A relay double power drive circuit and a power supply device

Abstract

The utility model relates to relay drive technical field discloses a relay double power drive circuit and power supply equipment, including drive power supply, maintenance power supply, switching control circuit and control unit, utilize drive power supply output relay attraction required high voltage, utilize maintenance power supply output and maintain the low voltage of relay attraction, and high low voltage supplies power to the coil simultaneously, realizes quick attraction, and drive power supply exits drive after completing attraction, achieves seamless switching maintenance attraction action, remarkably reduced drive power consumption, and simple and reliable structure, high stability.

Description

Technical Field

[0001] This utility model relates to the field of relay drive technology, and in particular to a relay dual-power drive circuit and backup power equipment. Background Technology

[0002] Traditional relays typically use a single-supply constant voltage drive. To ensure the relay can engage quickly and reliably, the power supply voltage must match the coil's rated engagement voltage. However, once engaged, the relay only requires a small current to maintain its engaged state. If the rated voltage is continued to be used, the coil will operate in a high-power state for an extended period, wasting energy and affecting the relay's lifespan due to prolonged heat generation. This problem is particularly pronounced in battery-powered portable electronic devices or low-power devices.

[0003] While some existing technologies have attempted to reduce relay power consumption, they suffer from complex control logic, high cost, and susceptibility to electromagnetic interference, making them unsuitable for scenarios with high stability requirements. Therefore, there is an urgent need for a driving solution that is simple in structure, low in cost, and can effectively reduce relay power consumption. Utility Model Content

[0004] Therefore, the technical problem to be solved by this utility model is to overcome the problem of high power consumption when the relay is in the energized state in the prior art.

[0005] To solve the above technical problems, this utility model provides a relay dual-power drive circuit, comprising: Drive power supply; Maintain power supply, with the output terminal connected to one end of the relay coil; Switching control modules includes: The first MOSFET has its emitter connected to the output terminal of the drive power supply and its collector connected to one end of the relay coil. The timing capacitor has one end connected to the base of the first MOSFET and the other end connected to the other end of the relay coil. The second MOSFET has its collector connected to the other end of the relay coil and its emitter grounded. The control unit is communicatively connected to the drive power supply and the sustaining power supply, and electrically connected to the base of the second MOSFET. It is used to control the operation of the drive power supply and the sustaining power supply and to control the conduction of the second diode when the relay needs to be turned on. The rated output voltage of the driving power supply is higher than the rated pull-in voltage of the relay coil, and the rated pull-in voltage of the relay coil is higher than the rated output voltage of the sustaining power supply.

[0006] In one embodiment of this utility model, the switching control module further includes: The current-limiting resistor is connected at one end to the output terminal of the drive power supply and at the other end to the base of the first MOSFET. The pull-up resistor is connected at one end to the base of the first MOSFET and at the other end to one end of the timing capacitor.

[0007] In one embodiment of this utility model, the switching control module further includes: The base discharge resistor is connected at one end to the output terminal of the control unit and at the other end to the base of the second MOSFET. The coil discharge resistor has one end connected to the base of the second MOSFET and the other end grounded.

[0008] In one embodiment of this utility model, a first diode is included, with its positive terminal connected to the output terminal of the power supply and its negative terminal connected to one end of the relay coil.

[0009] In one embodiment of this utility model, a second diode is included, with its positive terminal connected to the other end of the relay coil and its negative terminal connected to the output terminal of the drive power supply.

[0010] In one embodiment of this utility model, the ratio of the rated output voltage of the driving power supply to the rated pull-in voltage of the relay coil is in the range of [1.0, 1.3]; the ratio of the rated output voltage of the sustaining power supply to the rated pull-in voltage of the relay coil is in the range of [0.4, 0.6].

[0011] In one embodiment of this utility model, the rated output voltage of the driving power supply is 12V, and the rated output voltage of the sustaining power supply is 5V.

[0012] In one embodiment of this utility model, the first MOS transistor is a PNP type MOS transistor, and the second MOS transistor is an NPN type MOS transistor.

