CN115087165A

CN115087165A - Dimming circuit for lighting assembly and lighting assembly

Info

Publication number: CN115087165A
Application number: CN202210667083.4A
Authority: CN
Inventors: 何浩铭; 何流; 何登峰
Original assignee: Shaanxi Huasheng Zhike Electric Co ltd
Current assignee: Shaanxi Huasheng Zhike Electric Co ltd
Priority date: 2022-06-14
Filing date: 2022-06-14
Publication date: 2022-09-20

Abstract

The invention provides a dimming circuit for a lighting assembly and the lighting assembly, wherein the lighting assembly comprises a light source and a control chip, the control chip is used for generating a Pulse Width Modulation (PWM) signal, the dimming circuit comprises a transformer, the transformer comprises a primary side and a secondary side, the primary side is connected with the control chip, the secondary side is connected with a dimmer, and the transformer can transmit and output a dimming signal to the control chip based on a 0-10V signal at a dimmer end so as to control the light source.

Description

Dimming circuit for lighting assembly and lighting assembly

Technical Field

The present invention relates to a lighting device, and more particularly, to a dimming circuit for a lighting assembly, and a lighting assembly.

Background

The light source has been widely focused and applied due to its advantages of small size, high brightness, low power consumption, long service life, etc.

The existing light source is generally provided with a dimming function, a dimming circuit is required to be independently powered according to safety regulations, and otherwise, potential safety hazards exist.

Disclosure of Invention

The dimming circuit of the lighting assembly provided by the invention provides an independent power supply mode, is safe and reliable, controls the transformer to switch between the energy storage state and the energy release state through the PWM signal, and further provides preset current for the light source according to the turn ratio relationship of the transformer so as to realize dimming of the light source. The transformer is arranged in the dimming circuit, so that the dimming circuit can further supply power to the dimmer, partial power supply devices and the optical couplers of the isolation transmission devices are saved, and the dimming circuit has the remarkable cost advantage.

The invention provides a dimming circuit of an illumination assembly, wherein the illumination assembly comprises a light source and a control chip, the control chip is used for generating a Pulse Width Modulation (PWM) signal, the dimming circuit comprises a transformer, the transformer comprises a primary side and a secondary side, the primary side is connected with the control chip, the secondary side is connected with a dimmer, and the transformer can output a dimming signal to control the light source based on the PWM signal.

The invention also provides a lighting assembly comprising the dimming circuit as described above.

Other features and aspects will become apparent from the following detailed description, the accompanying drawings, and the claims.

Drawings

The invention may be better understood by describing exemplary embodiments thereof in conjunction with the following drawings, in which:

FIG. 1 is a schematic view of a lighting assembly of some embodiments of the present invention; and

fig. 2 is a schematic view of a lighting assembly of further embodiments of the present invention.

Detailed Description

While specific embodiments of the invention will be described below, it should be noted that in the course of describing these embodiments in detail, it is not possible for this specification to describe in detail all of the features of an actual embodiment in order to provide a concise description. It should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions are made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another.

The use of "first," "second," and similar terms in the description and claims of the present application do not denote any order, quantity, or importance, but rather the terms are used to distinguish one element from another. The terms "a" or "an," and the like, do not denote a limitation of quantity, but rather denote the presence of at least one. The word "comprise" or "comprises", and the like, means that the element or item listed before "comprises" or "comprising" covers the element or item listed after "comprising" or "comprises" and its equivalent, and does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, nor are they restricted to direct or indirect connections.

The lighting assemblies of the present application include, but are not limited to, Light Emitting Diode (LED) lamps, Organic Light Emitting Diode (OLED) lamps, fluorescent lamps, and High Intensity Discharge (HID) lamps. The LED lamp will be described in detail below as an example.

Fig. 1 shows a schematic view of a lighting assembly of some embodiments of the present invention. As shown in fig. 1, the lighting assembly 100 includes a light source 110 and a control chip 130, and the control chip 130 is used for generating a Pulse Width Modulation (PWM) signal. Specifically, pulse width modulation is an analog control method.

