CN210867630U

CN210867630U - Solid state relay circuit

Info

Publication number: CN210867630U
Application number: CN201922135497.9U
Authority: CN
Inventors: 张儒光; 虢建祥; 吴芳
Original assignee: Churod Electronics Co ltd
Current assignee: Churod Electronics Co ltd
Priority date: 2019-12-03
Filing date: 2019-12-03
Publication date: 2020-06-26
Anticipated expiration: 2029-12-03

Abstract

The utility model discloses a solid state relay circuit, this solid state relay circuit includes: the power supply comprises an input signal end, an input and protection module, a driving circuit module, an MOSFET power control and feedback module, an output protection module and an output control end. The input end of the input and protection module is connected with the input signal end; the input end of the driving circuit module is connected with the output end of the input and protection module; the input end of the MOSFET power control and feedback module is connected with the output end of the drive circuit module; the input end of the output protection module is connected with the output end of the MOSFET power control and feedback module; the output control end is connected with the output end of the MOSFET power control and feedback module and is used for being connected with the control end of the load circuit. The solid-state relay circuit has high short-circuit reliability, excellent current monitoring and excellent temperature protection, the designed product is extremely high in monitoring precision, small in size and low in cost, and the production and development costs of the product can be effectively reduced.

Description

Solid state relay circuit

Technical Field

The utility model relates to an electronic circuit technical field especially relates to a solid state relay circuit.

Background

The solid-state relay is a control switch (hereinafter referred to as a common relay), is a common phenomenon when used on an automobile, and has the same function as an electromagnetic relay so as to realize the switching function of switching on and off. The intelligent solid-state relay adopts a monitoring, feedback and protection circuit composed of discrete devices such as a Hall device and an operational amplifier, and has the functions of overcurrent protection, short-circuit protection and over-temperature protection.

However, the common solid-state relay has a single switching function and a small load volume ratio, and has certain advantages compared with an electromagnetic relay due to the high reliability and long service life in application, but has a single function and high cost, and is difficult to realize large-scale market popularization and application. The intelligent solid-state relay has the functions of overcurrent, short circuit, over-temperature protection and the like, but most of application circuits of the intelligent solid-state relay adopt Hall devices, discrete devices such as operational amplifiers and the like to form monitoring, feedback and protection circuits, and the intelligent solid-state relay has the defects of complex circuit structure design, low precision, low integration level, large volume, high cost and the like, and cannot adapt to popularization and application in the market range of the solid-state relay.

SUMMERY OF THE UTILITY MODEL

Therefore, it is necessary to provide a solid-state relay circuit aiming at the technical problems of single switch function, small load volume ratio, complex circuit structure design, low precision, low integration level, large volume and high cost of the common solid-state relay.

A solid state relay circuit, comprising: the power supply comprises an input signal end, an input and protection module, a driving circuit module, an MOSFET power control and feedback module, an output protection module and an output control end. The input end of the input and protection module is connected with the input signal end, the input signal end is used for inputting a digital or analog first control signal to the input and protection module, and the input and protection module is used for generating a second control signal according to the control signal; the input end of the driving circuit module is connected with the output end of the input and protection module, and the driving circuit module is used for receiving and generating a driving signal according to the second control signal; the input end of the MOSFET power control and feedback module is connected with the output end of the driving circuit module, and the MOSFET power control and feedback module is used for receiving and generating a third control signal according to the driving signal; the input end of the output protection module is connected with the output end of the MOSFET power control and feedback module, and the output protection module is used for controlling the current and the voltage of the MOSFET power control and feedback module to be preset stable values when a load circuit generates a noise pulse signal; the output control end is connected with the output end of the MOSFET power control and feedback module and is used for being connected with the control end of the load circuit.

In one embodiment, the input and protection module includes a rectifier bridge, an ac input terminal of the rectifier bridge is connected to the input signal terminal, an ac output terminal of the rectifier bridge is grounded, and a first dc output terminal of the rectifier bridge and a second dc output terminal of the rectifier bridge are respectively connected to the driving circuit module.

