CN209767879U

CN209767879U - PCB compatible with multi-mode constant-current dimming circuit

Info

Publication number: CN209767879U
Application number: CN201920216574.0U
Authority: CN
Inventors: 辛士民
Original assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd
Current assignee: Guangzhou Shiyuan Electronics Thecnology Co Ltd
Priority date: 2019-02-20
Filing date: 2019-02-20
Publication date: 2019-12-10
Anticipated expiration: 2029-02-20

Abstract

The utility model discloses a compatible multimode constant current dimmer circuit's PCB board, PWM dimmer circuit is when setting for the out of work of simulation dimmer circuit, receives the PWM dimming signal of PWM modulator circuit output to export to the IC chip, drive IC chip realizes the PWM mode of adjusting luminance, and simulation dimmer circuit is when setting for the out of work of PWM dimmer circuit, adjusts the direct current of LED load through the adjustable circuit of voltage, so that the IC chip realizes the simulation mode of adjusting luminance. The embodiment of the utility model provides a PCB board can be set for by PWM dimmer circuit work or by simulation dimmer circuit work, can realize on a circuit board, need not design two circuit boards, has solved and has need two kinds of PCB boards of manufacturing and designing among the prior art, the change of the debugging anchor clamps that cause, reduces production efficiency and increases manufacturing cost's problem, has improved production efficiency, has reduced manufacturing cost.

Description

PCB compatible with multi-mode constant-current dimming circuit

Technical Field

the embodiment of the utility model provides a constant current technical field that adjusts luminance especially relates to a PCB board of compatible multimode constant current dimming circuit.

Background

Recently, as an environmentally friendly and energy saving solution, Light Emitting Diode (LED) lighting has found its own use in a wide range of applications such as automobiles, homes, office buildings, hotels, airports, road loads, and the like. With the widespread use of LED loads, the brightness of the LED load needs to be changed accordingly in different applications. This means that the driver of the LED should be able to support the function of adjusting the brightness of the LED. Currently, there are two main dimming techniques: pulse Width Modulation (PWM) dimming and analog dimming.

The PWM dimming means that on the premise of not changing the PWM square wave period, the duty ratio of PWM is adjusted through a certain control method to control the operation and cut-off time of an IC chip and control the duty ratio of output current so as to adjust the brightness of the LED lamp. The analog dimming means that the dimming purpose is achieved by controlling the direct current of the LED load. LED brightness is almost proportional to the magnitude of the dc current through the LED load. Detecting the size of a resistor by changing the current connected with the LED load in series; or the LED driving chip is provided with a voltage input interface, and the input voltage is changed, so that the current of the LED load can be changed.

In the prior art, the PWM dimming Circuit has a Printed Circuit Board (PCB) corresponding thereto, and the analog dimming Circuit has a PCB Board corresponding thereto. The PCB of the PWM dimming circuit and the PCB of the analog dimming circuit are different only in the dimming circuit, and the design structures of other peripheral circuits are basically the same. When other requirements of customers on the PCB are the same and only the dimming circuit is different, two different PCBs are designed and manufactured. Then, a plurality of moulds need to be developed in a PCB factory to meet the requirement, and the production line causes the replacement of the debugging clamp only because of the difference of the dimming circuit, thereby greatly hindering the production efficiency and increasing the production cost.

SUMMERY OF THE UTILITY MODEL

The utility model provides a PCB board of compatible multimode constant current dimmer circuit has solved and has needed the design to make two kinds of PCB boards among the prior art, the change of the debugging anchor clamps that cause, reduces production efficiency and increases manufacturing cost's problem.

