Capacitive sensor with multiple output functions

Abstract

The utility model relates to the technical field of capacitive sensors, in particular to a capacitive sensor with multiple output functions, which comprises a first output module, a second output module, a protection module and a reverse logic module, the input end of the reverse logic module is connected with external signals, and the output end of the reverse logic module is connected with the input end of the protection module; the output end of the protection module is respectively connected with the first output module and the second output module; the input end of the first output module is connected with a first load, the input end of the second output module is connected with a second load, the output end of the first output module and the output end of the second output module are collinearly connected between the first load and the second load, and an NPN NO / NC or PNP NO / NC output form can be flexibly configured through different wiring modes. Therefore, the universality and the flexibility of the product are greatly improved, and the production and storage cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of capacitance sensors, in particular to a capacitance sensor with multiple output functions. Background Art

[0002] In industrial automation, capacitive sensors are key components for detecting object position, and their output characteristics are crucial for achieving precise control and safety monitoring. Traditionally, capacitive sensor outputs vary depending on region and technology. Specifically, when an object approaches and reaches a preset position, the sensor outputs a voltage signal to indicate its presence.

[0003] Furthermore, capacitive sensors, as switching signals with voltage outputs, play different roles in different device applications. In safety-related applications such as limit switches and interlocks, an NC (normally closed) output is often used to ensure the circuit remains closed when the sensor is not triggered, providing additional safety. In applications such as detecting the presence of an object, a NO (normally open) output is more common because it quickly opens the circuit when the sensor is triggered, achieving a fast response.

[0004] Therefore, to meet the needs of different regions and usage scenarios, universal capacitive sensors are usually required to provide four output types: NPN, PNP, NO, and NC. However, this diverse output type places an additional burden on sensor production and storage, increasing manufacturing costs and making inventory management more difficult. Utility Model Content

[0005] In order to overcome the shortcomings of the existing technology, the present application provides a capacitive sensor with multiple output functions. By adopting different wiring methods, the sensor can be flexibly configured as NPN NO / NC or PNP NO / NC output form, thereby greatly improving the versatility and flexibility of the product and reducing production and storage costs.

[0006] The technical means adopted by the present invention to solve its technical problems are: a capacitive sensor with multiple output functions, the improvement of which is that it includes: a first output module, a second output module, a protection module, and a reverse logic module, wherein the input end of the reverse logic module is connected to an external signal, and the output end is connected to the input end of the protection module; the output end of the protection module is respectively connected to the first output module and the second output module; the input end of the first output module is connected to a first load, the input end of the second output module is connected to a second load, and the output end of the first output module and the output end of the second output module are collinearly connected between the first load and the second load.

[0007] In the above technical solution, the first output module includes a first switching tube, a first resistor and a first abnormality detection unit, the emitter of the first switching tube is connected to the first resistor and one end of the first abnormality detection unit, and the other end of the first resistor is connected to the first load; the base of the first switching tube is connected to the protection module.

[0008] In the above technical solution, the second output module includes a second switching tube, a second resistor and a second abnormality detection unit, the emitter of the second switching tube is connected to the second resistor and one end of the second abnormality detection unit, the other end of the second resistor is connected to the second load, and the base of the second switching tube is connected to the protection module; the collector of the first switching tube and the collector output of the second switching tube are collinear.

[0009] In the above technical solution, the first output module is used to output source current and detect whether the wiring status of the first load is abnormal; when the first load current exceeds the design range, the high-level output is maintained through the first resistor and the first abnormality detection unit; when the load current exceeds the design range, the first abnormality detection unit outputs a low level to close the subsequent transmission gate to protect the output circuit of the first output module; the second output module is used to output sink current and detect whether the wiring status of the second load is abnormal; when the second load current is within the design range, the high-level output is maintained through the second resistor and the second abnormality detection unit; when the load current exceeds the design range, the second abnormality detection unit outputs a low level to close the subsequent transmission gate to protect the output circuit of the second output module.

[0010] The protection module in the above technical solution is used to prevent the first output module and the second output module from being turned on at the same time, and includes a delay unit, a diode, a NAND gate circuit and a transmission gate circuit, wherein the other end of the first abnormality detection unit and the other end of the second abnormality detection unit are connected to the input end of the NAND gate circuit, and the output end of the NAND gate circuit is connected to the output end of the transmission gate circuit; the base of the first switching tube is connected to the output end of the transmission gate circuit through the delay unit, and the base of the second switching tube is connected to the output end of the transmission gate circuit through the diode.

[0011] The reverse logic module in the above technical solution is used to realize the output state flipping function when different wiring is used, and includes an exclusive OR logic circuit, a state output unit and a level conversion unit, wherein the input end of the transmission gate circuit is connected to the output end of the exclusive OR logic circuit, and the input end of the exclusive OR logic circuit is respectively connected to the state output unit and the level conversion unit; the other end of the level conversion unit serves as the input end.

