An output circuit of a controller, a PCB board and a controller

Abstract

The application discloses an output circuit of a controller, a PCB and the controller. The output circuit comprises an input processing unit, a switching unit, an operational amplifier unit, an output protection unit and an adjusting unit. An input end of the input processing unit is used for receiving a PWM signal. An output end of the input processing unit is connected with one end of the adjusting unit. The other end of the adjusting unit is connected with an input end of the output protection unit. The adjusting unit is also connected with an input end of the operational amplifier unit. Output ends of the operational amplifier unit and the input end of the output protection unit are respectively connected with sampling ends of the switching unit. An input end of the switching unit is used for receiving a switching level signal. An output end of the switching unit is connected with an input end of the operational amplifier unit. The output circuit of the controller disclosed by the application receives the switching level signal through the switching unit to realize output switching of a voltage signal or a current signal, and has the advantages of low circuit cost, high output precision and strong anti-interference capability.

Description

Technical Field

[0001] This invention relates to the field of output circuit technology, and in particular to an output circuit, PCB board and controller of a controller. Background Technology

[0002] In the current fields of industrial control and building control, control systems require analog output of 0-10V and 4-20mA signals to control and adjust the working state of equipment, such as controlling and adjusting the speed of fans. Therefore, when planning and designing controllers, in order to meet the needs of different scenarios for different types and quantities of analog signals, the analog output ports will adopt multi-signal multiplexing detection functions as much as possible to ensure the flexibility of port functions.

[0003] However, existing conventional controllers generally only implement separate outputs of voltage or current signals, that is, designing the voltage signal output or the current signal output as an independent output port, or using jumper caps to manually switch between voltage and current signals. This results in problems such as inflexible port operation and cumbersome switching.

[0004] It is evident that existing technologies still need improvement and enhancement. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an output circuit of a controller, which receives a switching level signal through a switching unit to realize the output switching of voltage signal or current signal, and has the advantages of low circuit cost, high output accuracy and strong anti-interference ability.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An output circuit for a controller includes an input processing unit, a switching unit, an operational amplifier unit, an output protection unit, and an adjustment unit. The input terminal of the input processing unit receives a PWM signal. The output terminal of the input processing unit is connected to one end of the adjustment unit, and the other end of the adjustment unit is connected to the input terminal of the output protection unit. The adjustment unit is also connected to the input terminal of the operational amplifier unit. The output terminal of the operational amplifier unit and the input terminal of the output protection unit are respectively connected to the sampling terminal of the switching unit. The operational amplifier unit is also connected to the input terminal of the output protection unit. The input terminal of the switching unit receives a switching level signal, and the output terminal of the switching unit is connected to the input terminal of the operational amplifier unit.

[0008] In the output circuit of the controller, the operational amplifier unit includes a first operational amplifier IC1A, a fourth resistor R4, a first transistor Q1, a first capacitor C1, and a fourth capacitor C4. Pins 2 and 3 of the first operational amplifier IC1A are connected to the adjustment unit, and pin 2 of the first operational amplifier IC1A is also connected to the output terminal of the switching unit and one end of the fourth capacitor C4. Pin 1 of the first operational amplifier IC1A is connected to one end of the fourth resistor R4 and the collector of the first transistor Q1, and the other end of the fourth resistor R4 is connected to the base of the first transistor Q1. The emitter of the first transistor Q1 is connected to the sampling terminal of the switching unit. Pin 4 of the first operational amplifier IC1A is connected to one end of the first capacitor C1 and is used to connect to an external power supply mechanism. The other end of the fourth capacitor C4 is connected to the input terminal of the output protection unit. Pin 11 of the first operational amplifier IC1A and the other end of the first capacitor C1 are grounded.

[0009] In the output circuit of the controller, the adjustment unit includes a second resistor R2, a fifth resistor R5, an eleventh resistor R11, and a third capacitor C3. One end of the second resistor is connected to the output terminal of the input processing unit. The other end of the second resistor R2 is connected to one end of the third capacitor C3 and pin 3 of the first operational amplifier IC1A. One end of the fifth resistor R5 is connected to pin 2 of the first operational amplifier IC1A and one end of the eleventh resistor R11. The other end of the eleventh resistor R11 is connected to the input terminal of the output protection unit. The other ends of the third capacitor C3 and the fifth resistor R5 are grounded.

