Relay isolation driving circuit

Abstract

The utility model relates to the field of electronic circuits, and provides a relay isolation driving circuit, which comprises a master control module, a power supply module, an optocoupler relay driving module, an electromagnetic switch and a man-machine interaction module, the output end of the man-machine interaction module is connected with the main control module, the optocoupler relay driving module and the electromagnetic switch, the man-machine interaction module is connected with the main control module, the controlled end of the optocoupler relay driving module is connected with the output end of the main control module, and the output end of the optocoupler relay driving module is connected with the controlled end of the electromagnetic switch. The photoelectric isolation module is used for carrying out photoelectric isolation on the control signal sent by the main control module and then outputting the control signal and controlling the power-on state of a coil of the electromagnetic switch, and an open point of the electromagnetic switch is connected with a load and controls the conduction state of the load and a power supply; according to the utility model, while control signals of the electromagnetic switch are transmitted, conduction of interference signals is isolated, and the stability of the circuit is improved.

Description

Technical Field

[0001] This utility model relates to the field of electronic circuits, and more specifically, to a relay isolation drive circuit. Background Technology

[0002] Relays and contactors, as electromagnetic switches, are widely used in the control of electrical loads. In traditional circuits, the control signals issued by the controller are mostly transmitted directly to the relays through transistors, resistors, etc. The control signals are not isolated and have poor anti-interference ability. Utility Model Content

[0003] The problem solved by this invention is how to provide a relay isolation drive circuit that can isolate the transmission of interference signals while transmitting control signals for electromagnetic switches.

[0004] To address the aforementioned problems, this utility model provides a relay isolation drive circuit, comprising: a main control module, a power supply module, an optocoupler relay drive module, an electromagnetic switch, and a human-machine interface module. The input terminal of the power supply module is connected to an external input power source, and its output terminals are respectively connected to the main control module, the optocoupler relay drive module, and the electromagnetic switch. The human-machine interface module is connected to the main control module. The controlled terminal of the optocoupler relay drive module is connected to the output terminal of the main control module, and its output terminal is connected to the controlled terminal of the electromagnetic switch. This allows the module to output control signals from the main control module after opto-isolation, controlling the energization state of the coil of the electromagnetic switch. The open contact of the electromagnetic switch is connected to the load, controlling the conduction state between the load and the power supply.

[0005] Furthermore, the optocoupler relay driving module includes a first MOS transistor and a first optocoupler relay. The gate of the first MOS transistor is connected to the output terminal of the main control module via a second resistor, and the source is grounded. The anode of the internal photodiode on the input side of the first optocoupler relay is connected to a 3.3V voltage via a first resistor, and the cathode is connected to the drain of the first MOS transistor. The first terminal on the output side of the first optocoupler relay is connected to a 24V voltage via the coil of the electromagnetic switch, and the second terminal is grounded.

[0006] Furthermore, the optocoupler relay driving module also includes a first TVS diode, which is connected in parallel between the two ends of the output side of the first optocoupler relay.

[0007] Furthermore, the power module includes a first power switch, a power protection and filtering circuit, a load output port, and an auxiliary power supply circuit. The input terminal of the first power switch is connected to an external power input, and the output terminal is connected to the input terminal of the power protection and filtering circuit. The output terminal of the power protection and filtering circuit is connected to the load output port and the auxiliary power supply circuit, respectively.

[0008] Furthermore, the auxiliary power supply circuit includes a second power switch, a switching power supply, and a voltage regulator circuit. The input terminal of the second power switch is connected to the output terminal of the power protection filter circuit, and the output terminal is connected to the input terminal of the switching power supply. The switching power supply is used to output a 24V DC voltage. The input terminal of the voltage regulator circuit is connected to the output terminal of the switching power supply, and the output terminal outputs a 3.3V DC voltage.

[0009] Furthermore, the power protection filter circuit includes a protection circuit and a filter circuit. The input terminal of the protection circuit is connected to the first power switch, and the output terminal is connected to the filter circuit.