[0012] In the above technical solution, the first switch tube is a PNP tube, and the second switch tube is an NPN tube.

[0013] The level conversion unit in the above technical solution is used to convert the external VCC 24vdc into a low voltage of 5v or 3.3vdc; when the external signal is connected to VCC, it becomes a high level of the internal logic after level conversion; when the external signal is connected to GND, it becomes a low level of the internal logic after level conversion.

[0014] The beneficial effects of the utility model are:

[0015] Different wiring methods are used to flexibly configure the output form as NPN NO / NC or PNP NO / NC, which greatly improves the versatility and flexibility of the product and reduces production and storage costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of a capacitive sensor with multiple output functions according to an embodiment of the present invention;

[0017] Figure 2 This is a wiring diagram of the NPN NO output function shown in an embodiment of the present utility model;

[0018] Figure 3 This is a wiring diagram of the NPN NC output function shown in an embodiment of the present utility model;

[0019] Figure 4 This is a timing diagram of the NPN operation shown in an embodiment of the present utility model;

[0020] Figure 5 This is a wiring diagram of the PNP NO output function shown in an embodiment of the present utility model;

[0021] Figure 6 This is a wiring diagram of the PNP NC output function shown in an embodiment of the present utility model;

[0022] Figure 7 This is a PNP action timing diagram shown in an embodiment of the present utility model. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with the embodiments and drawings, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by technical personnel in this field without creative work are within the scope of protection of the present invention. In addition, all the connection / connection relationships involved in the patent do not refer to the direct connection of components, but refer to the fact that a better connection structure can be formed by adding or reducing connection accessories according to the specific implementation situation. The various technical features in the creation of the present invention can be combined interactively without conflicting with each other.

[0025] like Figure 1 As shown, the present application provides a capacitive sensor with multiple output functions, including: a first output module, a second output module, a protection module, and a reverse logic module.

[0026] Among them, the input end of the reverse logic module is connected to the external signal NO / NC, and the output end is connected to the input end of the protection module; the output end of the protection module is respectively connected to the first output module and the second output module; the input end of the first output module is connected to the first load, the input end of the second output module is connected to the second load, and the output end of the first output module and the output end of the second output module are collinearly connected between the first load and the second load.

[0027] In one possible implementation, the first output module includes a first switching transistor Q1, a first resistor Rs1, and a first abnormality detection unit. The emitter of the first switching transistor Q1 is connected to the first resistor Rs1 and one end of the first abnormality detection unit, and the other end of the first resistor Rs1 is connected to a first load LOAD1. The base of the first switching transistor Q1 is connected to the protection module. Optionally, the first switching transistor Q1 is a PNP transistor.

[0028] The second output module includes a second switch Q2, a second resistor Rs2, and a second abnormality detection unit. The emitter of the second switch Q2 is connected to the second resistor Rs2 and one end of the second abnormality detection unit. The other end of the second resistor Rs2 is connected to a second load LOAD2. The base of the second switch Q2 is connected to the protection module. The collector of the first switch Q1 and the collector of the second switch Q2 are collinear. Optionally, the second switch is an NPN transistor.

[0029] The first output module is configured to output a source current and detect whether the wiring status of the first load is abnormal; the abnormality refers to a scenario in which the customer accidentally short-circuits the load or exceeds the rated output current.

[0030] like Figure 1 As shown, when the current of the first load LOAD1 is within the design range, an OCA signal is output, and the first resistor Rs1 and the first abnormality detection unit maintain a high-level output. The first resistor Rs1 is a low-resistance element. When the load current is within the design range, the VE1 voltage is close to VCC, and the first abnormality detection unit outputs a high level. When the load current exceeds the design range, a certain voltage drop is formed on the first resistor RS1, resulting in a decrease in the VE1 voltage. The first abnormality detection unit outputs a low level to close the subsequent transmission gate and protect the output circuit of the first output module.

[0031] The second output module is used to output the sink current and detect whether the wiring status of the second load is abnormal; when the current of the second load LOAD2 is within the design range, the OCB signal is output, and the high-level output is maintained by the second resistor Rs2 and the second abnormality detection unit. The second resistor Rs1 is a low-resistance element. When the load current is within the design range, the VE2 voltage is close to GND, and the second abnormality detection unit outputs a high level; when the load current exceeds the design range, a certain voltage drop is formed on the second resistor RS1, resulting in a decrease in the VE2 voltage, and a low level is output through the second abnormality detection unit to close the subsequent transmission gate and protect the output circuit of the second output module.

