Sleep aid lighting system, dimming power supply and method

Abstract

This invention relates to the field of sleep-aid lighting technology, specifically to a sleep-aid lighting system, a dimming power supply, and a method. The dimming power supply includes: a driver module for sending PWM signals to a main light dimming circuit and an auxiliary light dimming circuit; a main light dimming circuit that adjusts the power output of the lighting source according to the received first PWM signal; and an auxiliary light dimming circuit that adjusts the power output of the stroboscopic light source according to the received second PWM signal. The power supply of the main light dimming circuit is greater than that of the auxiliary light dimming circuit. This invention abandons low-cost RC analog driving and adopts a digital constant frequency drive module to achieve high-precision frequency locking, full-process closed-loop sampling correction, and deep stepless dimming of the main light, eliminating flicker and providing uniform and soft light. When the sleep-aid auxiliary light is activated, because the power of the auxiliary light is less than that of the main light, relying on the principle of light and shadow superposition and neutralization, it can eliminate visible flicker, thus balancing eye protection and comfort while stably outputting standard stroboscopic light waves.

Description

Technical Field

[0001] This invention relates to the field of sleep-aid lighting technology, and in particular to a sleep-aid lighting system, a dimming power supply, and a method. Background Technology

[0002] Sleep-aid lighting systems are suitable for photobiological rhythm regulation in home, medical, and sensitive population settings. In recent years, the sleep economy has continued to expand, and gamma-frequency light wave sleep-aid technology has received widespread attention due to its potential efficacy in inducing brain wave rhythms and improving sleep quality.

[0003] Currently, a large number of lamp products claiming to have light wave sleep-aiding functions have emerged on the market. However, those skilled in the art know that existing sleep-aid lamps generally suffer from the following technical defects, which seriously limit their actual effectiveness and user experience.

[0004] Defects in the core optical architecture make it difficult to eliminate the flickering problem. Most existing affordable sleep aid lamps use a single low-frequency pulse driving method to directly output flickering auxiliary light. Their driving circuit design is rudimentary, lacking integrated main light superposition cancellation or high-frequency compensation technology, and also lacking any flicker suppression or human eye visual compensation mechanism.

[0005] This results in two types of flickering problems:

[0006] Firstly, the low-frequency flicker frequency falls within the critical flicker frequency range of the human eye (usually below 100Hz). When visually sensitive people and patients with neurasthenia look directly at a light before going to sleep, they can clearly perceive the alternating light and shadow. This change in light and shadow continuously induces the ciliary muscle of the eye to contract and the pupillary sphincter to adjust frequently. Not only does it fail to calm the mind and help with sleep, but it also aggravates visual fatigue and nerve excitability, which runs counter to the original intention of helping with sleep. Secondly, due to unstable driving waveforms and insufficient power supply ripple suppression, some products have hidden high-frequency flicker and frequency drift problems. The actual flicker amplitude fluctuates greatly, and the driving frequency deviates from the standard frequency range, which cannot stably induce brain gamma oscillations, resulting in the substantial failure of the sleep aid effect, and even causing discomfort due to irregular flicker.

[0007] The aforementioned flicker problem is a structural defect in existing driving solutions. There is no effective solution that balances low cost, visual safety, and frequency accuracy. Furthermore, there is a lack of systematic optimization design for flicker amplitude, frequency stability, and human eye perception threshold.

[0008] It is evident that existing sleep aid lamps have significant shortcomings in terms of flicker suppression, visual comfort, and frequency accuracy. Summary of the Invention

[0009] The purpose of this invention is to overcome the obvious shortcomings of existing sleep aid lamps in terms of flicker suppression, visual comfort and frequency accuracy, and to provide a dimming power supply, a fast shutdown circuit, a method and a lighting system.

[0010] In a first aspect, the present invention provides a dimming power supply for powering a light source in a sleep-aid lighting system. The dimming power supply includes: a driving module, a main light dimming circuit, and an auxiliary light dimming circuit. The driving module sends PWM signals to the main light dimming circuit and the auxiliary light dimming circuit. The main light dimming circuit adjusts the power output of the lighting source according to a received first PWM signal. The auxiliary light dimming circuit adjusts the power output of the strobe light source according to a received second PWM signal. The driving module adjusts the duty cycle of the first PWM signal and the second PWM signal according to different lighting modes. The auxiliary light dimming circuit is composed of transistors Q2 and Q6 and a power MOSFET Q5.

[0011] According to a preferred embodiment, the main light dimming circuit includes an output filtering circuit and a constant current control circuit. The output filtering circuit includes at least an electrolytic capacitor EC1, a diode D3, and an inductor B2; one end of the inductor B2 is connected to VOUT, and the other end is connected to the constant current control circuit. The constant current control circuit includes at least a constant current control chip U2, a connector COM1, a power MOSFET Q4, a diode D7, and several resistors. The constant current control chip U2 adjusts the power supply output of connector COM1 in response to a first PWM signal sent by the drive module.

[0012] According to a preferred embodiment, the dimming power supply further includes a rectifier-filter EMI suppression circuit. The rectifier-filter EMI suppression circuit includes: an external power input terminal, a first filter unit, a rectifier unit, and a second filter unit. The external power input terminal is used to connect the live wire and neutral wire of an external power supply. The first filter unit uses common-mode inductors LF1 and LF2 to form a composite electromagnetic interference filter circuit for filtering noise signals. The rectifier unit is used to rectify the AC signal into a DC signal. The second filter unit includes at least: a differential-mode inductor L1, a diode D1, and capacitors CB1, CB2, and EC2, for filtering lightning surges and high-frequency interference.

