Phase cut dimming phase detection circuit

Abstract

The utility model relates to the technical field of circuit structures, and particularly discloses a phase cut dimming phase detection circuit. Comprising a rectifier bridge which is provided with four pins. A third pin of the rectifier bridge is connected with a power supply live wire, and a first node and a second node are arranged between the third pin of the rectifier bridge and the power supply live wire; a fourth pin of the rectifier bridge is connected with a zero line end of the power supply; a first node is arranged between the fourth pin of the rectifier bridge and the zero line end of the power supply; the phase cut dimming phase detection circuit comprises a first diode and a second diode. The positive electrode of the first diode is connected with a first node I, and the positive electrode of the second diode is connected with a first node II; the phase cut dimming phase detection circuit is simple in structure, low in cost, reliable in performance, high in compatibility and high in practicability.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit structures, and particularly relates to a phase detection circuit for phase-cut dimming. Background Art

[0002] In a current phase detection circuit for phase-cut dimming, when the voltage value is the same, in the case of the analog detection method at the same phase-cut angle, when the frequency is 50HZ or 60HZ, the detected voltage value will be different; when the AC voltage frequency is the same, in the case of the analog detection method at the same phase-cut angle, when the voltage is 0AC or 220AC, the detected voltage value will be different; as a result, it cannot better be compatible with the frequencies and voltage values of AC voltages in different regions, and the circuit components are complex, and the response speed lags behind during fast phase-cutting. Summary of the Invention

[0003] The utility model provides a phase detection circuit for phase-cut dimming with a simple structure, low cost, reliable performance, high compatibility, and strong practicability.

[0004] The technical solution adopted by the utility model is as follows: a phase detection circuit for phase-cut dimming includes a rectifier bridge, and the rectifier bridge is provided with four pins; the third pin of the rectifier bridge is connected to the live wire of the power supply, and a first two-node is provided between the third pin of the rectifier bridge and the live wire of the power supply; the fourth pin of the rectifier bridge is connected to the neutral wire end of the power supply; and a first one-node is provided between the fourth pin of the rectifier bridge and the neutral wire end of the power supply;

[0005] The phase detection circuit for phase-cut dimming includes a first diode and a second diode; the positive electrode of the first diode is connected to the first one-node, and the positive electrode of the second diode is connected to the first two-node;

[0006] The phase detection circuit for phase-cut dimming is provided with a first resistor branch, a second resistor branch, and a third resistor branch; one end of the first resistor branch is provided with a first three-node, and the other end is provided with a first four-node; and a first five-node is provided between the first three-node and the first four-node; the first three-node is respectively connected to the negative electrodes of the first diode and the second diode; the first four-node is grounded and is connected to the second pin of the rectifier bridge;

[0007] One end of the second resistor branch is connected to the VCC terminal, and the other end is grounded, and the grounded end is connected to the first four-node; the second resistor branch includes a second resistor, a fifth resistor, and a triode connected in series in sequence; a first six-node is provided between the second resistor and the fifth resistor, the fifth resistor is connected to the collector of the triode, and a first seven-node is provided therebetween; the emitter of the triode is grounded, and the base is connected to the first five-node;

[0008] The phase detection circuit for phase-cut dimming includes an optocoupler. The optocoupler has four pins. Its first pin is connected to the first six-node, the second pin of the optocoupler is connected to the first seven-node, and the third pin of the optocoupler is grounded; the fourth pin of the optocoupler U1 is connected to the MCU_CHECK_IO terminal, and there is a first eight-node between them.

[0009] One end of the third resistor branch is connected to the MCU_VCC terminal, and the other end is connected to the first eight-node.

[0010] Furthermore, the first resistor branch includes a first resistor, a fourth resistor, and a sixth resistor connected in series in sequence; one end of the first resistor is connected to the first three-node, and the other end is connected to the fourth resistor; the first five-node is located between the fourth resistor and the sixth resistor, and one end of the sixth resistor is connected to the first four-node.

[0011] Furthermore, the first pin of the optocoupler is the anodic terminal, the second pin is the cathodic terminal, the third pin is the emitter, and the fourth pin is the collector.

[0012] Furthermore, the third resistor branch includes a third resistor.

