requirement is not met at the beginning, there is no power output, VOUT is 0, and the first resistor R1 and the second resistor R8 form a voltage divider, VEN = VIN*R8 / (R8+R1); when the input voltage VIN rises from the voltage to the enabling requirement, there is power output, and VOUT is set to turn on the first diode D2. At this time, the VEN voltage increases, and a lower input voltage is required to turn off the output voltage of the DCDC chip; the output voltage is set to be slightly larger than the release voltage of the relay itself to prevent the relay from being disconnected at low voltage but the delay switch unit 20 is not discharged, which causes the relay to be unable to be excited when returning to normal voltage.

[0031] In addition, the voltage output feedback unit 30 includes a fourth resistor R2, a fifth resistor R7, a sixth resistor R6 and a MOS transistor Q1.

[0032] Among them, one end of the fourth resistor R2 is connected to the power supply output; one end of the fifth resistor R7 is connected to the other end of the fourth resistor R2, and the other end of the fifth resistor R7 is grounded GND; one end of the sixth resistor R6 is connected to the feedback pin FB of the DCDC chip; the drain of the MOS tube Q1 is connected to the other end of the sixth resistor R6, the source of the MOS tube Q1 is grounded GND, and the gate of the MOS tube Q1 is connected to the delay switch unit 20.

[0033] It should be noted that when the relay is in the energized state, the gate of the MOS tube Q1 is controlled to be high, so that the MOS tube Q1 is turned on, and the voltage output feedback unit 30 is composed of the fourth resistor R2, the fifth resistor R7 and the sixth resistor R6 to form a voltage divider circuit, and the output voltage is relatively high. This voltage is used as the voltage when the relay is excited; the output voltage VH = VFB*[1+R2 / (R6 / / R7)], where VFB is the feedback control voltage of the DCDC chip, which can be found in the specification sheet.

[0034] When the relay is in the hold state, the gate of the MOS tube Q1 is controlled to be low, so that the MOS tube Q1 is disconnected, and the voltage output feedback unit 30 is composed of the fourth resistor R2 and the fifth resistor R7 to form a voltage divider circuit, and the output voltage is low. This voltage is used as the voltage when the relay is held; the output voltage VL=VFB*(1+R2 / R7).

[0035] In addition, the delay switch unit 20 includes a seventh resistor R10, a second diode D4, a first capacitor C10, an eighth resistor R13, a ninth resistor R12, a transistor Q2, a tenth resistor R9 and an eleventh resistor R11.

[0036] Among them, one end of the seventh resistor R10 is connected to the power output; the cathode of the second diode D2 is connected to the other end of the seventh resistor R10; one end of the first capacitor C10 is connected to the anode of the second diode D4 and has a first node A, and the other end of the first capacitor C10 is grounded GND; one end of the eighth resistor R13 is connected to the first node A, and the other end of the eighth resistor R13 is grounded GND; one end of the ninth resistor R12 is connected to the power output, and the other end of the ninth resistor R12 is connected to the first node A; the base of the transistor Q2 is connected to the first node A, the emitter of the transistor Q2 is grounded GND, and the collector of the transistor Q2 is connected to the gate of the MOS tube Q1; one end of the tenth resistor R9 is connected to the power input, and the other end of the tenth resistor R9 is connected to the collector of the transistor Q2, and has a second node B; one end of the eleventh resistor R11 is connected to the second node B, and the other end of the eleventh resistor R11 is grounded GND.

[0037] It should be noted that the eighth resistor R13, the ninth resistor R12 and the first capacitor C10 form a delay circuit to delay the conduction of the transistor Q2; when the power input voltage VIN is powered on, the power output VOUT is also powered on subsequently. Due to the effect of the delay circuit, the transistor Q2 is not turned on first, and the voltage divider circuit composed of the tenth resistor R9 and the eleventh resistor R11 has a high output, so that the voltage output feedback unit 30 is controlled in an excitation state to excite the relay coil; as the base voltage of the transistor Q2 gradually increases, the transistor Q2 is turned on, and the collector voltage of the transistor Q2 is low, so that the voltage output feedback unit 30 is controlled in a holding state to hold the relay coil.

[0038] In addition, the seventh resistor R10 and the second diode D4 play a role of rapid discharge to ensure the stability of the delay time during the secondary power-on. The delay time is jointly set by the eighth resistor R13, the ninth resistor R12, the first capacitor C10 and the base conduction voltage of the transistor Q2.