[0013] According to a preferred embodiment, the dimming power supply further includes a flyback buck circuit. The flyback buck circuit includes at least: a control chip U1, a switching transistor Q1, a transistor Q3, a Zener diode ZD1, a diode D6, and two sets of input windings N1 and N3 of a transformer T1.

[0014] According to a preferred embodiment, the dimming power supply further includes an output rectifier circuit. The output rectifier circuit includes: an output winding N2 of a transformer T1, a rectifier diode D4, two resistors R1 and R12, two electrolytic capacitors EC4 and EC3, and a capacitor C1, used to suppress voltage spikes, smooth the output voltage, and filter out high-frequency noise.

[0015] According to a preferred embodiment, the dimming power supply further includes an auxiliary light power supply circuit. The auxiliary light power supply circuit includes at least: a diode D8, a transistor Q7, a step-down chip U8, and a linear regulator U12, for supplying power to the driving module and the auxiliary light dimming circuit.

[0016] According to a preferred embodiment, the lighting modes include: a first lighting mode, a second lighting mode, a third lighting mode, and a fourth lighting mode. In the first lighting mode, the power supply output of the auxiliary light dimming circuit is cut off, and only the power supply output of the main light dimming circuit is adjusted. In the second, third, and fourth lighting modes, the duty cycles of the first PWM signal and the second PWM signal are adjusted synchronously; and in the second, third, and fourth lighting modes, the duty cycle ratios of the first PWM signal and the second PWM signal are different but constant.

[0017] In a second aspect, the present invention also provides a sleep-aid lighting system, comprising: a light source and a dimming power supply. The dimming power supply is a dimming power supply provided by the present invention.

[0018] According to a preferred embodiment, the proportion of the main light source in the light source is greater than the proportion of the auxiliary light source.

[0019] In a third aspect, the present invention also provides a dimming method for a sleep-aid lighting system, which uses a dimming power supply provided by the present invention for dimming.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a dimming power supply that abandons low-cost analog RC drive and adopts a digital constant frequency drive module to achieve high-precision frequency locking and closed-loop sampling correction throughout the process. At the same time, the main light uses a DC-DC dimming scheme, and the output high-frequency PWM can achieve deep stepless dimming, without flicker, and the light is uniform and soft. When the sleep-aid auxiliary light is turned on, since the power of the auxiliary light is less than that of the main light, it can eliminate the visible flicker in the human eye by relying on the principle of light and shadow superposition and neutralization. Thus, while stably outputting standard strobe light waves, it also takes into account eye protection and comfort. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a dimming power supply circuit according to a preferred embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of an auxiliary light dimming circuit according to a preferred embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of a filter rectification and filtering EMI anti-interference circuit according to a preferred embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of a flyback buck circuit according to a preferred embodiment of the present invention.

[0025] Figure 5 This is a schematic diagram of the output rectifier circuit according to a preferred embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of the main light dimming circuit according to a preferred embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram of an auxiliary light power supply circuit according to a preferred embodiment of the present invention. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to specific embodiments. However, this should not be construed as limiting the scope of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0029] Unless otherwise specified, the terms "upper," "lower," "left," "right," "center," "inner," and "outer," etc., used in the description of specific embodiments of the present invention to indicate orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is usually placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, and for enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0030] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," "parallel," and "coaxial" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, parallel, or coaxial. Slight tilt or deviation is permissible, as long as it does not affect the normal function of the relevant component. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," not that the structure must be perfectly horizontal; a slight tilt is acceptable. "Coaxial" means that two components are arranged as coaxially as possible, allowing them to move coaxially or approximately coaxially when their relative positions change. Alternatively, it can be simplified to mean that the corresponding device / component / element, when arranged in "horizontal," "vertical," "suspended," "parallel," or "coaxial" directions, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. For example, the deviation in the "coaxial" direction is controlled within 0.2-1mm, preferably within 0.2-0.5mm. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the solution of the present invention.

[0031] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0032] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as two, three, four, five, six, seven, eight, or nine, and can even exceed nine.

[0033] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to connection methods commonly used in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0034] Example 1 This embodiment provides a dimming power supply. See also... Figure 1 The dimming power supply includes: The driver module is used to send PWM signals to the main light dimming circuit and the auxiliary light dimming circuit; The main light dimming circuit adjusts the power output of the lighting source according to the received first PWM signal; The auxiliary light dimming circuit adjusts the power output of the stroboscopic light source according to the received second PWM signal; The drive module adjusts the duty cycle of the first PWM signal and the second PWM signal according to different lighting modes; The auxiliary light dimming circuit is composed of transistors Q2 and Q6 and power MOSFET Q5. The power supply of the main light dimming circuit is greater than that of the auxiliary light dimming circuit.

[0035] The dimming power supply provided in this embodiment is used to power the light source of the sleep-aid lighting system. It abandons the low-cost resistor-capacitor analog drive and adopts a digital constant frequency drive module to achieve high-precision frequency locking and closed-loop sampling correction throughout the process. At the same time, the main light uses a DC-DC dimming scheme to output high-frequency PWM to achieve deep stepless dimming, no flicker, and uniform and soft light. When the sleep-aid auxiliary light is turned on, since the power of the auxiliary light is less than that of the main light, it can eliminate the visible flicker in the human eye by relying on the principle of light and shadow superposition and neutralization. Thus, it can stably output standard strobe light waves while taking into account eye protection and comfort.

