A universal switching value detection circuit

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By designing a rectifier filter circuit, optocoupler U1, constant current source circuit, and switching switch S1, the problem of poor versatility of existing switch quantity detection circuits is solved, enabling compatibility detection of a wide range of AC and DC signals, reducing costs, and improving the stability and flexibility of the circuit.

CN224500798UActive Publication Date: 2026-07-14JIANGSU HIMARK TECH

Patent Information

Authority / Receiving Office: CN · China
Patent Type: Utility models(China)
Current Assignee / Owner: JIANGSU HIMARK TECH
Filing Date: 2025-07-17
Publication Date: 2026-07-14

AI Technical Summary

Technical Problem

Existing switch quantity detection circuits have poor versatility, narrow potential range, and complex AC signal detection, making them unable to be processed directly.

Method used

The design incorporates a rectifier and filter circuit, optocoupler U1, constant current source circuit, switching switch S1, and auxiliary power supply to achieve constant current source technology and mode switching, while being compatible with AC/DC switching quantity detection.

Benefits of technology

It achieves universal detection of a wide range of AC and DC switching quantities, with low cost, strong compatibility, and high stability. It avoids optocoupler damage caused by voltage fluctuations and improves the reliability and flexibility of the circuit.

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Abstract

The utility model discloses a switch quantity detection technical field's a kind of general switch quantity detection circuit, comprising: rectifier filter circuit: input end is connected with switch quantity access point A1, A2, output end is connected with photoelectric coupler U1 input end;Photoelectric coupler U1: input end is connected in rectifier filter circuit output end, output end is connected with signal output end Kin;Constant current source circuit: is connected with photoelectric coupler U1 input end;Switching switch S1: set between switch quantity access point A2 and rectifier filter circuit input end;Auxiliary power supply: is connected with constant current source circuit and switching switch S1, to constant current source circuit and switch quantity access point A2 power supply;Signal output end Kin: is connected with rear stage signal processing unit.This detection circuit passes through constant current source design and mode switching function, has realized the general detection of wide-range ac and dc switch quantity, with the advantages of low cost, strong compatibility, high stability.

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Description

Technical Field

[0001] This utility model relates to the field of switch quantity detection technology, and in particular to a general switch quantity detection circuit. Background Technology

[0002] With the continuous development of electronic technology and the increasing level of intelligence, the requirements for industrial monitoring systems such as power are becoming higher and higher. Real-time detection of the operating status of various devices has become an important part of modern industry, and the operating status of these devices can be reflected through switch status.

[0003] Currently, the main types of switching signals include no-node signals, potential signals, and switching signals from NPN transistors (or NMOS transistors).

[0004] Most commonly used methods for detecting switch signals employ optocoupler isolation, requiring different circuits for different types of switch signals, resulting in poor circuit versatility and compatibility. For AC signal detection, direct detection is not possible; an external rectifier circuit is needed. Furthermore, no-node signals and potential signals cannot be used interchangeably, leading to a narrow potential range. Utility Model Content

[0005] This application provides a universal switching quantity detection circuit, which solves the problems of poor versatility, narrow potential range, and complex AC signal detection in the prior art.

[0006] This application provides a general-purpose switch quantity detection circuit, including: a rectifier filter circuit, an optocoupler U1, a constant current source circuit, a switching switch S1, an auxiliary power supply, and a signal output terminal Kin;

[0007] The input terminal of the rectifier filter circuit is connected to the switch input points A1 and A2, and the output terminal is connected to the input terminal of the optocoupler U1.

[0008] The input terminal of the optocoupler U1 is connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the signal output terminal Kin.

[0009] The constant current source circuit is connected to the input terminal of the optocoupler U1 to maintain a constant current.

[0010] The switching switch S1 is located between the switch input point A2 and the input terminal of the rectifier filter circuit, and is used to switch the detection mode;

[0011] The auxiliary power supply is connected to the constant current source circuit and the switching switch S1 to supply power to the constant current source circuit and the switch input point A2;

[0012] The signal output terminal Kin is connected to the subsequent signal processing unit.

