High-power-factor wireless multi-path stroboflash-free dimming circuit

Abstract

The utility model relates to a high-power-factor wireless multi-path stroboflash-free dimming circuit. The high-power-factor positive DC / DC dimming circuit adopts an isolation type design, comprises an anti-interference rectifying circuit, a high-power-factor positive DC / DC voltage stabilizing circuit, a DC / DC dimming circuit and an MCU (Microprogrammed Control Unit) control unit, and is characterized in that the anti-interference rectifying circuit is connected with the high-power-factor positive DC / DC voltage stabilizing circuit and is used for converting an input alternating-current voltage into a double-frequency direct-current pulsating voltage; the DC / DC dimming circuit is connected with the MCU control unit, the DC / DC dimming circuit converts stable DC voltage into a high-frequency stable current source to supply power to an LED, the LED current is controlled to change between a minimum set current value and a maximum set current value according to the magnitude of a PWM signal or an analog voltage signal, and the magnitude of the current of the circuit is determined by a control signal provided by the MCU control unit. According to the utility model, the voltage and current ripples are effectively reduced, the light stroboflash is reduced, the stability is high, the control is flexible, and the interference is small.

Description

Technical Field

[0001] The utility model relates to the field of driving and wireless intelligent control of LED lamps, in particular to a high power factor wireless multi-channel non-stroboscopic dimming circuit. Background Art

[0002] With the improvement of wireless technology and the development of strategic emerging industries, as well as the rapid rise of smart homes and the Internet of Things, applications such as home lighting, industrial lighting, automotive lighting, and medical lighting are increasingly tending towards intelligent control and high light efficiency conversion. Traditional lighting drivers have high standby power consumption, unstable dimming characteristics and wireless control performance, light flicker, and poor reliability. The surge current input at the moment the switch is powered on is too large, which can easily damage the switch and affect the AC power grid. When multiple lamps are turned on at low dimming brightness, the brightness is uneven, and there is flickering when the lamps are turned on and off quickly. Utility Model Content

[0003] In view of the above problems existing in the prior art, the utility model aims to provide a high power factor wireless multi-channel flicker-free dimming circuit with high stability, flexible control and low interference.

[0004] To this end, the utility model provides a high power factor wireless multi-channel flicker-free dimming circuit, which adopts an isolated design and includes an anti-interference rectifier circuit, a high power factor positive DC / DC voltage regulator circuit, a DC / DC dimming circuit and an MCU control unit. The utility model is characterized in that the anti-interference rectifier circuit is connected to the high power factor positive DC / DC voltage regulator circuit, the anti-interference rectifier circuit converts the input AC voltage into a DC pulsating voltage with twice the frequency, the DC / DC dimming circuit is connected to the MCU control unit, the DC / DC dimming circuit converts the stable DC voltage into a high-frequency stable current source to power the LED, and controls the LED current to change between the minimum and maximum set current values ​​through the size of the PWM signal or the analog voltage signal, and the current size of the circuit is determined by the control signal provided by the MCU control unit.

[0005] The anti-interference circuit is used to suppress the differential and common mode interference generated by the switch tube under high frequency operation and the differential and common mode interference generated by the switch that supplies power to the lighting fixture in the critical contact state, and to suppress the lightning voltage of the AC power grid to ensure safe and stable operation of the circuit.

[0006] Preferably, the high power factor positive DC / DC voltage stabilizing circuit tracks a wide range of DC pulsating signals after AC rectification on the primary side of the transformer, controls the switching tubes to work synchronously to suppress harmonics and improve the power factor, samples the voltage on the secondary side, obtains a stable isolated DC voltage through PWM control and transformer conversion, and provides power for the DC / DC dimming circuit.

[0007] Preferably, the anti-interference rectifier circuit includes a rectifier bridge stack BD1, a diode D2, a resistor R4, a resistor R8 and an electrolytic capacitor EC3. The input AC live wire L and the AC neutral wire N are connected to the AC side of the rectifier bridge stack BD1 through the varistor TVR1, the X capacitor CX2, the common mode inductor LF1 and the common mode inductor LF2, and the X capacitor CX1 in sequence. The positive end of the rectifier bridge stack BD1 is connected to the capacitor C2 and the differential mode inductor L1, the positive pole of the diode D2 is connected to the differential mode inductor L1, the resistor R49, the capacitor C3, and the resistor R4, the negative pole of the diode D2 is connected to the resistor R8 and the positive pole of the electrolytic capacitor EC3, and the negative end of the rectifier bridge stack BD1 is connected to the negative pole of the capacitor C2, the capacitor C3, and the electrolytic capacitor EC3.