[0036] Example 2 This embodiment is a further improvement on embodiment 1, and the repeated content will not be described again.

[0037] See Figure 2 The auxiliary light dimming circuit is specifically configured as follows: The positive terminal of the 12V power supply is directly connected to the source of the power MOSFET Q5, and simultaneously connected to the gate of the power MOSFET Q5 through a pull-up resistor R47. The power MOSFET Q5 acts as the main switch, with its drain connected to the positive output terminal LED+FS of the auxiliary light dimming circuit. The gate of the power MOSFET Q5 is also connected to the collector of the NPN transistor Q6, while the emitter of Q6 is directly grounded (SGND1). This connection method constitutes the driving loop for Q5: when Q6 is on, it pulls the gate of Q5 low, thus turning on Q5; when Q6 is off, R47 pulls the gate of Q5 high to 12V, thus turning off Q5.

[0038] The control signal section consists of NPN transistor Q2 and its surrounding resistors. The second PWM signal is connected to the base of Q2 through a current-limiting resistor R48, while the base of Q2 is grounded through a pull-down resistor R50 to ensure reliable cutoff of Q2 when there is no signal. The collector of Q2 is connected to the base of Q6 through a resistor R43, while the emitter of Q2 is also grounded. The second PWM signal is a 40Hz PWM signal.

[0039] When the PWM signal is high, Q2 is turned on, which in turn pulls down the base potential of Q6 and turns Q6 off; when the PWM signal is low, Q2 is turned off, and current flows into the base of Q6 through R43, turning it on.

[0040] At the output terminal, in addition to connecting LED+FS, the drain of Q5 is also connected in parallel with capacitor EC22 and resistor R52. One end of these resistors is connected to LED+FS, and the other end is grounded, serving as a filter and voltage regulator. The drain of Q5 is connected to the positive terminal of capacitor EC22.

[0041] The final load interface consists of pins 1 and 2 of the COM4 connector, as well as LED-FS and LED+FS. LED+FS is the positive output, and LED-FS is the negative output (ground), together forming a complete LED driving circuit. The COM4 connector is used to connect the flickering LED; pin 1 of the COM4 connector connects to LED+FS, and pin 2 of the COM4 connector connects to LED-FS. The auxiliary light dimming circuit uses two stages of inverting transistors to drive the P-MOS transistor, realizing the PWM dimming or switching control function of the LED backlight.

[0042] The auxiliary light dimming circuit uses two NPN transistors (Q2 and Q6) to invert the power MOSFET Q5, thereby achieving precise control of the MOSFET switching by the PWM signal. The entire process can be broken down into two states: When the input 40Hz PWM signal is high, current flows through resistor R48 into the base of Q2, turning it on. After Q2 is turned on, its collector potential is pulled low to near ground, causing the base of Q6 to also be low, thus turning Q6 off. At this time, the 12V power supply pulls the gate voltage of Q5 up to near 12V through pull-up resistor R47, making the gate-source voltage Vgs of Q5 approximately 0V. Q5 is in the off state, and no current flows through the LED load.

[0043] When the PWM signal is low, no current flows into the base of Q2, and Q2 is off. At this time, the 12V power supply provides bias current to the base of Q6 through resistor R43, turning Q6 on. After Q6 turns on, its collector is pulled low to near ground, thereby pulling down the gate voltage of Q5. Since Q5 is a power MOSFET, its source is connected to 12V, and the gate being pulled low forms a negative Vgs voltage (e.g., -12V), satisfying the conduction condition. Q5 turns on, and current flows from 12V through Q5 to LED+FS, lighting the LED load.

[0044] The advantages of the inverting drive structure used in the auxiliary light dimming circuit are: It achieves logic level conversion and isolation, and low-voltage PWM signals can safely control high-voltage MOSFETs; Q6 acts as a driver transistor, which can quickly pull down the gate voltage of Q5, accelerate the turn-off speed of the MOSFET, and reduce switching losses. R47 ensures that Q5 is reliably turned off when Q6 is off, and R50 ensures that Q2 is reliably turned off when there is no signal, thus improving circuit stability. Capacitor EC22 and resistor R52 are connected in parallel at the output terminal to filter and absorb transient energy, thus protecting the LED load.

[0045] Based on the above working principle, the light source can emit a low-frequency flickering auxiliary light that is visible to the human body at 40Hz. Using the 40Hz low-frequency visible light as an auxiliary flickering light source, the main light is simultaneously superimposed to neutralize the low-frequency flickering effect, eliminating the flickering sensation that can be perceived by the human eye, and creating a soft light environment suitable for sleep.

[0046] See Figure 1 The dimming power supply also includes: a filter rectifier filtering EMI anti-interference circuit, a flyback buck circuit, an output rectifier circuit, a main dimming circuit, and an auxiliary power supply circuit.

[0047] See Figure 3 The EMI filtering and anti-interference circuit includes: an external power input terminal for connecting the live and neutral wires of an external power supply; a first filtering unit, which uses common-mode inductors LF1 and LF2 to form a composite electromagnetic interference filtering circuit for filtering noise signals; a rectification unit for rectifying AC signals into DC signals; and a second filtering unit, which includes at least: a differential-mode inductor L1, a diode D1, and capacitors CB1, CB2, and EC2 for filtering lightning surges and high-frequency interference.

