CN218041177U - Switching value input circuit and control system - Google Patents
Switching value input circuit and control system Download PDFInfo
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- CN218041177U CN218041177U CN202221698229.3U CN202221698229U CN218041177U CN 218041177 U CN218041177 U CN 218041177U CN 202221698229 U CN202221698229 U CN 202221698229U CN 218041177 U CN218041177 U CN 218041177U
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Abstract
The application discloses a switching value input circuit and a control system, wherein the switching value input circuit is used for controlling a plurality of controlled devices through a switching value signal source and comprises a switching value input terminal, a blocking circuit and an internal transmission circuit, the switching value input terminal is connected with the switching value signal source, the switching value input terminal and the switching value signal source are grounded together, the internal transmission circuit is connected with a controller of the controlled devices, and the switching value input terminal, the blocking circuit and the internal transmission circuit are connected in sequence; the blocking circuit comprises a blocking diode, the cathode of the blocking diode is connected with the switching value input terminal, and the anode of the blocking diode is connected with the internal transmission circuit; and the internal transmission circuit is used for transmitting the switching value signal to a controller of the controlled equipment. According to the scheme, when the same switching value is used for simultaneously controlling a plurality of controlled devices, the switching value detection of the controlled devices which are not powered down is prevented from being influenced by the controlled devices which are powered down.
Description
Technical Field
The application belongs to the technical field of frequency converters, and particularly relates to a switching value input circuit and a control system.
Background
The existing frequency converter switching value input circuit usually adopts an optical coupling isolation type or a resistance voltage division type, and compared with the optical coupling isolation type, the switching value input circuit adopting the resistance voltage division type has the cost advantage. However, when a switching value signal source is used to control a plurality of frequency converters, the switching value input circuits of the plurality of frequency converters need to be connected in parallel. When one of the frequency converters is powered down, the switching value detection of other non-powered-down frequency converters can be influenced.
Disclosure of Invention
An object of the utility model is to provide a switching value input circuit, when aiming at the switching value input circuit who aims at analyzing that prior art exists when resistance partial pressure formula is applied to and uses a switching value signal source control many converters, one of them converter falls the electricity and can influence other reasons that do not fall the switching value of electricity converter and detect and solve corresponding problem.
The utility model provides a first aspect provides a switching value input circuit for control many controlled devices through a switching value signal source, including switching value input terminal, blocking circuit, internal transmission circuit, switching value input terminal connects the switching value signal source, switching value input terminal and the common ground connection of switching value signal source, internal transmission circuit connects the controller of controlled device, switching value input terminal, blocking circuit and internal transmission circuit connect gradually; the switching value input terminal is used for transmitting the switching value signal output by the switching value signal source to the blocking circuit and the internal transmission circuit; the blocking circuit is used for preventing reverse current from flowing to the internal transmission circuit, and comprises a blocking diode, the cathode of the blocking diode is connected with the switching value input terminal, and the anode of the blocking diode is connected with the internal transmission circuit; the internal transmission circuit is used for transmitting the switching value signal to the controller of the controlled device, and comprises a voltage division circuit which is used for dividing the voltage input to the controller of the controlled device.
In one embodiment, the internal transmission circuit further includes a high-level clamp circuit and a clamp protection circuit, and the high-level clamp circuit, the voltage divider circuit and the clamp protection circuit are connected in sequence; the high-level clamping circuit is used for pulling up the voltage at the input end of the voltage division circuit to a high level, and the clamping protection circuit is used for preventing a controller of the controlled device from being damaged due to the fact that the received voltage exceeds a voltage range defined by a pin.
In one embodiment, the circuit further comprises a first filter circuit, the first filter circuit comprises a first inductor and a first capacitor, a first end of the first inductor is connected to the anode of the blocking diode, a second end of the first inductor is connected to a first end of the first capacitor, and a second end of the first capacitor is grounded.
In one embodiment, the high-level clamp circuit includes a pull-up resistor, a first terminal of the pull-up resistor is connected to a third power supply, and a second terminal of the pull-up resistor is connected to a common terminal of the first capacitor and the first inductor.
In one embodiment, the voltage divider circuit includes a seventh resistor and an eighth resistor, a first end of the seventh resistor is connected to a common terminal of the first inductor and the first capacitor, a second end of the seventh resistor is connected to a first end of the eighth resistor, and a second end of the eighth resistor is grounded.
In one embodiment, the circuit further comprises a second filter circuit connected between the voltage divider circuit and the clamp protection circuit.