[0013] Furthermore, the resistance values of the first resistor and the fourth resistor are 220K; the resistance value of the sixth resistor is 22K.

[0014] In the circuit structure of the phase detection circuit for phase-cut dimming of the present utility model, the peripheral circuit is simple, the cost is low, the performance is reliable, it is highly compatible with leading-edge phase-cut and trailing-edge phase-cut, and it can accurately detect the phase-cut signal in power grids with different frequencies and different voltages, and there is no lag in the phase-cut signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It shows a schematic circuit diagram of a phase detection circuit for phase-cut dimming of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] As Figure 1 shown, it is a schematic circuit diagram of a phase detection circuit for phase-cut dimming of the present utility model; the phase detection circuit for phase-cut dimming of the present utility model includes a rectifier bridge DB. The rectifier bridge DB has four pins; the third pin of the rectifier bridge DB is connected to the power supply live wire L, and there is a first two-node 12 between the third pin of the rectifier bridge DB and the power supply live wire L; the fourth pin of the rectifier bridge DB is connected to the power supply neutral line terminal N; and there is a first one-node 11 between the fourth pin of the rectifier bridge DB and the power supply neutral line terminal N. Exemplarily, in the present utility model, the model of the rectifier bridge DB is MB10S.

[0017] The phase detection circuit for phase-cut dimming includes a first diode D1 and a second diode D2; the positive electrode of the first diode D1 is connected to the first node 11, and the positive electrode of the second diode D2 is connected to the second node 12;

[0018] The phase detection circuit for phase-cut dimming is provided with a first resistor branch, a second resistor branch, and a third resistor branch; one end of the first resistor branch is provided with a third node 13, and the other end is provided with a fourth node 14; and a fifth node 15 is provided between the third node 13 and the fourth node 14; the third node 13 is respectively connected to the negative electrodes of the first diode D1 and the second diode D2; the fourth node 14 is grounded and is connected to the second pin of the rectifier bridge DB;

[0019] One end of the second resistor branch is connected to the VCC terminal, and the other end is grounded, and the grounded end is connected to the fourth node 14; the second resistor branch includes a second resistor R2, a fifth resistor R5, and a triode Q1 connected in series in sequence; a sixteenth node 16 is provided between the second resistor R2 and the fifth resistor R5, the fifth resistor R5 is connected to the collector of the triode Q1, and a seventeenth node 17 is provided therebetween; the emitter of the triode Q1 is grounded, and the base is connected to the fifth node 15;

[0020] The phase detection circuit for phase-cut dimming includes an optocoupler U1. The optocoupler U1 includes four pins. Its first pin is connected to the sixteenth node 16, the second pin of the optocoupler U1 is connected to the seventeenth node 17, and the third pin of the optocoupler U1 is grounded; the fourth pin of the optocoupler U1 is connected to the MCU_CHECK_IO terminal, and an eighteenth node 18 is provided therebetween; wherein, the first pin of the optocoupler U1 is the anode terminal, the second pin is the cathode terminal, the third pin is the emitter, and the fourth pin is the collector; Exemplarily, in the present invention, the model of the optocoupler U1 is PC817.

[0021] One end of the third resistor branch is connected to the MCU_VCC terminal, and the other end is connected to the eighteenth node 18. Exemplarily, the third resistor branch includes a third resistor R3.

[0022] As a preferred implementation, in the present invention, the first resistor branch includes a first resistor R1, a fourth resistor R4, and a sixth resistor R6 connected in series in sequence; one end of the first resistor R1 is connected to the third node 13, and the other end is connected to the fourth resistor R4; the fifth node 15 is located between the fourth resistor R4 and the sixth resistor R6, and one end of the sixth resistor R6 is connected to the fourth node 14.

[0023] Therefore, in the present utility model, L and N are the AC voltages of the mains power supply. After the L and N pass through the diodes D1 and D2 and output a steamed bun wave, and are divided by the resistors R1, R4, and R6, a small voltage steamed bun wave is formed at the bases of R4, R6, and Q1, causing Q1 to be in the on and off states, and causing U1 to be in the switching state. Thus, a pulsed square wave is output from the 4th pin of U1.