[0048] Connector COM2 is the external power input terminal. Pin 1 connects to fuse F1, and the other end of F1 connects to one end of varistor RV2 and the left winding entrance of common-mode inductor LF2. Pin 6 directly connects to the other end of RV2 and the right winding entrance of LF2. Before LF2, thermistor RT1 and indicator light N1 are connected in series and then bridged between the line at pin 6 and the line before F1 (actually, the N1 and RT1 branch is connected in parallel at the input terminal for indication or protection). In addition, indicator light L1 is connected in parallel between the line after F1 and pin 6 (i.e., bridged before the LF2 input terminal).

[0049] The output terminals of common-mode inductor LF2 are connected to resistors R32 and R33. The other ends of these two resistors are joined together and then connected in the middle by capacitor CX1 (CX1 is connected between the two main lines at the output terminal of LF2). After filtering by CX1, the circuit enters the second-stage common-mode inductor LF1.

[0050] The output of LF1 is directly connected to the AC input of rectifier bridge DB1 (pins 1 and 4). At the same time, varistor RV1 is connected in parallel with the AC input of DB1 (i.e., across pins 1 and 4) to absorb surge voltage.

[0051] The positive DC output terminal (pin 3) of the rectifier bridge DB1 is connected to the second filter unit. The second filter unit consists of diode D1, resistors R7 and R11, and electrolytic capacitor EC2. The anode of D1 is connected to the output terminal of DB1, and the cathode is connected to the front end of L1 (inductor) and grounded. Meanwhile, R7 and R11 are connected in series and then in parallel with EC2, bridging the cathode of D1 and ground.

[0052] After exiting DB1, the main DC path passes through inductor L1 and resistor R5 (L1 and R5 appear to be connected in parallel, or R5 may be a damping resistor), and then connects to capacitors CB1 and CB2. CB1 and CB2 are connected in parallel between the positive line and ground (GND) as the final filter capacitors. The negative output terminal of the rectifier bridge (pin 2) is directly grounded (GND).

[0053] like Figure 3 The rectifier-filter EMI suppression circuit shown rectifies the AC signal from the power grid into a DC signal with a swivel pattern. Simultaneously, it uses a π-type filter to remove noise signals from the power grid, absorbs power surges, filters out high-frequency interference from the incoming line, provides light load protection, stabilizes the voltage across the capacitor, eliminates DC bias, delays capacitor aging, absorbs surges, discharges residual current, protects the downstream C-type flyback buck circuit, and improves power supply reliability. The rectifier-filter EMI suppression circuit performs surge clamping, interference absorption, and residual current discharge, protecting downstream components and balancing equipment reliability with personal safety.

[0054] See Figure 4 The flyback buck circuit is specifically configured as follows: The high-voltage startup pin HV (Pin4) of the control chip U1 (OB5686) is connected to the high-voltage bus VBUS through resistors R10 and R13 to provide the initial startup current for the chip. The feedback pin FB of the control chip U1 is used to receive the output voltage feedback signal.

[0055] The current detection pin CS (Pin6) of the control chip U1 is connected to a series of sampling resistors (R21, R22, R23) between the chip and ground to detect the current flowing through the main switch.

[0056] The gate drive pin GATE (Pin7) of control chip U1 outputs a drive signal, which is connected to the gate of the main switch Q1 through resistor R16. Simultaneously, to accelerate turn-off, the anode of diode D5 is connected to the gate of Q1, and the cathode is connected to R16. The power supply pin VDD (Pin8) of control chip U1 is connected to the positive terminal of capacitor C4, providing it with its operating voltage, which is supplied by the auxiliary winding circuit.

[0057] The drain of switching transistor Q1 is connected to one end of the primary winding N1 of transformer T1 (labeled 1), and the other end of the primary winding (labeled 2) is connected to the high-voltage bus VBUS. The other primary winding of transformer T1 (or a winding with the same name but different terminals, labeled 3) forms an RCD absorption circuit or buffer network through resistors R2, R3, R4, and capacitor C2, and is connected in parallel between the drain and source of Q1 (or across the winding terminals, depending on the labels; in the diagram, R2 / R3 / R4 are connected in series and then in parallel with C2, and then in series with diode D2 connected to the auxiliary winding B1). The source of Q1 is connected to the current sampling resistor network R21, R22, and R23, with the other ends of these resistors grounded. Resistor R14 and capacitor C4 are connected in parallel between the source of Q1 and ground.

[0058] The auxiliary winding B1 of transformer T1 is used to generate the chip's operating voltage VCC. One end of winding B1 (labeled 2) is rectified by diode D2 and connected to the VCC network. This network includes filter capacitors EC5 and C8, and Zener diode ZD1 (a precision voltage regulator or protection circuit composed of transistor Q3 and resistor R27). VCC is ultimately connected to the chip's VDD pin. The other end of the auxiliary winding (labeled 1) is grounded. In addition, there is a feedback winding N3 (labeled 4-5), whose induced voltage, after being divided by resistors R15 and R18 and filtered by capacitor C5, generates an FB signal which is sent to the FB pin of chip U1 for voltage regulation control. Diode D6 and resistor R19 are connected in series in the auxiliary circuit to participate in voltage clamping or reset.

[0059] Preferably, the flyback buck circuit relies on a transformer for electrical isolation. When the switching transistor Q1 is on, grid energy is stored in the primary winding of the transformer, the secondary diode is cut off, and there is no output. At the instant the switch is turned off, the transformer's magnetic field is released, the secondary diode conducts, and power is supplied to the load. The control chip U1 samples the voltage through the auxiliary winding, calculates the output value, and provides closed-loop voltage regulation. It uses a constant on-time to raise the power factor and quasi-resonant valley-level turn-on to reduce losses. The sampling resistor of the control chip U1 limits the peak current and integrates overvoltage, short-circuit, and over-temperature protection, and automatically reduces the frequency under light load to prevent howling.

