CN215871919U

CN215871919U - Two-wire system PWM changes constant current module of adjusting luminance

Info

Publication number: CN215871919U
Application number: CN202121985081.7U
Authority: CN
Inventors: 刘滨
Original assignee: Nanjing Puietel Technology Co ltd
Current assignee: Nanjing Puietel Technology Co ltd
Priority date: 2021-08-23
Filing date: 2021-08-23
Publication date: 2022-02-18
Anticipated expiration: 2031-08-23

Abstract

The utility model discloses a two-wire system PWM-to-constant current dimming module which comprises a constant current dimming chip, a PNP type triode, an inductor, a first diode, a second diode, an electrolytic capacitor, a current-limiting resistor, a second resistor, a third resistor and a fourth resistor. The base level of the PNP type triode is connected with the first input terminal through the second resistor, the base level of the PNP type triode is connected with the second input terminal through the third resistor and is grounded after being connected with the negative electrode of the second diode, the collector electrode of the PNP type triode is connected with the constant-current dimming chip through the fourth resistor, and the emitter level of the PNP type triode is connected with the power supply and the current-limiting resistor in sequence and then is connected with the first output terminal. Through VCC signal and PWM signal two-wire system input, power and PWM signal fuse, carry out the constant current drive and PWM adjusts luminance to the constant current dimming lamp, need not external power cord again, saved the quantity of electric wire.

Description

Two-wire system PWM changes constant current module of adjusting luminance

Technical Field

The utility model relates to the technical field of electronic circuits, in particular to a two-wire system PWM-to-constant current dimming module.

Background

Many dimming controllers on the market at present have multiple modes such as PWM dimming, 0-10V dimming, DALI dimming, constant current dimming, and PWM dimming controller can the direct connection lamp area, realizes the PWM function of adjusting luminance, but PWM dimming controller can't directly connect the constant current dimming lamp, for example adjust luminance down lamp, adjust luminance shot-light etc. then need a kind of PWM change constant current dimming module urgently, be used for being connected the constant current dimming lamp to PWM adjusts the light control module, realizes the function of adjusting luminance.

SUMMERY OF THE UTILITY MODEL

In order to solve the above problems in the prior art, an object of the present invention is to provide a two-wire system PWM-to-constant current dimming module, which performs constant current driving and PWM dimming on a constant current dimming lamp by using two-wire system input and power supply and PWM signal fusion.

In order to solve the technical problems, the technical scheme adopted by the utility model is as follows: a two-wire PWM-to-constant current dimming module comprises a constant current dimming chip, a PNP type triode, an inductor, a first diode, a second diode, an electrolytic capacitor, a current-limiting resistor, a second resistor, a third resistor, a fourth resistor, a second input terminal, a fourth input terminal, a first output terminal and a third output terminal;

the base level of PNP type triode passes through the second resistance and connects the second input terminal, the second input terminal is used for inputing the VCC signal, and the base level of PNP type triode passes through the third resistance and connects the fourth input terminal and connect the negative pole of second diode, the anodal ground connection of second diode, the fourth input terminal is used for inputing the PWM signal, the collecting electrode of PNP type triode passes through the fourth resistance and is connected with pin 3 of constant current dimming chip, and the emitter of PNP type triode connects first output terminal after being connected with power, current-limiting resistance in proper order, first output terminal is used for being connected with the positive terminal of LED lamps and lanterns.

As a further improvement of the utility model, the model of the constant-current dimming chip is PT 4115.

As a further improvement of the utility model, the model of the PNP type triode is BC 857.

As a further improvement of the utility model, the first diode and the second diode are both SS34SMA in type.

As a further improvement of the utility model, the capacity of the electrolytic capacitor is 220uF, and the upper limit value of the voltage born by the electrolytic capacitor is 35V.

As a further improvement of the utility model, the inductance of the inductor is 100 uH.

Compared with the prior art, the utility model has the following beneficial effects:

1. according to the two-wire system PWM-to-constant current dimming module, two-wire system input is adopted, the power supply and the PWM signals are fused, constant current driving is carried out on the constant current dimming lamp, PWM dimming is carried out, an external power line is not needed, and the number of wires is saved.

2. According to the two-wire PWM-to-constant current dimming module, the service life of a lamp is effectively prolonged by outputting constant current signals for dimming driving, and the two-wire PWM-to-constant current dimming module is high in conversion efficiency, low in heating and free of delay.

Drawings

Fig. 1 is a schematic circuit connection diagram of a two-wire PWM-to-constant current dimming module according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 1 is a schematic structural diagram of an embodiment of a two-wire PWM-to-constant current dimming module according to the present invention, a main body of the two-wire PWM-to-constant current dimming module includes a constant current dimming chip U1, a PNP transistor Q1, an inductor L1, a first diode D1, a second diode D2, an electrolytic capacitor C1, a current limiting resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a second input terminal P2, a fourth input terminal P4, a first output terminal P1, and a third output terminal P3.

