CN212628504U - Lamp power supply circuit and lamp - Google Patents

Abstract

The application provides a lamp power supply circuit and a lamp. The lamp power supply circuit comprises: the power supply comprises a power supply conversion circuit, a first switching circuit, a second power supply, a feedback circuit and a controller. The first end of the power supply conversion circuit is used for being electrically connected with the first end of the fan. The second end of the power conversion circuit is used for being electrically connected with a first power supply. The first end of the first switching circuit is used for being electrically connected with the first end of the fan. The second power supply is electrically connected with the second end of the first switching circuit. The first end of the feedback circuit is used for being electrically connected with the second end of the fan. The feedback circuit is used for acquiring waveform signals of the rotating speed of the fan. The controller is respectively electrically connected with the power conversion circuit, the third end of the first switching circuit and the second end of the feedback circuit. When the waveform signal is a non-zero signal and the output voltage of the power conversion circuit is lower than a preset threshold, the controller controls the power conversion circuit to stop working. The controller controls the second power supply to supply power to the fan through the first switching circuit.

Description

Lamp power supply circuit and lamp

Technical Field

The application relates to the technical field of lamps, in particular to a lamp power supply circuit and a lamp.

Background

The FINE1200L series products of the lamp have high brightness and high color rendering index. Among them, the LED lamp with high color rendering index is mainly used in tv stations and theaters. At present, with the increasingly advanced high definition television technology, the requirement for the LED lamp is also higher and higher. The specific requirements of the LED lamp are that the color temperature is controlled to be about 6000K, Ra is more than or equal to 95, R9 is more than or equal to 90 and the like. In order to achieve these three technical parameters, a specific heat dissipation condition is required in addition to the high color rendering index and the optical lens set matching of the white light module in the LED lamp.

When the brightness of the white light module in the LED lamp changes from dark to bright, the color temperature of light spots emitted by the lamp has large deviation. In order to achieve heat balance of heat dissipation of the LED lamp, color temperature deviation is reduced. The traditional mode is a technical scheme of radiating heat by using a 12V three-wire or four-wire fan. In the scheme of using the 12V three-wire fan, the FB pin of the DC-to-DC power supply IC is controlled to output the required voltage through a signal PWMFAN. The working voltage of the fan is generally between 6 and 12V, and when the output voltage of the DC/DC power supply circuit is lower than 6V, the fan can not rotate or stop surreptitiously in a clearance mode. And in the scheme of using the 12V four-wire fan, the fan rotating speed is controlled through a PWM signal line of the 12V four-wire fan. The maximum rotating speed of the fan is 3800RPM +/-10%, the input frequency of a PWM signal line of the fan is 25KHz, and when the duty ratio of a PWM signal is 0%, the rotating speed of the fan is still maintained at 950RPM and cannot be lower than 950 RPM.

Namely, when the brightness of the white light module in the LED lamp changes from dark to bright, the technical scheme of radiating by adopting a 12V three-wire or four-wire fan is adopted, and the color temperature of light spots emitted by the lamp still has large deviation.

SUMMERY OF THE UTILITY MODEL

Therefore, it is necessary to provide a lamp power supply circuit and a lamp, aiming at the problem that when the brightness of a white light module in the conventional LED lamp changes from dark to bright, the color temperature of a light spot emitted by the lamp has a large deviation.

A luminaire supply circuit comprising:

the first end of the power supply conversion circuit is used for being electrically connected with the first end of the fan, and the second end of the power supply conversion circuit is used for being electrically connected with a first power supply;

the first end of the first switching circuit is electrically connected with the fan;

the second power supply is electrically connected with the second end of the first switching circuit;

the first end of the feedback circuit is electrically connected with the second end of the fan and used for acquiring a waveform signal of the rotating speed of the fan; and

and the controller is electrically connected with the power supply conversion circuit, the third end of the first switching circuit and the second end of the feedback circuit respectively.

In one embodiment, the lamp power supply circuit further includes:

the first end of the first voltage detection circuit is electrically connected with the first end of the first switching circuit, the second end of the first voltage detection circuit is electrically connected with the controller, the third end of the first voltage detection circuit is grounded and used for detecting the output voltage of the second power supply, and when the output voltage is smaller than or equal to a first set threshold value, the controller controls the second power supply and the loop between the fan to be disconnected through the first switching circuit and controls the power supply switching circuit to convert the supply voltage provided by the first power supply and then output the converted supply voltage to the fan.

In one embodiment, the lamp power supply circuit further includes:

and the charging circuit is electrically connected with the third end of the first switching circuit, and when the output voltage is less than or equal to the first set threshold, the controller controls the conduction of a loop between the second power supply and the charging circuit through the first switching circuit.

In one embodiment, the lamp power supply circuit further includes:

and the first end of the second voltage detection circuit is connected with the third end of the first switching circuit and the charging circuit in a common way, the second end of the second voltage detection circuit is electrically connected with the controller and is used for detecting the input voltage of the second power supply, and when the input voltage reaches a second set threshold value, the second power supply is determined to be charged.