[0032] In one possible implementation, see Figure 1 The protection module is used to prevent the first output module and the second output module from being turned on at the same time, and includes a delay unit de l ay, a diode D, a NAND gate circuit NAND and a transmission gate circuit BUF, wherein,

[0033] The other end of the first abnormality detection unit and the other end of the second abnormality detection unit are connected to the input end of the NAND gate circuit NAND, and the output end of the NAND gate circuit NAND is connected to the output end of the transmission gate circuit BUF;

[0034] The base of the first switch tube is connected to the output end of the transmission gate circuit BUF through the delay unit de la ay, and the base of the second switch tube is connected to the output end of the transmission gate circuit BUF through the diode D.

[0035] The delay unit de la ay and the diode D constitute a dead zone control to prevent the first output module and the second output module from being turned on at the same time.

[0036] When the control circuit outputs a low level, the first switch tube Q1 of the first output module is turned on. Because the low level output by the control circuit is lower than 0.5V, and due to the presence of a diode D at the base of the second switch tube Q2 of the second output module, the base current of the first switch tube Q1 will not flow into the second switch tube Q2 after the first switch tube Q1 is turned on. Therefore, the second output module is turned off, and the output is a current source. When the internal control output is a high level, the base voltage of the first switch tube Q1 of the first output module rises to the emitter voltage, the first switch tube Q1 is turned off, and the second output module is turned on. At this time, the circuit outputs a current sink.

[0037] NAND is a two-input NAND gate circuit. When signals OCA and OCB are normal, it outputs a high level. According to the NAND gate logic, when both inputs are high, it outputs a low level. If either input detects an abnormality and outputs a low level, the NAND gate circuit outputs a high level. The transmission gate circuit BUF is a buffer circuit with an enable terminal. According to the symbol in the diagram, it enables the valid signal to be low. The transmission gate is normally open only when the enable signal is low. When the enable signal is high, the transmission gate is cut off and the output is in a high-impedance state.

[0038] In one possible implementation, see Figure 1 As shown, the reverse logic module is used to realize the output state flipping function when different wiring is used, and includes an exclusive OR logic circuit XOR, a state output unit and a level conversion unit, wherein,

[0039] The input end of the transmission gate circuit BUF is connected to the output end of the exclusive OR logic circuit XOR, and the input end of the exclusive OR logic circuit XOR is respectively connected to the state output unit and the level conversion unit; the other end of the level conversion unit serves as the input end.

[0040] Among them, the function of the level conversion unit is to convert the external VCC 24vdc high voltage into the low voltage of 5v or 3.3vdc required by the logic judgment chip. This voltage is recognized by the exclusive OR logic circuit XOR to realize the inverted logic. If the NO / NC described in the utility model is connected to VCC, it becomes the high level of the internal logic after level conversion. When the NO / NC is connected to GND, it becomes the low level of the internal logic after level conversion. This level is XORed with the internal state output ON / OFF and output OPR to the protection module to realize the output state flipping function when different NO / NC wiring is used.

[0041] The capacitive sensor with multiple output functions provided in this application can realize NPN and PNP co-wire output (same terminal line). At this time, the wiring method of the customer load determines the output mode of the sensor at this time, and NO / NC is used to change the high and low signal logic of the output.

[0042] like Figure 2 As shown, taking NPN NO as an example, the customer load LOAD1 is connected to the OUT and VCC terminals, and the NO / NC selection terminal is connected to the GND terminal.

[0043] When the object to be measured approaches the effective measurement area of ​​the sensor from a remote end, the on / off signal inside the sensor outputs a high level. After the high level and the low level formed by the NO / NC wiring are subjected to an XOR logic, the high level is output, driving the NPN transistor of the second output module to conduct, forming a current sink. The external power supply VCC sinks current from the OUT terminal through the load LOAD1, indicating that the load is turned on;

[0044] When the object to be measured leaves the effective measurement area of ​​the sensor from the near end, the on / off signal inside the sensor outputs a low level. After the low level is XORed with the low level formed by the NO / NC wiring, the sensor outputs a low level, turning off the NPN tube of the second output module. No current flows through the load LOAD1, indicating that the load is disconnected.

[0045] like Figure 3 As shown, it is obvious that when the NO / NC selection terminal is connected to VCC, due to the effect of the exclusive OR logic, the logic of load connection and disconnection is exactly opposite to that of NO, that is, the NPN NC action mode is realized; the action timing diagrams of the two wiring methods are shown in Figure 4 shown.

[0046] like Figure 5 As shown, taking PNP NO as an example, the customer load LOAD2 is connected to the OUT and GND terminals, and the NO / NC selection terminal is connected to the VCC terminal.