[0013] This utility model provides a backup power device based on the relay dual-power drive circuit described above, comprising: Main power supply interface, used to connect to the main power supply; A backup power supply interface is provided for connecting at least one backup power source. Load output interface, used to connect external loads; The main relay has its input terminal connected to the main power supply interface and its output terminal connected to the load output interface. The dual-power drive circuit for the main relay is connected to the main relay and controls the power supply status of the main power supply by controlling the on / off state of the main relay. The backup relay has its input terminal connected to the backup power supply interface and its output terminal connected to the load output interface. The backup relay dual-power drive circuit is connected to the backup relay and controls the power supply status of the backup power supply by controlling the switching on and off of the backup relay.

[0014] In one embodiment of this utility model, the main power supply is AC mains power; the backup power supply includes an uninterruptible power supply or an emergency power supply.

[0015] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0016] The dual-power drive circuit for the relay described in this utility model adopts a dual-power drive mode of high-voltage activation and low-voltage maintenance, combining the drive power supply and the maintenance power supply. When the trigger signal arrives, both high and low voltages are supplied simultaneously to ensure rapid activation of the relay. After activation, the high voltage automatically withdraws, and only the low voltage maintains the activation state of the relay. At the same time, a timing capacitor is used to control the high voltage power supply time. By adjusting the capacitance of the timing capacitor, the automatic delay shutdown of the drive power supply time can be achieved.

[0017] This invention achieves seamless switching between dual power supplies by using the coordinated control of the first MOSFET by the second MOSFET and the timing capacitor, with only a few common components to complete the control logic of simultaneous high and low voltage start-up, and low voltage maintenance after high voltage delay exit. Since the maintenance current is much smaller than the pull-in current, the power consumption is greatly reduced.

[0018] Furthermore, this invention can directly modify existing single-power relay systems. By adding a few general-purpose components, dual-power supply control logic can be achieved, resulting in a simple and easily expandable structure. Attached Figure Description

[0019] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein: Figure 1 This is a schematic diagram of the relay dual-power drive circuit of this utility model; Figure 2 This is a circuit connection diagram of the relay dual-power drive circuit of this utility model. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0021] Reference Figure 1 As shown in the schematic diagram, the relay dual-power drive circuit of this utility model includes: Drive power supply; Maintain power supply, with the output terminal connected to one end of the relay coil; Switching control modules includes: The first MOSFET has its emitter connected to the output terminal of the drive power supply and its collector connected to one end of the relay coil. The timing capacitor has one end connected to the base of the first MOSFET and the other end connected to the other end of the relay coil. The second MOSFET has its collector connected to the other end of the relay coil and its emitter grounded. The control unit is communicatively connected to the drive power supply and the sustaining power supply, and electrically connected to the base of the second MOSFET. It is used to control the operation of the drive power supply and the sustaining power supply and to control the conduction of the second diode when the relay needs to be turned on. The rated output voltage of the driving power supply is higher than the rated pull-in voltage of the relay coil, and the rated pull-in voltage of the relay coil is higher than the rated output voltage of the sustaining power supply.

[0022] The dual-power drive circuit for the relay described in this utility model adopts a dual-power drive mode of high-voltage activation and low-voltage maintenance, combining the drive power supply and the maintenance power supply. When the trigger signal arrives, both high and low voltages are supplied simultaneously to ensure rapid activation of the relay. After activation, the high voltage automatically withdraws, and only the low voltage maintains the activation state of the relay. At the same time, a timing capacitor is used to control the high voltage power supply time. By adjusting the capacitance of the timing capacitor, the automatic delay shutdown of the drive power supply time can be achieved.

[0023] In this embodiment, to ensure stable and reliable circuit operation, the switching control circuit further includes multiple resistors: The current-limiting resistor has one end connected to the output terminal of the drive power supply and the other end connected to the base of the first MOSFET, and is used to limit the base current of the first MOSFET. A pull-up resistor is connected at one end to the base of the first MOSFET and at the other end to one end of the timing capacitor to ensure that Q1 is reliably cut off in the initial state. The base discharge resistor is connected at one end to the output terminal of the control unit and at the other end to the base of the second MOSFET. It is used to improve the anti-interference capability of Q2 and provide a discharge path for the control signal. The coil discharge resistor is connected at one end to the base of the second MOSFET and at the other end to ground. It is used to absorb the reverse induced electromotive force generated when the relay coil is de-energized, and to protect the first and second MOSFETs from breakdown.