[0008] Preferably, the high power factor positive DC / DC voltage stabilizing circuit includes a transformer T1, a MOS tube Q1, a chip U2, a chip U6 and a chip U7. Pin 1 of the transformer T1 is connected to the positive electrode of the electrolytic capacitor EC6 and pin 6 of the chip U2 through a resistor R18 and a diode D6, and is connected to pin 1 of the chip U2 through a resistor R34 and a capacitor C13, and a resistor R32. The positive electrode of the Schottky diode D1 is connected to the positive electrodes of the electrolytic capacitor EC1 and the electrolytic capacitor EC2, and is connected to the control pin of the chip U7 through a resistor R56 and a capacitor C25.

[0009] Preferably, the DC / DC dimming circuit includes chip U1, chip U3, Schottky diode D8, Schottky diode D9, inductor L2, inductor L3, electrolytic capacitor EC4 and electrolytic capacitor EC7. When peak current control is adopted, the positive electrode of electrolytic capacitor EC5 is connected to pin 7 of chip U1 through resistor R15, and pin 7 of chip U1 is connected to the negative electrode of electrolytic capacitor EC5 and pin 4 of chip U1 through resistor R25, and then connected to pin 2 of chip U1 through resistor R62, or pin 7 of chip U1 is directly connected to pin 2. When average current control is adopted, pin 2 of chip U1 is connected to pin 4 of chip U1 through capacitor C8.

[0010] When the control signal received by the DC / DC dimming circuit is zero, the LED current is turned off, and the DC / DC dimming circuit enters a dormant state. At the same time, the rest of the circuit also enters a dormant state. The circuit is in a skip cycle working mode, with small switching losses and low standby power consumption. The control signal of the DC / DC dimming circuit can be a PWM signal or a DC voltage signal, and the main dimming control mode can be a peak current and average current control mode.

[0011] Preferably, the MCU control unit includes a chip U5 and a MOS tube Q2. The control signals outputted from the pins 2 and 3 of the chip U5 are connected to the pins 7 of the DC / DC dimming circuit chip U1 and the chip U3 through resistors R42 and R45, respectively. The MCU control unit also includes a wireless module or a Bluetooth module. The signal sent by the remote control or other smart devices is received through the wireless module or the Bluetooth module and transmitted to the MCU control unit. The MCU control unit includes an MCU controller and a night light control circuit. The signal received from the wireless module or the Bluetooth module is converted into a command to send a control signal to control the current of the DC / DC dimming circuit through identification, so as to achieve the purpose of controlling the brightness of the LED and control the operation of the night light.

[0012] Preferably, an auxiliary power supply circuit is also included, and the auxiliary power supply circuit supplies power to the MCU control unit, the wireless module or the Bluetooth module, and the night light. When the night light control circuit receives a signal and works, the other dimming circuits do not work, and the two work alternately to provide a weak current to the night light to achieve night lighting.

[0013] Preferably, the auxiliary power supply circuit includes a chip U4, a Schottky diode D10, an inductor L4 and an electrolytic capacitor EC9. Pin 3 of the chip U4 is connected to the positive terminal of the inductor L4 and the electrolytic capacitor EC9 via capacitor C19 and resistor R38. The positive electrode of the electrolytic capacitor EC10 is connected to pin 4 of the chip U4 via resistor R39 and then to the negative electrode of the electrolytic capacitor EC10 via resistor R41.

[0014] Preferably, the output voltage of the auxiliary power supply circuit is connected in parallel with the resistor R36 and the resistor R37 to supply power to the night light LED+, and the LED- of the night light is connected to the ground through the MOS tube Q2 and the voltage regulator tube ZD1 in parallel.

[0015] Preferably, the DC / DC dimming circuit is a single-channel, dual-channel or multi-channel dimming circuit.