In one embodiment, the lamp power supply circuit further includes:

a third power supply; and

a first end of the second switching circuit is connected with a fourth end of the first switching circuit and the third power supply in common, a second end of the second switching circuit is used for being electrically connected with the fan, and a third end of the second switching circuit is electrically connected with the controller;

when the second power supply supplies power to the fan, the controller controls the third power supply to supply power to the fan through the second switching circuit within preset time.

In one embodiment, the lamp power supply circuit further includes:

and the first end of the voltage stabilizing circuit is electrically connected with a power supply, the second end of the voltage stabilizing circuit is connected with the fifth end of the first switching circuit and the fourth end of the second switching circuit in a common mode, and the third end of the voltage stabilizing circuit is electrically connected with the controller.

In one embodiment, the lamp power supply circuit further includes:

the first end of the switch circuit is used for being electrically connected with the third end of the fan, the second end of the switch circuit is grounded, the third end of the switch circuit is electrically connected with the controller, and the controller controls the starting and stopping of the fan through the switch circuit.

In one embodiment, the lamp power supply circuit further includes:

and a first end of the power supply indicating circuit is electrically connected with a first end of the first switching circuit, and a second end of the power supply indicating circuit is grounded.

In one embodiment, the first switching circuit includes:

the first end of the relay switch is electrically connected with the fan, the second end of the relay switch is electrically connected with the second power supply, and the third end of the relay switch is grounded;

the first end of the controllable switch tube is electrically connected with the relay coil, the second end of the controllable switch tube is grounded, and the control end of the controllable switch tube is electrically connected with the controller.

A lamp comprising the lamp power supply circuit of any one of the above embodiments;

the fan is connected with the first end of the power supply conversion circuit, the first end of the first switching circuit and the first end of the feedback circuit in a common way; and

and the white light module is electrically connected with the controller.

Compared with the prior art, the lamp power supply circuit and the lamp have the advantages that the second power supply is electrically connected with the fan through the first switching circuit. And electrically connecting the power conversion circuit, the first switching circuit and the feedback circuit with the controller. When the feedback circuit collects that the waveform signal of the rotating speed of the fan is a non-zero signal and determines that the output voltage of the power supply conversion circuit is lower than a preset threshold value, the controller can control the first power supply to stop supplying power through the power supply conversion circuit and control the second power supply to supply power to the fan through the first switching circuit, so that the fan works in a state of low voltage and low rotating speed, and the color temperature deviation caused by the change of a white light module in the lamp from dark to bright is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic circuit diagram of a lamp power supply circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic circuit diagram of a lamp power supply circuit according to an embodiment of the present disclosure;

fig. 3 is a schematic circuit diagram of a part of a lamp power supply circuit according to an embodiment of the present application;

fig. 4 is a schematic circuit diagram of a portion of a lamp power supply circuit according to another embodiment of the present application;

fig. 5 is a circuit block diagram of a lamp power supply circuit according to an embodiment of the present application;

FIG. 6 is a circuit schematic diagram of a voltage regulator circuit according to an embodiment of the present application;

fig. 7 is a schematic circuit diagram of a lamp according to an embodiment of the present disclosure.

Description of reference numerals:

10. a lamp power supply circuit; 100. a power conversion circuit; 101. a fan; 102. a first power supply; 20. A light fixture; 200. a first switching circuit; 210. a relay; 220. a controllable switching tube; 230. a first resistor; 240. a second resistor; 300. a second power supply; 310. a third power supply; 320. a second switching circuit; 400. A feedback circuit; 500. a controller; 501. a white light module; 510. a voltage stabilizing circuit; 511. a power source; 520. A switching circuit; 530. a power supply indicating circuit; 600. a first voltage detection circuit; 700. a charging circuit; 800. and a second voltage detection circuit.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and those skilled in the art will be able to make similar modifications without departing from the spirit of the application and it is therefore not intended to be limited to the embodiments disclosed below.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1, an embodiment of the present application provides a lamp power supply circuit 10. The luminaire supply circuit 10 comprises: the power conversion circuit 100, the first switching circuit 200, the second power supply 300, the feedback circuit 400 and the controller 500. The first end of the power conversion circuit 100 is electrically connected to the first end of the fan 101. The second terminal of the power conversion circuit 100 is electrically connected to a first power source 102. A first end of the first switching circuit 200 is configured to be electrically connected to a first end of the blower 101. The second power source 300 is electrically connected to the second terminal of the first switching circuit 200. A first end of the feedback circuit 400 is configured to be electrically connected to a second end of the fan 101. The feedback circuit 400 is configured to collect a waveform signal of the rotational speed of the fan 101.

The controller 500 is electrically connected to the power conversion circuit 100, the third terminal of the first switching circuit 200, and the second terminal of the feedback circuit 400. When the waveform signal is a non-zero signal and the output voltage of the power conversion circuit 100 is lower than a preset threshold, the controller 500 controls the power conversion circuit 100 to stop working. The controller 500 controls the second power source 300 to supply power to the blower 101 through the first switching circuit 200.