In one embodiment, the second filter circuit includes a ninth resistor and a second capacitor, a first terminal of the ninth resistor is connected to a common terminal of the seventh resistor and the eighth resistor, a second terminal of the ninth resistor is connected to a first terminal of the second capacitor, and a second terminal of the second capacitor is grounded.
In one embodiment, the clamp protection circuit includes a first diode and a second diode, a cathode of the first diode is connected to a fourth power supply, an anode of the first diode is connected to a cathode of the second diode, an anode of the second diode is grounded, and a common connection point of the first diode and the second diode is connected to a common terminal of the ninth resistor and the second capacitor.
In one embodiment, the controlled device is a frequency converter.
The utility model discloses an on the other hand still provides a control system, including a switching value signal source and n platform controlled equipment, wherein, n > 1, its characterized in that: the controlled device comprises the switching value input circuit.
The utility model discloses a set up blocking circuit between switching value input terminal and the internal transmission circuit of switching value input circuit, when using many controlled equipment of same switching value simultaneous control, when many controlled equipment's switching value input circuit were parallelly connected each other, if one of them converter falls the electricity, the blocking circuit on the switching value input circuit of falling the electricity converter can avoid falling the electricity converter influence and not fall the switching value detection of electricity converter.
Drawings
FIG. 1 is a diagram of a prior art exemplary parallel circuit configuration of a switching value input circuit;
fig. 2 is a schematic block diagram of a switching value input circuit provided in an embodiment of the present application;
fig. 3 is a circuit diagram of an example of a switching value input circuit provided in an embodiment of the present application;
fig. 4 is an exemplary circuit diagram for controlling four frequency converters by the switching value input circuit provided in the embodiment of the present application.
Detailed Description
In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.
It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.
The switching value refers to the on and off states of the contacts, is used for controlling the running state of equipment in a system, and is divided into a passive switching value signal and an active switching value signal. The passive switching value signal refers to the state of "on" and "off" as a signal without power supply, while the active switching value signal refers to the state of "on" and "off" as a step signal with power supply, commonly used 5V, 12V, 24V and the like.
The existing resistance voltage division type switching value input circuit is used for controlling a plurality of controlled devices through one switching value signal source, wherein one controlled device is powered off, and the switching value signal detection of other devices which are not powered off can be influenced. The inventor found that, referring to fig. 1, when two frequency converters are controlled by using one switching value signal source, the controller of the frequency converter is usually configured to be active at a low level, the switching value input circuits of the frequency converter 1 and the frequency converter 2 are connected in parallel with each other, the switching value input circuit includes a connection terminal and an internal transmission circuit, and the internal transmission circuit includes a pull-up resistor and a voltage division circuit. When the frequency converter 2 is powered off, namely the voltage value of V2 is 0, because the wiring terminals of the frequency converter 1 and the frequency converter 2 are grounded together, a voltage division circuit consisting of a fourth resistor R4 and a fifth resistor R5 on the switching value input circuit of the frequency converter 2 can be connected to the switching value input circuit of the frequency converter 1 in parallel, so that the voltage at a U0 point on the switching value input circuit in the frequency converter 1 is reduced. When the connection terminal of the frequency converter 1 is connected with the active switching value signal and the voltage value of the active switching value signal is at a high level, the voltage detected by the controller of the frequency converter 1 may be lower than the upper limit of the GPIO low level due to the voltage reduction at the U0 point, and the controller of the frequency converter 1 may control the malfunction of the frequency converter 1. Therefore, the blocking circuit provided in the switching value input circuit can prevent the reverse current from flowing through the switching value input circuit of the inverter 2 and thus prevent the voltage dividing circuit of the inverter 2 from being connected in parallel to the switching value input circuit of the inverter 1.
Fig. 2 shows a switching value input circuit provided in an embodiment of the present application, and for convenience of description, only the portions related to the embodiment of the present application are shown, and detailed descriptions are as follows:
a switching value input circuit is arranged in a controlled device and used for controlling a plurality of controlled devices through a switching value signal source, and comprises a switching value input terminal, a blocking circuit 10 and an internal transmission circuit 100, wherein the switching value input terminal is connected with the switching value signal source, the switching value input terminal and the switching value signal source are grounded together, the internal transmission circuit 100 is connected with a controller 200 of the controlled device, and the switching value input terminal, the blocking circuit 10 and the internal transmission circuit 100 are connected in sequence; the switching value input terminal is used for transmitting a switching value signal output by a switching value signal source to the blocking circuit 10 and the internal transmission circuit 100, the blocking circuit 10 is used for preventing a reverse current from flowing to the internal transmission circuit 100, the blocking circuit 10 comprises a blocking diode D0, a cathode of the blocking diode D0 is connected with the switching value input terminal, an anode of the blocking diode D0 is connected with the internal transmission circuit 100, the internal transmission circuit 100 is used for transmitting the switching value signal to the controller 200 of the controlled device, the internal transmission circuit 100 comprises a voltage division circuit 102, and the voltage division circuit 102 is used for dividing voltage input to the controller 200 of the controlled device.