[0024] This embodiment also includes a first diode, whose positive terminal is connected to the output terminal of the sustaining power supply and whose negative terminal is connected to one end of the relay coil, in order to prevent current from flowing back into the sustaining power supply during the high-voltage driving phase.

[0025] This embodiment also includes a second diode, whose positive terminal is connected to the other end of the relay coil and whose negative terminal is connected to the output terminal of the drive power supply, forming another freewheeling protection circuit.

[0026] In this embodiment, the ratio of the rated output voltage of the driving power supply to the rated pull-in voltage of the relay coil ranges from [1.0, 1.3]; the ratio of the rated output voltage of the sustaining power supply to the rated pull-in voltage of the relay coil ranges from [0.4, 0.6]. Specifically, the rated output voltage of the driving power supply is 12V, and the rated output voltage of the sustaining power supply is 5V.

[0027] Reference Figure 2 The diagram shows the circuit connection of the dual-power drive circuit for the relay. In this invention, a high-voltage power supply is used as the driving power supply, and a low-voltage power supply is used as the maintaining power supply. The high-voltage power supply provides the high voltage required for the relay to engage, while the low-voltage power supply provides the low voltage required to maintain the relay engagement. The low voltage is lower than the high voltage. A switching control module is connected to the coils of the high-voltage power supply, the low-voltage power supply, and the relay body, respectively. It receives external trigger signals, controls the voltage of the high-voltage power supply and the low-voltage power supply and the conduction state of the coil, and achieves seamless switching. The relay body's coil seamlessly switches to output a high voltage through the switching control module, realizing the engagement action and maintaining the engagement state.

[0028] Specifically, Q2 turns on after receiving an external trigger signal, controlling the low-voltage power supply to power the relay coil. Q1 turns on after receiving a trigger signal, outputting a high voltage to one end of the relay. After the coil is energized, Q1 stops working because capacitor C1 has finished charging, and the high voltage stops working. Only the low-voltage power supply continues to power the coil, maintaining the energized state. The input terminal of the first MOSFET is connected to the high-voltage power supply voltage, and the output terminal is connected to one end of the coil. The input terminal of the second MOSFET is connected to the other end of the coil. The control terminal of the first MOSFET and the output terminal of the second MOSFET constitute the simplest conduction timing unit to achieve conduction. The duration of the high voltage supplied to the relay coil L1 can be adjusted by changing the capacitance of the timing capacitor C1.

[0029] This invention achieves a dual-power drive mode of high-voltage activation and low-voltage hold using the simplest and most universal components. While ensuring reliable relay operation, maintaining the activation state with low voltage reduces coil power consumption by 40%-60%, extending device runtime and minimizing the impact of heat generation on relay lifespan. It solves the technical problem of excessive power consumption in traditional single-power-driven relays and is suitable for electronic devices with strict energy consumption requirements. This invention is highly compatible, allowing direct modification of traditional single-power-driven relays. By rationally combining current-limiting resistors, pull-up resistors, timing capacitors, and the first MOSFET, the continuous high-voltage drive time of the relay is set. It uses fewer components, resulting in an extremely simple circuit that does not require replacement of the relay body, thus reducing application costs. Furthermore, it employs conventional power modules and switching elements, resulting in clear control logic, avoiding complex PWM adjustment circuits, low electromagnetic interference, simple and reliable structure, and high stability.

[0030] In this embodiment, the working principle of the relay dual-power drive circuit includes:

[0031] ①Initial state: The control unit does not output a control signal, and the second MOSFET Q2 is turned off; the base of the first MOSFET Q1 is pulled up to a high voltage through the current limiting resistor R1 and the pull-up resistor R2, and the first MOSFET Q1 is turned off; no current flows through the relay coil L1, and the relay is in the released state.

[0032] ② Simultaneous High and Low Voltage Driven Engagement Stage: When the relay needs to be engaged, the MCU controls the drive power supply and the sustaining power supply to power on, and outputs a high-level signal to the base of the second MOSFET Q2; the second MOSFET Q2 quickly turns on, pulling its collector voltage down to near ground level; since the voltage across the timing capacitor C1 cannot change abruptly, the base voltage of the first MOSFET Q1 is pulled down instantaneously, causing the first MOSFET Q1 (PNP type) to turn on; at this time, there are two drive current paths: one is a high-voltage, high-current drive path from the drive power supply through the relay coil, the first MOSFET, the second diode to ground, and the other is a low-voltage auxiliary drive path from the sustaining power supply through the first diode, the relay coil, the second MOSFET to ground; the drive power supply and the sustaining power supply work together through the two paths to power the relay, enabling the coil L1 to obtain drive energy far exceeding its rated voltage, thereby achieving fast and reliable engagement.