In one embodiment, the power conversion circuit 100 may be an AC/DC conversion circuit. In one embodiment, the power conversion circuit 100 may also be a DC/DC conversion circuit. Specifically, a specific circuit topology of the DC/DC conversion circuit is shown in fig. 2: the DC/DC conversion circuit mainly adopts a circuit topology taking TPS54560DDA (U8) as a main device. Wherein the capacitor C45 is the guiding capacitor of U8. The VIN pin of U8 is used to input +48V (i.e., the supply voltage of the first power supply 102). The electrolytic capacitor E1 mainly plays a role in filtering and energy storage. The capacitors C53, C54 are decoupling capacitors. The resistors R62, R63 constitute the enable for the lowest input voltage of U8. Resistor R64 controls the switching frequency of U8. The resistor R65 and the capacitors C57 and C58 form a compensation circuit. The diode D4, the inductor L1 and the electrolytic capacitor C20 form a voltage output circuit of the U8, that is, the U8 outputs voltage to the fan 101 through the voltage output circuit.

In one embodiment, the output voltage of the DC/DC conversion circuit can be changed by adjusting the resistance value of the FB pin to ground of U8. Specifically, the resistance value of the resistor connected in parallel to the ground in the voltage dividing circuit composed of the resistors R66 and R67 can be changed by changing the input signal PWMFAN of the triode amplifying circuit composed of the triode Q2 and the resistors R55, R40 and R41. For example, when the input signal PWMFAN is 0% on duty, the output voltage of the DC/DC conversion circuit is 6V; when the input signal PWMFAN duty ratio is 100%, the output voltage of the DC/DC conversion circuit is 12V; when the input signal PWMFAN duty cycle is changed between 0% -100%, the output voltage of the DC/DC conversion circuit is changed between 6-12V. Wherein the input signal PWMFAN may be output through the controller 500. The FB pin of the U8 can be adjusted to the resistance to ground by the controller 500, so as to change the output voltage of the DC/DC conversion circuit. In one embodiment, the input signal PWMFAN may also be output by other devices (e.g., CPU, etc.).

In one embodiment, the EN pin of U8 is used to electrically connect a triode amplifier circuit consisting of a triode Q3 and resistors R26 and R42. The enabling of the DC/DC conversion circuit can be changed through the triode amplifying circuit. Specifically, the transistor Q1 can be controlled to be turned on or off by the signal ENFAN. When the ENFAN signal is low, the transistor Q1 is turned off, and no voltage is output from the output terminal of U8. When the signal ENFAN is at a high level, the transistor Q1 is turned on, and the output terminal of the U8 outputs a voltage. Wherein the signal ENFAN can be outputted through the controller 500. That is, whether the DC/DC conversion circuit outputs a voltage may be controlled by the controller 500. In one embodiment, the signal ENFAN may also be output by other devices (e.g., CPU, etc.).

It is understood that the specific circuit structure of the first switching circuit 200 is not limited as long as the second power supply 300 is controlled to supply power to the blower 101. In one embodiment, the first switching circuit 200 may include a switch tube. The switch tube may be a controllable switch tube such as an IGBT (Insulated Gate Bipolar Transistor), a MOSFET (Metal Oxide Semiconductor Field-Effect Transistor), and the like.

In one embodiment, as shown in fig. 2, the first switching circuit 200 may also include: a relay 210 and a controllable switch tube 220. Specifically, a first end of the relay 210 switch is electrically connected to a first end of the fan 101. A second terminal of the switch of the relay 210 is electrically connected to the second power source 300, and a third terminal of the switch of the relay 210 is grounded. A first end of the controllable switching tube 220 is electrically connected to the coil of the relay 210. The second terminal of the controllable switching tube 220 is grounded. The control terminal of the controllable switch tube 220 is electrically connected to the controller 500.

In one embodiment, the controllable switch 220 may be an IGBT, a MOSFET, or the like. In one embodiment, the controllable switch 220 may be a high-level conducting and low-level disconnecting switch. Specifically, when the controller 500 outputs a high level (i.e., the signal LI _ unchrg is a high level) to the first switching circuit 200, that is, the controller 500 outputs a high level to the control terminal of the controllable switching tube 220, the controllable switching tube 220 is turned on, and at this time, the coil of the relay 210 controls the switching action of the relay 210. That is, the relay 210 switch can control the loop between the second power source 300 and the fan 101 to conduct, so that the second power source 300 supplies power to the fan 101. When the controller 500 outputs a low level to the controllable switch 220, the controllable switch 220 is turned off. At this time, the coil of the relay 210 controls the switching operation of the relay 210, and the circuit between the second power supply 300 and the fan 101 is disconnected. I.e. the fan 101 loses the power supply of the second power supply 300.

In one embodiment, the first switching circuit 200 may further include: a first resistor 230 and a second resistor 240. Specifically, a first end of the first resistor 230 is electrically connected to a control end of the controllable switching tube 220. A second terminal of the first resistor 230 is electrically connected to the controller 500. A first end of the second resistor 240 is electrically connected to a control end of the controllable switching tube 220. A second terminal of the second resistor 240 is grounded. The controllable switching tube 220 can be protected from damage by the voltage stabilization effect of the first resistor 230 and the second resistor 240.