In a first aspect, the embodiment of the utility model provides a PCB board of compatible multimode constant current dimmer circuit, include: an IC chip, a PWM dimming circuit, and an analog dimming circuit, wherein,

The dimming control pin of the IC chip is connected with the PWM dimming circuit, and the load current detection pin of the IC chip is connected with the analog dimming circuit;

The PWM dimming circuit is used for receiving a PWM dimming signal output by the PWM modulation circuit when the analog dimming circuit is set to be out of work, outputting the PWM dimming signal to the IC chip and driving the IC chip to realize a PWM dimming mode;

And the analog dimming circuit is used for adjusting the direct current of the LED load through the voltage adjustable circuit when the PWM dimming circuit is set to be out of work so as to enable the IC chip to realize an analog dimming mode.

the PCB compatible with the multi-mode constant-current dimming circuit, the IC chip, the PWM dimming circuit and the analog dimming circuit are provided by the embodiment of the invention, wherein when the PWM dimming circuit is set to be out of work, the PWM dimming signal output by the PWM modulation circuit is received and output to the IC chip to drive the IC chip to realize the PWM dimming mode, and when the analog dimming circuit is set to be out of work, the DC of an LED load is adjusted through the voltage adjustable circuit, so that the IC chip realizes the analog dimming mode. The PCB provided by the embodiment of the invention can set whether the PWM dimming circuit works or the analog dimming circuit works, can be realized on one circuit board without designing two circuit boards, solves the problems of replacement of a debugging clamp, reduction of production efficiency and increase of production cost caused by the need of designing and manufacturing two PCB in the prior art, improves the production efficiency and reduces the production cost.

Drawings

fig. 1 is a schematic diagram of a PCB board compatible with a multimode constant current dimming circuit in an embodiment of the present invention;

fig. 2 is a schematic diagram of a PCB board of a PWM dimming circuit according to an embodiment of the present invention;

Fig. 3 is a schematic diagram of a PCB board of an analog dimming circuit according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

Fig. 1 is a schematic diagram of a PCB board compatible with a multimode constant current dimming circuit in an embodiment of the present invention; the embodiment can be suitable for designing and manufacturing a PCB, and the PCB compatible with the multi-mode constant-current dimming circuit is arranged in a control circuit of the LED lamp. As shown in fig. 1, the PCB compatible with the multimode constant current dimming circuit mainly includes the following parts: a PWM dimming circuit 101, an analog dimming circuit 102, and an IC chip 103.

A dimming control pin of the IC chip 103 is connected with the PWM dimming circuit 101, a load current detection pin of the IC chip is connected with the analog dimming circuit 103, and the dimming control pin of the IC chip 103 is an 8 th pin of the IC chip; the load current detection pin of the IC chip is the 5 th pin of the IC chip.

The PWM dimming circuit 101 is configured to receive a PWM dimming signal output by the PWM modulation circuit 110 and output the PWM dimming signal to the IC chip 103 when the analog dimming circuit 102 is set to be not in operation, and drive the IC chip 103 to implement a PWM dimming mode; and the analog dimming circuit 102 is configured to adjust a direct current of the LED load through the voltage adjustable circuit 104 when the PWM dimming circuit 101 is set to be not in operation, so that the IC chip 103 implements an analog dimming mode.

In this embodiment, the IC chip 103 is an integrated chip capable of implementing an analog dimming mode or a PWM dimming mode by designing different peripheral circuits. Preferably, the IC chip 103 is OB 3350E. The present embodiment provides only one preferred chip, and does not limit the model of the chip, and an appropriate IC chip 103 may be selected as needed. The PWM dimming circuit 101 is a circuit that can implement a PWM dimming method in cooperation with the IC chip 103 and its peripheral circuits. The analog dimming circuit 102 is a circuit that can realize an analog dimming mode in cooperation with the IC chip 103 and its peripheral circuits.

Setting the analog dimming circuit 102 not to operate means that a welding position of the analog dimming circuit 102 is provided on the PCB, and when the analog dimming mode is not required to be implemented but only the PWM dimming mode is implemented, the welding position of the analog dimming circuit 102 is left out and the analog dimming circuit 102 is not installed.