[0010] In the output circuit of the controller, the switching unit includes a conducting part and an adjusting part. The input terminal of the conducting part is used to receive a switching level signal. The output terminal of the conducting part is connected to pin 2 of the first operational amplifier IC1A. The conducting part is also connected to the output terminal of the adjusting part. The sampling terminal of the adjusting part is connected to the input terminal of the output protection unit.

[0011] In the output circuit of the controller, the conducting part includes a second transistor Q2 and a sixth resistor R6. One end of the sixth resistor R6 is used to receive a switching level signal, and the other end of the sixth resistor R6 is connected to the base of the second transistor Q2. The collector of the second transistor Q2 is connected to pin 2 of the first operational amplifier IC1A, and the emitter of the second transistor Q2 is connected to the adjustment part.

[0012] In the output circuit of the controller, the adjustment unit includes a second operational amplifier IC1B, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and a third resistor R3. Pin 7 of the second operational amplifier IC1B is connected to the emitter of the second transistor Q2 and one end of the ninth resistor R9. Pin 5 of the second operational amplifier IC1B is connected to one end of the seventh resistor R7 and one end of the eighth resistor R8. Pin 6 of the second operational amplifier IC1B and the other end of the ninth resistor R9 are connected to one end of the tenth resistor R10. The other end of the eighth resistor R8 is connected to the emitter of the first transistor Q1 and one end of the third resistor R3. The other end of the third resistor R3 is connected to the other end of the tenth resistor R10, the other end of the adjustment unit, and the input terminal of the output protection unit.

[0013] In the output circuit of the controller, the input processing unit includes a first resistor R1 and a second capacitor C2. One end of the first resistor R1 is used to receive the PWM signal, and the other end of the first resistor R1 is connected to one end of the second capacitor C2 and one end of the adjustment unit, respectively. The other end of the second capacitor C2 is grounded.

[0014] In the output circuit of the controller, the output protection unit includes a first diode D1, a second diode D2, and a first connector P1. The cathode of the first diode D1, the anode of the second diode D2, and pin 1 of the first connector P1 are respectively connected to the sampling terminal of the switching unit and the operational amplifier unit. The cathode of the second diode D2 is used to connect to an external power supply mechanism. The anode of the first diode D1 and pin 2 of the first connector P1 are respectively grounded.

[0015] The present invention also provides a PCB board on which the output circuit of the controller as described above is printed.

[0016] The present invention also provides a controller, which uses the output circuit of any of the controllers described above to achieve operation control.

[0017] Beneficial effects:

[0018] This invention provides an output circuit for a controller. The switching unit can adjust its own working state according to the received switching level signal to realize the switching output of analog voltage and current signals, that is, to realize a two-in-one output circuit. It has sufficient flexibility to adapt to more application scenarios and has the advantages of low circuit cost, strong anti-interference ability, high output accuracy and good output stability. Attached Figure Description

[0019] Figure 1 A circuit block diagram of the output circuit of the controller provided by the present invention;

[0020] Figure 2 The circuit structure diagram of the output circuit of the controller provided by the present invention.

[0021] Explanation of key component symbols: 1-Input processing unit, 2-Switching unit, 21-Conduction section, 22-Adjustment section, 3-Operational amplifier unit, 4-Output protection unit, 5-Adjustment unit. Detailed Implementation

[0022] This invention provides an output circuit, PCB board, and controller. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0023] In the description of this invention, it should be understood that the terms "installation" and "connection" should be interpreted broadly, and those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0024] Please see Figure 1 and Figure 2 This invention provides an output circuit for a controller, comprising an input processing unit 1, a switching unit 2, an operational amplifier unit 3, an output protection unit 4, and an adjustment unit 5. The input terminal of the input processing unit 1 is used to receive a PWM signal. The output terminal of the input processing unit 1 is connected to one end of the adjustment unit 5, and the other end of the adjustment unit 5 is connected to the input terminal of the output protection unit 4. The adjustment unit 5 is also connected to the input terminal of the operational amplifier unit 3. The output terminal of the operational amplifier unit 3 and the input terminal of the output protection unit 4 are respectively connected to the sampling terminal of the switching unit 2. The input terminal of the output protection unit 4 is also connected to the operational amplifier unit 3. The input terminal of the switching unit 2 is used to receive a switching level signal, and the output terminal of the switching unit 2 is connected to the input terminal of the operational amplifier unit 3.