In one embodiment, the second power supply 300 may be a lithium battery. Specifically, the lithium battery may be electrically connected to the first switching circuit 200 through a lithium battery connector. It is understood that the specific circuit structure of the feedback circuit 400 is not limited as long as the feedback circuit has the function of collecting the waveform signal (i.e., the signal IN1B) of the rotation speed of the fan 101. In one embodiment, as shown in fig. 2, the feedback circuit 400 may include a pull-up resistor R47 and a current limiting resistor R45. After the feedback circuit 400 collects the waveform signal of the rotation speed of the fan 101, the waveform signal may be sent to the controller 500.

If the voltage corresponding to the waveform signal received by the controller 500 is zero, it is determined that the fan 101 is in a shutdown state. At this time, the controller 500 stops outputting the PWM signal to the LED module in the lamp, so that the LED module in the lamp is turned off, thereby protecting the LED module and preventing the LED module from being damaged. If the voltage corresponding to the waveform signal received by the controller 500 is a non-zero voltage, it is determined that the fan 101 is in a working state. At this time, the controller 500 may continue to output PWM signals to the LED modules in the lamp, so that the LED modules operate.

In one embodiment, when the waveform signal received by the controller 500 is a non-zero signal and the output voltage of the power conversion circuit 100 is lower than the preset threshold, the controller 500 may output a low level to the power conversion circuit 100, so as to control the power conversion circuit 100 to stop operating. That is, the power conversion circuit 100 does not convert the power supply voltage provided by the first power supply 102.

Meanwhile, the controller 500 outputs a high level to the first switching circuit 200. That is, the controller 500 outputs a high level to the controllable switch 220, so as to control the controllable switch 220 to be turned on. Further, the relay 210 controls the loop between the second power supply 300 and the fan 101 to be turned on, so that the second power supply 300 supplies power to the fan 101, the fan 101 operates in a low-voltage low-rotation-speed state, and color temperature deviation caused by change of a white light module in a lamp from dark to bright is reduced. That is to say, the fan 101 adopts the above power supply logic, and can realize the switching from the first power supply 102 to the second power supply 300, so that the fan 101 is in a low-voltage low-rotation-speed working state, thereby reducing the color temperature deviation caused by the change from dark to bright of a white light module in a lamp, and improving the display effect of the lamp. In one embodiment, the preset threshold may be set according to actual requirements, for example, the preset threshold may be set to 6V.

In one embodiment, the blower 101 may be electrically connected to the first terminal of the power conversion circuit 100 and the first terminal of the first switching circuit 200 through a blower socket. In one embodiment, one or two of the fans 101 may be connected to the same fan receptacle. In one embodiment, the fan 101 may be a fan with a size of 92 × 25mm and a rated current of 0.38A. Other sizes and currents of fans may be used for the fan 101.

In this embodiment, the second power supply 300 is electrically connected to the blower 101 through the first switching circuit 200. The power conversion circuit 100, the first switching circuit 200, and the feedback circuit 400 are all electrically connected to the controller 500. When the feedback circuit 400 collects a waveform signal of the rotation speed of the fan 101 as a non-zero signal and determines that the output voltage of the power conversion circuit 100 is lower than a preset threshold, the controller 500 may control the first power source 102 to stop supplying power through the power conversion circuit 100 and control the second power source 300 to supply power to the fan 101 through the first switching circuit 200, so that the fan 101 operates in a state of low voltage and low rotation speed, and the color temperature deviation caused by the change of a white light module in a lamp from dark to bright is reduced.

Referring to fig. 2, in an embodiment, the lamp power supply circuit 10 further includes: the first voltage detection circuit 600. A first terminal of the first voltage detection circuit 600 is electrically connected to a first terminal of the first switching circuit 200. A second terminal of the first voltage detection circuit 600 is electrically connected to the controller 500. The third terminal of the first voltage detection circuit 600 is grounded. When the power supply of the fan 101 is the second power supply 300, the first voltage detection circuit 600 is configured to detect the output voltage of the second power supply 300. When the output voltage is less than or equal to a first set threshold, the controller 500 controls the loop between the second power supply 300 and the fan 101 to be disconnected through the first switching circuit 200, and controls the power conversion circuit 100 to convert the supply voltage provided by the first power supply 102 and output the converted supply voltage to the fan 101.

It is to be understood that the specific circuit configuration of the first voltage detection circuit 600 is not limited as long as it has a function of detecting the output voltage of the second power supply 300. In one embodiment, the first voltage detection circuit 600 may include resistors R90 and R91. In one embodiment, the first voltage detection circuit 600 is used for detecting the output voltage of the second power supply 300 by: when the power supply of the fan 101 is the second power supply 300, the first voltage detection circuit 600 detects the voltage output by the first terminal of the first switching circuit 200 (i.e., the output voltage of the second power supply 300).