When one switching value signal source controls a plurality of controlled devices through the switching value input circuit of each controlled device, the switching value input circuits of the controlled devices are connected in parallel; by arranging the blocking circuit 10 between the switching value input terminal of the switching value input circuit and the internal transmission circuit 100, one controlled device is powered down, reverse current cannot flow into the internal transmission circuit 100 of the powered-down controlled device, and the voltage division circuit 102 of the switching value input circuit of the powered-down controlled device cannot be connected to the switching value input circuit of the unpowered-down controlled device in parallel, so that the switching value input circuit of the unpowered-down controlled device is prevented from being influenced by the powered-down controlled device, and the phenomenon that a controller of the unpowered-down controlled device cannot normally identify the switching value and misoperation of the unpowered-down controlled device is avoided.
The internal transmission circuit 100 further comprises a high-level clamping circuit 101 and a clamping protection circuit 103, wherein the high-level clamping circuit 101, the voltage division circuit 102 and the clamping protection circuit 103 are sequentially connected; the high-level clamp circuit 101 is used to pull up the voltage at the input terminal of the voltage divider circuit 102 to a high level, and the clamp protection circuit 103 is used to prevent the controller 200 of the controlled device from being damaged due to the received voltage exceeding the voltage range defined by its pin.
Fig. 3 shows an example circuit structure of a switching value input circuit provided in an embodiment of the present application. The high clamp 101 includes a pull-up resistor R6, and a first terminal of the pull-up resistor R6 is connected to the third power source V3. Alternatively, the third power supply V3 may be a power supply of the controller, or other power supply.
The switching value input circuit further includes a first filter circuit 104, and the blocking diode D0 is connected to the high level clamp circuit 101 through the first filter circuit 104. The first filter circuit 104 includes a first inductor L1 and a first capacitor C1, a first end of the first inductor L1 is connected to an anode of the blocking diode D0, a second end of the first inductor L1 is connected to a first end of the first capacitor C1, a second end of the first capacitor C1 is grounded, and a common end of the first inductor L1 and the first capacitor C1 is connected to a second end of the pull-up resistor R6. Alternatively, the blocking diode D0 may be a silicon diode or a germanium diode, and is not particularly limited herein.
The first filter circuit 104 is disposed between the blocking diode D0 and the high-level clamp circuit 101, and mainly prevents the external environment from generating electromagnetic interference on the switching value input signal of the switching value input terminal, which may cause the switching value input signal to be unstable. Alternatively, the first filter circuit 104 may be an RC filter or an LC filter, and is not limited in particular.
The voltage divider circuit 102 includes a seventh resistor R7 and an eighth resistor R8, a first end of the seventh resistor R7 is connected to a common terminal of the first inductor L1 and the first capacitor C1, a second end of the seventh resistor R7 is connected to a first end of the eighth resistor R8, and a second end of the eighth resistor R8 is grounded.
A second filter circuit 105 is provided between the voltage dividing circuit 102 and the clamp protection circuit 103, and the second filter circuit 105 is connected between the voltage dividing circuit 102 and the clamp protection circuit 103. The second filter circuit 105 includes a ninth resistor R9 and a second capacitor C2, a first end of the ninth resistor R9 is connected to a common terminal of the seventh resistor R7 and the eighth resistor R8, a second end of the ninth resistor R9 is connected to a first end of the second capacitor C2, a second end of the second capacitor C2 is grounded, and a common terminal of the ninth resistor R9 and the second capacitor C2 is connected to the controller 200. The second filter circuit 105 is used for preventing the external environment from generating electromagnetic interference on the switching value input signal collected by the controller, thereby causing the switching value input signal to be unstable. Alternatively, the second filter circuit 105 may be an RC filter or an LC filter, and is not particularly limited herein.