[0016] The utility model high power factor wireless multi-channel flicker-free dimming circuit adopts a two-stage DC / DC circuit, which effectively solves the size of voltage and current ripples and reduces light flicker. The front-stage high power factor positive DC / DC voltage regulator circuit solves the influence of harmonic current on the power grid, and adopts an isolation type to completely isolate the AC power from the rear-stage circuit, avoiding the risk of electric shock, and is suitable for a wide range of global input AC voltages. The AC and DC ripple voltage signals output by the high power factor positive DC / DC voltage regulator circuit are collected through RC coupling and fed back to the voltage control loop, which quickly improves the loop response of the high power factor positive DC / DC voltage regulator circuit and effectively prevents the flickering phenomenon caused by the rapid switching of LEDs under different brightness states. The utility model high power factor wireless multi-channel flicker-free dimming circuit has high stability, flexible control, low interference, and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The utility model discloses an MCU control unit of a high power factor wireless multi-channel non-stroboscopic dimming circuit.

[0018] Figure 2 The utility model discloses an anti-interference rectifier circuit of a high power factor wireless multi-channel non-stroboscopic dimming circuit.

[0019] Figure 3 The utility model discloses a high power factor positive DC / DC voltage stabilizing circuit of a high power factor wireless multi-channel non-stroboscopic dimming circuit.

[0020] Figure 4 The utility model discloses a peak current controlled DC / DC dimming circuit of a high power factor wireless multi-channel non-stroboscopic dimming circuit.

[0021] Figure 5 Average current control DC / DC dimming circuit of high power factor wireless multi-channel flicker-free dimming circuit

[0022] Figure 6 The utility model discloses an auxiliary power supply circuit for a high power factor wireless multi-channel non-stroboscopic dimming circuit. DETAILED DESCRIPTION

[0023] The high power factor wireless multi-channel flicker-free dimming circuit of the utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0024] like Figure 1-Figure 6 As shown, the utility model discloses a high power factor wireless multi-channel flicker-free dimming circuit, including an anti-interference rectifier circuit, a high power factor positive DC / DC voltage regulator circuit, a DC / DC dimming circuit, an auxiliary power supply circuit and an MCU control unit.

[0025] The anti-interference rectifier circuit is electrically connected to the high power factor positive DC / DC voltage regulator circuit to suppress the differential common mode interference generated by the switch tube under high frequency operation and the differential common mode interference generated by the switch that powers the lighting fixture under critical contact state, and eliminate the impact of the lightning voltage of the AC power grid on circuit safety. The wide range of AC input voltage is sent to the high power factor positive DC / DC voltage regulator circuit after red filtering and rectification, and the DC pulsating signal is tracked to control the synchronous operation of the switch tube to achieve the purpose of high power factor positive effect, and the voltage on the secondary side is sampled to obtain a stable DC voltage through PWM control, providing a stable and reliable power supply for the subsequent DC / DC dimming circuit. The auxiliary power supply circuit is connected to the DC / DC dimming circuit and the MCU control unit.

[0026] Specifically, the anti-interference rectifier circuit includes a rectifier bridge stack BD1, a diode D2, a resistor R4, a resistor R8, and an electrolytic capacitor EC3. The input AC live wire L and the AC neutral wire N are connected to the AC side of the rectifier bridge stack BD1 through the varistor TVR1, the X capacitor CX2, the common mode inductor LF1 and the common mode inductor LF2, and the X capacitor CX1 in sequence. The positive end of the rectifier bridge stack BD1 is connected to the capacitor C2 and the differential mode inductor L1, the positive pole of the diode D2 is connected to the differential mode inductor L1, the resistor R49, the capacitor C3, and the resistor R4, the negative pole of the diode D2 is connected to the resistor R8 and the positive pole of the electrolytic capacitor EC3, and the negative end of the rectifier bridge stack BD1 is connected to the capacitor C2, the capacitor C3, and the negative pole of the electrolytic capacitor EC3.

[0027] Specifically, the high power factor positive DC / DC voltage stabilizing circuit includes a transformer T1, a MOS tube Q1, a chip U2, a chip U6, and a chip U7. Pin 1 of the transformer T1 is connected to the positive electrode of the electrolytic capacitor EC6 and the 6th pin of the chip U2 through a resistor R18 and a diode D6, and is connected to the capacitor C13 and the pin 1 of the chip U2 through a resistor R34 and a resistor R32. The positive electrode of the Schottky diode D1 is connected to the positive electrodes of the electrolytic capacitor EC1 and the electrolytic capacitor EC2, and is connected to the control pin of the chip U7 through a resistor R56 and a capacitor C25.

