A chopping circuit for wall control switch signal coding and power-down misjudgment protection
By designing chopper circuits and isolating optocoupler signals, the problems of false judgment due to power failure and limited functionality of wall-mounted switches were solved. Multi-button encoding and anti-interference capabilities were achieved, improving the stability and functional expandability of the system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHONGSHAN TULIN ELECTRONIC TECH CO LTD
- Filing Date
- 2025-08-19
- Publication Date
- 2026-07-24
AI Technical Summary
Traditional wall-mounted switches are prone to misjudgment when power is off, have limited functionality, poor anti-interference capabilities, and cannot implement complex control logic and multi-button coding.
A chopper circuit design is adopted, using optocoupler U1 for signal isolation and controlling the conduction and cutoff of the AC terminal through a thyristor. Combined with the digital encoding display terminal, multi-digit data communication is realized. TVS diodes and varistors are added for overvoltage protection, and the chopper position and timing are optimized.
It effectively prevents false alarms during power outages, supports multi-key encoding, improves system stability and reliability, and enhances functional expandability.
Smart Images
Figure CN224555602U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of chopper circuit technology, specifically a chopper circuit for signal encoding and power failure misjudgment protection of wall-controlled switches. Background Technology
[0002] Technical Background: Traditional wall-mounted switches use mechanical contacts to directly cut off half-cycles of AC power, and determine the switch status through a zero-crossing detection circuit. This approach has two inherent drawbacks: first, residual power on the circuit board can cause false detections when power is off; second, it can only transmit a single control signal through half-cycle truncation, and cannot implement complex control logic.
[0003] Traditional wall-mounted switches use a half-cycle truncation method to detect button actions. When external power is lost, the residual charge in the circuit board's energy storage components (such as filter capacitors) allows the zero-crossing detection circuit and microcontroller to continue operating for hundreds of milliseconds to several seconds after power failure. The zero-crossing signal generated during this period is completely identical to a normal button signal, making it impossible for the system to distinguish between a genuine power failure and a human button press. This leads to misinterpretations as long / short presses, affecting the reliability of functions such as power-off memory. Traditional solutions can only achieve two states by truncating the positive / negative half-cycle, resulting in poor functional scalability.
[0004] Existing solutions: Most existing wall-mounted switches use simple zero-crossing detection circuits, controlling the switch by cutting off half of the AC signal. The zero-crossing detection signal is typically only high or low, thus limiting the available selection and making it difficult to improve the switch's reliability and flexibility.
[0005] Therefore, the main disadvantages of the existing technology are as follows: (1) False detection problem: When power is lost, the discharge of energy storage components causes a false detection window of hundreds of milliseconds; (2) Single function: It can only detect two states: on and off; (3) Low reliability: Power grid interference can easily lead to false triggering; (4) Poor scalability: Cannot support multi-key encoding. Utility Model Content
[0006] The purpose of this invention is to provide a chopper circuit for signal encoding and power failure misjudgment protection of wall-controlled switches, so as to solve the problems mentioned in the background art.
[0007] To achieve the above objectives, this utility model provides the following technical solution: a chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch, comprising an optocoupler U1, wherein the output terminal 1 of the optocoupler U1 is connected to one end of a resistor R24, the input terminal 3 of the optocoupler U1 is connected to the input terminal 1 of a TVS diode DB2, the input terminal 2 of the TVS diode DB2 is connected to one end of a resistor R26, one end of a capacitor C6, and the gate terminal 3 of a transistor Q3, the input terminal 4 of the optocoupler U1 is connected to one end of a resistor R27, the other end of a resistor R27 and the input terminal 2 of a transistor Q3 are connected to one end of a varistor VR1 and a digital encoding display terminal LAMP-L, and the input terminal 1 of a transistor Q3, the other end of a resistor R26, the other end of a capacitor C6, and the other end of a varistor VR1 are all connected to the L1 terminal.