When the output voltage (TEST) detected by the first voltage detection circuit 600 is less than or equal to the first set threshold, it indicates that the second power supply 300 is in low-power discharge. At this time, the controller 500 may output a low level to the first switching circuit 200. The first switching circuit 200 controls the loop between the second power supply 300 and the fan 101 to be disconnected according to a low level, that is, controls the second power supply 300 not to continuously supply power to the fan 101. Meanwhile, the controller 500 outputs a high level to the power conversion circuit 100, so that the power conversion circuit 100 continues to operate, and converts the supply voltage provided by the first power source 102 and outputs the converted supply voltage to the fan 101.

When the output voltage (TEST) detected by the first voltage detection circuit 600 is greater than the first set threshold, it indicates that the second power supply 300 is discharging with normal power. At this time, the controller 500 may control a loop between the second power source 300 and the fan 101 to be turned on through the first switching circuit 200, so that the second power source 300 supplies power to the fan 101. In one embodiment, the first set threshold may be set according to actual requirements, for example, the first set threshold may be set to 1.5V.

In one embodiment, the lamp power supply circuit 10 further includes: a charging circuit 700. The charging circuit 700 is electrically connected to the third terminal of the first switching circuit 200. When the output voltage is less than or equal to the first set threshold, the controller 500 controls the loop between the second power supply 300 and the charging circuit 700 to be conducted through the first switching circuit 200.

In one embodiment, the specific circuit topology of the charging circuit 700 is not limited as long as it has a function of charging the second power supply 300. In one embodiment, the circuit topology of the charging circuit 700 may be as shown in fig. 2: the charging circuit 700 mainly adopts a circuit topology with LTC4079 as a main device. The electrolytic capacitor E2 is a filter capacitor. The capacitor C9 is a decoupling capacitor. Resistor R13 is a constant mode for setting the charging current. The resistors R6 and NTC1 are used to detect the temperature of the charging IC (i.e., LTC 4079). The resistors R14 and R15 set the output voltage of the charging IC, i.e., the charging voltage of the second power supply 300.

In one embodiment, when the output voltage of the second power supply 300 is less than or equal to the first set threshold, that is, the second power supply 300 does not continue to supply power to the fan 101, the controller 500 may output a low level to the first switching circuit 200. The first switching circuit 200 controls the loop between the second power supply 300 and the charging circuit 700 to conduct according to a low level. That is, the second power supply 300 may be charged by the charging circuit 700 at this time. That is, when the second power supply 300 is not discharged, the second power supply 300 is in a state where it is charged by the charging circuit 700. In one embodiment, when the charging circuit 700 is charging, the charging power of the charging circuit 700 may be provided by a 48V power source.

In one embodiment, the lamp power supply circuit 10 further includes: the second voltage detection circuit 800. The first terminal of the second voltage detection circuit 800 is connected to the third terminal of the first switching circuit 200 and the charging circuit 700. A second terminal of the second voltage detection circuit 800 is electrically connected to the controller 500. The second voltage detection circuit 800 is configured to detect an input voltage of the second power supply 300 when the charging circuit 700 charges the second power supply 300. When the input voltage reaches a second set threshold, it is determined that the charging of the second power supply 300 is completed.

It is to be understood that the specific circuit configuration of the second voltage detection circuit 800 is not limited as long as it has a function of detecting the input voltage of the second power supply 300. In one embodiment, the second voltage detection circuit 800 may include resistors R92 and R93. When the input voltage detected by the second voltage detection circuit 800 reaches the second set threshold, that is, the input voltage is equal to the second set threshold, it indicates that the charging of the second power supply 300 is completed. At this time, if the waveform signal is a non-zero signal and the output voltage of the power conversion circuit 100 is lower than a preset threshold, the controller 500 may control the second power supply 300 to supply power to the fan 101 through the first switching circuit 200, so that the fan 101 operates in a low-voltage low-rotation-speed state, and the color temperature deviation caused by the change of the white light module in the lamp from dark to bright is reduced.

In an embodiment, the lamp power supply circuit 10 may be configured to switch charging and discharging of the second power supply 300 by cooperation of the first voltage detection circuit 600, the second voltage detection circuit 800 and the controller 500 (for specific switching logic, please refer to the above embodiment, which is not described herein again). Thus, when the waveform signal is a non-zero signal and the output voltage of the power conversion circuit 100 is lower than the preset threshold, the second power supply 300 can be cyclically charged and discharged. For example, if the dimming value of the lamp is between 0% and 70% and the output voltage of the power conversion circuit 100 is lower than the preset threshold, the power supply of the fan 101 must be switched to the power conversion circuit 100. At this time, the second power supply 300 is switched to the charging mode.

In one embodiment, the lamp power supply circuit 10 further includes: a third power supply 310 and a second switching circuit 320. The first terminal of the second switching circuit 320 is connected to the fourth terminal of the first switching circuit 200 and the third power supply 310. A second end of the second switching circuit 320 is used for electrically connecting with the fan 101. The third terminal of the second switching circuit 320 is electrically connected to the controller 500. When the second power supply 300 supplies power to the fan 101, the controller 500 controls the third power supply 310 to supply power to the fan 101 through the second switching circuit 320 within a preset time. In one embodiment, the preset time may be set according to actual requirements, for example, the preset time may be set to 5 s.