[0028] Specifically, the DC / DC dimming circuit includes chip U1, chip U3, Schottky diode D8, Schottky diode D9, inductor L2, inductor L3, electrolytic capacitor EC4, electrolytic capacitor EC7. When peak current control is adopted, the positive electrode of electrolytic capacitor EC5 is connected to pin 7 of chip U1 through resistor R15, and pin 7 of chip U1 is connected to the negative electrode of electrolytic capacitor EC5 and pin 4 of chip U1 through resistor R25, and then connected to pin 2 of chip U1 through resistor R62, or pin 7 of chip U1 is directly connected to pin 2. When average current control is adopted, pin 2 of chip U1 is connected to pin 4 of chip U1 through capacitor C8.

[0029] Specifically, the auxiliary power supply circuit includes chip U4, Schottky diode D10, inductor L4, and electrolytic capacitor EC9. Pin 3 of chip U4 is connected to the positive terminal of inductor L4 and electrolytic capacitor EC9 via capacitor C19 and resistor R38. The positive terminal of electrolytic capacitor EC10 is connected to pin 4 of chip U4 through resistor R39 and then to the negative terminal of electrolytic capacitor EC10 via resistor R41.

[0030] Specifically, the MCU control unit includes a chip U5 and a MOS tube Q2. The control signals output from pins 2 and 3 of the chip U5 are connected to pins 7 of the DC / DC dimming circuit chip U1 and chip U3 through resistors R42 and R45, respectively, to realize the dimming and color adjustment functions. Pin 1 of the interface XH-1, that is, the output voltage of the auxiliary power supply circuit, is connected in parallel with resistor R36 and resistor R37 to supply power to the night light LED+, and the LED- of the night light is connected to the ground through the MOS tube Q2 in parallel with the voltage regulator tube ZD1.

[0031] In the present invention, the chip U2 is preferably LD7838, the chips U1 and U3 are preferably SY8745, the chip U4 is preferably SY8291, and the chip U5 is preferably PIC12F1572.

[0032] The working principle of the utility model is as follows:

[0033] After being rectified and filtered by the anti-interference rectifier circuit, the wide range AC voltage is transformed into a DC pulsating voltage with twice the low frequency, which supplies power to the high power factor positive DC / DC voltage stabilizing circuit. The circuit suppresses the differential common mode interference generated by the switch tube under high frequency operation and the differential common mode interference generated by the switch that supplies power to the lighting fixture under the critical contact state, and suppresses the lightning voltage of the AC power grid to make the circuit work safely and stably. After isolation and conversion by the high power factor positive DC / DC voltage stabilizing circuit, a DC safe low voltage completely isolated from the AC power is obtained. The circuit also tracks the DC pulsating signal and controls the synchronous operation of the switch tube, so that the harmonics of the circuit are effectively suppressed, and the power factor is improved.

[0034] After the DC safe low voltage passes through the DC / DC dimming circuit, the size of the LED power supply is changed by changing the current size of the DC / DC dimming circuit. It works in a high-frequency state, which effectively improves the impact of light flicker on the human eye. The current size of the circuit is determined by the control signal provided by the MCU control unit. The MCU control unit receives the signal transmitted by the wireless module or the Bluetooth module, identifies it, converts it into an instruction, and sends a signal to control the DC / DC dimming circuit and the night light control circuit to work alternately. By changing the size of the signal, the size of the LED current is finally controlled, thereby achieving dimming and color adjustment.

[0035] The embodiments described above are merely descriptions of preferred implementation modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A high power factor wireless multi-channel flicker-free dimming circuit, adopting an isolated design, including an anti-interference rectifier circuit, a high power factor positive DC / DC voltage regulator circuit, a DC / DC dimming circuit and an MCU control unit, characterized in that The anti-interference rectifier circuit is connected to a high power factor positive DC / DC voltage stabilizing circuit, which converts the input AC voltage into a DC pulsating voltage with twice the frequency. The DC / DC dimming circuit is connected to an MCU control unit, which converts a stable DC voltage into a high-frequency stable current source to power the LED. The LED current is controlled to change between the minimum and maximum set current values ​​through the size of a PWM signal or an analog voltage signal. The current size of the circuit is determined by a control signal provided by the MCU control unit.

2. According to claim 1, a high power factor wireless multi-channel flicker-free dimming circuit is characterized in that The high power factor positive DC / DC voltage stabilizing circuit tracks a wide range of DC pulsating signals after AC rectification on the primary side of the transformer, controls the synchronous operation of the switch tubes to suppress harmonics and improve the power factor, and samples the voltage on the secondary side. A stable isolated DC voltage is obtained through PWM control and transformer conversion to provide power for the DC / DC dimming circuit.