[0060] See Figure 5 The output rectifier circuit is specifically configured as follows: The upper end (pin 8) of the secondary winding N2 of transformer T1 is first connected in series with a fuse or zero-ohm resistor Sec, and then connected to the anode of rectifier diode D4. The cathode of diode D4 serves as the positive output node after rectification and is directly connected to the output terminal VOUT. At the same time, a branch is led out from the cathode node of D4, with resistor R1 and capacitor C1 connected in series in sequence. The other end of this R1-C1 branch is connected to the lower end (pin 7) of transformer T1, forming an RC snubber circuit across the rectifier diode to suppress voltage spikes.

[0061] On the DC output side, resistor R12 and two electrolytic capacitors EC4 and EC3 are connected in parallel between the positive terminal of VOUT and ground SGND1. R12 acts as a dummy load or bleed resistor, with one end connected to VOUT and the other end connected to SGND1. The positive terminals of capacitors EC4 and EC3 are both connected to VOUT, and the negative terminals are both connected to SGND1. Together, they form an output filter network to smooth the output voltage and filter out high-frequency noise.

[0062] The lower end (pin 7) of the secondary winding N2 of transformer T1 is connected to the secondary ground SGND1.

[0063] Preferably, since the output of the flyback buck circuit is still a pulsating waveform, it cannot be directly used for the LED load. An output rectifier circuit is needed to rectify and filter the output of the flyback buck circuit. The output rectifier circuit uses diodes for rectification and electrolytic capacitors at the output terminal for energy storage and filtering. After the load is connected, it continuously supplies power to the load while also filtering out some noise signals.

[0064] See Figure 6 The main light dimming circuit includes an output filter circuit and a constant current control circuit.

[0065] Specifically, the output filter circuit: The main DC voltage VOUT (from the pre-stage rectifier and filter) serves as the input power for the main light dimming circuit. An electrolytic capacitor EC1 is connected in parallel between the positive terminal of VOUT and ground SGND1 for energy storage and filtering. Simultaneously, the positive terminal of VOUT is directly connected to pin 1 (labeled LED+1) of connector COM1, serving as the positive power supply terminal for the LED string. Furthermore, diode D3 and inductor B2 are connected in series across the positive terminal of VOUT and ground, with the anode of D3 grounded and the cathode connected to VOUT, providing reverse connection protection or freewheeling current. One end of inductor B2 is connected to VOUT, and the other end is connected to the constant current control circuit.

[0066] Constant current control loop: Pin 6 (labeled LED-1) of connector COM1 is the negative return terminal of the LED string. This pin is connected to one end of inductor L2, and the other end of L2 is connected to the drain of power MOSFET Q4. Q4 acts as a constant current switch, with its source connected to current sampling resistors R30 and R31 (connected in parallel), the other ends of which are grounded at SGND1. This branch forms the loop for the LED current, and the current magnitude is controlled by detecting the voltage drop across R30 / R31. Meanwhile, capacitor C6 is connected in parallel between the drain and source of Q4 (or drain to ground) to absorb voltage spikes. Resistor R26 is also connected in parallel between the drain and source of Q4, possibly for bleed-out or protection purposes.

[0067] The constant current control chip U2 (Hi7020) drives Q4. The chip's PWM pin (Pin5) receives an external dimming signal and is grounded through resistor R28. The GATE pin (Pin6) outputs a drive signal, which is connected to the gate of Q4 through a network of resistors R24, R25, and R39. Diode D7 is connected in parallel on the drive resistor network (anode to the gate side, cathode to the chip side) to accelerate the turn-off of Q4. The chip's CS pin (Pin1) is connected to the upper end of the sampling resistors R30 / R31 at the source of Q4 for real-time current monitoring. The chip's VN pin (Pin3) is connected to a 12V power supply through capacitor C8 and resistor R29 to power or bias the internal circuitry of the chip. The GND pin (Pin2) is directly grounded to SGND1.

[0068] See Figure 1 , Figure 4 , Figure 5 , Figure 6 The front-end adopts a high PSR primary-side feedback architecture, eliminating optocouplers and secondary feedback loops, simplifying secondary components and reducing failure points. It relies on precise sampling and voltage regulation via the auxiliary winding of transformer T1, ensuring a stable VOUT output voltage. This topology exhibits extremely low light-load and no-load losses, resulting in outstanding standby energy efficiency and easily meeting stringent new energy efficiency regulations. The front-end and rear-end circuits are completely decoupled; the front-end outputs only a stable DC bus, and the PWM dimming independently controls the rear-end DC-DC constant current loop. The dimming light characteristics and depth are not constrained by the front-end loop, eliminating flickering at high and low brightness levels. Dual-chip hierarchical protection, with integrated peak current limiting and winding undervoltage protection on the primary side, makes it suitable for wide-voltage commercial LED lighting, achieving a balance between ultra-low standby power consumption, overall reliability, and a superior dimming experience.

[0069] See Figure 7 The auxiliary light power supply circuit is specifically configured as follows: The circuit's input, VOUT (from the preceding circuit), first passes through diode D8 for reverse connection protection or isolation. The cathode of D8 is connected to the main power supply network. On this network, resistors R53 and R57 are connected in series across the main power supply line and ground SGND1, forming a voltage divider detection circuit. The junction of R53 and R57 is connected to the base of transistor Q8. The emitter of Q8 is grounded, and its collector is connected to the base of transistor Q7 through resistor R54. The emitter of Q7 is grounded, and its collector is connected to the enable signal network EN. Simultaneously, electrolytic capacitor EC6 is connected in parallel between the EN network and ground to filter and stabilize the enable voltage.