[0013] The beneficial effects of the above embodiments are as follows: the detection circuit, through constant current source design and mode switching function, realizes universal detection of AC and DC switching quantities over a wide range, and has the advantages of low cost, strong compatibility and high stability.

[0014] Based on the above embodiments, this application can be further improved as follows:

[0015] In one embodiment of this application, the rectifier-filter circuit includes rectifier diodes D1-D4 and filter capacitor C1. The rectifier diodes D1-D4 form a bridge rectifier structure, and the filter capacitor C1 is connected in parallel to the output terminal of the rectifier diodes.

[0016] In one embodiment of this application, the constant current source circuit includes resistors R1 and R2, transistors Q1 and Q2, and diode D5, wherein resistor R2 is used to adjust the constant current value, and diode D5 is used to protect the constant current source.

[0017] In one embodiment of this application, pin 1 of the optocoupler U1 is connected to the output terminal of the rectifier filter circuit, pin 2 is connected to the constant current source circuit, pin 3 is grounded, and pin 4 is connected to the signal output terminal Kin.

[0018] In one embodiment of this application, the switching switch S1 is a toggle switch, which switches to the potential signal detection mode when switched to the upper end and to the empty node signal detection mode when switched to the lower end.

[0019] In one embodiment of this application, the general-purpose switch quantity detection circuit further includes a status indication circuit, which is connected to the output terminal of the optocoupler U1 and is used to indicate the on / off state of the switch quantity signal.

[0020] In one embodiment of this application, the status indication circuit includes a light-emitting diode L1 and a current-limiting resistor R3. The light-emitting diode L1 and the current-limiting resistor R3 are connected in series and then connected to the output terminal of the optocoupler U1.

[0021] One or more technical solutions provided in the embodiments of this application have at least the following technical effects or advantages:

[0022] 1. Wide range of versatility: Constant current source technology ensures a constant optocoupler conduction current, making it compatible with a wide range of AC and DC potential signals and no-node signals, avoiding optocoupler failure or damage due to voltage fluctuations;

[0023] 2. AC / DC compatibility: The rectifier and filter circuit can directly process AC or DC input signals without the need for an additional rectifier circuit;

[0024] 3. Flexible mode switching: The potential signal and no-node signal detection modes can be quickly switched via the toggle switch S1, improving circuit compatibility;

[0025] 4. Low cost and high reliability: The circuit structure is simple, the core components are general electronic devices, and the constant current source design improves the stability of long-term operation. Attached Figure Description

[0026] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0027] Figure 1 This is a circuit diagram of a general-purpose switch quantity detection circuit in an embodiment of this application;

[0028] Figure 2 This is a circuit diagram of the potential signal detection mode in an embodiment of this application;

[0029] Figure 3 This is a circuit diagram of the empty node signal detection mode in the embodiments of this application. Detailed Implementation

[0030] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are only for illustrating the present invention and not for limiting the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0031] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0032] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0033] In the description of this utility model, the illustrative expressions of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate different embodiments or examples described in this utility model, as well as the features of different embodiments or examples.

[0034] This application provides a universal switching quantity detection circuit, which solves the problems of poor versatility, narrow potential range, and complex AC signal detection in the prior art.

[0035] The technical solution in this application is to solve the above problems, and the overall approach is as follows:

[0036] Example:

[0037] like Figure 1 As shown, a general-purpose switch quantity detection circuit includes: a rectifier and filter circuit, an optocoupler U1, a constant current source circuit, a switch S1, an auxiliary power supply, a signal output terminal Kin, and a status indicator circuit. The specific connections are as follows:

[0038] The rectifier and filter circuit consists of rectifier diodes D1-D4 and filter capacitor C1. Its input terminal is connected to the switch input points A1 and A2 (no polarity requirement) to convert AC or DC input signals into a stable DC voltage. Its output terminal is connected to the input terminal of optocoupler U1.

[0039] Optocoupler U1: Its input terminal is connected to the output terminal of the rectifier and filter circuit, and its output terminal is connected to the status indicator circuit and the signal output terminal Kin respectively, in order to achieve electrical isolation between the input and output;

[0040] The constant current source circuit consists of resistors R1 and R2, transistors Q1 and Q2, and diode D5. Its input terminal is connected to the input terminal of optocoupler U1 to maintain a constant current and ensure that the conduction current of optocoupler U1 is not affected by input voltage fluctuations. R1 provides base current to Q2, so that Q2 operates in saturation. R2 is used to regulate the current, and diode D5 is used to protect the constant current source.