[0039] Among them, the transistor Q2 can also be replaced by other switching tubes such as MOS tubes, and this application does not make specific limitations on this.

[0040] In summary, the energy-saving control circuit of the single-coil relay of the present application can realize the starting excitation, holding and disconnection of the single-coil relay, and the circuit structure is simple, the cost is low, and it has the functions of voltage slow rise and fall and limiting the maximum excitation current.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element 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 invention.

[0042] 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.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0045] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms should not be understood as necessarily being directed to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0046] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An energy-saving control circuit for a single-coil relay, characterized in that: include: A voltage conversion unit, wherein the input end of the voltage conversion unit is connected to the power input, the output end of the voltage conversion unit is connected to the relay coil, and the voltage conversion unit is used to convert the voltage of the power input into a first control voltage or a second control voltage of the power output, so as to control the normal operation of the relay; A delay switch unit, wherein a first input end of the delay switch unit is connected to the power input, a second input end of the delay switch unit is connected to the output end of the voltage conversion unit, and the delay switch unit is used to output a first control signal and output a second control signal after a delay of a preset time; A voltage output feedback unit, wherein a first input terminal of the voltage output feedback unit is connected to an output terminal of the voltage conversion unit, a second input terminal of the voltage output feedback unit is connected to an output terminal of the delay switch unit, an output terminal of the voltage output feedback unit is connected to a feedback terminal of the voltage conversion unit, and the voltage output feedback unit generates a first feedback signal according to the first control signal so that the voltage conversion unit outputs a first control voltage according to the first feedback signal, or generates a second feedback signal according to the second control signal so that the voltage conversion unit outputs a second control voltage according to the second feedback signal.

2. The energy-saving control circuit of the single-coil relay according to claim 1, characterized in that: When the voltage conversion unit outputs the first control voltage, the relay is in an energized state, and when the voltage conversion unit outputs the second control voltage, the relay is in a held state, wherein the first control voltage is greater than the second control voltage.

3. The energy-saving control circuit of the single-coil relay according to claim 1, characterized in that: Also includes: A start-shutdown unit, wherein the first output terminal of the start-shutdown unit is connected to the power input, the second output terminal of the start-shutdown unit is connected to the output terminal of the voltage conversion unit, the output terminal of the start-shutdown unit is connected to the enable terminal of the voltage conversion unit, and the start-shutdown unit is used to control the minimum input voltage output by the voltage conversion unit and shut down the maximum input voltage output by the voltage conversion unit.

4. The energy-saving control circuit of the single-coil relay according to claim 3, characterized in that: The voltage conversion unit includes a DCDC chip.

5. The energy-saving control circuit of the single-coil relay according to claim 4, characterized in that: The startup and shutdown unit comprises: A first resistor, one end of which is connected to the voltage input; a second resistor, one end of the second resistor being connected to the other end of the first resistor, and the other end of the second resistor being grounded; A third resistor, one end of which is connected to the power supply output; A first diode, wherein an anode of the first diode is connected to the other end of the third resistor, and a cathode of the first diode is connected to an enable pin of the DCDC chip.

6. The energy-saving control circuit of the single-coil relay according to claim 4, characterized in that: The voltage output feedback unit comprises: a fourth resistor, one end of which is connected to the power output; a fifth resistor, one end of the fifth resistor being connected to the other end of the fourth resistor, and the other end of the fifth resistor being grounded; a sixth resistor, one end of which is connected to a feedback pin of the DCDC chip; A MOS tube, wherein a drain of the MOS tube is connected to the other end of the sixth resistor, a source of the MOS tube is grounded, and a gate of the MOS tube is connected to the delay switch unit.

7. The energy-saving control circuit of the single-coil relay according to claim 6, characterized in that: The time delay switch unit comprises: a seventh resistor, one end of which is connected to the power output; a second diode, wherein a cathode of the second diode is connected to the other end of the seventh resistor; A first capacitor, one end of which is connected to the anode of the second diode and has a first node, and the other end of which is grounded; an eighth resistor, one end of the eighth resistor being connected to the first node, and the other end of the eighth resistor being grounded; a ninth resistor, one end of which is connected to the power supply output, and the other end of which is connected to the first node; A transistor, wherein the base of the transistor is connected to the first node, the emitter of the transistor is grounded, and the collector of the transistor is connected to the gate of the MOS tube; a tenth resistor, one end of which is connected to the power input, the other end of which is connected to the collector of the transistor, and has a second node; An eleventh resistor, one end of the eleventh resistor is connected to the second node, and the other end of the eleventh resistor is grounded.

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