[0070] The main power supply network is connected to the input pin IN (Pin5) and enable pin EN (Pin4) of the buck converter chip U8 (HI9205). U8's GND (Pin2) is grounded. The chip's switching node SW (Pin6) outputs a high-frequency pulse, which is connected in series with the ferrite bead / inductor B2 and the power inductor L2. Between the SW pin and ground, capacitor C21 and diode D9 (a Schottky diode, anode grounded, cathode connected to SW) are connected in parallel to form a freewheeling circuit. The output terminal of inductor L2 is the 12V output node. For filtering, capacitors C16 and C21 (C21 is connected to IN if it's for input filtering, and to 12V if it's for output; see the diagram, C21 is between SW and ground, and C16 is between 12V and ground) and electrolytic capacitor EC7 are all connected in parallel between the 12V output line and ground. In addition, resistor R51 is connected between the 12V output and the chip's feedback pin FB (Pin 3), and resistor R58 is connected between the FB pin and ground. These two resistors form a feedback voltage divider network to set the output voltage. Resistor R55 is also connected between the 12V line and the FB pin (possibly for fine-tuning or as a pull-up). Finally, resistor R56 acts as a dummy load or bleeder resistor, connected in parallel between the 12V output and ground.

[0071] The 12V output network also serves as the input to the next stage power supply, connected to the input pin VIN (Pin3) of the linear regulator U12. U12's GND (Pin2) is grounded. Its output pin Vout (Pin1) generates a 5V voltage. At the 5V output, capacitor C31 and electrolytic capacitor EC10 are connected in parallel for filtering; one end of each capacitor is connected to 5V, and the other end is grounded to SGND1.

[0072] The final 5V power supply is connected to pins 1 and 2 of the driver module COM3.

[0073] Pins 4 and 6 of the driver module COM3 generate the signal network PWMW (first PWM signal) and 40Hz PWM (first PWM signal) respectively, used to transmit control signals externally. The ground lines of the entire circuit ultimately converge at SGND1.

[0074] Preferably, the driver module COM3 is an MCU digital constant frequency driver module, and the specific model is not limited. Pins 1 and 2 of the driver module COM3 are power supply pins, and pins 4 and 6 of the driver module COM3 are PWM signal output pins.

[0075] Example 3 This embodiment provides a sleep-aid lighting system, including a light source and a dimming power supply. The dimming power supply in this embodiment is the same as that described in Embodiment 1 or Embodiment 2. In this embodiment, the proportion of the main light source is greater than that of the auxiliary light source. Both the main light source and the auxiliary light source are LED light sources. The main LED light source and the auxiliary LED light source are connected to different power supply output ports of the dimming power supply.

[0076] Preferably, the main LED in the light source accounts for 97% of the luminous flux, and the 40Hz auxiliary LED accounts for 3% of the luminous flux. Based on the principle of light and shadow superposition and neutralization, the flicker of the light is almost imperceptible to the naked eye.

[0077] The drive module adjusts the duty cycle of the first PWM signal and the second PWM signal according to different lighting modes.

[0078] Preferably, the lighting mode includes: Daily lighting mode: Turn off the auxiliary light and adjust only the main light to suit regular lighting needs for reading and living. Gentle Sleep Aid Mode: Native standard output ratio, main light and auxiliary light are synchronously adjusted, the light is gentle and soothes the brain nerves; Lightweight Relaxing Mode: Based on the original standard ratio, the proportion of auxiliary light is further reduced, and the main light and auxiliary light are adjusted in sync to weaken the light wave stimulation, which is suitable for light relaxation and rest. Deep Sleep Mode: Reduces the brightness of the main light and increases the brightness of the auxiliary light. The main light and auxiliary light are adjusted synchronously to enhance the calming effect of the light waves, making it suitable for scenarios such as falling asleep and resting in the middle of the night.

[0079] The driver module adjusts the duty cycle of the first PWM signal and the second PWM signal according to different lighting modes. Specifically, for example: In normal lighting mode, the duty cycle of the first PWM signal is adjusted within the range of 0-100%, while the duty cycle of the second PWM signal is 0. In the gentle sleep aid mode, the duty cycles of the first PWM signal and the second PWM signal are synchronously adjusted in a fixed ratio. For example, the duty cycle of the second PWM signal is set to one-tenth of the duty cycle of the first PWM signal. When the duty cycle of the first PWM signal is set to 100%, the duty cycle of the second PWM signal is set to 10%; when the duty cycle of the first PWM signal is set to 50%, the duty cycle of the second PWM signal is set to 5%.

[0080] In the lightweight calming mode, the duty cycles of the first PWM signal and the second PWM signal are synchronously adjusted in a fixed ratio. For example, the duty cycle of the second PWM signal is set to one-twentieth of the duty cycle of the first PWM signal. When the duty cycle of the first PWM signal is set to 100%, the duty cycle of the second PWM signal is set to 5%; when the duty cycle of the first PWM signal is set to 50%, the duty cycle of the second PWM signal is set to 2.5%.

