CN218647796U - Switch detection circuit and electronic switch - Google Patents

Abstract

The application discloses switch detection circuit belongs to electron electric technical field. The switch detection circuit is applied to an electronic switch which can be used in cooperation with at least one mechanical switch, the electronic switch comprises a power supply module and at least one detection terminal, and each detection terminal is used for being connected with a live wire outlet of one mechanical switch; the switch detection circuit includes: the detection input end is connected with one detection wiring end; the detection output end is connected with the working voltage output end of the power supply module; and the positive input end of the photoelectric coupler is connected with the detection input end, the negative input end of the photoelectric coupler is connected with the zero line connecting end of the electronic switch, the positive output end of the photoelectric coupler is connected with the detection output end, and the negative output end of the photoelectric coupler is connected with the public voltage output end of the power supply module. The problem that electronic switch can not be used in linkage with a mechanical switch can be solved.

Description

Switch detection circuit and electronic switch

Technical Field

The application relates to the technical field of electronics and electricity, in particular to a switch detection circuit and an electronic switch.

Background

Compared with a traditional mechanical switch, the electronic switch can realize rich and diverse application functions by means of the logic circuit, the micro control unit or the processor matched with various functional modules such as the environment sensor, the fingerprint sensor, the pressure sensor, the communication module and the touch module, and is widely applied to the fields of internet of things, security, industrial manufacturing, smart home and the like.

However, the current electronic switch products face the problem that the electronic switch products cannot be used in conjunction with the traditional mechanical switch. For example, bath heaters and cold heaters with electronic controllers on the market at present have lighting functions, and are provided with an electronic switch to control the switch of the lighting function based on wireless communication or infrared remote control; however, the lighting function is a function with high frequency of use, there is a demand for using switch linkage control (for example, a user may want a mechanical switch in a bathroom and an electronic switch outside the bathroom to be able to control the lighting function of a bathroom heater in a linkage manner, i.e., form a group of double-control or multi-control switches), but the electronic switch and the mechanical switch are difficult to realize linkage due to different switch control principles and independence on a line connection manner, so that electronic products with remote lighting functions, such as a bathroom heater and a cooling heater, are difficult to meet the simple application demand of switch linkage control with an indoor mechanical switch.

Disclosure of Invention

The application provides a switch detection circuit and electronic switch can help solve the problem that electronic switch can't use with mechanical switch linkage.

The embodiment of the application provides a switch detection circuit, which is applied to an electronic switch capable of being matched with at least one mechanical switch for use, wherein the electronic switch comprises a power supply module and at least one detection terminal, and each detection terminal is used for being connected with a live wire outlet of one mechanical switch; the switch detection circuit includes: the detection input end is connected with one detection wiring terminal; the detection output end is connected with the working voltage output end of the power supply module; the positive input end of the photoelectric coupler is connected with the detection input end, the negative input end of the photoelectric coupler is connected with the zero line connecting end of the electronic switch, the positive output end of the photoelectric coupler is connected with the detection output end, and the negative output end of the photoelectric coupler is connected with the public voltage output end of the power supply module.

In one possible implementation, the switch detection circuit further includes a reverse protection sub-circuit, the reverse protection sub-circuit is respectively connected to the positive input end of the photoelectric coupler and the zero line connection end of the electronic switch, and the reverse protection sub-circuit is configured to reduce the voltage at the zero line connection end of the electronic switch when the voltage at the zero line connection end of the electronic switch is higher than the voltage at the positive input end of the photoelectric coupler.

In a possible implementation manner, the reverse protection sub-circuit includes a clamping diode, an anode of the clamping diode is connected to the zero line connection end of the electronic switch, and a cathode of the clamping diode is connected to the anode input end of the photoelectric coupler.

In a possible implementation manner, the switch detection circuit further includes a voltage divider sub-circuit, the voltage divider sub-circuit includes a first resistor disposed between the detection input end and a positive input end of the optoelectronic coupler, and the positive input end of the optoelectronic coupler is connected to the detection input end through two ends of the first resistor.

In a possible implementation manner, the voltage divider circuit further includes a second resistor, and two ends of the second resistor are respectively connected to the positive input end of the photoelectric coupler and the negative input end of the photoelectric coupler.

In a possible implementation manner, the switch detection circuit further includes an input filter sub-circuit, the input filter sub-circuit includes a first capacitor, and two ends of the first capacitor are respectively connected to the positive input end of the optoelectronic coupler and the negative input end of the optoelectronic coupler.