[0041] Switch S1: This is a toggle switch for switching between potential and no-node inputs. Its moving contact is connected to the switch input point A2. The upper stationary contact of the switch is connected to the input terminal of the rectifier filter circuit, and the lower stationary contact is connected to the positive terminal of the auxiliary power supply through the protection diode D6. Diode D6 protects the auxiliary power supply from the influence of external switch potential. Switch S1 is a toggle switch, with the upper end corresponding to the potential signal detection mode and the lower end corresponding to the no-node signal detection mode.

[0042] Auxiliary power supply, V+ and V- are the positive and negative terminals of the internal auxiliary power supply, used to provide stable power to the constant current source circuit, and also used to supply power to the switch input point A2 when the switch is switched to the empty node signal detection mode.

[0043] Signal output terminal Kin: Connected to the output terminal of optocoupler U1 and connected to the subsequent signal processing unit such as CPU or CPLD, to output switch status signals;

[0044] Status indication circuit: It consists of LED L1 and current limiting resistor R3 connected in series and in parallel to the output terminal of optocoupler U1, and is used to visually indicate the on / off status of switch signal.

[0045] In this circuit, rectifier diodes D1-D4 form a bridge rectifier structure, filter capacitor C1 is connected in parallel to the output of the bridge rectifier structure, the output of the rectifier and filter circuit is connected to pin 1 of optocoupler U1, pin 2 of optocoupler U1 is connected to the collector of transistor Q2, pin 3 is grounded, and pin 4 is connected to the signal output terminal Kin. The base of transistor Q2 is connected to the positive terminal of the auxiliary power supply through resistor R1, the emitter of transistor Q2 is connected to the negative terminal of the auxiliary power supply through resistor R2 and diode D5, the collector of transistor Q1 is connected to the base of transistor Q2, the base of transistor Q1 is connected to the emitter of transistor Q2, and the emitter of transistor Q1 is connected to the negative terminal of the auxiliary power supply.

[0046] When a switching signal is input, pins 1 and 2 of the optocoupler U1 are turned on. The conduction current is determined by the constant current source circuit (the voltage from the upper end of R2 to the lower end of D5 is always constant, and the current flowing through R2 is also constant, adjusted by the resistance value of R2 to ensure the optocoupler is in a reliable working state and will not burn out due to excessively high external potential), and is not affected by the magnitude of the external switching signal potential. After pins 1 and 2 of the optocoupler are turned on, pins 3 and 4 of the output are immediately turned on, and Kin changes from a high level to a low level. When no external switching signal is input, the optocoupler is not turned on, and Kin is at a high level. That is, as long as there is a change in the switching input, Kin will change accordingly.

[0047] The specific working principle of this utility model is as follows:

[0048] (1) Potential signal detection mode: When S1 is switched to the upper position, AC / DC potential measurement is performed. The equivalent circuit is as follows. Figure 2 As shown:

[0049] Regardless of whether DC or AC is connected to terminals A1 and A2, the voltage applied to pin 1 of optocoupler U1 is always a DC positive voltage. As long as the peak-to-peak value of the voltage signal applied to A1 and A2 is greater than 3V, the optocoupler can reliably conduct, L1 lights up, and the state of Kin changes from high to low. The subsequent signal processing unit, such as the CPU, receives the action information and processes it. When there is no signal input to A1 and A2, the optocoupler is cut off, L1 is off, and Kin is at a high level.

[0050] (2) No-node signal detection mode: When S1 is switched to the lower position, no-node signal detection is performed, and the circuit is as follows: Figure 3 As shown:

[0051] When there are node signals on A1 and A2, the auxiliary power supply V+ is applied to pin 1 of optocoupler U1 through an external node, the optocoupler is turned on, L1 is lit, and the state of Kin changes from high to low. The subsequent signal processing unit such as the CPU receives the action information and processes it. When there are no node signals on A1 and A2, the optocoupler is turned off, L1 is off, and Kin is high.