[0033] ③ Low-voltage sustaining phase: During the continuous conduction of the second MOSFET Q2, the timing capacitor C1 is charged through the base-emitter junction of the first MOSFET Q1 and the second MOSFET Q2. As the voltage across the timing capacitor C1 increases, the current flowing through the base of the first MOSFET Q1 gradually decreases. After a period of time determined by the capacitance of the timing capacitor C1, the base current of the first MOSFET Q1 is insufficient to maintain its conduction, and the first MOSFET Q1 automatically turns off, thereby cutting off the power supply to the drive power supply. Afterward, only the sustaining power supply passes through the first diode D1, the relay coil L1, and the second MOSFET Q2 before grounding, supplying power to the relay coil L1 to maintain the relay's engaged state with low power consumption.

[0034] ④ Release stage: When the relay needs to be released, the control unit sets the signal output to the base of the second MOSFET Q2 to a low level, the second MOSFET Q2 is turned off, the power supply circuit of the power supply is cut off, the relay coil L1 is de-energized, and the relay is released; the residual energy in the coil is consumed through the discharge resistor R4.

[0035] Specifically, when Q1 and Q2 receive the on signal, they both conduct, and the relay is energized. After detecting coil energization, the high-voltage power supply module stops supplying power to the coil, and the low-voltage module independently maintains the relay's energized state. In this embodiment, the high-voltage power supply uses a PNP transistor as a switch to supply power to the relay coil, with an output voltage of 12V to match the relay's rated energizing voltage of 12V. The actual output can be finely adjusted to 13V to improve the energizing speed. The low-voltage module supplies power to the coil after the second MOSFET Q2 is turned on, with an output voltage of 5V, approximately 41.7% of the rated energizing voltage.

[0036] Specifically, in the switching control circuit, the second MOSFET Q2 receives the control signal and its collector pin 3 is at a low level; the lower end of the timing capacitor C1 is pulled to a low level, causing it to be in a charging state, which causes the base pin 1 of the first MOSFET Q1 to be at a low level, and the collector pin 3 of the first MOSFET Q1 outputs a high voltage and injects it into the upper end of the relay coil, causing the relay to be energized in a high voltage state.

[0037] This embodiment transforms a traditional single-power relay into a dual-power drive in the simplest way through the above design. It only adds 4 components. Under the premise of ensuring the reliability of the pull-in, the long-term working power consumption of the coil is reduced from the original 1.44W (12V×120mA) to 0.6W (5V×120mA), which is a 60% reduction in power consumption and significantly improves the energy efficiency of the equipment.

[0038] Based on the above embodiments, in this embodiment of the utility model, a backup power device based on the relay dual-power drive circuit as described above is provided, comprising: Main power supply interface, used to connect to the main power supply; A backup power supply interface is provided for connecting at least one backup power source. Load output interface, used to connect external loads; The main relay has its input terminal connected to the main power supply interface and its output terminal connected to the load output interface. The dual-power drive circuit for the main relay is connected to the main relay and controls the power supply status of the main power supply by controlling the on / off state of the main relay. The backup relay has its input terminal connected to the backup power supply interface and its output terminal connected to the load output interface. The backup relay dual-power drive circuit is connected to the backup relay and controls the power supply status of the backup power supply by controlling the switching on and off of the backup relay.

[0039] The main power supply is AC power; the backup power supply includes uninterruptible power supply or emergency power supply.

[0040] In this embodiment, the coil of the main relay is driven by a main relay dual-power drive circuit; the coil of the standby relay is driven by a standby relay dual-power drive circuit. Both the main relay dual-power drive circuit and the standby relay dual-power drive circuit employ the aforementioned relay dual-power drive circuit.

[0041] Taking the dual-power drive circuit for the main relay as an example, under the control of the control unit, 12V and 5V are initially supplied simultaneously to quickly engage the main relay. Subsequently, the 12V is automatically cut off through the charging of the timing capacitor, and only the 5V maintains the engaged state of the main relay. The structure and operation of the dual-power drive circuit for the standby relay are exactly the same.