In one embodiment, the third power supply 310 and the second power supply 300 may have the same structure. That is, the third power source 310 may also employ a lithium battery. Similarly, the second switching circuit 320 may also have the same circuit topology as the first switching circuit 200, and the specific circuit topology is shown in fig. 2.

When the controller 500 controls the second power source 300 to supply power to the fan 101, the controller 500 may control the third power source 310 to supply power to the fan 101 through the second switching circuit 320 during the preset time. Specifically, when the controller 500 outputs a high level to the first switching circuit 200, the controller may output a high level to the second switching circuit 320 within the preset time, so as to control the third power supply 310 to supply power to the fan 101. I.e. when the second power supply 300 and the third power supply 310 are discharged in parallel. The third power supply 310 is controlled to supply power to the fan 101 within a preset time, so that overcurrent impact generated when the third power supply 310 and the second power supply 300 supply power simultaneously can be avoided, and safety is improved.

On the contrary, when the controller 500 controls the charging circuit 700 to charge the second power supply 300, the controller 500 may also output a low level to the second switching circuit 320, so that the second switching circuit 320 controls the loop between the third power supply 310 and the blower 101 to be disconnected. While the second power supply 300 is connected in series with the third power supply 310 through the fourth terminal of the first switching circuit 200. That is, the charging circuit 700 may simultaneously charge the second power supply 300 and the third power supply 310. In this way, the lamp power supply circuit 10 respectively performs logic control on the first switching circuit 200 and the second switching circuit 320 through the controller 500, so that parallel discharge or series charge can be performed between the second power supply 300 and the third power supply 310 at the same time, thereby improving charge-discharge efficiency.

Referring to fig. 3, in an embodiment, the output end of the power conversion circuit 100 may load a plurality of fans 101. For example, the output terminal of the power conversion circuit 100 may load 6 12V three-wire fans. Specifically, the output end of the power conversion circuit 100 may be connected in parallel with three fan sockets, and each fan socket is electrically connected with two three-wire fans. Correspondingly, each fan socket is electrically connected with one feedback circuit 400. Thus, by matching each feedback circuit 400 with the controller 500 (how to implement the logic described with reference to the above embodiment, which is not described herein), it can be determined whether the fan 101 electrically connected to each fan socket is in a working state, so that the controller 500 can determine whether to extinguish the LED module in the lamp.

Similarly, as shown in fig. 4, the number of the first switching circuit 200, the second power supply 300, the charging circuit 700, the second voltage detection circuit 800, the third power supply 310, and the second switching circuit 320 may be plural. For example, when the output end of the power conversion circuit 100 loads 6 12V three-wire fans, the number of the first switching circuit 200, the second power supply 300, the charging circuit 700, the second voltage detection circuit 800, the third power supply 310, and the second switching circuit 320 may be three.

At this time, the controller 500 may respectively perform logic switching on each first switching circuit 200 and each second switching circuit 320, so that the three second power supplies 300 and the three third power supplies 310 connected in parallel discharge simultaneously, and drive the 6 12V three-wire fans to be in a low-voltage low-rotation-speed working state, thereby reducing color temperature deviation caused by a change from dark to bright of a white light module in the lamp. On the contrary, when three second power supplies 300 and three third power supplies 310 need to be charged, each charging circuit 700 corresponds to one second power supply 300 and one third power supply 310. That is, one of the charging circuits 700 may simultaneously charge the second power supply 300 and the third power supply 310 connected in series.

In one embodiment, if the output end of the power conversion circuit 100 loads a fan set composed of 6 12V three-wire fans, the working voltage of the fan set changes according to the change of the dimming value of the white light module, and each dimming value corresponds to different color temperature values, CCI values, Ra values, R9 values, and temperature values displayed on the panel. The specific parameters are shown in the following table:

the FAN1-FAN6 correspond to 6 12V three-wire FANs. When the dimming value of the white light module is between 80% and 70% (i.e. above 70%), the operating voltage of each fan in the fan set is greater than or equal to 6V (i.e. the preset threshold). In other words, the power supply voltage provided by the first power supply 102 may be converted by the power conversion circuit 100 and then output to the fan set, so as to drive the fan set to operate. And when the dimming value of the white light module is between 0% and 70%, the working voltage of each fan in the fan set is less than 6V. At this time, the controller 500 may sequentially control the second power supply 300 and the third power supply 310 to supply power to the fan group through the first switching circuit 200 and the second switching circuit 320. Meanwhile, when the temperature of the NTC exceeds 75 ℃, the operating voltage of each fan needs to be increased step by step until the temperature of the NTC is lower than 75 ℃ (the operating voltage of each fan maintains the dynamic change). Therefore, by adopting the dynamic adjustment logic, the color temperature of the white light module in the lamp can be controlled between 6000K-6200K, Ra is more than or equal to 95, and R9 is more than or equal to 90. That is to say, the lamp adopts the lamp power supply circuit 10, so that the color temperature deviation caused by the change of the white light module from dark to bright can be reduced.