In a possible implementation manner, the switch detection circuit further includes a current-limiting sub-circuit, the current-limiting sub-circuit is disposed at a third resistor between the detection output end and the working voltage output end of the power supply module, and the detection output end is connected to the working voltage output end of the power supply module through two ends of the third resistor.

In a possible implementation manner, the switch detection circuit further includes an output filter sub-circuit, the output filter sub-circuit includes a second capacitor, and two ends of the second capacitor are respectively connected to the detection output end and the common voltage output end of the power supply module.

In a possible implementation manner, a power supply module of the electronic switch is disposed in the switch detection circuit, the power supply module includes an AC-DC converter, an anode input end of the AC-DC converter is connected to a live wire connection end of the electronic switch, a cathode input end of the AC-DC converter is connected to a zero line connection end of the electronic switch, an anode output end of the AC-DC converter is connected to the working voltage output end, and a cathode output end of the AC-DC converter is connected to the common voltage output end.

The embodiment of the application further provides an electronic switch, the electronic switch comprises at least one detection terminal and at least one switch detection circuit, the detection terminal is used for being connected with a live wire of the mechanical switch, the detection terminal is connected with the detection input end of the switch detection circuit, and the detection terminal is connected with the detection input end of the switch detection circuit.

It can be seen that, in the embodiment of the present disclosure, by providing the switch detection circuit connected to the live wire outlet of the mechanical switch in the electronic switch, the photoelectric coupler can be used to output the electrical signal representing the switching state of the mechanical switch in a manner of isolating the strong current from the weak current, so that the electronic switch can determine the switching state of the mechanical switch based on the electrical signal, and then the linked use of the electronic switch and the mechanical switch becomes possible, which is helpful to widen the application scene and the application range of the electronic switch, and implement more diversified functional applications.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained without creative efforts.

FIG. 1 is a schematic diagram of an electronic switch according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a switch detection circuit according to an embodiment of the present application;

fig. 3 is a circuit diagram of a switch detection circuit according to an embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and encompass, for example, both fixed and removable connections or integral connections; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as the case may be. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Fig. 1 is a schematic structural diagram of an electronic switch capable of being used with a mechanical switch according to an embodiment of the present disclosure. Referring to fig. 1, the electronic switch includes a switch upper cover 11, an operation circuit board 12, a power box cover plate 13, a power circuit board 14, and a rear case 15. The switch upper cover 11 includes a plurality of touch keys, and a weak current circuit (not shown) on the operation circuit board 12 can receive signals of the touch keys pressed by fingers and process the signals to execute corresponding operation instructions, such as controlling on/off of internal circuits, turning on or off an indicator light, or sending wireless signals. The power circuit board 14 installed between the power box cover 13 and the rear case 15 is mainly responsible for receiving and processing the mains signal belonging to strong current, and for example, a power supply module (not shown) may be provided for converting the input mains signal into direct current voltage for the weak current circuit. As shown in fig. 1, a live wire connection end L0, a zero line connection end N0 and a detection connection end S1 are disposed on the power circuit board 14, wherein the live wire connection end L0 and the zero line connection end N0 are respectively used for connecting a live wire and a zero line to realize the connection of a mains supply signal, and the detection connection end S1 is used for connecting the live wire outgoing line of the mechanical switch used in cooperation with the electronic switch, so as to cooperate with a switch detection circuit disposed in the electronic switch to realize the detection of the on-off state of the mechanical switch.

Fig. 2 is a schematic diagram of a switch detection circuit according to an embodiment of the present application. Referring to fig. 2, the switch detection circuit 21 includes a detection input terminal IN, a detection output terminal OUT, and a photoelectric coupler U1, where the detection input terminal IN is connected to the detection terminal S1, and the detection output terminal OUT is connected to the working voltage output terminal V1 of the power supply module 22 (the detection output terminal OUT may be indirectly connected to the working voltage output terminal V1 of the power supply module 22, and the connection types therebetween may be pull-up connections, that is, one of the purposes of the connection is to pull up the potential at the detection output terminal OUT by using the working voltage output by the power supply module); the positive input end P11 of the photoelectric coupler U1 is connected with the detection input end S1, the negative input end P12 is connected with the zero line connecting end N0 of the electronic switch, the positive output end P21 is connected with the detection output end OUT, and the light negative output end P22 is connected with the public voltage output end V0 of the power supply module 22.

