Magnetic latching relay control circuit and device

Abstract

The utility model provides a magnetic latching relay control circuit and device, and in the magnetic latching relay control circuit, an AC / DC module and a phase detection module are respectively connected with an AC input; the AC / DC module is respectively connected in parallel with the temporary energy storage module, the phase detection module, the oscillator, the power failure judgment module, the relay driving module and the magnetic latching relay; the output end of the phase detection module, the oscillation end of the oscillator and the first control end of the relay driving module are electrically connected with the input end, the control end and the output end of the power failure judgment module in sequence; the output end of the relay driving module is electrically connected with the control end of the magnetic latching relay; when no alternating current input is caused by external power failure, the temporary energy storage module provides electric energy for the phase detection module, the oscillator, the power failure judgment module, the relay driving module and the magnetic latching relay in a short time, so that the technical scheme that contact connection of the magnetic latching relay can be disconnected in time when no alternating current input is caused by external power failure is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, and in particular to a magnetic latching relay control circuit and a device. Background Art

[0002] In some power supply control systems using magnetic latching relays, such as Figure 1 The power supply of the control system is generated by the AC / DC circuit, and the electric energy comes from the alternating current; the device used to close and disconnect the power supply is a magnetic latching relay. Although this relay has the advantage of not requiring continuous input current, it still remains closed after power failure in ordinary systems. When there is no AC input, the control system loses power, and it is unable to detect the power failure and close the magnetic latching relay. This system can only quickly close the magnetic latching relay when it is powered on next time to avoid the impact of abnormal conditions such as overvoltage and undervoltage on the load circuit.

[0003] When such a system encounters a power outage and then power restoration, but the restored power supply has abnormal conditions such as overvoltage or undervoltage, there is still some time from the restoration of power to the disconnection of the magnetic latching relay. If the power supply abnormality is very serious during this period, the load electrical appliances may heat up, break down, burn out or even catch fire, seriously endangering the safety of users' lives and property.

[0004] Therefore, it is necessary to provide a technical solution that can promptly disconnect the contact connection of the magnetic latching relay when there is no AC input due to external power failure. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a magnetic latching relay control circuit and device.

[0006] The utility model provides a magnetic latching relay control circuit, comprising: an AC / DC module, a temporary energy storage module, a phase detection module, an oscillator, a power failure judgment module, and a relay drive module;

[0007] The input end of the AC / DC module and the input end of the phase detection module are respectively used to electrically connect to an AC input;

[0008] The internal power positive terminal and the internal power negative terminal of the AC / DC module are respectively connected in parallel with the positive and negative power supply terminals of the temporary energy storage module, the phase detection module, the oscillator, the power failure judgment module, and the relay driving module, and are also used to connect the positive and negative power supply terminals of the magnetic latching relay in parallel;

[0009] The output end of the phase detection module is electrically connected to the input end of the power failure judgment module;

[0010] The oscillating end of the oscillator is electrically connected to the control end of the power-off judgment module;

[0011] The output end of the power-off judgment module is electrically connected to the first control end of the relay driving module;

[0012] The output end of the relay driving module is used to electrically connect to the control end of the magnetic latching relay;

[0013] The temporary energy storage module is used to provide power to the phase detection module, the oscillator, the power failure judgment module, the relay drive module and the magnetic latching relay in a short period of time when there is no AC input due to external power failure.

[0014] In a possible implementation, the temporary energy storage module is composed of at least one of a capacitor and a battery.

[0015] In a possible implementation, the power-off determination module is implemented based on a single-chip microcomputer.

[0016] In a possible implementation, the relay driving module is further provided with a second control terminal for electrically connecting to a relay operation instruction channel and receiving instructions through the relay operation instruction channel.

[0017] The utility model also provides a magnetic latching relay device, comprising a magnetic latching relay and the magnetic latching relay control circuit;

[0018] The positive and negative power supply terminals of the magnetic latching relay are connected in parallel to the internal power supply positive terminal and the internal power supply negative terminal of the AC / DC module;

[0019] The output end of the relay driving module is electrically connected to the control end of the magnetic latching relay;

[0020] The input end of the magnetic latching relay is used to electrically connect to an AC input, and the output end thereof is used to electrically connect to an AC output.

[0021] In a possible implementation, in the magnetic latching relay device, the temporary energy storage module is composed of at least one of a capacitor and a battery.

[0022] In a possible implementation, in the magnetic latching relay device, the power failure determination module is implemented based on a single chip microcomputer.