In one embodiment, the lamp power supply circuit 10 further includes: a switching circuit 520. The first terminal of the switching circuit 520 is electrically connected to the third terminal of the fan 101. The second terminal of the switching circuit 520 is connected to ground. The third terminal of the switching circuit 520 is electrically connected to the controller 500. The controller 500 controls the start and stop of the fan 101 through the switch circuit 520.

In one embodiment, the specific circuit topology of the switching circuit 520 may be as shown in fig. 2 or fig. 4: the switching circuit 520 comprises a pull-down resistor R4, a current-limiting resistor R43 and a MOS transistor Q200. When the signal FANEN1 output by the controller 500 is at a high level, the fan 101 is turned on and operates normally. When the signal FANEN1 is low, the fan 101 stops operating. That is, the controller 500 can control the start and stop of the fan 101 through the switch circuit 520, so as to improve controllability.

In one embodiment, the lamp power supply circuit 10 further includes: a power indication circuit 530. A first terminal of the power indication circuit 530 is electrically connected to a first terminal of the first switching circuit 200. The second terminal of the power indication circuit 530 is grounded. In one embodiment, the circuit topology of the power indication circuit 530 may be as shown in fig. 2 or fig. 4: the power indication circuit 530 includes a light emitting diode D18 and a resistor R93. When the second power supply 300 or the third power supply 310 discharges, D18 is lit. On the contrary, when the second power supply 300 and the third power supply 310 are charged, D18 is extinguished. That is, by observing whether the light emitting diode D18 is lighted, the operating states of the second power supply 300 and the third power supply 310 can be determined, and the safety of the power supply use can be improved.

In one embodiment, the lamp power supply circuit 10 further includes a diode D2 and a diode D3. The diode D2 is disposed at the output terminal of the power conversion circuit 100, and the anode of the diode D2 is electrically connected to the output terminal of the power conversion circuit 100. The diode D3 is disposed between the first terminal of the fan 101 and the first terminal of the first switching circuit 200, and the anode of the diode D3 is electrically connected to the first terminal of the first switching circuit 200. D2 and D3 are both voltage-directed output diodes. In one embodiment, the reverse breakdown voltage of D2 and D3 is 100V and the maximum overload current is 20A. When the second power supply 300 supplies power to the fan 101, D2 may protect the output terminal of the power conversion circuit 100. Likewise, D3 may protect the second power source 300 when the first power source 102 is supplying power to the fan 101.

Referring to fig. 5, in an embodiment, the lamp power supply circuit 10 further includes: the voltage stabilizing circuit 510. The first end of the voltage stabilizing circuit 510 is used for electrically connecting with a power supply 511. The second terminal of the voltage stabilizing circuit 510 is commonly connected to the fifth terminal of the first switching circuit 200 and the fourth terminal of the second switching circuit 320. The third terminal of the voltage stabilizing circuit 510 is electrically connected to the controller 500.

In one embodiment, the voltage regulation circuit 510 may employ a circuit topology as shown in FIG. 6. Wherein PL1 and PL2 are connected to two ends of the power supply 511, respectively. The supply voltage provided by the power supply 511 can be converted into +5V and +3.3V by the voltage stabilizing circuit 510. The voltage stabilizing circuit 510 can provide +5V to the first switching circuit 200 and the second switching circuit 320, respectively. The regulation circuit 510 may also provide +5V as a pull-up level to a resistor R47. The stabilizing circuit 510 provides +3.3V to the controller 500. That is, +5V is the power supply voltage of the first switching circuit 200 and the second switching circuit 320. +3.3V is the supply voltage for the controller 500. The voltage stabilizing circuit 510 converts the power supply voltage provided by the power supply 511 into +5V and +3.3V, so that the stability of voltage conversion can be improved.

Referring to fig. 7, another embodiment of the present application provides a lamp 20. The lamp 20 includes the lamp power supply circuit 10, at least one fan 101, and the white light module 501 according to any of the embodiments. The fan 101 is connected to the first end of the power conversion circuit 100, the first end of the first switching circuit 200, and the first end of the feedback circuit 400. The white light module 501 is electrically connected to the controller 500. The lamp 20 of this embodiment adopts the logic for dynamically adjusting the operating voltage of the fan 101 in the above embodiments, so as to ensure that the color temperature of the white light module 501 in the lamp is controlled between 6000K and 6200K, Ra is greater than or equal to 95, and R9 is greater than or equal to 90. That is to say, the lamp 20 using the lamp power supply circuit 10 can reduce the color temperature deviation caused by the change from dark to bright of the white light module.