In one embodiment, the input and protection module further comprises a filter circuit, and the filter circuit is connected in series between the first dc output end of the rectifier bridge and the second dc output end of the rectifier bridge.

In one embodiment, the input and protection module further includes a voltage stabilizing circuit, the voltage stabilizing circuit is connected in series between the first dc output terminal of the rectifier bridge and the second dc output terminal of the rectifier bridge, and the voltage stabilizing circuit is connected in parallel with the filter circuit.

In one embodiment, the driving circuit module includes a switching circuit, an input terminal of the switching circuit is connected to the first dc output terminal of the rectifier bridge, and an output terminal of the switching circuit is connected to an input terminal of the MOSFET power control and feedback module.

In one embodiment, the switching circuit includes an NPN-type triode and a PNP-type triode, a base of the NPN-type triode is connected to the first dc output terminal of the rectifier bridge, an emitter of the NPN-type triode is connected to the second dc output terminal of the rectifier bridge, a collector of the NPN-type triode is connected to the base of the PNP-type triode, a collector of the PNP-type triode is connected to a power source VCC, and an emitter of the PNP-type triode is connected to the input terminal of the MOSFET power control and feedback module.

In one embodiment, the driving circuit module includes a voltage divider circuit, an input terminal of the voltage divider circuit is connected to the first dc output terminal of the rectifier bridge, and an output terminal of the voltage divider circuit is connected to an input terminal of the MOSFET power control and feedback module.

In one embodiment, the voltage dividing circuit comprises a resistor R1, a resistor R2 and a resistor R3, one end of the resistor R1 is connected with the first direct current output end of the rectifier bridge, and the other end of the resistor R1 is connected to the input end of the MOSFET power control and feedback module; one end of the resistor R2 is connected with the second direct current output end of the rectifier bridge, and the other end of the resistor R2 is connected to the input end of the MOSFET power control and feedback module; one end of the resistor R3 is connected with the second direct current output end of the rectifier bridge, and the other end of the resistor R3 is grounded.

In one embodiment, the MOSFET power control and feedback module comprises a MOSFET field effect transistor.

In one embodiment, the output protection module comprises a TVS tube circuit and/or a resistance-capacitance circuit connected in series between the output control terminal and the access terminal of the load circuit.

The solid-state relay circuit adopts a small-size and high-power vehicle gauge-level power output device with advanced diagnosis and protection functions through the MOSFET power control and feedback module, and can realize protection functions of overheating, overload, sudden load reduction, reverse polarity, short circuit and the like. When the circuit is used as a component of a relay output circuit, the circuit can replace circuits such as monitoring, feedback and protection formed by Hall type or other discrete devices, has high short-circuit reliability, excellent current monitoring and excellent temperature protection, reduces the complexity of circuit design in the design process, improves the design flexibility to the maximum extent, has extremely high monitoring precision of the designed product, small volume and low cost, and can effectively reduce the production and development cost of the product.

Drawings

FIG. 1 is a functional block diagram of a solid state relay circuit in one embodiment;

FIG. 2 is a functional block diagram of a solid state relay circuit according to the embodiment of FIG. 1;

FIG. 3 is a circuit diagram of a solid state relay circuit in one embodiment;

fig. 4 is a circuit diagram of a solid state relay circuit in another embodiment.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

Referring to fig. 1 to 4, the present invention provides a solid-state relay circuit, including: the power protection circuit comprises an input signal terminal 100, an input and protection module 200, a driving circuit module 300, a MOSFET power control and feedback module 400, an output protection module 500 and an output control terminal 600. The input end of the input and protection module 200 is connected to the input signal end 100, the input signal end 100 is used for inputting a digital or analog first control signal to the input and protection module 200, and the input and protection module 200 is used for generating a second control signal according to the control signal; the input end of the driving circuit module 300 is connected to the output end of the input and protection module 200, and the driving circuit module 300 is configured to receive and generate a driving signal according to a second control signal; the input end of the MOSFET power control and feedback module 400 is connected to the output end of the driving circuit module 300, and the MOSFET power control and feedback module 400 is configured to receive the driving signal and generate a third control signal according to the driving signal; the input end of the output protection module 500 is connected to the output end of the MOSFET power control and feedback module 400, and the output protection module 500 is used for controlling the current and the voltage of the MOSFET power control and feedback module 400 to a preset stable value when the load circuit generates a noise pulse signal; the output control terminal 600 is connected to the output terminal of the MOSFET power control and feedback module 400, and the output control terminal 600 is used for accessing the control terminal of the load circuit.