[0025] The output circuit of the controller disclosed in this application allows the switching unit 2 to adjust its own working state according to the received switching level signal, so as to realize the switching output of analog voltage and current signals, that is, to realize a two-in-one output circuit. This provides sufficient flexibility to adapt to more application scenarios, reduces the number and types of analog output channels, and has the advantages of low circuit cost, strong anti-interference ability, high output accuracy and good output stability. The adjustment unit 5 is used to adjust its total resistance value according to the PWM signal received by the input processing unit 1, so that the voltage output by the output protection unit 4 can meet the usage requirements of the scenario and improve the flexibility of the output circuit during operation.

[0026] In this embodiment, the PWM signal and the level switching signal are output to the output circuit from the controller's MCU module. The controller's MCU module allows adjustment of the output signal type configuration parameters according to the user's software, such as voltage type 0-10V or current type 4-20mA. For details, please refer to [link to relevant documentation]. Figure 2 The signals output by the MCU module include GPIO_EN and GPIO. GPIO_EN is used to switch between various analog output modes, and GPIO is the PWM signal for outputting analog signals.

[0027] Further, please refer to Figure 1 and Figure 2 The operational amplifier unit 3 includes a first operational amplifier IC1A, a fourth resistor R4, a first transistor Q1, a first capacitor C1, and a fourth capacitor C4. Pins 2 and 3 of the first operational amplifier IC1A are respectively connected to the adjustment unit 5. Pin 2 of the first operational amplifier IC1A is also connected to the output terminal of the switching unit 2 and one end of the fourth capacitor C4. Pin 1 of the first operational amplifier IC1A is respectively connected to one end of the fourth resistor R4 and the collector of the first transistor Q1. The other end of the fourth resistor R4 is connected to the base of the first transistor Q1. The emitter of the first transistor Q1 is connected to the sampling terminal of the switching unit. Pin 4 of the first operational amplifier IC1A is connected to one end of the first capacitor C1 and is used to connect to an external power supply mechanism. The other end of the fourth capacitor C4 is connected to the input terminal of the output protection unit. Pin 11 of the first operational amplifier IC1A and the other end of the first capacitor C1 are respectively grounded.

[0028] In this embodiment, the operational amplifier unit 3 is used to regulate and filter the input power signal, and the external power supply mechanism can provide a 24V voltage; the operational amplifier unit 3 includes a fourth capacitor C4, which is connected in parallel with the negative feedback of the first operational amplifier IC1A, which can improve the output oscillation of the first operational amplifier IC1A and improve the stability of the output circuit during operation.

[0029] Further, please refer to Figure 1 and Figure 2The adjustment unit 5 includes a second resistor R2, a fifth resistor R5, an eleventh resistor R11, and a third capacitor C3. One end of the second resistor is connected to the output terminal of the input processing unit 1. The other end of the second resistor R2 is connected to one end of the third capacitor C3 and pin 3 of the first operational amplifier IC1A. One end of the fifth resistor R5 is connected to pin 2 of the first operational amplifier IC1A and one end of the eleventh resistor R11. The other end of the eleventh resistor R11 is connected to the input terminal of the output protection unit 4. The other ends of the third capacitor C3 and the fifth resistor R5 are grounded.

[0030] In this embodiment, by setting the total resistance of the adjustment unit 5, the operational amplifier output factor of the first operational amplifier IC1A can be set to 2-4 times to ensure that the voltage signal output by the output protection unit 4 can meet the load's usage requirements.

[0031] Further, please refer to Figure 1 and Figure 2 The switching unit 2 includes a conducting part 21 and an adjusting part 22. The input terminal of the conducting part 21 is used to receive a switching level signal. The output terminal of the conducting part 21 is connected to pin 2 of the first operational amplifier IC1A. The conducting part 21 is also connected to the output terminal of the adjusting part 22. The sampling terminal of the adjusting part 22 is connected to the input terminal of the output protection unit 4.

[0032] Further, please refer to Figure 1 and Figure 2 The conducting part 21 includes a second transistor Q2 and a sixth resistor R6. One end of the sixth resistor R6 is used to receive a switching level signal, and the other end of the sixth resistor R6 is connected to the base of the second transistor Q2. The collector of the second transistor Q2 is connected to pin 2 of the first operational amplifier IC1A, and the emitter of the second transistor Q2 is connected to the adjustment part 22.

[0033] In this embodiment, the switching level signal fed back by GPIO_EN is used to control the second transistor Q2 to turn on or off, thereby realizing the switching between voltage signal output and current signal output.