[0024] The 4th pin of U1 is connected to MCU_CHECK_IO. The MCU obtains the phase-cutting angle by detecting the high-level time and low-level time of this IO. This detection method does not have the disadvantages of analog detection. For example, in mains power supplies of different frequencies such as 50HZ or 60HZ, there will be errors in analog detection; also, when the mains power is 120AC or 220AC, there will be errors in analog detection; analog detection also has a lag. However, if the above method is used for detection, these problems will not exist.

[0025] As a preferred embodiment, the resistance values of the first resistor R1 and the fourth resistor R4 are 220K; the resistance value of the sixth resistor R6 is 22K; the resistance value of the second resistor R2 is 3K, the resistance value of the fifth resistor R5 is 2K, and the resistance value of the third resistor R3 is 10K. Exemplarily, the model of the triode Q1 is 2N3904.

[0026] The above are only the preferred embodiments of the present utility model and are not used to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A phase detection circuit for phase-cut dimming, characterized in that, The phase detection circuit for phase-cut dimming includes a rectifier bridge (DB), and the rectifier bridge (DB) has four pins; the third pin of the rectifier bridge (DB) is connected to the live wire L of the power supply, and a first two-node (12) is provided between the third pin of the rectifier bridge (DB) and the live wire L of the power supply; the fourth pin of the rectifier bridge (DB) is connected to the neutral wire end N of the power supply; and a first one-node (11) is provided between the fourth pin of the rectifier bridge (DB) and the neutral wire end N of the power supply. The phase detection circuit for phase-cut dimming includes a first diode (D1) and a second diode (D2); the positive electrode of the first diode (D1) is connected to the first one-node (11), and the positive electrode of the second diode (D2) is connected to the first two-node (12). The phase detection circuit for phase-cut dimming is provided with a first resistor branch, a second resistor branch, and a third resistor branch; one end of the first resistor branch is provided with a first three-node (13), and the other end is provided with a first four-node (14); and a first five-node (15) is provided between the first three-node (13) and the first four-node (14); the first three-node (13) is respectively connected to the negative electrodes of the first diode (D1) and the second diode (D2); the first four-node (14) is grounded and is connected to the second pin of the rectifier bridge (DB). One end of the second resistor branch is connected to the VCC terminal, and the other end is grounded, and the grounded end is connected to the first four-node (14); the second resistor branch includes a second resistor (R2), a fifth resistor (R5), and a triode (Q1) connected in series in sequence; a first six-node (16) is provided between the second resistor (R2) and the fifth resistor (R5), the fifth resistor (R5) is connected to the collector of the triode (Q1), and a first seven-node (17) is provided therebetween; the emitter of the triode (Q1) is grounded, and the base is connected to the first five-node (15). The phase detection circuit for phase-cut dimming includes an optocoupler (U1), and the optocoupler (U1) includes four pins, its first pin is connected to the first six-node (16), the second pin of the optocoupler (U1) is connected to the first seven-node (17), the third pin of the optocoupler (U1) is grounded; the fourth pin of the optocoupler (U1) is connected to the MCU_CHECK_IO terminal, and a first eight-node (18) is provided therebetween. One end of the third resistor branch is connected to the MCU_VCC terminal, and the other end is connected to the first eight-node (18).

2. The phase detection circuit for phase-cut dimming according to claim 1, wherein The first resistor branch includes a first resistor (R1), a fourth resistor (R4), and a sixth resistor (R6) connected in series in sequence; one end of the first resistor (R1) is connected to the first three-node (13), and the other end is connected to the fourth resistor (R4); the first five-node (15) is located between the fourth resistor (R4) and the sixth resistor (R6), and one end of the sixth resistor (R6) is connected to the first four-node (14).

3. The phase detection circuit for phase-cut dimming according to claim 1, wherein The first pin of the optocoupler (U1) is the anode terminal, the second pin is the cathode terminal, the third pin is the emitter, and the fourth pin is the collector.

4. The phase detection circuit for phase-cut dimming according to claim 1, wherein The third resistor branch includes a third resistor (R3).

5. The phase detection circuit for phase-cut dimming according to claim 2, wherein The resistance values of the first resistor (R1) and the fourth resistor (R4) are 220K; the resistance value of the sixth resistor (R6) is 22K.

Images