The lighting assembly 100 further includes a dimmer 140, which is an electric device for changing the luminous flux of the light source and adjusting the illumination level, and can achieve the purpose of dimming by changing the current value of the light source. The preset voltage amplitude of the dimmer is 0V to 10V. The voltage amplitude preset by the dimmer corresponds to different light source brightness, for example, 10V may be set to represent brightest, 0V to represent darkest, or of course, 10V may be set to be darkest, and 0V to be brightest.

In some embodiments, the lighting assembly 100 further comprises a dimming circuit 150, the dimming circuit 150 comprises a transformer 151, the transformer 151 comprises a primary side 166 and a secondary side 167, the primary side 166 of the transformer is connected to the control chip 130, the secondary side 167 is connected to the dimmer 140, and the transformer 151 can output a dimming signal to control the light source 110 based on the pulse signal. Specifically, the dimming signal includes a voltage value or a current value.

In some embodiments, the control chip is specifically an IC chip, i.e. a microelectronic device. Of course, any suitable control chip may be used. The control chip 130 has at least one control port, and preferably, the control chip 130 includes a first port for inputting or outputting the PWM signal and a second port for receiving the dimming signal, and the control chip 130 can control the light source 110 based on the dimming signal. Specifically, the first port of the control chip 130 is a PWM terminal, the second port is a DIM terminal, the PWM terminal can generate a PWM signal to transmit the PWM signal to the dimming circuit, so as to generate a dimming signal, and on the other hand, the PWM terminal can also generate a dimmed PWM signal (for example, change an amplitude and/or a duty ratio, etc.) based on the dimming signal received by the DIM terminal, and provide the dimmed PWM signal to the light source, so as to implement a dimming function. The DIM terminal is capable of receiving a dimming signal from the dimming circuit.

It should be noted by those skilled in the art that how the control chip controls the light source after the DIM terminal receives the dimming signal is not limited to the above-mentioned manner of adjusting the PWM signal, and may include any other suitable manner.

Even though only two ports are shown in fig. 1, it should be understood by one of ordinary skill in the art that the control chip may include any number of ports, and that any number of ports may include different functions.

In some embodiments, the lighting assembly further comprises a main control circuit 120, the main control circuit 120 is disposed between the light source 110 and the control chip 130, and the main control circuit 120 is capable of controlling the light source 110, e.g., on or off, based on a signal of the control chip 130. Specifically, the main control circuit 120 includes a rectifying unit (not shown in the figure) including a rectifying bridge for converting the alternating current into the direct current to be supplied to the light source. Of course, the main control circuitry may also include anti-interference circuitry for limiting EMI signals. Of course, the main control circuit may further include a detection circuit for detecting whether the two ends of the light source are properly installed or connected to the power source, and so on. It will be appreciated by those skilled in the art that the main control circuit is not limited to the above-mentioned circuits, but may also comprise any other circuits capable of implementing light source control.

The lighting assembly 100 further includes a first switch 170, an input terminal of the first switch 170 is connected to the control chip 130, and the dimming circuit 150 further includes a first diode D1, and a first diode D1 is connected between an output terminal of the first switch 170 and a first terminal of the primary side of the transformer 151.

Specifically, the first switch 170 may be, for example, Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), Insulated Gate Bipolar Transistors (IGBTs), Bipolar Junction Transistors (BJTs), thyristors, relays, or the like, or may be an LED control device such as a switching power supply or a linear power supply. In particular, the first switch may be constructed using any one or combination of materials including, but not limited to, silicon carbide

Specifically, taking a MOSFET as an example, the first switch 170 includes three ports, i.e., a gate g, a drain d and a source s, in this application, the gate g is defined as a first end of the first switch, the drain d is defined as a second end of the first switch, and the source s is defined as a third end of the first switch, in this application, the first end of the first switch 170 is connected to the control chip 130, the first end is an input end, and the second end is an output end. Specifically, the first terminal is connected to the PWM terminal of the control chip 130, the second terminal of the first switch 170 is connected to the first terminal of the primary side of the transformer through the first diode D1, and the third terminal of the first switch 170 is grounded.