The solid-state relay circuit adopts a small-size and high-power vehicle gauge-level power output device with advanced diagnosis and protection functions through the MOSFET power control and feedback module 400, and can realize protection functions of overheating, overload, sudden load reduction, reverse polarity, short circuit and the like. When the circuit is used as a component of a relay output circuit, the circuit can replace circuits such as monitoring, feedback and protection formed by Hall type or other discrete devices, has high short-circuit reliability, excellent current monitoring and excellent temperature protection, reduces the complexity of circuit design in the design process, improves the design flexibility to the maximum extent, has extremely high monitoring precision of the designed product, small volume and low cost, and can effectively reduce the production and development cost of the product.

When the input signal terminal 100 sends an "on" or "off" digital or analog control signal, the input and protection module 200 converts the input signal into an effective and reliable control signal required by the driving circuit module 300, and the input and protection module 200 provides protection functions such as rectification, voltage stabilization, filtering and the like. The electronic components of the cost module are devices such as a current limiting resistor, a rectifier bridge, a voltage stabilizing diode and a filter capacitor, and the parts of rectification, voltage stabilization, filtering and the like can be realized in other modes. When the input end VCC power supply or the control signal is stable, the rectification or voltage stabilization or filtering module in the module can be removed.

In one embodiment, the input and protection module 200 includes a rectifier bridge, an ac input terminal of the rectifier bridge is connected to the input signal terminal 100, an ac output terminal of the rectifier bridge is grounded, and a first dc output terminal of the rectifier bridge and a second dc output terminal of the rectifier bridge are respectively connected to the driving circuit module 300. It should be noted that the ac input end of the rectifier bridge and the ac output end of the rectifier bridge refer to ports for accessing ac power, and since ac power is alternating power, the ac input end and the ac output end are only convenient for distinguishing the ports, and are not limited to current input and output of the ports.

In one embodiment, the input and protection module 200 further comprises a filter circuit, and the filter circuit is connected in series between the first dc output terminal of the rectifier bridge and the second dc output terminal of the rectifier bridge.

In one embodiment, the input and protection module 200 further includes a voltage regulator circuit connected in series between the first dc output terminal of the rectifier bridge and the second dc output terminal of the rectifier bridge, and the voltage regulator circuit is connected in parallel with the filter circuit.

It will be appreciated that the effective, reliable control signal output by the input and protection module 200 is translated into a drive signal that drives the MOSFET power control and feedback module 400. According to the circuit configuration, as shown in fig. 3, the MOSFET power control and feedback module 400 may be driven indirectly, or as shown in fig. 4, the input terminal is driven directly, i.e. the MOSFET power control and feedback module 400 is driven directly by dividing the voltage through the resistor. In fig. 3: the indirect drive, i.e., the input and protection module 200 outputs a signal to drive the base of the transistor, and the emitters of the PNP and NPN transistors drive the MOSFET power control and feedback module 400. In fig. 4, the output signal of the input and protection module 200 is divided by resistors to directly drive the MOSFET power control and feedback module 400. The electronic components forming the module comprise PNP type and NPN type triodes, current limiting resistors and freewheeling diodes, and the components can be realized by other modes, such as optical couplers and other isolation devices. As shown by the dotted line on the driving circuit module in fig. 2, when the input control signal is insufficient to drive the subsequent circuit, a bias power supply or an output power supply may be used to supply power to the driving circuit, and at this time, a certain isolation circuit should be added, especially when the output signal of the single chip microcomputer is used as the input signal of the relay, the I/O port loading capability is weak. Example analysis: as shown in the circuit of fig. 3, the collector output signal of the transistor Q1 is used as the control signal of the high-side driver, and the emitter signal thereof is mainly from the output terminal of the relay. The control signal from resistor R2 of MOSFET power control and feedback module 400 of fig. 4 drives high-side driver IN, which is provided by the signal at relay input VCC.