[0008] Among them, the chopper control terminal is the input terminal of the optocoupler U1, which is controlled by the microcontroller input and uses the isolation function of the optocoupler to isolate high and low voltage.
[0009] Thyristor control: The control signal of optocoupler U1 is sent to the control pin of the thyristor to control the conduction and cutoff of the AC terminal.
[0010] Data encoding: The LAMP-L digital encoding display terminal has a 0 chopping indicator and a 1 chopping indicator. A new fixed header, such as 1010 followed by n bits of data, is added to enable communication.
[0011] Chopping position and timing: Different chopping positions will have varying degrees of impact on the circuit. Too much chopping can cause flickering in circuits such as lighting fixtures. Too little chopping may result in a blurred signal after conduction. Therefore, it is best to chop at the beginning of the AC signal, with a chopping time of approximately 2ms or less.
[0012] Preferably, the output terminal 2 of the optocoupler U1 is grounded, and the other end of the resistor R24 is connected to the TR-OUT terminal.
[0013] Preferably, the resistance of the resistor R24 is 470 ohms and the accuracy is ±5%.
[0014] Preferably, the resistance of the resistor R27 is 1000 ohms and the accuracy is ±1%.
[0015] Preferably, the maximum reverse voltage of the TVS diode DB2 is 12V.
[0016] Preferably, the resistance of the resistor R26 is 100 ohms and the accuracy is ±1%.
[0017] Preferably, the capacitor C6 has a capacitance of 4.7nF, a rated operating voltage of 1000V, and a model number of WSC0147.
[0018] Preferably, the optocoupler U1 is a TDM3052 and the transistor Q3 is a JST139C 600D.
[0019] Preferably, the diameter of the varistor VR1 is 10mm and the nominal varistor voltage is 470V.
[0020] Compared with the prior art, the beneficial effects of this utility model are: This invention achieves reliable status recognition through chopper encoding, solving the problem of misjudgment; it utilizes a combination of chopper and non-chopper to achieve multi-bit data communication; it designs an anti-interference communication protocol; it supports multi-button combination encoding; and it effectively avoids the influence of residual power, reducing the possibility of misjudgment. The introduction of the chopper circuit provides more selection options and enhances the functionality of the switch. The simple chopper communication method can achieve more functions while improving the stability and reliability of the system. Attached Figure Description
[0021] Figure 1 This is the circuit diagram of this utility model. Detailed Implementation
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.
[0023] Please see Figure 1 This utility model provides a chopper circuit for signal encoding and power failure misjudgment protection of wall-controlled switches, including an optocoupler U1. The output terminal 1 of the optocoupler U1 is connected to one end of the resistor R24. The input terminal 3 of the optocoupler U1 is connected to the terminal 1 of the TVS diode DB2. The terminal 2 of the TVS diode DB2 is connected to one end of the resistor R26, one end of the capacitor C6, and the gate terminal 3 of the transistor Q3. The input terminal 4 of the optocoupler U1 is connected to one end of the resistor R27. The other end of the resistor R27 and the terminal 2 of the transistor Q3 are connected to one end of the varistor VR1 and the digital encoding display terminal LAMP-L. The terminal 1 of the transistor Q3, the other end of the resistor R26, the other end of the capacitor C6, and the other end of the varistor VR1 are all connected to the L1 terminal.
[0024] Specifically, the chopper control terminal is the input terminal of the optocoupler U1. Control is achieved through input from a microcontroller, and the isolation function of the optocoupler is used to isolate high and low voltage.
[0025] Thyristor control: The control signal of optocoupler U1 is sent to the control pin of the thyristor to control the conduction and cutoff of the AC terminal.
[0026] Data encoding: The LAMP-L digital encoding display terminal has a 0 chopping indicator and a 1 chopping indicator. A new fixed header, such as 1010 followed by n bits of data, is added to enable communication.