[0052] If the switching signal is output by an NPN transistor (or NMOS), the auxiliary power supply V+ can still provide the power conditions for the transistor (NMOS) to conduct.

[0053] Thanks to the use of constant current source technology, the conduction current flowing through pins 1 and 2 of the optocoupler remains constant regardless of changes in external potential voltage. This prevents the optocoupler from failing to conduct completely due to low voltage or from being damaged due to high voltage, thus improving versatility and compatibility, and effectively ensuring the reliability and stability of the circuit.

[0054] This circuit can reliably detect any changes in the external switching signal.

[0055] The technical solutions described in the embodiments of this application, through constant current source design and mode switching function, achieve universal detection of a wide range of AC and DC switching quantities, and have the advantages of low cost, strong compatibility, and high stability, as detailed below:

[0056] 1. Wide range of versatility: Constant current source technology ensures a constant optocoupler conduction current, making it compatible with a wide range of AC and DC potential signals and no-node signals, avoiding optocoupler failure or damage due to voltage fluctuations;

[0057] 2. AC / DC compatibility: The rectifier and filter circuit can directly process AC or DC input signals without the need for an additional rectifier circuit;

[0058] 3. Flexible mode switching: The potential signal and no-node signal detection modes can be quickly switched via the toggle switch S1, improving circuit compatibility;

[0059] 4. Low cost and high reliability: The circuit structure is simple, the core components are general electronic devices, and the constant current source design improves the stability of long-term operation.

Claims

1. A general-purpose switching quantity detection circuit, characterized in that, include: Rectifier and filter circuit, optocoupler U1, constant current source circuit, switch S1, auxiliary power supply, signal output terminal Kin; The input terminal of the rectifier filter circuit is connected to the switch input points A1 and A2, and the output terminal is connected to the input terminal of the optocoupler U1. The input terminal of the optocoupler U1 is connected to the output terminal of the rectifier and filter circuit, and the output terminal is connected to the signal output terminal Kin. The constant current source circuit is connected to the input terminal of the optocoupler U1 to maintain a constant current. The switching switch S1 is located between the switch input point A2 and the input terminal of the rectifier filter circuit, and is used to switch the detection mode; The auxiliary power supply is connected to the constant current source circuit and the switching switch S1 to supply power to the constant current source circuit and the switch input point A2; The signal output terminal Kin is connected to the subsequent signal processing unit.

2. The general-purpose switching quantity detection circuit according to claim 1, characterized in that: The rectifier and filter circuit includes rectifier diodes D1-D4 and filter capacitor C1. The rectifier diodes D1-D4 form a bridge rectifier structure, and the filter capacitor C1 is connected in parallel to the output terminal of the rectifier diodes.

3. The general-purpose switching quantity detection circuit according to claim 1, characterized in that: The constant current source circuit includes resistors R1 and R2, transistors Q1 and Q2, and diode D5. Resistor R1 provides base current to transistor Q2, and resistor R2 is used to adjust the constant current value.

4. The general-purpose switch quantity detection circuit according to claim 1, characterized in that: Pin 1 of the optocoupler U1 is connected to the output terminal of the rectifier filter circuit, pin 2 is connected to the constant current source circuit, pin 3 is grounded, and pin 4 is connected to the signal output terminal Kin.

5. The general-purpose switching quantity detection circuit according to claim 1, characterized in that: The switching switch S1 is a toggle switch. When it is switched to the upper end, it switches to the potential signal detection mode, and when it is switched to the lower end, it switches to the empty node signal detection mode.

6. The general-purpose switch quantity detection circuit according to claim 1, characterized in that: It also includes a status indicator circuit, which is connected to the output terminal of the optocoupler U1 and is used to indicate the on / off status of the switch signal.

7. The general-purpose switch quantity detection circuit according to claim 6, characterized in that: The status indication circuit includes a light-emitting diode L1 and a current-limiting resistor R3. The light-emitting diode L1 and the current-limiting resistor R3 are connected in series and then connected to the output terminal of the optocoupler U1.