Setting the PWM dimming circuit 101 not to operate means that a welding position of the PWM dimming circuit 101 is provided on the PCB, and when the PWM dimming mode is not required to be implemented and only the analog dimming mode is implemented, the welding position of the PWM dimming circuit 101 is left without installing the analog PWM dimming circuit 101.

The PWM dimming signal refers to a square wave signal with adjustable duty ratio, and the PWM modulation circuit 110 refers to a circuit capable of generating the PWM dimming signal, i.e., the square wave signal with adjustable duty ratio. In this embodiment, the circuit configuration of the PWM modulation circuit 110 is not limited, and the user can select an appropriate PWM modulation circuit 110 as needed.

the voltage adjustable circuit 140 is a circuit with adjustable output voltage. The voltage is adjusted, so that the direct current of the LED load is adjusted, and the analog dimming mode is realized. It should be noted that the voltage adjustable circuit 140 outputs any voltage between 0 and 5V. The voltage adjustable circuit 140 may be an adjustable voltage-stabilized power supply or a fixed power supply, and the adjustable output voltage is realized through an adjustable resistor. In this embodiment, the voltage adjustable circuit 140 is only illustrated, and is not limited thereto, and a user may select any circuit capable of implementing the output voltage adjustable function according to a requirement.

The PCB has an IC chip 103 integrated thereon, and the PCB has the IC chip 103 and peripheral circuits of the IC chip 103 integrated thereon. When the PWM dimming mode needs to be implemented, the analog dimming circuit 102 is not installed, so that the PCB implements the PWM dimming mode. When the analog dimming mode needs to be realized, the PWM dimming circuit 101 is not installed, so that the analog dimming mode is realized on the PCB. The PCB provided by the embodiment is only provided with the PWM dimming circuit to realize the PWM dimming mode, the installation 101 of the simulation dimming circuit 102 realizes the simulation dimming mode, the positions of the IC chip and the peripheral circuit do not need to be changed, the design of two PCBs is avoided, the problems that in the prior art, two PCBs need to be designed and manufactured, the replacement of a debugging clamp is caused, the production efficiency is reduced, the production cost is increased are solved, the production efficiency is improved, and the production cost is reduced.

Further, fig. 2 is a schematic diagram of a PCB board of the PWM dimming circuit provided in the embodiment of the present invention; as shown in fig. 2, the PWM dimming circuit 101 includes: a first resistor R1, a second resistor R2, a first jumper J1 and a first diode D1; the dimming control pin 8 of the IC chip 103 is connected to one end of a first jumper J1 through a first resistor R1, and the other end of the first jumper J1 is connected to the PWM modulation circuit 110; the dimming control pin 8 of the IC chip 103 is connected to the anode of the first diode D1, and the cathode of the first diode D1 is connected to the pulse signal generating circuit through the second resistor R2.

The jumper wire refers to a metal connecting wire for connecting two required points in the PCB. In the present embodiment, two ends of the first jumper J1 are respectively connected to the first resistor R1 and the PWM modulation circuit 110.

When PWM dimming is realized, the working principle of the PCB is as follows: the PWM modulation circuit 110 outputs a PWM dimming signal; the PWM dimming signal is output to the dimming control pin 8 of the IC chip 103 through the first jumper J1 and the first resistor R1, and when the PWM dimming signal is a low level signal, the dimming control pin 8 of the IC chip 103 receives the low level signal, and triggers the output driving pin 5 of the IC chip to generate the low level signal, so as to control the power tube in the conversion circuit 107 to be turned off. When the PWM dimming signal is a high level signal, the dimming control pin 8 of the IC chip 103 receives the high level signal, and triggers the output driving pin 5 of the IC chip to generate the high level signal, so as to control the power tube in the conversion circuit 107 to be turned on. The regulation of the LED load brightness is realized by controlling the duty ratio of the driving signal output by the output driving pin 5 of the IC chip.

