A dimmer control method compatible with leakage protection circuit

Abstract

The present invention discloses a dimmer control method compatible with a leakage protection circuit. The method involves integrating a leakage protection circuit, which detects the falling edge of voltage or current at the zero-crossing point of a sine wave, into the dimmer's control loop for the dimmer's dimmable circuit. Furthermore, a processing module is added to the dimmer, which performs the following operations: setting the dimmer's operating mode to a leading-edge mode; setting the conduction angle of the dimmer's switch to 2 to 4 ms and operating for 3 to 10 cycles; setting the dimmer's operating mode to a trailing-edge mode; and detecting whether current is flowing through the dimmer's switch. By adding corresponding logic judgment processing to the dimmer, the present invention ensures normal startup of the lamp when the leakage protection circuit is integrated into the dimmer's circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of dimmers, and in particular to a dimmer control method compatible with a leakage protection circuit. Background Art

[0002] As we all know, dimmers achieve the purpose of dimming by changing the conduction time, or conduction angle, of the switching tube. The main operating modes of dimmers can be divided into two types: leading-cut control and trailing-cut control. Leading-cut dimmers mean that when the AC sine wave passes through zero in one cycle, the switching tube in the dimmer is in the off state, and is turned on after a period of time, and is turned off until the next zero crossing. Conversely, trailing-cut dimmers mean that when the sine wave passes through zero in one cycle, the switching tube in the dimmer is in the on state, and is turned off after a period of time, and is turned on again until the next zero crossing.

[0003] Since the lamp is powered by two ends, when one end is connected to the live wire first, the other end will be charged. If touched by a human body, there will be a risk of electric shock. Therefore, it is necessary to add a leakage protection circuit to the circuit. That is, when a human body touches the live lamp, the circuit in contact with the human body is disconnected. The principle of leakage protection is to detect whether the voltage or current in the circuit during the rising or falling edge of the zero-crossing point within one cycle of the sine wave is within the normal operating range. If it is abnormal, the output is disconnected.

[0004] The leakage protection circuit in the existing technology usually detects on the rising edge of the sine wave's zero crossing point, or on the falling edge of the sine wave's zero crossing point, and the dimmer operates in the leading or trailing cutting mode. Therefore, when the dimmer is connected to a circuit with leakage protection, the leakage protection circuit will detect abnormal voltage or current operation and shut down the output, causing the lamp to fail to start normally. Summary of the Invention

[0005] The purpose of the present invention is to overcome the shortcomings of the existing technology and provide a dimmer control method compatible with a leakage protection circuit. By adding corresponding logical judgment processing in the dimmer, the normal startup of the lamp tube can be guaranteed when the leakage protection circuit is connected to the dimmer circuit.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a dimmer control method compatible with a leakage protection circuit, wherein a leakage protection circuit that detects the falling edge of the voltage or current at the zero-crossing point of the sine wave is connected to the circuit of the dimmer that controls the dimmable circuit, and a processing module is added to the dimmer, which performs the following processing:

[0007] A. Set the dimmer's working mode to front-cut mode;

[0008] B. Set the conduction angle of the switch in the dimmer to 2-4ms and operate for 3-10 cycles;

[0009] C. Set the dimmer's operating mode to post-cut mode;

[0010] D. Detect whether current is flowing through the switch tube in the dimmer. If the detection result is that current is flowing through the switch tube, return to step C. If the detection result is that current is not flowing through the switch tube, return to step A.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] The present invention connects a leakage protection circuit that detects the falling edge of the voltage or current at the zero-crossing point of the sine wave into a loop of a dimmer that controls a dimmable circuit, and adds a processing module to the dimmer. This ensures that the normal startup of the lamp tube can be guaranteed when the leakage protection circuit is connected to the circuit controlled by the dimmer.

[0013] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments; however, the dimmer control method compatible with a leakage protection circuit of the present invention is not limited to the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a circuit principle block diagram of an embodiment of the present invention;

[0015] Figure 2 FIG. 4 is a flowchart of a processing module of a dimmer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0016] Example

[0017] See also Figure 1 、 Figure 2 As shown, a dimmer control method compatible with a leakage protection circuit of the present invention is to connect a leakage protection circuit 2 that detects the falling edge of the voltage or current at the zero-crossing point of the sine wave to the circuit of the dimmer 1 that controls the dimmable circuit 3, and add a processing module in the dimmer 1, which performs the following processing:

[0018] Step A. Set the working mode of the dimmer 1 to the front-cut mode; Figure 2 As shown in the box 101;

[0019] Step B. Set the conduction angle of the switch tube in dimmer 1 to 2 to 4 ms and operate for 3 to 10 cycles;

[0020] Step C. Setting the working mode of the dimmer 1 to the post-cut mode;

[0021] Step D: Detect whether current flows through the switch tube in the dimmer 1. When the detection result is that current flows through the switch tube, return to step C; when the detection result is that current does not flow through the switch tube, return to step A.

[0022] The present invention designs the detection method of the leakage protection circuit 2 to be performed on the falling edge of the zero-crossing point of the sine wave, so the dimmer 1 is first operated in the leading cutting mode; because the power supply design of the lamp tube adopts an open source power supply design, if it operates in the leading cutting mode, the impact of the dimmer switch tube will be relatively large, so the dimmer 1 operates in the leading cutting mode at a smaller conduction angle (2 to 4ms) for 3 to 10 cycles and then switches to the trailing cutting working mode, which can be more compatible with the lamp tube; when the dimmer 1 operates in the trailing cutting mode, there is a phenomenon that the low end cannot turn on the lamp tube. At this time, it can be judged whether the lamp tube is started normally by judging whether there is current in the main circuit, that is, flowing through the switch tube. If it is abnormal, the above steps A, B and C are repeated when the lamp tube is dimmed until the lamp tube is started; this method of the present invention can solve the problem of the lamp tube not being able to start.

[0023] The present invention provides a dimmer control method compatible with a leakage protection circuit. By connecting a leakage protection circuit that detects the falling edge of the voltage or current at the zero-crossing point of a sine wave to a loop used by a dimmer to control a dimmable circuit, and adding a processing module to the dimmer, the method ensures that the lamp starts normally when the leakage protection circuit is connected to the circuit controlled by the dimmer.

[0024] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, use the technical content disclosed above to make many possible changes and modifications to the technical solution of the present invention, or modify it into an equivalent equivalent embodiment. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention should fall within the scope of protection of the technical solution of the present invention.

Claims

1. A dimmer control method compatible with a leakage protection circuit, characterized by: The leakage protection circuit that detects the falling edge of the voltage or current at the zero-crossing point of the sine wave is connected to the circuit of the dimmer that controls the dimmable circuit, and a processing module is added to the dimmer. The processing module performs the following processing: A. Set the dimmer's working mode to front-cut mode; B. Set the conduction angle of the switch in the dimmer to 2-4ms and operate for 3-10 cycles; C. Set the dimmer's operating mode to post-cut mode; D. Detect whether current is flowing through the switch tube in the dimmer. If the detection result is that current is flowing through the switch tube, return to step C. If the detection result is that current is not flowing through the switch tube, return to step A.

Images