[0034] Further, please refer to Figure 1 and Figure 2The adjustment unit 22 includes a second operational amplifier IC1B, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and a third resistor R3. Pin 7 of the second operational amplifier IC1B is connected to the emitter of the second transistor Q2 and one end of the ninth resistor R9. Pin 5 of the second operational amplifier IC1B is connected to one end of the seventh resistor R7 and one end of the eighth resistor R8. Pin 6 of the second operational amplifier IC1B and the other end of the ninth resistor R9 are connected to one end of the tenth resistor R10. The other end of the eighth resistor R8 is connected to the emitter of the first transistor Q1 and one end of the third resistor R3. The other end of the third resistor R3 is connected to the other end of the tenth resistor R10, the other end of the adjustment unit 5, and the input terminal of the output protection unit 4.

[0035] In this embodiment, by adjusting the resistance values ​​of the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, and the third resistor R3, the current signal output by the output protection unit 4 can meet the usage requirements; the third resistor R3 is a sampling resistor.

[0036] Further, please refer to Figure 1 and Figure 2 The input processing unit 1 includes a first resistor R1 and a second capacitor C2. One end of the first resistor R1 is used to receive PWM signals, and the other end of the first resistor R1 is connected to one end of the second capacitor C2 and one end of the adjustment unit 5, respectively. The other end of the second capacitor C2 is grounded.

[0037] In this embodiment, the input processing unit 1 is an RC filter circuit used to convert the input PWM signal into an analog 0-3.3V voltage signal or a 0-5V voltage signal.

[0038] Further, please refer to Figure 1 and Figure 2 The output protection unit 4 includes a first diode D1, a second diode D2, and a first connector P1. The cathode of the first diode D1, the anode of the second diode D2, and pin 1 of the first connector P1 are respectively connected to the sampling terminal of the switching unit 2 and the other end of the fourth capacitor C4 of the operational amplifier unit 3. The cathode of the second diode D2 is used to connect to an external power supply mechanism. The anode of the first diode D1 and pin 2 of the first connector P1 are respectively grounded.

[0039] In this embodiment, by using the first diode D1 and the second diode D2 in combination, the output circuit can be protected from damage caused by surge voltage, and the voltage clamping can be kept within a safe range, thereby improving the safety and stability of the output circuit during operation.

[0040] The output circuit of the controller disclosed in this application, in actual operation, when a 0-10V signal is needed to drive the fan speed adjustment or adjust the working state of other external loads, the MCU module of the controller will send the control signal GPIO_EN to a high level and GPIO output PWM signals with different duty cycles. Through switching unit 2, the feedback loop of the second operational amplifier IC1B is made to enter a disconnected and non-conducting state. By designing the resistance values ​​of the second resistor R2, the fifth resistor R5, and the eleventh resistor R11, the output factor of the first operational amplifier is adjusted. When the GPIO output voltage is 0-3.3V, the parameter resistor of the first operational amplifier IC1A is designed to amplify by 4 times to output a 0-10V analog voltage; when the GPIO output voltage is 0-5V, the parameter resistor of the first operational amplifier IC1A is designed to amplify by 4 times. The output voltage is doubled to 0-10V analog voltage, ensuring that the output voltage signal meets the working requirements of the load. When a 4-20mA current signal is needed to drive an external load, the MCU module of the controller will send a control signal GPIO_EN to a low level. Through the conduction part 21, the feedback loop of the second operational amplifier ICB1 will enter the conduction state. The GPIO output adjustable duty cycle PWM signal is converted into a 0-3.3V or 0-5V analog signal by the input processing unit 1, i.e., the RC filter circuit. By designing the resistance values ​​of the feedback circuit resistors of the second operational amplifier ICB1B, i.e., the seventh resistor R7, the eighth resistor R8, the ninth resistor R9, the tenth resistor R10 and the third resistor R3, the output of the output protection unit 4 is stabilized at 4-20mA, ensuring that the output current signal meets the working requirements of the load.

[0041] The present invention also provides a PCB board on which the output circuit of the controller as described above is printed.

[0042] The present invention also provides a controller that uses the output circuit of any of the controllers described above to achieve operational control.

[0043] It is understood that those skilled in the art can make equivalent substitutions or changes to the technical solution and inventive concept of the present invention, and all such changes or substitutions should fall within the protection scope of the present invention.