Based on the above connection relationship, the operation principle of the switch detection circuit 22 is roughly as follows: when the mechanical switch connected to the detection terminal S1 is IN a closed (disconnected) state, there is no mains voltage on the live wire outgoing line of the mechanical switch, there is no voltage input at the detection input terminal IN, and no current flows between the positive input terminal P11 and the positive output terminal P12 of the photoelectric coupler U1, so that an open circuit (disconnected) state is approximated between the positive output terminal P21 and the negative output terminal P22 of the photoelectric coupler U1, and at this time, the detection output terminal OUT outputs a working voltage (for example, a 5V dc voltage) provided by the working voltage output terminal V1 of the power supply module 22. When the mechanical switch connected to the detection terminal S1 is IN an open (closed) state, the detection input terminal IN is a mains voltage provided by a live wire outgoing line of the mechanical switch, so that the light emitting device between the positive input terminal P11 and the negative input terminal P12 inside the photoelectric coupler U1 emits light, a current from the positive output terminal P21 to the negative output terminal P22 is formed inside the photoelectric coupler U1, and the voltage at the detection output terminal OUT gradually decreases to a stable value. That is, the voltage level of the detection output terminal OUT of the switch detection circuit 22 may indicate the switching state in which the mechanical switch connected to the detection terminal S1 is placed.

It can be seen that, compared with a general electronic switch, the electronic switch of the embodiment of the present disclosure is provided with a detection terminal S1 for connecting a live line and an outgoing line of a mechanical switch and a switch detection circuit 22 for detecting a signal on the detection terminal S1, and the switch detection circuit 22 can output an electrical signal representing a switching state of the mechanical switch by using a photoelectric coupler in a manner of isolating a strong current from a weak current, so that the electronic switch can determine the switching state of the mechanical switch based on the electrical signal. In one example, the detection output terminal OUT of the switch detection circuit 22 may be connected to one input terminal of a logic gate circuit, and the other input terminal of the logic gate circuit may be connected to a voltage output terminal of a touch button, so that a switch control signal comprehensively controlled by the switch states of the mechanical switch and the touch button is output based on the logic operation function of the logic gate circuit (when both the mechanical switch and the touch button are used to control the switch of the same electrical device, the function of the double-control switch of the corresponding processing logic is realized). It can be seen that the use of the electronic switch in conjunction with the mechanical switch is made possible based on the above-described arrangement of the detection terminal S1 and the switch detection circuit 22.

Furthermore, the number of the detection terminals S1 in the electronic switch may be more than one, such as two, three, four or more, and each detection terminal S1 may be connected to a separate switch detection circuit to detect the switch state of the corresponding mechanical switch. At this time, the logic processing circuit in the electronic switch can perform logic operation on the switch states of any plurality of mechanical switches and the switch state of the touch switch, so as to realize the required application function according to the application requirement. It can be seen that the switch detection circuit and the electronic switch provided by the embodiment of the disclosure can help to broaden application scenes and application ranges of the electronic switch, and realize more diversified functional applications.

In addition, since the power supply module and the switch detection circuit in the electronic switch are connected to the zero line connection end N0 of the electronic switch, the switch detection circuit can realize the switch detection of the mechanical switch by connecting only one detection terminal S1 to the live line outgoing line of one mechanical switch, without connecting other lines (such as other live line outgoing lines or zero line outgoing lines, etc.) led out from the mechanical switch; it can be seen that the above example can have a simpler connection relationship and be more convenient to use than an implementation that requires multiple lines between the electronic switch and the mechanical switch to enable switch detection.

Fig. 3 is a circuit diagram of a switch detection circuit according to an embodiment of the present application.

Referring to fig. 3, compared to the circuit configuration shown IN fig. 2, the switch detection circuit shown IN fig. 3 further includes a voltage divider 31, and the voltage divider 31 includes a first resistor R1 disposed between the detection input terminal IN and the positive input terminal P11 of the photocoupler U1, so that the positive input terminal P11 of the photocoupler U1 is not directly connected to the detection input terminal IN, but is connected to the detection input terminal IN through both ends of the first resistor R1. This limits the amount of current flowing from the detection input terminal IN, and thus can protect the internal circuit devices. The voltage division sub-circuit further comprises a second resistor R2, and two ends of the second resistor R2 are respectively connected with a positive input end P11 of the photoelectric coupler U1 and a negative input end P12 of the photoelectric coupler U1. So, first resistance R1 and second resistance R2 can play the effect of partial pressure to detecting input IN for the voltage range between positive input end P11 and negative input end P12 drops to suitable within range from the mains voltage amplitude range, helps protecting photoelectric coupler U1 and prolongs its life.