To sum up, the second power supply 300 is electrically connected to the fan 101 through the first switching circuit 200. The power conversion circuit 100, the first switching circuit 200, and the feedback circuit 400 are all electrically connected to the controller 500. When the feedback circuit 400 collects a waveform signal of the rotation speed of the fan 101 as a non-zero signal and determines that the output voltage of the power conversion circuit 100 is lower than a preset threshold, the controller 500 may control the first power source 102 to stop supplying power through the power conversion circuit 100 and control the second power source 300 to supply power to the fan 101 through the first switching circuit 200, so that the fan 101 operates in a state of low voltage and low rotation speed, and the color temperature deviation caused by the change of a white light module in a lamp from dark to bright is reduced.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (10)

1. A lamp power supply circuit, comprising:

the first end of the power supply conversion circuit (100) is used for being electrically connected with the first end of the fan (101), and the second end of the power supply conversion circuit (100) is used for being electrically connected with the first power supply (102);

a first switching circuit (200), wherein a first end of the first switching circuit (200) is electrically connected with a first end of the fan (101);

a second power supply (300) electrically connected to a second terminal of the first switching circuit (200);

a first end of the feedback circuit (400) is electrically connected with a second end of the fan (101) and used for acquiring a waveform signal of the rotating speed of the fan (101); and

and the controller (500) is respectively and electrically connected with the third end of the power supply conversion circuit (100), the third end of the first switching circuit (200) and the second end of the feedback circuit (400).

2. The lamp power supply circuit of claim 1 further comprising:

a first voltage detection circuit (600), wherein a first end of the first voltage detection circuit (600) is electrically connected with a first end of the first switching circuit (200), a second end of the first voltage detection circuit (600) is electrically connected with the controller (500), and a third end of the first voltage detection circuit (600) is grounded;

when the second power supply (300) supplies power to the fan (101), the first voltage detection circuit (600) is used for detecting the output voltage of the second power supply (300), and when the output voltage is smaller than or equal to a first set threshold, the controller (500) controls the loop between the second power supply (300) and the fan (101) to be disconnected through the first switching circuit (200), and controls the power conversion circuit (100) to convert the supply voltage provided by the first power supply (102) and output the converted supply voltage to the fan (101).

3. The lamp power supply circuit of claim 2 further comprising:

and the charging circuit (700) is electrically connected with the third end of the first switching circuit (200), and when the output voltage is less than or equal to the first set threshold, the controller (500) controls the loop between the second power supply (300) and the charging circuit (700) to be conducted through the first switching circuit (200).

4. The lamp power supply circuit of claim 3 further comprising:

the first end of the second voltage detection circuit (800), the third end of the first switching circuit (200) and the charging circuit (700) are connected in common, the second end of the second voltage detection circuit (800) is electrically connected with the controller (500), when the charging circuit (700) charges the second power supply (300), the second voltage detection circuit (800) is used for detecting the input voltage of the second power supply (300), and when the input voltage reaches a second set threshold value, the charging of the second power supply (300) is determined to be completed.

5. The lamp power supply circuit of claim 1 further comprising:

a third power supply (310); and

a second switching circuit (320), a first end of the second switching circuit (320) is connected to the fourth end of the first switching circuit (200) and the third power supply (310), a second end of the second switching circuit (320) is used for being electrically connected to the fan (101), and a third end of the second switching circuit (320) is electrically connected to the controller (500);

when the second power supply (300) supplies power to the fan (101), the controller (500) controls the third power supply (310) to supply power to the fan (101) through the second switching circuit (320) within a preset time.

6. The lamp power supply circuit of claim 5 further comprising:

the first end of the voltage stabilizing circuit (510) is used for being electrically connected with a power supply (511), the second end of the voltage stabilizing circuit (510) is connected with the fifth end of the first switching circuit (200) and the fourth end of the second switching circuit (320) in a common mode, and the third end of the voltage stabilizing circuit (510) is electrically connected with the controller (500).

7. The lamp power supply circuit of claim 1 further comprising:

the first end of the switch circuit (520) is used for being electrically connected with the third end of the fan (101), the second end of the switch circuit (520) is grounded, the third end of the switch circuit (520) is electrically connected with the controller (500), and the controller (500) controls the fan (101) to be started or stopped through the switch circuit (520).

8. The lamp power supply circuit of claim 1 further comprising:

a power supply indication circuit (530), a first end of the power supply indication circuit (530) is electrically connected with a first end of the first switching circuit (200), and a second end of the power supply indication circuit (530) is grounded.

9. A lamp supply circuit according to any one of the claims 1-8, characterized in that the first switching circuit (200) comprises:

a first end of a switch of the relay (210) is used for being electrically connected with a first end of the fan (101), a second end of the switch of the relay (210) is electrically connected with the second power supply (300), and a third end of the switch of the relay (210) is grounded; and

a controllable switch tube (220), wherein a first end of the controllable switch tube (220) is electrically connected with the coil of the relay (210), a second end of the controllable switch tube (220) is grounded, and a control end of the controllable switch tube (220) is electrically connected with the controller (500).

10. A luminaire characterized by comprising a luminaire power supply circuit (10) as claimed in any one of claims 1-8;

at least one fan (101), wherein the fan (101) is connected with the first end of the power conversion circuit (100), the first end of the first switching circuit (200) and the first end of the feedback circuit (400) in common; and

and the white light module (501) is electrically connected with the controller (500).

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