[0047] When the object to be measured approaches the effective measurement area of ​​the sensor from a remote end, the on / off signal inside the sensor outputs a high level. After the high level is XORed with the high level formed by the NO / NC wiring, the sensor outputs a low level, driving the PNP tube of the first output module to turn on, forming a source current. The OUT end outputs current, which flows into GND through the load LOAD2, indicating that the load is turned on.

[0048] When the object to be measured leaves the effective measurement area of ​​the sensor from the near end, the on / off signal inside the sensor outputs a low level. After the low level and the high level formed by the NO / NC wiring are subjected to an XOR logic, a high level is output, which turns off the PNP tube of the first output module and no current flows through the load LOAD2, indicating that the load is disconnected.

[0049] like Figure 6 As shown, it is obvious that when the NO / NC selection terminal is connected to VCC, due to the effect of the XOR logic, the logic of load connection and disconnection is exactly opposite to that of NO, that is, the PNP NC action mode is realized; the action timing diagrams of the two wiring methods are shown in Figure 7 shown.

[0050] The capacitive sensor with multiple output functions provided by the utility model can be flexibly configured as NPN NO / NC or PNP NO / NC output form through different wiring methods, thereby greatly improving the versatility and flexibility of the product and reducing production and storage costs.

[0051] The above is a specific description of the preferred implementation of the present invention, but the invention of the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without violating the spirit of the present invention. These equivalent modifications or substitutions are all included in the scope defined by the claims of this application.

Claims

1. A capacitive sensor with multiple output functions, characterized in that: It includes: a first output module, a second output module, a protection module, and a reverse logic module, wherein the input end of the reverse logic module is connected to an external signal, and the output end is connected to the input end of the protection module; the output end of the protection module is respectively connected to the first output module and the second output module; the input end of the first output module is connected to a first load, the input end of the second output module is connected to a second load, and the output end of the first output module and the output end of the second output module are collinearly connected between the first load and the second load.

2. The capacitive sensor with multiple output functions according to claim 1, characterized in that: The first output module includes a first switching tube, a first resistor and a first abnormality detection unit, the emitter of the first switching tube is connected to the first resistor and one end of the first abnormality detection unit, and the other end of the first resistor is connected to the first load; the base of the first switching tube is connected to the protection module.

3. The capacitive sensor with multiple output functions according to claim 2, characterized in that: The second output module includes a second switching tube, a second resistor and a second abnormality detection unit, the emitter of the second switching tube is connected to the second resistor and one end of the second abnormality detection unit, the other end of the second resistor is connected to the second load, and the base of the second switching tube is connected to the protection module; the collector of the first switching tube and the collector output of the second switching tube are collinear.

4. The capacitive sensor with multiple output functions according to claim 3, characterized in that: The first output module is used to output a source current and detect whether the wiring state of the first load is abnormal; when the first load current is within a designed range, a high level output is maintained through the first resistor and the first abnormality detection unit; When the load current exceeds the design range, the first abnormality detection unit outputs a low level to close the subsequent transmission gate to protect the output circuit of the first output module; The second output module is used to output the sink current and detect whether the wiring status of the second load is abnormal; when the second load current is within the design range, the high-level output is maintained through the second resistor and the second abnormality detection unit; when the load current exceeds the design range, the second abnormality detection unit outputs a low level to close the subsequent transmission gate to protect the output circuit of the second output module.

5. The capacitive sensor with multiple output functions according to claim 4, characterized in that: The protection module is used to prevent the first output module and the second output module from being turned on at the same time, and includes a delay unit, a diode, a NAND gate circuit and a transmission gate circuit, wherein: The other end of the first abnormality detection unit and the other end of the second abnormality detection unit are connected to the input end of the NAND gate circuit, and the output end of the NAND gate circuit is connected to the output end of the transmission gate circuit; The base of the first switch tube is connected to the output end of the transmission gate circuit through the delay unit, and the base of the second switch tube is connected to the output end of the transmission gate circuit through the diode.

6. The capacitive sensor with multiple output functions according to claim 5, characterized in that: The reverse logic module is used to realize the output state flipping function when different wiring is used, and includes an XOR logic circuit, a state output unit and a level conversion unit, wherein, The input end of the transmission gate circuit is connected to the output end of the XOR logic circuit, and the input end of the XOR logic circuit is respectively connected to the state output unit and the level conversion unit; the other end of the level conversion unit serves as the output end.

7. The capacitive sensor with multiple output functions according to claim 3, characterized in that: The first switch tube is a PNP tube, and the second switch tube is an NPN tube.

8. The capacitive sensor with multiple output functions according to claim 6, characterized in that: The level conversion unit is used to convert the external VCC 24vdc into a low voltage of 5v or 3.3vdc; when the external signal is connected to VCC, it becomes a high level of the internal logic after level conversion; when the external signal is connected to GND, it becomes a low level of the internal logic after level conversion.

Images