The PWM terminal of the control chip 130 is capable of outputting a first set of PWM signals, where the first set of PWM signals includes a first PWM signal and a second PWM signal, the first PWM signal and the second PWM signal are alternately and repeatedly arranged, and a ratio of the first PWM signal to the second PWM signal is a duty ratio, and the duty ratio is fixed for the first set of PWM signals.

Specifically, when the PWM terminal of the control chip 130 outputs the first set of PWM signals, for the first PWM signal, the voltage of the first terminal of the first switch 170 is greater than the voltage of the second terminal, the first switch 170 is turned on, and for the second PWM signal, the voltage of the first terminal of the first switch 170 is not greater than the voltage of the second terminal, and the first switch 170 is turned off. Accordingly, when the PWM terminal of the control chip 130 outputs the first set of PWM signals, the first switch repeatedly switches between on and off, the switching time depends on the duty ratio of the PWM signal, and the PWM signal can control the on or off of the first switch 170.

The dimming circuit 150 further includes a dc power source Vcc, which is connected to the second terminal of the primary side of the transformer 151. Specifically, the dc power supply Vcc can be used to charge the transformer.

The dimming circuit 150 further includes a second diode D2 disposed on the primary side 166 and a first capacitor C1, the second diode D2 being connected between the positive terminal of the first diode D1 and the control chip 130, and the first capacitor C1 being connected between the negative terminal of the second diode D2 and ground.

Specifically, the positive terminal of the second diode D2 is connected to the first terminal of the primary side of the transformer, i.e., the positive terminal of the first diode D1, the negative terminal of the second diode D2 is connected to the first capacitor C1, and the second port DIM terminal of the control chip 130 is connected between the second diode D2 and the first capacitor C1.

Specifically, the dimming circuit further comprises a third diode D3 and a second capacitor C2 arranged on the secondary side, the positive terminal of the third diode D3 is connected to the first terminal of the secondary side of the transformer, and the dimmer and the second capacitor C2 are connected in parallel to two ends of the secondary side.

In some embodiments, the transformer can store energy based on the first PWM signal output by the control chip 130, and the transformer can release energy based on the second PWM signal output by the control chip 130 and output the dimming signal while releasing energy.

Specifically, when the PWM terminal of the control chip 130 outputs the first set of PWM signals, during the first PWM signal, the first switch 170 is turned on, the first diode D1 is turned on, and the dc power Vcc can charge the transformer 151, i.e., the transformer is in the energy storage state, and no output, i.e., no current or voltage, is provided to the dimmer on the secondary side; during the second PWM signal period, the first switch 170 is turned off, the first diode D1 is turned off, the transformer 151 discharges, i.e. releases energy, at this time, the secondary side has output, because the load of the dimmer is fixed, and the dimmer is adjusted or selected to a preset brightness, i.e. corresponding to a preset voltage value, therefore, for the secondary side, there is a fixed voltage and a fixed load, therefore, a fixed current value is generated, the current of the secondary side is also mapped to the primary side through the turns ratio relationship of the transformer, therefore, a fixed current is correspondingly generated in the primary side, the given current is the dimming signal, and is provided to the control chip, thereby controlling the light source.

In some embodiments, the transformer is further configured to power the dimmer when outputting the dimming signal. During the second PWM signal, the transformer is de-energized, at which time the transformer is able to provide voltage to the dimmer, thereby enabling power to be supplied to the dimmer. Therefore, the dimming circuit in the present application can realize a stable and safe dimming function through the transformer on the one hand, and can supply power to the dimmer on the other hand.

In some embodiments, the dimming signal can be identified based on the turns-ratio relationship of the transformer. Specifically, the turn ratio relationship refers to a proportional relationship between the windings of the primary side and the secondary side of the transformer, and in a non-limiting embodiment, the turn ratio relationship of the transformer may be 1:1, i.e., the primary side winding and the secondary side winding are identical, although the turn ratio relationship may be any suitable proportional relationship.