[0010] Furthermore, the protection circuit includes a first fuse and a first varistor. The first end of the first fuse is connected to the positive output terminal of the first power switch, and the second end is connected to the filter circuit. The first end of the first varistor is connected to the second end of the first fuse, and the second end is connected to the negative output terminal of the first power switch.

[0011] Furthermore, the filtering circuit includes a first common-mode inductor, a first capacitor, and a second capacitor. The first input terminal of the first common-mode inductor is connected to the second terminal of the first fuse, and the second input terminal is connected to the negative output terminal of the first power switch. The two output terminals of the first common-mode inductor are respectively connected to the load output port and the input terminal of the auxiliary power supply circuit. The first capacitor is connected in parallel between the two input terminals of the first common-mode inductor, and the second capacitor is connected in parallel between the two output terminals of the first common-mode inductor.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] The optocoupler relay in the optocoupler relay driver module performs photoelectric conversion on the control signal output from the input-side main control module, realizing the isolation of signals on both sides, achieving isolated control of the electromagnetic switch, avoiding direct electrical connection, and isolating the transmission of interference signals while transmitting signals, thus improving the stability of the circuit. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall principle structure of an embodiment of the present utility model;

[0015] Figure 2 This is a schematic diagram of the principle structure of the optocoupler relay driving module according to an embodiment of the present invention;

[0016] Figure 3 This is a schematic diagram of the principle structure of the power module according to an embodiment of the present utility model;

[0017] Figure 4 This is a schematic diagram of the principle structure of the power protection filter circuit in an embodiment of this utility model. Detailed Implementation

[0018] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or illustrative embodiment of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0021] like Figure 1 As shown, this utility model provides a relay isolation drive circuit, including: a main control module, a power supply module, an optocoupler relay drive module, an electromagnetic switch, and a human-machine interface module. The input terminal of the power supply module is connected to an external input power supply, and the output terminals are respectively connected to the main control module, the optocoupler relay drive module, and the electromagnetic switch. The human-machine interface module is connected to the main control module. The controlled terminal of the optocoupler relay drive module is connected to the output terminal of the main control module, and the output terminal is connected to the controlled terminal of the electromagnetic switch. It is used to output the control signal sent by the main control module after opto-isolation, and control the energization state of the coil of the electromagnetic switch. The open contact of the electromagnetic switch is connected to the load, and controls the conduction state of the load and the power supply.

[0022] It should be noted that the electromagnetic switch in this embodiment can be a relay or a contactor. The load is connected to the power supply through the two ends of the relay or contactor. When the coil of the electromagnetic switch is energized, the load in the main circuit will be powered on.

[0023] The optocoupler relay driver module performs photoelectric conversion on the control signal output from the input-side main control module, achieving signal isolation between the two sides and isolating the electromagnetic switch. This avoids direct electrical connection, isolates interference signal transmission while transmitting signals, and improves circuit stability.

[0024] The main control module can be a microcontroller or other control chip with I / O ports, and the human-machine interaction module can be a button, touch screen, etc., connected to the main control module. When the load needs to be driven, the user issues a command through the human-machine interaction module, and the main control module issues a control signal to the electromagnetic switch.

[0025] In one embodiment of this utility model, the optocoupler relay driving module includes a first MOS transistor and a first optocoupler relay. The gate of the first MOS transistor is connected to the output terminal of the main control module via a second resistor, and the source is grounded. The anode of the internal photodiode on the input side of the first optocoupler relay is connected to a 3.3V voltage via a first resistor, and the cathode is connected to the drain of the first MOS transistor. The first terminal on the output side of the first optocoupler relay is connected to a 24V voltage via the coil of the electromagnetic switch, and the second terminal is grounded.