Illustratively, a 9V power supply supplies power to the LED lamp, a switch connecting the power supply and the LED is closed for 50ms, and the LED lamp is supplied with 9V power within the 50 ms; if the switch is turned off in the next 50ms, the LED lamp gets 0V power in the 50 ms. If the switch is turned on and off 10 times in 1 second, the LED lamp will be turned on and the power supply of 4.5V is continuously turned on. The voltage at the two ends of the LED lamp is in a linear relation with the brightness, and the LED lamp can obtain different voltages by controlling the on-off time of the switch, so that the brightness of the LED lamp can be adjusted.

in the present embodiment, when the PWM dimming mode is implemented, the pulse generating circuit 102 does not affect the PWM dimming signal. The pulse generating circuit 102 is used for generating a pulse signal. When the PWM dimming signal is a high level signal, if the pulse signal is a low level signal, the first diode D1 is turned on, and the dimming control pin 8 of the IC chip 103 is at a high level; when the PWM dimming signal is a low level signal, if the pulse signal is a high level signal, the first diode D1 is turned off, and the dimming control pin 8 of the IC chip 103 is at a low level. Whether the pulse generating circuit 102 is a high level signal or a low level signal does not affect the PWM dimming signal.

further, fig. 3 is a schematic diagram of a PCB board of the analog dimming circuit provided in the embodiment of the present invention; as shown in fig. 3, the analog dimming circuit 102 includes: a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a second diode D2, wherein the load current detection pin 5 of the IC chip 103 is connected to the load current detection circuit 130 through the third resistor R3; the load current detection pin 5 of the IC chip 103 is connected to one end of the fifth resistor R5 through the fourth resistor R4, the other end of the fifth resistor R5 is connected to the cathode of the second diode D2, and the anode of the second diode D2 is connected to the voltage-adjustable circuit 140.

Further, the analog dimming circuit 102 further includes: a third diode D3; the anode of the third diode D3 is connected to the pulse signal generating circuit 120 through the second resistor R2, and the cathode of the third diode is connected to the dimming control pin 8 of the IC chip 103.

When realizing the simulation mode of adjusting luminance, the theory of operation of PCB board: the voltage adjustable circuit 140 generates a voltage with any value of 0-5V, the voltage of the voltage adjustable circuit 140 is applied to the LED load through the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the second diode D2, and the current flowing through the LED lamp is adjusted by adjusting the output voltage of the voltage adjustable circuit 140. The current flowing through the LED lamp and the brightness of the LED lamp are in a linear relation, and different voltage values are output through the voltage adjustable circuit 140, so that the LED lamp can obtain different voltages, and the brightness of the LED lamp can be adjusted.

further, an analog dimming mode is implemented on the PCB, the pulse signal generated by the pulse generating circuit 120 is an enable signal, when the enable signal is at a high level, the IC chip starts to operate, and when the enable signal is at a high level, the IC chip stops operating. The enable signal is input to the dimming control pin 8 of the IC chip 103 through the third diode D3.

Further, the PCB further includes an overvoltage detection circuit 150; the overvoltage detection circuit 150 is connected to the overvoltage protection pin 7 of the IC chip 103, and is configured to detect an input voltage of the LED load, and when the input voltage of the LED load is higher than a preset value, the IC chip 103 is controlled to stop working, and the overvoltage protection pin 7 of the IC chip 103 is grounded through the sixth resistor R6 and the first capacitor C1, respectively.

in this embodiment, the voltage applied to the LED load may exceed the maximum voltage value that the LED load can withstand due to the fluctuation of the mains voltage or the failure of the control circuit, which may shorten the service life of the LED load or even burn the LED load. The overvoltage detection circuit 150 is configured to detect voltages at two ends of the LED load, and when the voltages at the two ends of the LED load exceed a preset maximum voltage value that the LED load can bear, generate an overvoltage control signal to control the IC chip 103 to stop working, so that the LED control circuit stops working, and the LED load is prevented from bearing the maximum voltage value for a long time. In the embodiment, different preset values can be set according to the application occasions and types of the LED loads and the control precision. Preferably, the preset value is the highest voltage that the LED load can withstand.