[0027] Chopping position and timing: Different chopping positions will have varying degrees of impact on the circuit. Too much chopping can cause flickering in circuits such as lighting fixtures. Too little chopping may result in a blurred signal after conduction. Therefore, it is best to chop at the beginning of the AC signal, with a chopping time of approximately 2ms or less.
[0028] The output terminal 2 of optocoupler U1 is grounded, and the other end of resistor R24 is connected to the TR-OUT terminal.
[0029] Resistor R24 has a resistance of 470 ohms and an accuracy of ±5%. Resistor R27 has a resistance of 1000 ohms and an accuracy of ±1%. The maximum reverse voltage of TVS diode DB2 is 12V. Resistor R26 has a resistance of 100 ohms and an accuracy of ±1%. Capacitor C6 has a capacitance of 4.7nF, a rated operating voltage of 1000V, and is model WSC0147. Optocoupler U1 is model TDM3052, and transistor Q3 is model JST139C 600D. Varistor VR1 has a diameter of 10mm and a nominal varistor voltage of 470V.
[0030] The working principle is as follows: A control signal is input to the input terminal of the optocoupler U1 via a microcontroller. Utilizing the isolation effect of the optocoupler, the control signal is transmitted to the high-voltage side, controlling the conduction and cutoff of transistor Q3, thereby achieving chopping control of the AC circuit. The chopping status is output through the digital encoding display terminal LAMP-L; no chopping represents 0, and chopping represents 1. Data communication is achieved by setting a fixed header, such as 1010 followed by n bits of data. Chopping is performed at the start of the AC circuit, with the chopping time controlled within 2ms to ensure effective signal transmission while avoiding significant impact on the load. TVS diode DB2 and varistor VR1 provide overvoltage protection. Capacitor C6 and resistors R26 and R27, among other components, work together to ensure stable circuit operation, effectively avoiding residual current interference and reducing the occurrence of misjudgments.
[0031] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch, comprising an optocoupler U1, characterized in that, The output terminal 1 of the optocoupler U1 is connected to one end of the resistor R24. The input terminal 3 of the optocoupler U1 is connected to the input terminal 1 of the TVS diode DB2. The input terminal 2 of the TVS diode DB2 is connected to one end of the resistor R26, one end of the capacitor C6, and the gate terminal 3 of the transistor Q3. The input terminal 4 of the optocoupler U1 is connected to one end of the resistor R27. The other end of the resistor R27 and the input terminal 2 of the transistor Q3 are connected to one end of the varistor VR1 and the digital encoding display terminal LAMP-L. The input terminal 1 of the transistor Q3, the other end of the resistor R26, the other end of the capacitor C6, and the other end of the varistor VR1 are all connected to the L1 terminal.
2. The chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch according to claim 1, characterized in that: The output terminal 2 of the optocoupler U1 is grounded, and the other end of the resistor R24 is connected to the TR-OUT terminal.
3. The chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch according to claim 1, characterized in that: The resistor R24 has a resistance of 470 ohms and an accuracy of ±5%.
4. The chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch according to claim 1, characterized in that: The resistor R27 has a resistance of 1000 ohms and an accuracy of ±1%.
5. The chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch according to claim 1, characterized in that: The maximum reverse voltage of the TVS diode DB2 is 12V.
6. The chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch according to claim 1, characterized in that: The resistor R26 has a resistance of 100 ohms and an accuracy of ±1%.
7. The chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch according to claim 1, characterized in that: The capacitor C6 has a capacitance of 4.7nF, a rated operating voltage of 1000V, and a model number of WSC0147.
8. The chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch according to claim 1, characterized in that: The optocoupler U1 is model TDM3052, and the transistor Q3 is model JST139C 600D.
9. The chopper circuit for signal encoding and power failure misjudgment protection of a wall-controlled switch according to claim 1, characterized in that: The varistor VR1 has a diameter of 10mm and a nominal varistor voltage of 470V.