[0026] It should be noted that, as Figure 2 As shown, the electromagnetic switch uses relay K1. During operation, the main control module outputs a control signal to the first MOSFET Q1 to turn it on. After the first MOSFET Q1 turns on, the photodiode inside the first optocoupler relay U1 turns on and emits light, causing the internal field-effect transistor of the first optocoupler relay U1 to turn on. The relay K1 coil forms a circuit, and the contacts close to the normally open terminal, connecting the load. After the main control module turns off the control signal, the first MOSFET Q1 disconnects the circuit, the photodiode inside the first optocoupler relay U1 turns off, the internal opto-field-effect transistor turns off, the relay K1 coil circuit is disconnected, and the contacts switch from the normally open terminal to the normally closed terminal, disconnecting the load circuit. Through photoelectric conversion by the first optocoupler relay U1, the isolation of signals on both sides is achieved, and the relay K1 is isolated and controlled.

[0027] In one embodiment of the present invention, the optocoupler relay driving module further includes a first TVS diode, which is connected in parallel between the two ends of the output side of the first optocoupler relay.

[0028] It should be noted that during operation, since the relay coil is an inductive device, it will generate an induced electromotive force when the circuit is cut off. When the voltage rises above the clamping voltage of the first TVS diode TVS1, the first TVS diode TVS1 will conduct, controlling the voltage within the voltage range that the first optocoupler relay U1 can withstand, thus preventing the induced electromotive force from breaking down the field-effect transistor inside the first optocoupler relay U1 and causing the circuit to become uncontrollable.

[0029] In one embodiment of the present invention, the power module includes a first power switch, a power protection filter circuit, a load output port, and an auxiliary power supply circuit. The input terminal of the first power switch is connected to an external power input, and the output terminal is connected to the input terminal of the power protection filter circuit. The output terminal of the power protection filter circuit is connected to the load output port and the auxiliary power supply circuit, respectively.

[0030] It should be noted that, as Figure 3 As shown, the first power switch serves as the main power switch and can be a power switching device such as a circuit breaker. The power protection and filtering circuit is used for the protection and filtering of the input AC power. The processed power is divided into two paths: one path is provided to the load through the load output port as the main circuit load power supply, and the other path is provided to the auxiliary power supply.

[0031] In one embodiment of this utility model, the auxiliary power supply circuit includes a second power switch, a switching power supply, and a voltage regulator circuit. The input terminal of the second power switch is connected to the output terminal of the power protection filter circuit, and the output terminal is connected to the input terminal of the switching power supply. The switching power supply is used to output a 24V DC voltage. The input terminal of the voltage regulator circuit is connected to the output terminal of the switching power supply, and the output terminal outputs a 3.3V DC voltage.

[0032] It should be noted that, as Figure 3 As shown, the second power switch serves as the power-on switch for the auxiliary power supply. Through the two power switches, the auxiliary power supply circuit can be powered on and off before being powered on. The auxiliary power supply uses a switching power supply to convert the AC input into a 24V DC output, providing a 24V voltage. The voltage regulator circuit uses a voltage regulator chip to convert the 24V voltage to a 3.3V voltage. The voltage regulator chip model can be PW6206, etc.

[0033] In one embodiment of this utility model, the power protection filter circuit includes a protection circuit and a filter circuit. The input terminal of the protection circuit is connected to the first power switch, and the output terminal is connected to the filter circuit.

[0034] It should be noted that the protection circuit is used to protect the input power supply, while the filtering circuit is used to filter the AC input to prevent power supply interference.

[0035] In one embodiment of this utility model, the protection circuit includes a first fuse and a first varistor. The first end of the first fuse is connected to the positive output terminal of the first power switch, and the second end is connected to the filter circuit. The first end of the first varistor is connected to the second end of the first fuse, and the second end is connected to the negative output terminal of the first power switch.

[0036] It should be noted that, as Figure 4As shown, the first fuse F1 can blow in case of overcurrent and is used for overcurrent protection of the circuit, and the first varistor RV1 is used for overvoltage protection of the circuit.

[0037] In one embodiment of this utility model, the filter circuit includes a first common-mode inductor, a first capacitor, and a second capacitor. The first input terminal of the first common-mode inductor is connected to the second terminal of the first fuse, and the second input terminal is connected to the negative output terminal of the first power switch. The two output terminals of the first common-mode inductor are respectively connected to the load output port and the input terminal of the auxiliary power supply circuit. The first capacitor is connected in parallel between the two input terminals of the first common-mode inductor, and the second capacitor is connected in parallel between the two output terminals of the first common-mode inductor.