[0081] In deep sleep mode, the duty cycle of the first PWM signal does not exceed 20%, and the duty cycle of the second PWM signal is set to several times the duty cycle of the first PWM signal. Furthermore, the duty cycles of the first PWM signal and the second PWM signal are synchronously adjusted in a fixed ratio. For example, the duty cycle of the first PWM signal does not exceed 16%, and the duty cycle of the second PWM signal is set to 6 times the duty cycle of the first PWM signal. When the duty cycle of the first PWM signal is set to 5%, the duty cycle of the second PWM signal is set to 30%; when the duty cycle of the first PWM signal is set to 10%, the duty cycle of the second PWM signal is set to 60%.

[0082] The lighting system provided in this embodiment incorporates 40Hz low-frequency visible light auxiliary flicker technology on top of ordinary lighting. Based on the principle of light and shadow superposition and neutralization, it is combined with a constant, soft main light to fully cover and cancel out the low-frequency auxiliary light flicker, achieving a zero-flicker perception and a constant, soft visual effect. Without being noticeable, it deeply regulates the brain's neural rhythm, comprehensively optimizing the pre-sleep mental and physical state and providing long-lasting, high-quality sleep. It offers multiple scientific sleep-aiding and health-preserving benefits from three levels: visual, neural, and circadian rhythm perspectives.

[0083] This solution achieves seamless eye protection from a visual perspective, avoiding the eye strain caused by flickering. Conventional low-frequency flickering lights create noticeable light and shadow fluctuations, causing the ciliary muscles to involuntarily contract and adjust, leading to soreness, dryness, and eye fatigue. Using the eyes before bed further burdens the eyes and increases nerve excitability. This embodiment uses a main light source to fully cover and cancel out the 40Hz auxiliary low-frequency flickering light, completely eliminating visible flicker. The light appears stable and uniform, without fluctuations in light and shadow or abrupt changes in brightness. The ciliary muscles do not need to adapt, maximizing relaxation of the eye muscles, alleviating eye fatigue caused by daytime electronic screens, reducing eye tension, and creating a relaxed and light-damage-free pre-sleep lighting environment.

[0084] Precise resonance at the brain level for calming and soothing, quickly shedding a state of heightened arousal. Scientific research confirms that 40Hz gamma brainwaves are calming and restorative brainwaves that can regulate the activity of the cerebral cortex and reduce anxiety and distracting thoughts. 40Hz low-frequency auxiliary light can penetrate the retina, gently resonating and inducing the brain to autonomously generate steady-state gamma brainwaves. Unlike passive hypnosis with strong light, this non-invasive optical frequency soothes the central nervous system, easing the mental tension from daytime work and social interactions, reducing pre-sleep overthinking and anxiety, shortening the sleep latency, and helping the body quickly switch from a state of wakefulness and arousal to a state of restful preparation.

[0085] The lighting system described in this embodiment can be installed in psychological counseling rooms, spas, and company lunch break rooms. It can cover a large area with soft light, and with the 40Hz soothing light effect, it can assist in mindfulness meditation and stress reduction therapy, and relieve anxiety in people under high pressure. When used during office lunch breaks, it can reduce the brain stimulation caused by electronic devices, and it is not easy to feel drowsy after a short rest. It can also help multiple people relax at the same time, and has the dual effects of rhythm regulation and soothing healing.

[0086] It repairs the circadian rhythm and optimizes sleep depth. Unlike ordinary warm light that only weakens blue light for shallow sleep aid, the discreet 40Hz strobe light gently regulates the rhythm of melatonin secretion. Without stimulating vision or disturbing light sleep, it increases nighttime melatonin concentration, stabilizing the deep and light sleep cycle. Long-term use can correct disordered sleep patterns, improve symptoms such as being easily startled, having light sleep with vivid dreams, and difficulty falling back asleep after waking up in the middle of the night, resulting in no fatigue or drowsiness upon waking. The light also blends seamlessly with the bedroom environment at night, without any jarring light effects, making it suitable for long-term home use by people who suffer from insomnia due to staying up late, neurasthenia, or difficulty falling asleep.

[0087] Example 4 This embodiment provides a dimming method using the dimming power supply described in Embodiment 1 or Embodiment 2. The dimming objects include a main light source and an auxiliary light source. Both the main light source and the auxiliary light source are LED light sources. The proportion of the main light source is greater than that of the auxiliary light source. The main LED light source and the auxiliary LED light source are connected to different power supply output ports of the dimming power supply.

[0088] Preferably, the main LED in the light source accounts for 97% of the luminous flux, and the 40Hz auxiliary LED accounts for 3% of the luminous flux. Based on the principle of light and shadow superposition and neutralization, the flicker of the light is almost imperceptible to the naked eye.

[0089] The drive module adjusts the duty cycle of the first PWM signal and the second PWM signal according to different lighting modes.

[0090] Preferably, the lighting mode includes: Daily lighting mode: Turn off the auxiliary light and adjust only the main light to suit regular lighting needs for reading and living. Gentle Sleep Aid Mode: Native standard output ratio, main light and auxiliary light are synchronously adjusted, the light is gentle and soothes the brain nerves; Lightweight Relaxing Mode: Based on the original standard ratio, the proportion of auxiliary light is further reduced, and the main light and auxiliary light are adjusted in sync to weaken the light wave stimulation, which is suitable for light relaxation and rest. Deep Sleep Mode: Reduces the brightness of the main light and increases the brightness of the auxiliary light. The main light and auxiliary light are adjusted synchronously to enhance the calming effect of the light waves, making it suitable for scenarios such as falling asleep and resting in the middle of the night.