Further, a high frequency or a low frequency signal may exist in the voltage value collected by the over voltage detection circuit 150, which affects the normal operation of the IC chip 103. The first capacitor C1 is used to filter out high frequency or low frequency signals in the voltage value, thereby enhancing the anti-interference performance of the IC chip 103.

the overvoltage protection pin 7 of the IC chip 103 is grounded via a sixth resistor R6. The sixth resistor R6 is a pull-down resistor, and is used to fix the voltage of the overvoltage protection pin 7 at a low level when no signal is input to the overvoltage protection pin 7, so as to avoid the input of an external signal and cause the misoperation of the IC chip 103.

furthermore, the PCB board further includes a power supply 160, the power supply 160 is connected to the power input pin of the IC chip 103 through a seventh resistor R7, and the power input pin 1 of the IC chip 103 is grounded through a second capacitor C2.

In the present embodiment, the power supply 160 is a power supply device that provides a normal operating voltage for the IC chip, and the required operating voltage is different according to the type of the IC chip 103. In this embodiment, the type of the power supply 160 is not limited, and the power supply 160 may be a battery for supplying a dc power, a constant current and voltage regulator, or other power supply device.

If the power supply 160 is directly connected to the power input pin 1 of the IC chip 103, the current passing through the IC chip 103 may exceed the current received by the power input pin 1 of the IC chip 103, and the IC chip 103 may be directly burned. The seventh resistor R7 has a current limiting function to prevent the IC chip from being burned out due to an excessive current passing through the power input pin 1 of the IC chip 103.

The first capacitor C1 is used to filter out high frequency or low frequency signals in the voltage signal provided by the power supply 160, thereby enhancing the anti-interference performance of the IC chip 103.

Further, the PCB board further includes: the conversion circuit 170 is connected with the output control pin 2 of the IC chip 103, and the dimming signal output by the output control pin 2 of the IC chip 103 controls the on and off of the MOS transistor in the conversion circuit, so as to adjust the LED load brightness.

Further, the PCB board further includes: the output current detection circuit 108, the output current detection circuit 108 is connected with the output current detection pin 4 of the IC chip 103 through the eighth resistor R8, and is used for detecting the current of the source of the MOS transistor in the conversion circuit 170, and the IC chip 103 adjusts the dimming signal output by the output control pin 5 according to the input signal of the output current detection pin; the output current detection pin of the IC chip is grounded through a third capacitor C3.

In this embodiment, the output current detection circuit 108 is used for detecting the current of the source of the MOS transistor in the converter circuit 170, and outputting the current to the IC chip 103 through the output current detection pin 4, so that the converter circuit 170 realizes constant current control.

the third capacitor C3 is used to output a high frequency or low frequency signal of the voltage signal provided by the current detection circuit 108, thereby enhancing the anti-interference performance of the IC chip 103.

Further, the IC chip 103 further includes: a ground pin 4 and a loop compensation pin 6; the IC chip 103 is grounded through the grounding pin 4; the loop compensation pin 6 of the IC chip 103 is grounded through the fourth capacitor C4, and the loop compensation pin 6 of the IC chip is grounded through the series connection of the fifth capacitor C5 and the ninth resistor R9.

the PCB compatible with the multi-mode constant-current dimming circuit, the IC chip, the PWM dimming circuit and the analog dimming circuit are provided by the embodiment of the invention, wherein when the PWM dimming circuit is set to be out of work, the PWM dimming signal output by the PWM modulation circuit is received and output to the IC chip to drive the IC chip to realize the PWM dimming mode, and when the analog dimming circuit is set to be out of work, the DC of an LED load is adjusted through the voltage adjustable circuit, so that the IC chip realizes the analog dimming mode. The PCB provided by the embodiment of the invention can set whether the PWM dimming circuit works or the analog dimming circuit works, can be realized on one circuit board without designing two circuit boards, solves the problems of replacement of a debugging clamp, reduction of production efficiency and increase of production cost caused by the need of designing and manufacturing two PCB in the prior art, improves the production efficiency and reduces the generation cost.