Specifically, for example, at this time, the dimmer is selected by the brightness preset by the dimming value, the voltage value corresponding to the brightness at this time is 5V, assuming that the load of the dimmer is 5 ohms, the current of the secondary side at this time is 1A, assuming that the turn ratio relationship of the transformer is 1:1, the current mapped to the primary side by the secondary side at this time is 1A, the current of the primary side is provided to the control chip as the dimming signal, and the control chip can correspondingly control the brightness of the light source.

Fig. 2 shows a schematic view of a lighting assembly of further embodiments of the present invention. For ease of illustration, the light source is not shown in FIG. 2, however, it should be understood by those skilled in the art that the main control circuit 120 is also connected to the light source. As shown in fig. 2, the lighting assembly 200 further includes a control chip 130, a dimmer 140, and a dimming circuit 150. The control chip comprises a first port PWM end and a second port DIM end.

The dimming circuit 150 includes a transformer 151, the transformer 151 includes a primary side 166 and a secondary side 167, the primary side 166 of the transformer is connected to the control chip 130, the secondary side 167 is connected to the dimmer 140, and the transformer 151 can output a dimming signal to control the light source 110 based on the pulse signal.

Unlike the lighting assembly 100 shown in fig. 1, the lighting assembly 200 further includes a pulse unit 280, and the pulse unit 280 is connected with the dimming circuit 140 for providing a stable PWM signal to the dimming circuit 140. In addition, the first diode is not provided in the lighting assembly 200.

Specifically, the lighting assembly 200 further includes a first switch 170, wherein a first port (input end) of the first switch 170 is connected to the control chip 130, specifically, to the PWM port of the control chip, a second port is connected to the main control circuit 120, and a third port is grounded. In the embodiment shown in fig. 2, the PWM signal generated at the PWM port of the control chip is no longer transmitted to the dimming circuit.

The dimming circuit 150 further includes a second diode D2 and a first capacitor C1 disposed on the primary side, the second diode D2 is connected in series with the first capacitor C1, the second diode D2 is connected to the first end of the primary side of the transformer, and the second end of the primary side of the transformer is connected to a dc power supply Vcc.

The secondary side of the transformer is provided with a third diode D3 and a second capacitor C2, the positive end of the third diode D3 is connected with the first end of the secondary side of the transformer, and the dimmer and the second capacitor C2 are connected in parallel at two ends of the secondary side.

Specifically, the output terminal of the pulse unit 280 is connected to the positive terminal of the second diode D2, that is, to the first terminal of the primary side of the transformer, and the pulse unit can generate a stable PWM signal to be transmitted to the dimming circuit.

Specifically, the pulse unit includes a second switch Q2, and an output terminal of the second switch is an output terminal of the pulse unit 280. The pulse unit is further connected with four resistors R1, R2, R3 and R4 in parallel, a third capacitor C3 connected between the resistor R1 and the resistor R2, and a fourth capacitor C4 connected between the resistor R3 and the resistor R4. Furthermore, the pulse unit further comprises another direct current power supply for supplying power to the four resistors.

Specifically, the pulse unit further comprises a third switch Q3 and a fourth switch Q4, a first end (input end) of the third switch Q3 is connected with the resistor R3, a second end of the third switch Q3 is connected with the resistor R1, a first end (input end) of the fourth switch Q4 is connected with the resistor R2, a second end of the fourth switch Q4 is connected with the resistor R4, and third ends of the third switch Q3 and the fourth switch Q4 are respectively connected with a third end of the second switch.