[0091] The driver module adjusts the duty cycle of the first PWM signal and the second PWM signal according to different lighting modes. Specifically, for example: In normal lighting mode, the duty cycle of the first PWM signal is adjusted within the range of 0-100%, while the duty cycle of the second PWM signal is 0. In the gentle sleep aid mode, the duty cycles of the first PWM signal and the second PWM signal are synchronously adjusted in a fixed ratio. For example, the duty cycle of the second PWM signal is set to one-tenth of the duty cycle of the first PWM signal. When the duty cycle of the first PWM signal is set to 100%, the duty cycle of the second PWM signal is set to 10%; when the duty cycle of the first PWM signal is set to 50%, the duty cycle of the second PWM signal is set to 5%.

[0092] In the lightweight calming mode, the duty cycles of the first PWM signal and the second PWM signal are synchronously adjusted in a fixed ratio. For example, the duty cycle of the second PWM signal is set to one-twentieth of the duty cycle of the first PWM signal. When the duty cycle of the first PWM signal is set to 100%, the duty cycle of the second PWM signal is set to 5%; when the duty cycle of the first PWM signal is set to 50%, the duty cycle of the second PWM signal is set to 2.5%.

[0093] In deep sleep mode, the duty cycle of the first PWM signal does not exceed 20%, and the duty cycle of the second PWM signal is set to several times the duty cycle of the first PWM signal. Furthermore, the duty cycles of the first PWM signal and the second PWM signal are synchronously adjusted in a fixed ratio. For example, the duty cycle of the first PWM signal does not exceed 16%, and the duty cycle of the second PWM signal is set to 6 times the duty cycle of the first PWM signal. When the duty cycle of the first PWM signal is set to 5%, the duty cycle of the second PWM signal is set to 30%; when the duty cycle of the first PWM signal is set to 10%, the duty cycle of the second PWM signal is set to 60%.

[0094] When the ratio of the luminous flux of the main LED to the luminous flux of the 40Hz auxiliary LED in the light source changes, the duty cycle of the first PWM signal and the second PWM signal can be adjusted adaptively.

[0095] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A dimming power supply, characterized in that, The dimming power supply is used to power the light source of the sleep-aid lighting system, and includes: The driver module is used to send PWM signals to the main light dimming circuit and the auxiliary light dimming circuit; The main light dimming circuit adjusts the power output of the lighting source according to the received first PWM signal; The auxiliary light dimming circuit adjusts the power output of the stroboscopic light source according to the received second PWM signal; The driving module adjusts the duty cycle of the first PWM signal and the second PWM signal according to different lighting modes; The auxiliary light dimming circuit is composed of transistors Q2 and Q6 and power MOSFET Q5. The power supply of the main light dimming circuit is greater than that of the auxiliary light dimming circuit.

2. The dimming power supply according to claim 1, characterized in that, The main light dimming circuit includes an output filtering circuit and a constant current control circuit; The output filter circuit includes at least an electrolytic capacitor EC1, a diode D3, and an inductor B2; one end of the inductor B2 is connected to VOUT, and the other end is connected to the constant current control circuit. The constant current control circuit includes at least a constant current control chip U2, a connector COM1, a power MOSFET Q4, a diode D7, and several resistors; The constant current control chip U2 adjusts the power supply output of connector COM1 in response to the first PWM signal sent by the drive module.

3. A dimming power supply according to claim 2, characterized in that, It also includes a rectifier filter EMI suppression circuit, including: External power input terminal, used to connect the live wire and neutral wire of an external power source; The first filtering unit uses common-mode inductors LF1 and LF2 to form a composite electromagnetic interference filtering circuit to filter noise signals. The rectifier unit is used to rectify AC signals into DC signals. The second filtering unit includes at least: differential mode inductor L1, diode D1, capacitor CB1, CB2, and EC2, used to filter lightning surges and high-frequency interference.

4. A dimming power supply according to claim 3, characterized in that, It also includes a flyback buck circuit; the flyback buck circuit includes at least: a control chip U1, a switching transistor Q1, a transistor Q3, a Zener diode ZD1, a diode D6, and two sets of input windings N1 and N3 of a transformer T1.

5. A dimming power supply according to claim 4, characterized in that, It also includes an output rectifier circuit; the output rectifier circuit includes: the output winding N2 of transformer T1, rectifier diode D4, two resistors R1 and R12, two electrolytic capacitors EC4 and EC3, and capacitor C1, which are used to suppress voltage spikes and smooth the output voltage and filter out high-frequency noise.

6. A dimming power supply according to claim 5, characterized in that, It also includes an auxiliary light power supply circuit; the auxiliary light power supply circuit includes at least: diode D8, transistor Q7, step-down chip U8, and linear regulator U12, for powering the driving module and the auxiliary light dimming circuit.

7. A dimming power supply according to claim 1, characterized in that, The lighting modes include: a first lighting mode, a second lighting mode, a third lighting mode, and a fourth lighting mode; In the first lighting mode, the power supply output of the auxiliary light dimming circuit is cut off, and only the power supply output of the main light dimming circuit is adjusted; In the second lighting mode, the third lighting mode, and the fourth lighting mode, the duty cycles of the first PWM signal and the second PWM signal are adjusted synchronously; and in the second lighting mode, the duty cycle ratio of the first PWM signal and the second PWM signal is different and constant in the third lighting mode and the fourth lighting mode.

8. A sleep-aid lighting system, comprising a light source and a dimming power supply, characterized in that, The dimming power supply is a dimming power supply as described in any one of claims 1-7.

9. A sleep-aid lighting system according to claim 8, characterized in that, The proportion of the primary light source in the light source is greater than that of the secondary light source.

10. A dimming method, characterized in that, Dimming is performed using a dimming power supply as described in any one of claims 1-7.

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