[0042] The coils of the main relay and the backup relay operate in a 5V low-voltage holding state, which minimizes the self-loss of the equipment control circuit during battery power supply, and uses more of the precious battery energy to maintain load operation, thereby significantly extending the backup power time.

[0043] This embodiment applies dual-power drive technology to the power path management of backup equipment, minimizing coil power consumption when the primary and backup paths remain conductive, thus improving overall efficiency and extending battery backup time. The relay's engagement is guaranteed by high voltage, ensuring decisive and resolute operation and preventing arcing and unreliable connections caused by contact bounce during switching, significantly improving the success rate of backup power switching and the overall reliability of the equipment. Furthermore, this solution achieves a significant leap in system-level performance by adding only a few general-purpose components, eliminating the need for complex control chips or expensive low-power relays, resulting in extremely high cost-effectiveness.

[0044] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A relay dual-power drive circuit, characterized in that, include: Drive power supply; Maintain power supply, with the output terminal connected to one end of the relay coil; Switching control modules includes: The first MOSFET has its emitter connected to the output terminal of the drive power supply and its collector connected to one end of the relay coil. The timing capacitor has one end connected to the base of the first MOSFET and the other end connected to the other end of the relay coil. The second MOSFET has its collector connected to the other end of the relay coil and its emitter grounded. The control unit is communicatively connected to the drive power supply and the sustaining power supply, and electrically connected to the base of the second MOSFET. It is used to control the operation of the drive power supply and the sustaining power supply and to control the conduction of the second diode when the relay needs to be turned on. The rated output voltage of the driving power supply is higher than the rated pull-in voltage of the relay coil, and the rated pull-in voltage of the relay coil is higher than the rated output voltage of the sustaining power supply.

2. The relay dual-power drive circuit according to claim 1, characterized in that, The switching control module also includes: The current-limiting resistor is connected at one end to the output terminal of the drive power supply and at the other end to the base of the first MOSFET. The pull-up resistor is connected at one end to the base of the first MOSFET and at the other end to one end of the timing capacitor.

3. The relay dual-power drive circuit according to claim 1, characterized in that, The switching control module also includes: The base discharge resistor is connected at one end to the output terminal of the control unit and at the other end to the base of the second MOSFET. The coil discharge resistor has one end connected to the base of the second MOSFET and the other end grounded.

4. The relay dual-power drive circuit according to claim 1, characterized in that, It includes a first diode, with its positive terminal connected to the output terminal of the power supply and its negative terminal connected to one end of the relay coil.

5. The relay dual-power drive circuit according to claim 1, characterized in that, It includes a second diode, with its positive terminal connected to the other end of the relay coil and its negative terminal connected to the output terminal of the drive power supply.

6. The relay dual-power drive circuit according to claim 1, characterized in that, The ratio of the rated output voltage of the driving power supply to the rated pull-in voltage of the relay coil ranges from [1.0, 1.3]; the ratio of the rated output voltage of the sustaining power supply to the rated pull-in voltage of the relay coil ranges from [0.4, 0.6].

7. The relay dual-power drive circuit according to claim 6, characterized in that, The rated output voltage of the drive power supply is 12V, and the rated output voltage of the sustaining power supply is 5V.

8. The relay dual-power drive circuit according to claim 1, characterized in that, The first MOSFET is a PNP type MOSFET, and the second MOSFET is an NPN type MOSFET.

9. A backup power device based on the relay dual-power drive circuit as described in any one of claims 1 to 7, characterized in that, include: Main power supply interface, used to connect to the main power supply; A backup power supply interface is provided for connecting at least one backup power source. Load output interface, used to connect external loads; The main relay has its input terminal connected to the main power supply interface and its output terminal connected to the load output interface. The dual-power drive circuit for the main relay is connected to the main relay and controls the power supply status of the main power supply by controlling the on / off state of the main relay. The backup relay has its input terminal connected to the backup power supply interface and its output terminal connected to the load output interface. The backup relay dual-power drive circuit is connected to the backup relay and controls the power supply status of the backup power supply by controlling the switching on and off of the backup relay.

10. The backup power equipment according to claim 9, characterized in that, The main power supply is AC power; backup power supplies include uninterruptible power supplies or emergency power supplies.

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