In one non-limiting embodiment, the second switch is a MOSFET and the third switch and the fourth switch are transistors. Specifically, the first terminal of the third switch is a base, the second terminal is a collector, the third terminal is an emitter, similarly, the first terminal of the fourth switch is a base, the second terminal is a collector, the third terminal is an emitter, the first terminal of the second switch is a gate, the second terminal is a drain, and the third terminal is a source. Specifically, the base of the third switch is connected with the resistor R3, the collector of the third switch is connected with the resistor R1, the base of the fourth switch is connected with the resistor R2, the collector of the fourth switch is connected with the resistor R4, the emitter of the third switch and the emitter of the fourth switch are respectively connected with the source of the second switch, the gate of the second switch is connected with the fourth resistor, and the drain of the second switch is the output end of the pulse circuit and is connected with the first end of the primary side of the transformer.

Specifically, the four resistors are configured to have different resistance values, so that the capacitors connected between every two resistors can be charged in turn, the third switch and the fourth switch are turned on in turn, the second switch can be turned on within a period of time, the voltage value is output, the voltage value is turned off within a period of time, no output is generated, and the turning-on and turning-off operations are continuously repeated, so that a stable and controllable PWM signal is output, and the duty ratio of the stable PWM signal can be changed by setting the resistance value.

Although one type of pulse circuit is shown in fig. 2, it should be understood by those skilled in the art that the pulse circuit is not limited to the above one type and may include any other suitable circuit form. In addition, although two switch modules are used in fig. 2, the same switch module or other combination may be used, for example, the second switch is a triode, the third switch and the fourth switch are MOSFET transistors, or both are MOSFET transistors, or other switch forms are used.

The present invention is illustrated in a circuit diagram that includes only some necessary circuits and components, and those skilled in the art will appreciate that the actual dimming circuit and/or the main control circuit and/or the lighting assembly may include other components and/or circuits, such as a rectifier circuit, a jamming-free circuit, etc. It will be appreciated by those skilled in the art that the present invention focuses on a dimming circuit, and the main control circuit can be controlled in any conventional manner without affecting the dimming circuit of the present invention.

In some embodiments, the present disclosure may include a plurality of light sources, and may also include a plurality of dimming circuits, so as to provide different dimming signals to different light sources, thereby implementing different dimming requirements. Specifically, the dimming in the present application may be adjusting the brightness, and may also be adjusting the color temperature.

The dimming circuit in the lighting assembly according to some embodiments of the present invention is safe, reliable and low in cost by using a separate power supply circuit, and in addition, the charging and discharging of the transformer are controlled by using the PWM signal, and the current fixed on the secondary side is mapped to the primary side based on the turn ratio of the transformer, and the current corresponding to the dimming brightness is provided to the control chip, thereby achieving the purpose of dimming. Meanwhile, the power supply module can supply power to the dimmer while dimming, and the power supply module of the dimmer does not need to be independently arranged. Moreover, the stability of the dimming circuit can be further improved by further arranging the pulse circuit.

Some embodiments of the present application provide a dimming circuit for a lighting assembly, the lighting assembly includes a light source and a control chip, the control chip is used for generating a Pulse Width Modulation (PWM) signal, the dimming circuit includes a transformer, which includes a primary side and a secondary side, the primary side is connected with the control chip, the secondary side is connected with a dimmer, the transformer is capable of outputting a dimming signal based on the PWM signal to control the light source.

Specifically, the transformer is further configured to supply power to the dimmer when outputting the dimming signal.

Specifically, the dimming signal can be confirmed based on a turn ratio relationship of the transformer.

Specifically, the transformer can store energy based on a first PWM signal output by the control chip, the transformer can release energy based on a second PWM signal output by the control chip, and the transformer outputs the dimming signal when releasing energy.

Specifically, the lighting assembly further comprises a main control circuit, which is disposed between the control chip and the light source and is configured to control the light source based on a signal of the control chip.

Specifically, the lighting assembly further comprises a pulse unit, and the pulse unit is connected with the dimming circuit and is used for providing a stable PWM signal to the dimming circuit.

Specifically, the control chip includes a first port and a second port, the first port is used for inputting or outputting the PWM signal, the second port is used for receiving the dimming signal, and the control chip can control the light source based on the dimming signal.