it should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims

1. The utility model provides a compatible multimode constant current dimmer circuit's PCB board which characterized in that includes: an IC chip, a PWM dimming circuit, and an analog dimming circuit, wherein,

The PWM dimming circuit is used for receiving a PWM dimming signal output by the PWM modulation circuit when the analog dimming circuit is set to be out of operation, outputting the PWM dimming signal to the IC chip and driving the IC chip to realize a PWM dimming mode;

2. The PCB board compatible with the multimode constant current dimming circuit according to claim 1, wherein the PWM dimming circuit comprises: the circuit comprises a first resistor, a second resistor, a first jumper and a first diode;

The dimming control pin of the IC chip is connected with one end of the first jumper through the first resistor, and the other end of the first jumper is connected with the PWM modulation circuit;

And a dimming control pin of the IC chip is connected with the anode of the first diode, and the cathode of the first diode is connected with a pulse signal generating circuit through the second resistor.

3. The PCB board of claim 1, wherein the analog dimming circuit comprises: the load current detection pin of the IC chip is connected with the load current detection circuit through the third resistor;

And a load current detection pin of the IC chip is connected with one end of a fifth resistor through a fourth resistor, the other end of the fifth resistor is connected with the cathode of a second diode, and the anode of the second diode is connected with the voltage adjustable circuit.

4. The PCB board of claim 3, wherein the analog dimming circuit further comprises: a third diode; and the anode of the third diode is connected with the pulse signal generating circuit through a second resistor, and the cathode of the third diode is connected with the dimming control pin of the IC chip.

5. The PCB board compatible with the multimode constant current dimming circuit according to claim 1, further comprising an overvoltage detection circuit;

The overvoltage detection circuit is connected with the overvoltage protection pin of the IC chip and is used for detecting the input voltage of the LED load, and when the input voltage of the LED load is higher than a preset value, the IC chip is controlled to stop working;

And the overvoltage protection pin of the IC chip is grounded through a sixth resistor and the first capacitor respectively.

6. The PCB board compatible with multimode constant current dimming circuit of claim 1, further comprising a power supply source,

The power supply is connected with the power input pin of the IC chip through a seventh resistor, and the power input pin of the IC chip is grounded through a second capacitor.

7. The PCB compatible with a multimode constant current dimming circuit of claim 1, further comprising: an AC/DC conversion circuit for converting AC/DC power,

The alternating current-direct current conversion circuit is connected with an output control pin of the IC chip, and a dimming signal output by the output control pin of the IC chip controls the on and off of an MOS (metal oxide semiconductor) tube in the alternating current-direct current conversion circuit so as to adjust the brightness of the LED load.

8. The PCB board compatible with multimode constant current dimming circuit of claim 7, further comprising: an output current detection circuit for detecting the output current of the power supply,

The output current detection circuit is connected with an output current detection pin of the IC chip through an eighth resistor and is used for detecting the current of the source electrode of the MOS transistor in the conversion circuit, and the IC chip adjusts the dimming signal output by the output control pin according to the input signal of the output current detection pin;

And the output current detection pin of the IC chip is grounded through a third capacitor.

9. The PCB board compatible with multimode constant current dimming circuit of claim 1, wherein the IC chip further comprises: a ground pin and a loop compensation pin;

The IC chip is grounded through the grounding pin;

And the loop compensation pin of the IC chip is grounded through a fourth capacitor, and the loop compensation pin of the IC chip is grounded after being connected in series through a fifth capacitor and a ninth resistor.