Referring to fig. 3, compared to the circuit configuration shown in fig. 2, the switch detection circuit shown in fig. 3 further includes a reverse protection sub-circuit 32, the reverse protection sub-circuit 32 respectively connects the positive input terminal P11 of the photocoupler U1 and the zero line connection terminal N0 of the electronic switch, and the reverse protection sub-circuit 32 is configured to decrease the voltage on the zero line connection terminal N0 of the electronic switch when the voltage on the zero line connection terminal N0 of the electronic switch is higher than the voltage at the positive input terminal P11 of the photocoupler U1. As an example, the reverse protection sub-circuit 32 in fig. 3 includes a clamping diode D1, the anode of the clamping diode D1 is connected to the neutral connection terminal N0 of the electronic switch, and the cathode of the clamping diode D1 is connected to the anode input terminal P11 of the photocoupler U1. Therefore, the negative half cycle of the mains supply signal from the detection input end IN is cut off under the unidirectional conduction action of the clamping diode D1, so that a light-emitting device IN the photoelectric coupler U1 cannot receive reverse current, and the phenomenon that the light-emitting device breaks down or the service life of the light-emitting device is shortened due to reverse breakdown is avoided. It will be appreciated that, since the negative half cycle of the mains signal is truncated, the voltage value at the detection output OUT when the mechanical switch to which the detection terminal S1 is connected is open (closed) will exhibit a periodic square waveform of alternating high and low voltages with the period of the fluctuations of the mains signal.

Referring to fig. 3, compared to the circuit structure shown in fig. 2, the switch detection circuit shown in fig. 3 further includes an input filter sub-circuit 33, the input filter sub-circuit 33 includes a first capacitor C1, and two ends of the first capacitor C1 are respectively connected to the positive input terminal P11 of the photocoupler U11 and the negative input terminal P12 of the photocoupler U11. Therefore, the first capacitor C1, the first resistor R1 and the second resistor R2 form a low-pass filter circuit which can filter out high-frequency signals of mains supply signals from the detection input end IN, avoid output noise generated by a switch detection circuit due to high-frequency signal noise and help to protect low-frequency devices IN the circuit.

Referring to fig. 3, compared to the circuit structure shown in fig. 2, the switch detection circuit shown in fig. 3 further includes a current limiting sub-circuit 34, where the current limiting sub-circuit 34 is disposed on a third resistor R3 between the detection output terminal OUT and the working voltage output terminal V1 of the power supply module, that is, two ends of the detection output terminal OUT further pass through the third resistor R3 and are connected to the working voltage output terminal V1 of the power supply module. Therefore, the photoelectric coupler U11 can be protected by utilizing the characteristic of the third resistor R3 for limiting the current, the voltage value of the lowest voltage at the detection output end OUT when the mechanical switch connected with the detection terminal S1 is opened (closed) can be further reduced based on the voltage division effect of the R3, and the signal distinguishability is enhanced. It should be noted that, in different examples, the third resistor R3 may be a resistor device disposed in the connection line, an equivalent resistor provided by another device or circuit structure disposed in the connection line, or a resistor structure in another unit or module in the connection line, and may at least partially combine the resistors of the connection line itself; of course, any of the above resistances may be set in a similar manner.

Referring to fig. 3, compared with the circuit structure shown in fig. 2, the switch detection circuit shown in fig. 3 further includes an output filter sub-circuit 35, where the output filter sub-circuit 35 includes a second capacitor C2, and two ends of the second capacitor C2 are respectively connected to the detection output terminal OUT and the common voltage output terminal V0 of the power supply module. In this manner, it is possible to help reduce high-frequency noise at the detection output terminal OUT.