The PNP triode Q1 has a base connected to a second input terminal P2 through a second resistor R2, the second input terminal P2 is used for inputting VCC signals, the base of the PNP triode Q1 is connected to a fourth input terminal P4 and the negative electrode of a second diode D2 through a third resistor R3, the positive electrode of the second diode D2 is grounded GND, the fourth input terminal P4 is used for inputting PWM signals, the collector of the PNP triode Q1 is connected to a pin 3 of a constant current dimming chip U1 through a fourth resistor R4, the emitter of the PNP triode Q1 is sequentially connected to a power supply VCC and a current limiting resistor R1 and then connected to a first output terminal P1, and the first output terminal P1 is used for being connected to the positive electrode of an LED lamp. The model of the NP type triode Q1 is BC857, and the model of the second diode D2 is SS34 SMA. A pin 3 of the constant current dimming chip U1 is grounded to GND through a fifth resistor R5, a pin 2 of the constant current dimming chip U1 is grounded, a pin 1 of the constant current dimming chip U1 is connected to the anode of a first diode D1, the cathode of the first diode D1 is connected to VCC, a pin 1 of the constant current dimming chip U1 is connected to a third output terminal P3 through an inductor L1, the third output terminal P3 is used for being connected to the cathode of an LED lamp, a pin 4 of the constant current dimming chip U1 is connected between a current limiting resistor R1 and the first output terminal P1, a pin 5 of the constant current dimming chip U1 is connected to the cathode of the first diode D1 and the anode of an electrolytic capacitor C1, and the cathode of the electrolytic capacitor C1 is grounded. The model of the constant-current dimming chip U1 is PT4115, the model of the first diode D1 is SS34SMA, the input signals are 2-wire VCC and PWM signals, the capacity of the electrolytic capacitor C1 is 220uF, the upper limit of the borne voltage is 35V, and the inductance of the inductor L1 is 100 uH. And additional wiring and GND signals are not needed, and the output signals are LED + and LED-signals and are connected with a constant-current dimming lamp. The constant current dimming chip U1 controls the output current through the LED _ DIM pin, and can support 1.2A output at most. The electrolytic capacitor C1 and the second diode D2 realize the energy storage function from the PWM signal, and provide stable voltage for the constant-current dimming chip U1 to work. The PNP type triode Q1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 are used for picking up PWM dimming signals and inputting the PWM dimming signals into the constant current dimming chip U1 to be used as dimming signals.

With reference to fig. 1, the two-wire PWM-to-constant current dimming module according to the present embodiment has the following specific principles: VCC connects the power supply positive pole, and when the PWM signal was the low level, VCC signal and PWM signal passed through second diode D2 and give electrolytic capacitor C1 charge, and after second resistance R2 and third resistance R3 divided voltage simultaneously, PNP type triode Q1 switched on, and the DIM signal of constant current chip U1 was pulled high, and constant current chip U1 enables to through current-limiting resistance R1, output constant current signal drive LED and light. When the PWM signal is at a high level, the power stored in the electrolytic capacitor C1 can ensure that the constant current dimming chip U1 continues to operate, the second resistor R2 pulls the base of the PNP transistor Q1 high, the PNP transistor Q1 is turned off, the DIM signal of the constant current dimming chip U1 is pulled low by the fifth resistor R5, the enable is turned off, and then the constant current dimming chip U1 turns off the LED driving output. Therefore, when the duty ratio of the PWM signal changes, the time for the constant current dimming chip U1 to drive the LED to light changes accordingly, so as to adjust the brightness of the LED. When the brightness of the LED needs to be increased, the duty ratio of the PWM signal is increased, and conversely, the duty ratio of the PWM signal is reduced.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A two-wire system PWM changes constant current module of adjusting luminance which characterized in that includes: the circuit comprises a constant-current dimming chip (U1), a PNP type triode (Q1), an inductor (L1), a first diode (D1), a second diode (D2), an electrolytic capacitor (C1), a current-limiting resistor (R1), a second resistor (R2), a third resistor (R3), a fourth resistor (R4), a second input terminal (P2), a fourth input terminal (P4), a first output terminal (P1) and a third output terminal (P3);

a base stage of the PNP triode (Q1) is connected to the second input terminal (P2) through the second resistor (R2), the second input terminal (P2) is used for inputting a VCC signal, the base stage of the PNP triode (Q1) is connected to the fourth input terminal (P4) and to the cathode of the second diode (D2) through the third resistor (R3), the anode of the second diode (D2) is Grounded (GND), the fourth input terminal (P4) is used for inputting a PWM signal, the collector of the PNP triode (Q1) is connected to the pin 3 of the constant current dimming chip (U1) through the fourth resistor (R4), the emitter of the PNP triode (Q1) is sequentially connected to the power supply (VCC) and the current limiting resistor (R1) and then connected to the first output terminal (P1), and the first output terminal (P1) is used for connecting to the anode of the LED lamp;

the pin 3 of the constant current dimming chip (U1) is Grounded (GND) through a fifth resistor (R5), the pin 2 of the constant current dimming chip (U1) is grounded, the pin 1 of the constant current dimming chip (U1) is connected with the anode of a first diode (D1), the cathode of the first diode (D1) is connected with a power supply (VCC), the pin 1 of the constant current dimming chip (U1) is connected with a third output terminal (P3) through an inductor (L1), the third output terminal (P3) is used for being connected with the cathode of an LED lamp, the pin 4 of the constant current dimming chip (U1) is connected between a current limiting resistor (R1) and the first output terminal (P1), the pin 5 of the constant current dimming chip (U1) is respectively connected with the cathode of the first diode (D1) and the anode of an electrolytic capacitor (C1), and the cathode of the electrolytic capacitor (C1) is grounded.

2. The two-wire PWM-to-constant current dimming module according to claim 1, wherein: the model of the constant current dimming chip (U1) is PT 4115.

3. The two-wire PWM-to-constant current dimming module according to claim 1, wherein: the model of the PNP type triode (Q1) is BC 857.

4. The two-wire PWM-to-constant current dimming module according to claim 1, wherein: the first diode (D1) and the second diode (D2) are both SS34SMA in model.

5. The two-wire PWM-to-constant current dimming module according to claim 1, wherein: the capacity of the electrolytic capacitor (C1) is 220uF, and the upper limit value of the voltage born by the electrolytic capacitor is 35V.

6. The two-wire PWM-to-constant current dimming module according to claim 1, wherein: the inductance of the inductor (L1) is 100 uH.