[0038] It should be noted that, as Figure 4 As shown, the combination of the first common-mode inductor T1, the first capacitor CX1, and the second capacitor CX2 can effectively perform common-mode filtering, eliminate interference noise, and ensure the stability of the power input.

[0039] Although the disclosure is as stated above, the scope of protection of this disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this utility model.

Claims

1. A relay isolation drive circuit, characterized in that, include: The system comprises a main control module, a power supply module, an optocoupler relay driver module, an electromagnetic switch, and a human-machine interface module. The input terminal of the power supply module is connected to an external power source, and its output terminals are connected to the main control module, the optocoupler relay driver module, and the electromagnetic switch, respectively. The human-machine interface module is connected to the main control module. The controlled terminal of the optocoupler relay driver module is connected to the output terminal of the main control module, and its output terminal is connected to the controlled terminal of the electromagnetic switch. This allows the system to output control signals from the main control module after opto-isolation, controlling the energization state of the electromagnetic switch coil. The open contact of the electromagnetic switch is connected to the load, controlling the conduction state between the load and the power supply.

2. The relay isolation drive circuit according to claim 1, characterized in that, The optocoupler relay driving module includes a first MOS transistor and a first optocoupler relay. The gate of the first MOS transistor is connected to the output terminal of the main control module via a second resistor, and the source is grounded. The anode of the internal photodiode on the input side of the first optocoupler relay is connected to a 3.3V voltage via a first resistor, and the cathode is connected to the drain of the first MOS transistor. The first terminal on the output side of the first optocoupler relay is connected to a 24V voltage via the coil of the electromagnetic switch, and the second terminal is grounded.

3. The relay isolation drive circuit according to claim 2, characterized in that, The optocoupler relay drive module also includes a first TVS diode, which is connected in parallel between the two ends of the output side of the first optocoupler relay.

4. The relay isolation drive circuit according to claim 1, characterized in that, The power module includes a first power switch, a power protection and filtering circuit, a load output port, and an auxiliary power supply circuit. The input terminal of the first power switch is connected to an external power supply, and the output terminal is connected to the input terminal of the power protection and filtering circuit. The output terminal of the power protection and filtering circuit is connected to the load output port and the auxiliary power supply circuit, respectively.

5. The relay isolation drive circuit according to claim 4, characterized in that, The auxiliary power supply circuit includes a second power switch, a switching power supply, and a voltage regulator circuit. The input terminal of the second power switch is connected to the output terminal of the power protection and filtering circuit, and the output terminal is connected to the input terminal of the switching power supply. The switching power supply is used to output a 24V DC voltage. The input terminal of the voltage regulator circuit is connected to the output terminal of the switching power supply, and the output terminal outputs a 3.3V DC voltage.

6. The relay isolation drive circuit according to claim 4, characterized in that, The power protection and filtering circuit includes a protection circuit and a filtering circuit. The input terminal of the protection circuit is connected to the first power switch, and the output terminal is connected to the filtering circuit.

7. The relay isolation drive circuit according to claim 6, characterized in that, The protection circuit includes a first fuse and a first varistor. The first end of the first fuse is connected to the positive output terminal of the first power switch, and the second end is connected to the filter circuit. The first end of the first varistor is connected to the second end of the first fuse, and the second end is connected to the negative output terminal of the first power switch.

8. The relay isolation drive circuit according to claim 7, characterized in that, The filtering circuit includes a first common-mode inductor, a first capacitor, and a second capacitor. The first input terminal of the first common-mode inductor is connected to the second terminal of the first fuse, and the second input terminal is connected to the negative output terminal of the first power switch. The two output terminals of the first common-mode inductor are respectively connected to the load output port and the input terminal of the auxiliary power supply circuit. The first capacitor is connected in parallel between the two input terminals of the first common-mode inductor, and the second capacitor is connected in parallel between the two output terminals of the first common-mode inductor.

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