Referring to fig. 3, in contrast to the circuit configuration shown in fig. 2, the power supply module 22 is provided in the switch detection circuit, i.e., is provided together as a part of the switch detection circuit. The power supply module 22 comprises an AC-DC converter, a positive input end of the AC-DC converter is connected to the live wire connection end L0 of the electronic switch, a negative input end of the AC-DC converter is connected to the zero line connection end N0 of the electronic switch, a positive output end of the AC-DC converter is connected to the working voltage output end V1, and a negative output end of the AC-DC converter is connected to the common voltage output end V0. In one example, the power supply module 22 and the switch detection circuit 21 are disposed together in the circuit implemented by the power supply circuit board 14, and the power supply of the weak current circuit and the signal output of the switch detection circuit by the power supply module 22 are implemented by the lead connection with the operation circuit board 12.

It should be noted that the above is only an optional embodiment of the present invention, and each implementation manner can be modified as appropriate according to the actual application requirements. For example, in any of the above circuit configurations, any one of the resistors may be implemented by a plurality of resistors having a series structure and/or a parallel structure, and any one of the capacitors may be implemented by a plurality of capacitors having a series structure and/or a parallel structure.

The above description is only an optional embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A switch detection circuit is characterized in that the switch detection circuit is applied to an electronic switch capable of being used in cooperation with at least one mechanical switch, the electronic switch comprises a power supply module and at least one detection terminal, and each detection terminal is used for being connected with a live wire outlet of one mechanical switch;

the switch detection circuit includes:

the detection input end is connected with one detection wiring terminal;

the detection output end is connected with the working voltage output end of the power supply module;

the positive pole input end of the photoelectric coupler is connected with the detection input end, the negative pole input end of the photoelectric coupler is connected with the zero line connecting end of the electronic switch, the positive pole output end of the photoelectric coupler is connected with the detection output end, and the negative pole output end of the photoelectric coupler is connected with the public voltage output end of the power supply module.

2. The switch detection circuit of claim 1, further comprising a reverse protection sub-circuit, the reverse protection sub-circuit respectively connecting the positive input terminal of the opto-coupler and the neutral connection terminal of the electronic switch, the reverse protection sub-circuit configured to reduce the voltage on the neutral connection terminal of the electronic switch when the voltage on the neutral connection terminal of the electronic switch is higher than the voltage at the positive input terminal of the opto-coupler.

3. The switch detection circuit of claim 2, wherein the reverse protection sub-circuit comprises a clamping diode, a positive electrode of the clamping diode is connected to the neutral connection terminal of the electronic switch, and a negative electrode of the clamping diode is connected to the positive input terminal of the photocoupler.

4. The switch detection circuit according to any one of claims 1 to 3, further comprising a voltage divider sub-circuit including a first resistor disposed between the detection input terminal and a positive input terminal of the photocoupler, the positive input terminal of the photocoupler being connected to the detection input terminal through both ends of the first resistor.

5. The switch detection circuit of claim 4, wherein the voltage divider sub-circuit further comprises a second resistor, and two ends of the second resistor are respectively connected to the positive input end of the photocoupler and the negative input end of the photocoupler.

6. The switch detection circuit of claim 4, further comprising an input filter sub-circuit, wherein the input filter sub-circuit comprises a first capacitor, and two ends of the first capacitor are respectively connected to the positive input end of the photocoupler and the negative input end of the photocoupler.

7. The switch detection circuit according to any one of claims 1 to 3, further comprising a current limiting sub-circuit, the current limiting sub-circuit being disposed at a third resistor between the detection output terminal and the operating voltage output terminal of the power supply module, wherein the detection output terminal is connected to the operating voltage output terminal of the power supply module via two ends of the third resistor.

8. The switch detection circuit according to any one of claims 1 to 3, further comprising an output filter sub-circuit, wherein the output filter sub-circuit comprises a second capacitor, and two ends of the second capacitor are respectively connected to the detection output end and the common voltage output end of the power supply module.

9. Switch detection circuit according to one of claims 1 to 3, characterized in that a supply module of the electronic switch is provided in the switch detection circuit,

the power supply module comprises an AC-DC converter, the positive input end of the AC-DC converter is connected with the live wire connecting end of the electronic switch, the negative input end of the AC-DC converter is connected with the zero line connecting end of the electronic switch, the positive output end of the AC-DC converter is connected with the working voltage output end, and the negative output end of the AC-DC converter is connected with the public voltage output end.

10. An electronic switch, characterized in that it comprises at least one detection terminal for connection to the live outlet of a mechanical switch and at least one switch detection circuit according to any one of claims 1 to 9, each of said detection terminals being connected to a respective one of said detection inputs of said switch detection circuit.

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