In one embodiment, the driving circuit module 300 includes a switching circuit, an input terminal of the switching circuit is connected to the first dc output terminal of the rectifier bridge, and an output terminal of the switching circuit is connected to an input terminal of the MOSFET power control and feedback module 400.

In one embodiment, the switching circuit includes an NPN type triode and a PNP type triode, a base of the NPN type triode is connected to the first dc output terminal of the rectifier bridge, an emitter of the NPN type triode is connected to the second dc output terminal of the rectifier bridge, a collector of the NPN type triode is connected to a base of the PNP type triode, a collector of the PNP type triode is connected to the power source VCC, and an emitter of the PNP type triode is connected to the input terminal of the MOSFET power control and feedback module 400.

In one embodiment, the driving circuit module 300 includes a voltage divider circuit, an input terminal of the voltage divider circuit is connected to the first dc output terminal of the rectifier bridge, and an output terminal of the voltage divider circuit is connected to an input terminal of the MOSFET power control and feedback module 400.

In one embodiment, the voltage divider circuit includes a resistor R1, a resistor R2, and a resistor R3, one end of the resistor R1 is connected to the first dc output terminal of the rectifier bridge, and the other end of the resistor R1 is connected to the input terminal of the MOSFET power control and feedback module 400; one end of the resistor R2 is connected with the second direct current output end of the rectifier bridge, and the other end of the resistor R2 is connected to the input end of the MOSFET power control and feedback module 400; one end of the resistor R3 is connected with the second direct current output end of the rectifier bridge, and the other end of the resistor R3 is grounded.

When the driving signal output by the driving circuit module 300 is at a high or low level, the driving signal is applied to the IN terminal of the high-side driver MOSFET, the output terminal of the high-side driver MOSFET is turned on or off, the switching between the on and off of the load line is realized, and the function of the relay is realized. In this circuit, the feedback enable terminal of the MOSFET power control and feedback module 400 is floating, i.e., the current monitoring feedback function is invalid. The high-end driver in the module is a power MOSFET integrating advanced protection functions of load current limitation, power limitation, active management, over-temperature shutoff and the like. Under the condition that the channel of the MOSFET is controlled to be opened by the driving control signal, the voltage monitoring/current monitoring/temperature monitoring circuit integrated in the MOSFET starts to work. The over-temperature module works according to the principle that: when the load current exceeds a certain threshold value, the temperature of the field effect tube channel continuously rises, and when the load current exceeds a specified temperature threshold value, the field effect tube channel is automatically closed to cut off the load circuit, so that the overcurrent protection and short circuit protection functions of the circuit are indirectly realized. When the feedback enable terminal of the MOSFET power control and feedback module 400 is active at a high level, the current sensor performs comparison operation on the load current in real time, and outputs the operated signal through the output port, for example, the enable terminal in the circuit is suspended, and the current monitoring and load management functions are not turned on; the electronic components of the cost module are a high-end driven MOSFET, a grounding resistor, a current-limiting resistor and the like.

In one embodiment, the MOSFET power control and feedback module 400 comprises a MOSFET field effect transistor. High-end driven MOSFET in this kind of relay, adopt the British flying to dash, ON, the high-end driven MOSFET of ST (meaning semiconductor) company series, as its core output and monitoring devices: the device of the type integrates advanced protection functions of load current limitation, POWER overload limiting active management, over-temperature shutdown and the like, can effectively improve the mean time to failure of equipment, and can be applied to an automobile POWER supply control system required by a high-safety system.