[0023] The technical solution provided by the utility model has at least the following beneficial effects:

[0024] By connecting a temporary energy storage module in parallel to the internal positive power terminal and the internal negative power terminal of the AC / DC module, and connecting an oscillator and a power-off judgment module, when a power supply system using a magnetic latching relay loses power, the electric energy stored in the temporary energy storage module can be used to complete the system power-off judgment and turn off the magnetic latching relay to protect the load circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A circuit diagram of a power supply control system using a magnetic latching relay in the background technology;

[0026] Figure 2 A circuit schematic diagram of a magnetic latching relay control circuit provided by the utility model;

[0027] Figure 3 Another circuit schematic diagram of a magnetic latching relay control circuit provided by the utility model;

[0028] Figure 4 A timing diagram provided by the utility model. DETAILED DESCRIPTION

[0029] In order to deepen the understanding of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and do not limit the protection scope of the present invention.

[0030] Please refer to Figures 1 to 4 The utility model provides a magnetic latching relay control circuit, comprising: an AC / DC module, a temporary energy storage module, a phase detection module, an oscillator, a power failure judgment module, and a relay driving module;

[0031] The input end of the AC / DC module and the input end of the phase detection module are respectively used to electrically connect to an AC input;

[0032] The internal power positive terminal and the internal power negative terminal of the AC / DC module are respectively connected in parallel with the positive and negative power supply terminals of the temporary energy storage module, the phase detection module, the oscillator, the power failure judgment module, and the relay driving module, and are also used to connect the positive and negative power supply terminals of the magnetic latching relay in parallel;

[0033] The output end of the phase detection module is electrically connected to the input end of the power failure judgment module;

[0034] The oscillating end of the oscillator is electrically connected to the control end of the power-off judgment module;

[0035] The output end of the power-off judgment module is electrically connected to the first control end of the relay driving module;

[0036] The output end of the relay driving module is used to electrically connect to the control end of the magnetic latching relay;

[0037] The temporary energy storage module is used to provide power to the phase detection module, the oscillator, the power failure judgment module, the relay drive module and the magnetic latching relay in a short period of time when there is no AC input due to external power failure.

[0038] In this embodiment, the AC / DC module is a conventional AC / DC circuit for converting alternating current into direct current. Its internal power supply positive terminal, i.e., the internal power supply +, and the internal power supply negative terminal, i.e., the internal power supply -, serve as the positive and negative poles of the internal power supply, and provide power for the temporary energy storage module, the phase detection module, the oscillator, the power-off judgment module, the relay drive module, and the magnetic holding relay. At the same time, the internal power supply - is connected to the ground. The temporary energy storage module has a temporary energy storage function, and for example, it can be composed of a capacitor. The phase detection module adopts a conventional module for detecting the phase of alternating current. The oscillator adopts a conventional model. The power-off judgment module is a conventional processing module, which can be implemented based on a single-chip microcomputer and can perform simple logical judgments, pulse outputs, etc. The relay drive module adopts a conventional module, which is composed of a MOS tube and a logic circuit, and is used to output a pulse of a corresponding action to the magnetic holding relay when receiving a closing / opening instruction of the magnetic holding relay to drive the magnetic holding relay. In a power supply control system using a magnetic latching relay, when there is no AC input and the magnetic latching relay control circuit is about to lose power, the phase signal obtained by the phase detection module detecting the phase of the AC input continues to be at a low level. When the power-off judgment module counts the oscillator to a certain threshold, it is determined that the system has lost power, thereby turning off the magnetic latching relay and protecting the load circuit.

[0039] In a possible implementation, the temporary energy storage module is composed of at least one of a capacitor and a battery.

[0040] In this embodiment, Figure 3 The temporary energy storage module can be composed of a single energy storage capacitor C. In a specific implementation, the energy storage capacitor C can be a capacitor with a total capacity of 470uF. The AC input is 220V, 50Hz AC.

[0041] In a possible implementation, the power-off determination module is implemented based on a single-chip microcomputer.

[0042] In a possible implementation, the phase detection module is used to detect the phase of the AC input, and send the detected phase signal to the power-off determination module;

[0043] When there is an AC input, the phase signal is a square wave representing phase information; when there is no AC input, the phase signal remains at a low level.

[0044] In this embodiment, when the pressure difference between the live line and the neutral line is positive, the square wave corresponding to the phase signal is at a high level, and when the pressure difference is zero or negative, the square wave corresponding to the phase signal is at a low level.

[0045] In a possible implementation, the oscillator oscillates or stops oscillating under the control of the power-off determination module; during oscillation, the power-off determination module receives a square wave signal generated by the oscillator.

[0046] In this embodiment, during oscillation, the power-off determination module can receive a square wave signal having a period of 50 microseconds generated by the oscillator.