Claims

1. An output circuit for a controller, characterized in that, The system includes an input processing unit, a switching unit, an operational amplifier unit, an output protection unit, and an adjustment unit. The input processing unit receives a PWM signal at its input terminal. Its output terminal is connected to one end of the adjustment unit, and the other end of the adjustment unit is connected to the input terminal of the output protection unit. The adjustment unit is also connected to the input terminal of the operational amplifier unit. The output terminal of the operational amplifier unit and the input terminal of the output protection unit are respectively connected to the sampling terminal of the switching unit. The operational amplifier unit is also connected to the input terminal of the output protection unit. The switching unit receives a switching level signal at its input terminal, and its output terminal is connected to the input terminal of the operational amplifier unit. The switching unit includes a conduction section and an adjustment section. The input terminal of the conduction section receives the switching level signal, and its output terminal is connected to pin 2 of the first operational amplifier IC1A. The conduction section is also connected to the output terminal of the adjustment section, and the sampling terminal of the adjustment section is connected to the input terminal of the output protection unit. The conduction section includes a second transistor Q2 and a sixth resistor R6. One end of the sixth resistor R6 receives the switching level signal. The other end of the sixth resistor R6 is connected to the base of the second transistor Q2. The collector of the second transistor Q2 is connected to pin 2 of the first operational amplifier IC1A. The emitter of the second transistor Q2 is connected to the adjustment unit. The adjustment unit includes a second operational amplifier IC1B, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, and a third resistor R3. Pin 7 of the second operational amplifier IC1B is connected to the emitter of the second transistor Q2 and one end of the ninth resistor R9. Pin 5 of the second operational amplifier IC1B is connected to one end of the seventh resistor R7 and one end of the eighth resistor R8. Pin 6 of the second operational amplifier IC1B and the other end of the ninth resistor R9 are connected to one end of the tenth resistor R10. The other end of the eighth resistor R8 is connected to the emitter of the first transistor Q1 and one end of the third resistor R3. The other end of the third resistor R3 is connected to the other end of the tenth resistor R10, the other end of the adjustment unit, and the input terminal of the output protection unit.

2. The output circuit of a controller according to claim 1, characterized in that, The operational amplifier unit includes a first operational amplifier IC1A, a fourth resistor R4, a first transistor Q1, a first capacitor C1, and a fourth capacitor C4. Pins 2 and 3 of the first operational amplifier IC1A are connected to the adjustment unit, and pin 2 of the first operational amplifier IC1A is also connected to the output terminal of the switching unit and one end of the fourth capacitor C4. Pin 1 of the first operational amplifier IC1A is connected to one end of the fourth resistor R4 and the collector of the first transistor Q1, and the other end of the fourth resistor R4 is connected to the base of the first transistor Q1. The emitter of the first transistor Q1 is connected to the sampling terminal of the switching unit. Pin 4 of the first operational amplifier IC1A is connected to one end of the first capacitor C1 and is used to connect to an external power supply mechanism. The other end of the fourth capacitor C4 is connected to the input terminal of the output protection unit. Pin 11 of the first operational amplifier IC1A and the other end of the first capacitor C1 are grounded.

3. The output circuit of a controller according to claim 2, characterized in that, The adjustment unit includes a second resistor R2, a fifth resistor R5, an eleventh resistor R11, and a third capacitor C3. One end of the second resistor is connected to the output terminal of the input processing unit. The other end of the second resistor R2 is connected to one end of the third capacitor C3 and pin 3 of the first operational amplifier IC1A. One end of the fifth resistor R5 is connected to pin 2 of the first operational amplifier IC1A and one end of the eleventh resistor R11. The other end of the eleventh resistor R11 is connected to the input terminal of the output protection unit. The other ends of the third capacitor C3 and the fifth resistor R5 are grounded.

4. The output circuit of a controller according to claim 1, characterized in that, The input processing unit includes a first resistor R1 and a second capacitor C2. One end of the first resistor R1 is used to receive PWM signals, and the other end of the first resistor R1 is connected to one end of the second capacitor C2 and one end of the adjustment unit, respectively. The other end of the second capacitor C2 is grounded.

5. The output circuit of a controller according to claim 1, characterized in that, The output protection unit includes a first diode D1, a second diode D2, and a first connector P1. The cathode of the first diode D1, the anode of the second diode D2, and pin 1 of the first connector P1 are respectively connected to the sampling terminal of the switching unit and the operational amplifier unit. The cathode of the second diode D2 is used to connect to an external power supply mechanism. The anode of the first diode D1 and pin 2 of the first connector P1 are respectively grounded.

6. A PCB board, characterized in that, The PCB board has the output circuit of the controller as described in any one of claims 1-5 printed on it.

7. A controller, characterized in that, The controller uses the output circuit of the controller as described in any one of claims 1-5 to achieve operation control.

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