The clamp protection circuit 103 includes a first diode D1 and a second diode D2, a cathode of the first diode D1 is connected to the fourth power source V4, an anode of the first diode D1 is connected to a cathode of the second diode D2, an anode of the second diode D2 is grounded, and a common node of the first diode D1 and the second diode D2 is connected to a common terminal of the ninth resistor R9 and the second capacitor C2. The clamp protection circuit 103 is used for clamping the voltage at the front end of the controller, and the forward conduction voltage of the first diode is V D1 The forward conduction voltage of the second diode is V D2 The voltage range received by the controller is-V D2 ～V4+V D1 The controller is prevented from being damaged due to the fact that the received voltage exceeds the voltage range defined by the pin.
Alternatively, the controller may be a Microprocessor (MCU) including a Central Processing Unit (CPU), a read-only memory (ROM), a Random Access Memory (RAM), a timing module, a Digital-to-analog converter (A/D converter), and a plurality of input/output ports, although not limited thereto, the controller may also be integrated circuits in other forms, such as Field Programmable Gate Array (FPGA) or Digital Signal Processor (DSP).
On the basis of the above embodiment, the third power supply V3 provides 24V, the seventh resistor R7 has a resistance of 10K Ω, and the eighth resistor R8 has a resistance of 3.3K Ω. The fourth power supply V4 provides 3.3V, the blocking diode D0 is a silicon diode, the controller 200 is an MCU, and the MCU is configured to be active low (< 1.65V). The working principle of the switching value input circuit is as follows: if the switch is suspended, under the action of the high-level clamping circuit 101, the voltage at the point U1 is pulled up to 24V, and passes through the voltage division circuit 102 formed by the seventh resistor R7 and the eighth resistor R8 and the second filter circuit 105 formed by the ninth resistor R9 and the second capacitor C2, and the voltage at the point U2 is greater than the lower limit of the GPIO high level of the MCU, the MCU does not output a signal for operating the device. If the switch is closed, when the switching value input terminal is connected with a passive switching value signal, the voltage of a point U1 is the forward conducting voltage of a blocking diode D0, usually 0.7V, the voltage of the point U2 is smaller than the upper limit of GPIO low level of the MCU through a voltage division circuit 102 consisting of a seventh resistor R7 and an eighth resistor R8 and a second filter circuit 105 consisting of a ninth resistor R9 and a second capacitor C2, and the voltage of the point U2 is smaller than the upper limit of GPIO low level of the MCU, the MCU outputs a signal for operating the device; when the switching value input terminal is connected with an active switching value signal and the voltage value of the active switching value signal is at a low level, for example, the voltage value is 5v, the voltage at the point U1 is the sum of the voltage at the switching value input terminal and the forward conduction voltage of a blocking diode D0, the voltage at the point U2 is smaller than the upper limit of the GPIO low level of the MCU through a voltage division circuit 102 composed of a seventh resistor R7 and an eighth resistor R8 and a second filter circuit 105 composed of a ninth resistor R9 and a second capacitor C2, and the voltage at the point U2 is smaller than the upper limit of the GPIO low level of the MCU; when the switching value input terminal is connected with an active switching value signal and the voltage value of the active switching value signal is at a high level, for example, the voltage value is 12V or 24v, the voltage at the point U1 is the sum of the voltage at the switching value input terminal and the forward conduction voltage of the blocking diode D0, and the voltage at the point U2 is higher than the lower limit of the GPIO high level of the MCU through the voltage dividing circuit 102 composed of the seventh resistor R7 and the eighth resistor R8 and the second filter circuit 105 composed of the ninth resistor R9 and the second capacitor C2, then the MCU does not output a signal for operating the device.
The embodiment of the utility model also provides a control system, including a switching value signal source and n controlled devices, wherein, n > 1; the controlled equipment comprises the switching value input circuit. Under normal conditions, one switching value signal source controls a plurality of controlled devices simultaneously through the switching value input circuit of each controlled device; when one controlled device is powered down, because the blocking circuit is arranged on the switching value input circuit of the power-down controlled device, the voltage dividing circuit in the switching value input circuit of the power-down controlled device cannot be connected to the switching value input circuit of the non-power-down controlled device in parallel, and therefore the influence of the power-down controlled device on the switching value detection of the non-power-down controlled device is avoided. Referring to fig. 4, for example, four frequency converters are controlled by one switching value signal source, the switching value input terminals of the four frequency converters are connected to the switching value signal source, and the switching value input terminals of the four frequency converters and the switching value signal source are commonly grounded. Under the normal condition, a switching value signal source controls four frequency converters simultaneously through a switching value input circuit in each frequency converter, if one of the frequency converters is powered down, because a blocking circuit is arranged on the switching value input circuit of the power-down frequency converter, a voltage dividing circuit in the switching value input circuit of the power-down frequency converter cannot be connected to the switching value input circuit of the power-down frequency converter in parallel, therefore, the influence of the power-down frequency converter on the detection of the switching value of the power-down frequency converter is avoided, and the malfunction of a controlled frequency converter is further prevented from being controlled by a controller of the power-down frequency converter.