[0047] In a possible implementation, when the phase signal is at a low level, the power-off determination module starts the oscillator and counts the rising edge or the falling edge of the square wave signal generated by the oscillator to obtain a counting result;

[0048] When the counting result reaches the set threshold, the power-off judgment module sends a closing instruction to the relay driving module, and the magnetic latching relay driving module sends a pulse to the magnetic latching relay to disconnect the contact connection;

[0049] When the phase signal is at a high level, the oscillator is disabled and the count result is cleared to zero.

[0050] In this embodiment, please refer to Figure 3 and Figure 4 The power-off judgment module starts the oscillator when the AC input phase signal is at a low level, and counts the rising edge (or falling edge) of the square wave signal generated by the oscillator. When the input phase signal is at a high level, the oscillator is disabled and the counting result is cleared. Assuming that the threshold is set to 8000, when the counting result reaches 8000 (i.e., the corresponding phase signal low level time is 40 milliseconds, and this count can be increased or decreased as needed), it means that the system has no AC input. At this time, the power-off judgment module sends information to the relay driver module, and the magnetic latching relay driver module sends a pulse to the magnetic latching relay to disconnect the contact connection.

[0051] In a possible implementation, the relay driving module is further provided with a second control terminal, which is used to electrically connect to the relay operation instruction channel and receive instructions through the relay operation instruction channel;

[0052] Among them, the execution priority of the shutdown instruction sent by the power-off judgment module is higher than the instruction from the relay operation instruction channel.

[0053] The utility model also provides a magnetic latching relay device, comprising a magnetic latching relay and the magnetic latching relay control circuit;

[0054] The positive and negative power supply terminals of the magnetic latching relay are connected in parallel to the internal power supply positive terminal and the internal power supply negative terminal of the AC / DC module;

[0055] The output end of the relay driving module is electrically connected to the control end of the magnetic latching relay;

[0056] The input end of the magnetic latching relay is used to electrically connect to an AC input, and the output end thereof is used to electrically connect to an AC output.

[0057] In a possible implementation, in the magnetic latching relay device, the temporary energy storage module is composed of at least one of a capacitor and a battery.

[0058] In a possible implementation, in the magnetic latching relay device, the power failure determination module is implemented based on a single chip microcomputer.

[0059] The above embodiments should not limit the present invention in any way, and any technical solutions obtained by equivalent replacement or equivalent conversion shall fall within the protection scope of the present invention.

Claims

1. A magnetic latching relay control circuit, characterized in that: include: AC / DC module, temporary energy storage module, phase detection module, oscillator, power failure judgment module, relay drive module; The input end of the AC / DC module and the input end of the phase detection module are respectively used to electrically connect to an AC input; The internal power positive terminal and the internal power negative terminal of the AC / DC module are respectively connected in parallel with the positive and negative power supply terminals of the temporary energy storage module, the phase detection module, the oscillator, the power failure judgment module, and the relay driving module, and are also used to connect the positive and negative power supply terminals of the magnetic latching relay in parallel; The output end of the phase detection module is electrically connected to the input end of the power failure judgment module; The oscillating end of the oscillator is electrically connected to the control end of the power-off judgment module; The output end of the power-off judgment module is electrically connected to the first control end of the relay driving module; The output end of the relay driving module is used to electrically connect to the control end of the magnetic latching relay; The temporary energy storage module is used to provide power to the phase detection module, the oscillator, the power failure judgment module, the relay drive module and the magnetic latching relay in a short period of time when there is no AC input due to external power failure.

2. The magnetic latching relay control circuit according to claim 1, characterized in that: The temporary energy storage module is composed of at least one of a capacitor and a battery.

3. The magnetic latching relay control circuit according to claim 1, characterized in that: The power-off judgment module is implemented based on a single-chip microcomputer.

4. The magnetic latching relay control circuit according to claim 1, characterized in that: The relay driving module is also provided with a second control terminal for electrically connecting to the relay operation instruction channel and receiving instructions through the relay operation instruction channel.

5. A magnetic latching relay device, characterized in that: comprising a magnetic latching relay and a magnetic latching relay control circuit as claimed in claim 1; The positive and negative power supply terminals of the magnetic latching relay are connected in parallel to the internal power supply positive terminal and the internal power supply negative terminal of the AC / DC module; The output end of the relay driving module is electrically connected to the control end of the magnetic latching relay; The input end of the magnetic latching relay is used to electrically connect to an AC input, and the output end thereof is used to electrically connect to an AC output.

6. The magnetic latching relay device according to claim 5, characterized in that: The temporary energy storage module is composed of at least one of a capacitor and a battery.

7. The magnetic latching relay device according to claim 6, characterized in that: The power-off judgment module is implemented based on a single-chip microcomputer.

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