Specifically, the lighting assembly further includes a first switch, an input end of the first switch is connected to the control chip, and the dimming circuit further includes a first diode connected between an output end of the first switch and a first end of a primary side of the transformer.

Specifically, the first switch includes a field effect transistor or a triode, a first end of the first switch is connected with the control chip, a second end of the first switch is connected with the first diode, and a third end of the first switch is grounded.

Specifically, the dimming circuit further includes a second diode and a first capacitor, the second diode and the first capacitor are disposed on the primary side, the second diode is connected between the positive terminal of the first diode and the control chip, and the first capacitor is connected between the negative terminal of the second diode and the ground.

Specifically, the dimming circuit further includes a third diode and a second capacitor disposed on the secondary side, the second capacitor and the dimmer are connected in parallel between two ends of the secondary side, and the third diode is connected between the first end of the secondary side and the second capacitor.

Some embodiments of the present application also provide a lighting assembly, which includes a light source, a control chip and a dimming circuit, wherein the control chip is configured to generate a PWM signal, the dimming circuit includes a transformer, which includes a primary side and a secondary side, the primary side is connected to the control chip, the secondary side is connected to a dimmer, and the transformer is configured to output a dimming signal to control the light source based on the PWM signal.

Specifically, the lighting assembly further comprises a pulse unit, and the pulse unit is connected with the dimming circuit and is used for providing a stable PWM signal for the dimming circuit.

Some exemplary embodiments have been described above, however, it should be understood that various modifications may be made. For example, suitable results may be achieved if the described techniques are performed in a different order and/or if components in the described systems, architectures, devices, or circuits are combined in a different manner and/or replaced or supplemented by additional components or their equivalents. Accordingly, other embodiments are within the scope of the following claims.

Claims

1. A dimming circuit for a lighting assembly, the lighting assembly including a light source and a control chip for generating a Pulse Width Modulation (PWM) signal from the dimming signal and for controlling the light source, the dimming circuit comprising:

and the transformer comprises a primary side and a secondary side, the primary side is connected with the control chip, the secondary side is connected with the dimmer, and the transformer can transmit and output a dimming signal to the control chip based on the PWM signal so as to control the light source.

2. The dimming circuit of claim 1, wherein the transformer is further configured to power the 0-10V dimming terminal when proportionally delivering the dimming signal based on a turns-ratio relationship of the transformer.

3. The dimming circuit of claim 1, wherein the transformer is capable of storing energy when turned on based on a first PWM signal output by the control chip, and is capable of releasing energy when turned off based on a second PWM signal output by the control chip, and wherein the transformer delivers the dimming signal when released.

4. The dimming circuit of claim 1, wherein the lighting assembly further comprises a main control circuit disposed between the control chip and the light source and configured to control the light source based on a signal of the control chip.

5. The dimming circuit of claim 1, wherein the lighting assembly further comprises a pulsing unit coupled to the dimming circuit for providing a PWM signal to the dimming circuit.

6. The dimming circuit of claim 1, wherein the control chip comprises a first port for inputting or outputting the PWM signal and a second port for receiving the dimming signal, the control chip being capable of controlling the light source based on the dimming signal.

7. The dimming circuit of claim 1, wherein the lighting assembly further comprises a first switch, an input of the first switch being coupled to the control chip, the dimming circuit further comprising a first diode coupled between an output of the first switch and the first end of the primary side of the transformer.

8. The dimming circuit of claim 8, further comprising a second diode disposed on the primary side, the second diode being coupled between a positive terminal of the first diode and the control chip, and a first capacitor coupled between a negative terminal of the second diode and ground.

9. The dimming circuit of claim 8, further comprising a third diode and a second capacitor disposed on the secondary side, the second capacitor and the dimmer being connected in parallel between the two ends of the secondary side, the third diode being connected between the first end of the secondary side and the second capacitor.

10. A lighting assembly comprising the dimming circuit as claimed in any one of claims 1 to 9.