In one embodiment, the output protection module 500 includes a TVS transistor circuit and/or a resistor-capacitor circuit connected in series between the output control terminal 600 and the input terminal of the load circuit. The output protection module 500 can provide the function of protecting the MOSFET in the MOSFET power control and feedback module 400 when a noise pulse signal such as a surge occurs in the load circuit. The electronic components forming the cost module are TVS tubes and capacitors. This portion may be implemented in other ways, such as a resistor-capacitor circuit.

It is worth mentioning that the high-side driving MOSFET also has a plurality of input stages and a plurality of output series, and each path of the high-side driving MOSFET has the functions of overcurrent protection, over-temperature protection and the like.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A solid state relay circuit, comprising:

an input signal terminal;

the input and protection module is connected with the input signal end, the input signal end is used for inputting a digital or analog first control signal to the input and protection module, and the input and protection module is used for generating a second control signal according to the control signal;

the input end of the driving circuit module is connected with the output end of the input and protection module, and the driving circuit module is used for receiving and generating a driving signal according to the second control signal;

the input end of the MOSFET power control and feedback module is connected with the output end of the driving circuit module, and the MOSFET power control and feedback module is used for receiving and generating a third control signal according to the driving signal;

the input end of the output protection module is connected with the output end of the MOSFET power control and feedback module, and the output protection module is used for controlling the current and the voltage of the MOSFET power control and feedback module to preset stable values when a load circuit generates a noise pulse signal;

and the output control end is connected with the output end of the MOSFET power control and feedback module and is used for being connected with the control end of the load circuit.

2. The solid state relay circuit according to claim 1, wherein the input and protection module comprises a rectifier bridge, an ac input terminal of the rectifier bridge is connected to the input signal terminal, an ac output terminal of the rectifier bridge is grounded, and a first dc output terminal of the rectifier bridge and a second dc output terminal of the rectifier bridge are respectively connected to the driving circuit module.

3. The solid state relay circuit of claim 2, wherein the input and protection module further comprises a filter circuit connected in series between the first dc output of the rectifier bridge and the second dc output of the rectifier bridge.

4. The solid state relay circuit of claim 3, wherein the input and protection module further comprises a voltage regulator circuit connected in series between the first DC output of the rectifier bridge and the second DC output of the rectifier bridge, and the voltage regulator circuit is connected in parallel with the filter circuit.

5. The solid state relay circuit of claim 2, wherein the driver circuit module comprises a switching circuit having an input connected to the first dc output of the rectifier bridge and an output connected to the input of the MOSFET power control and feedback module.

6. The solid state relay circuit according to claim 5, wherein the switching circuit comprises an NPN transistor and a PNP transistor, a base of the NPN transistor is connected to the first DC output terminal of the rectifier bridge, an emitter of the NPN transistor is connected to the second DC output terminal of the rectifier bridge, a collector of the NPN transistor is connected to a base of the PNP transistor, a collector of the PNP transistor is connected to a power supply VCC, and an emitter of the PNP transistor is connected to the input terminal of the MOSFET power control and feedback module.

7. The solid state relay circuit of claim 2, wherein the driver circuit module comprises a voltage divider circuit having an input connected to the first dc output of the rectifier bridge and an output connected to the input of the MOSFET power control and feedback module.

8. The solid state relay circuit according to claim 7, wherein the voltage divider circuit comprises a resistor R1, a resistor R2 and a resistor R3, one end of the resistor R1 is connected to the first DC output terminal of the rectifier bridge, and the other end of the resistor R1 is connected to the input terminal of the MOSFET power control and feedback module; one end of the resistor R2 is connected with the second direct current output end of the rectifier bridge, and the other end of the resistor R2 is connected to the input end of the MOSFET power control and feedback module; one end of the resistor R3 is connected with the second direct current output end of the rectifier bridge, and the other end of the resistor R3 is grounded.

9. The solid state relay circuit of any one of claims 1 to 8, wherein the MOSFET power control and feedback module comprises a MOSFET field effect transistor.

10. The solid state relay circuit according to claim 9, wherein the output protection module comprises a TVS tube circuit and/or a resistor-capacitor circuit connected in series between the output control terminal and an access terminal of a load circuit.