3. A high power factor wireless multi-channel flicker-free dimming circuit according to claim 2, characterized in that The anti-interference rectifier circuit includes a rectifier bridge stack BD1, a diode D2, a resistor R4, a resistor R8 and an electrolytic capacitor EC3. The input end AC live wire L and the AC neutral wire N are connected to the AC side of the rectifier bridge stack BD1 through the varistor TVR1, the X capacitor CX2, the common mode inductor LF1 and the common mode inductor LF2, the X capacitor CX1 in turn. The positive end of the rectifier bridge stack BD1 is connected to the capacitor C2 and the differential mode inductor L1, the positive pole of the diode D2 is connected to the differential mode inductor L1, the resistor R49, the capacitor C3, and the resistor R4, the negative pole of the diode D2 is connected to the resistor R8 and the positive pole of the electrolytic capacitor EC3, and the negative end of the rectifier bridge stack BD1 is connected to the negative pole of the capacitor C2, the capacitor C3, and the electrolytic capacitor EC3.

4. A high power factor wireless multi-channel flicker-free dimming circuit according to claim 3, characterized in that The high power factor positive DC / DC voltage stabilizing circuit includes a transformer T1, a MOS tube Q1, a chip U2, a chip U6 and a chip U7. Pin 1 of the transformer T1 is connected to the positive electrode of the electrolytic capacitor EC6 and the 6th pin of the chip U2 through a resistor R18 and a diode D6, and is connected to the capacitor C13 through a resistor R34 and the pin 1 of the chip U2 through a resistor R32. The positive electrode of the Schottky diode D1 is connected to the positive electrodes of the electrolytic capacitor EC1 and the electrolytic capacitor EC2, and is connected to the control pin of the chip U7 through a resistor R56 and a capacitor C25.

5. A high power factor wireless multi-channel flicker-free dimming circuit according to claim 4, characterized in that The DC / DC dimming circuit includes chip U1, chip U3, Schottky diode D8, Schottky diode D9, inductor L2, inductor L3, electrolytic capacitor EC4 and electrolytic capacitor EC7. When peak current control is adopted, the positive electrode of electrolytic capacitor EC5 is connected to pin 7 of chip U1 through resistor R15, and pin 7 of chip U1 is connected to the negative electrode of electrolytic capacitor EC5 and pin 4 of chip U1 through resistor R25, and then connected to pin 2 of chip U1 through resistor R62, or pin 7 of chip U1 is directly connected to pin 2. When average current control is adopted, pin 2 of chip U1 is connected to pin 4 of chip U1 through capacitor C8.

6. A high power factor wireless multi-channel flicker-free dimming circuit according to claim 5, characterized in that The MCU control unit includes a chip U5 and a MOS tube Q2. The control signals output by pins 2 and 3 of the chip U5 are connected to pins 7 of the DC / DC dimming circuit chip U1 and the chip U3 through resistors R42 and R45 respectively. The MCU control unit also includes a wireless module or a Bluetooth module, which receives signals sent by a remote control or other smart devices through the wireless module or the Bluetooth module and transmits them to the MCU control unit.

7. A high power factor wireless multi-channel flicker-free dimming circuit according to claim 6, characterized in that It also includes an auxiliary power supply circuit, which supplies power to the MCU control unit, the wireless module or the Bluetooth module, and the night light.

8. A high power factor wireless multi-channel flicker-free dimming circuit according to claim 7, characterized in that The auxiliary power supply circuit includes a chip U4, a Schottky diode D10, an inductor L4 and an electrolytic capacitor EC9. Pin 3 of the chip U4 is connected to the positive terminal of the inductor L4 and the electrolytic capacitor EC9 via a capacitor C19 and a resistor R38. The positive terminal of the electrolytic capacitor EC10 is connected to pin 4 of the chip U4 via a resistor R39 and then to the negative terminal of the electrolytic capacitor EC10 via a resistor R41.

9. A high power factor wireless multi-channel flicker-free dimming circuit according to claim 8, characterized in that The output voltage of the auxiliary power supply circuit is connected in parallel with the resistor R36 and the resistor R37 to supply power to the night light LED+, and the LED- of the night light is connected to the ground through the MOS tube Q2 and the voltage regulator tube ZD1 in parallel.

10. The high power factor wireless multi-channel flicker-free dimming circuit according to claim 1, characterized in that The DC / DC dimming circuit is a single-channel, dual-channel or multi-channel dimming circuit.

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