The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.
Claims (10)
1. A switching value input circuit is used for controlling a plurality of controlled devices through a switching value signal source, and is characterized in that:
the switching value input terminal is connected with the switching value signal source, the switching value input terminal and the switching value signal source are grounded together, the internal transmission circuit is connected with a controller of the controlled equipment, and the switching value input terminal, the blocking circuit and the internal transmission circuit are sequentially connected;
the switching value input terminal is used for transmitting the switching value signal output by the switching value signal source to the blocking circuit and the internal transmission circuit;
the blocking circuit is used for preventing reverse current from flowing to the internal transmission circuit, and comprises a blocking diode, the cathode of the blocking diode is connected with the switching value input terminal, and the anode of the blocking diode is connected with the internal transmission circuit;
the internal transmission circuit is used for transmitting the switching value signal to the controller of the controlled device, and comprises a voltage division circuit which is used for dividing the voltage input to the controller of the controlled device.
2. The switching value input circuit according to claim 1, characterized in that: the internal transmission circuit further comprises a high-level clamping circuit and a clamping protection circuit, and the high-level clamping circuit, the voltage division circuit and the clamping protection circuit are sequentially connected; the high-level clamping circuit is used for pulling the voltage at the input end of the voltage division circuit to a high level, and the clamping protection circuit is used for preventing a controller of the controlled device from being damaged due to the fact that the received voltage exceeds a voltage range defined by a pin.
3. The switching value input circuit according to claim 2, wherein: the first filter circuit comprises a first inductor and a first capacitor, the first end of the first inductor is connected with the anode of the blocking diode, the second end of the first inductor is connected with the first end of the first capacitor, and the second end of the first capacitor is grounded.
4. The switching value input circuit according to claim 3, characterized in that: the high-level clamping circuit comprises a pull-up resistor, wherein the first end of the pull-up resistor is connected with a third power supply, and the second end of the pull-up resistor is connected with the common end of the first capacitor and the first inductor.
5. The switching value input circuit according to claim 3, characterized in that: the voltage division circuit comprises a seventh resistor and an eighth resistor, a first end of the seventh resistor is connected with a common end of the first inductor and the first capacitor, a second end of the seventh resistor is connected with a first end of the eighth resistor, and a second end of the eighth resistor is grounded.
6. The switching value input circuit according to claim 5, wherein: the clamping protection circuit further comprises a second filter circuit, and the second filter circuit is connected between the voltage division circuit and the clamping protection circuit.
7. The switching value input circuit according to claim 6, wherein: the second filter circuit comprises a ninth resistor and a second capacitor, wherein the first end of the ninth resistor is connected with the common end of the seventh resistor and the eighth resistor, the second end of the ninth resistor is connected with the first end of the second capacitor, and the second end of the second capacitor is grounded.
8. The switching value input circuit according to claim 7, wherein: the clamping protection circuit comprises a first diode and a second diode, wherein the cathode of the first diode is connected with a fourth power supply, the anode of the first diode is connected with the cathode of the second diode, the anode of the second diode is grounded, and the common joint of the first diode and the second diode is connected with the common end of the ninth resistor and the second capacitor.
9. The switching value input circuit according to claim 8, wherein: the controlled device is a frequency converter.
10. A control system comprising a source of a switching value signal and n controlled devices, where n > 1, wherein: the controlled device comprises a switching value input circuit according to any one of claims 1 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221698229.3U CN218041177U (en) | 2022-06-30 | 2022-06-30 | Switching value input circuit and control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202221698229.3U CN218041177U (en) | 2022-06-30 | 2022-06-30 | Switching value input circuit and control system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN218041177U true CN218041177U (en) | 2022-12-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202221698229.3U Active CN218041177U (en) | 2022-06-30 | 2022-06-30 | Switching value input circuit and control system |
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| CN (1) | CN218041177U (en) |
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- 2022-06-30 CN CN202221698229.3U patent/CN218041177U/en active Active
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