CN111182677A

CN111182677A - LED control circuit

Info

Publication number: CN111182677A
Application number: CN201911362986.6A
Authority: CN
Inventors: 陆立群
Original assignee: Pulian International Co Ltd
Current assignee: Pulian International Co Ltd
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2020-05-19
Anticipated expiration: 2039-12-24
Also published as: CN111182677B

Abstract

The invention discloses an LED control circuit, which comprises at least one path of drive circuit; each path of the driving circuit correspondingly controls one path of the LED; the input end of the driving circuit is used for receiving a control signal, and the output end of the driving circuit is used for connecting the first end of the LED; the driving circuit comprises a NOR gate, an OR gate, a first NOT gate, a second NOT gate, a first capacitor, a second capacitor, a first resistor and a second resistor. By adopting the technical scheme of the invention, the LED can be stably controlled, and the LED has strong anti-interference capability and good reliability.

Description

LED control circuit

Technical Field

The invention relates to the technical field of LED control, in particular to an LED control circuit.

Background

The LED lamp is taken as a novel energy-saving light source, has been widely accepted and adopted by people due to the characteristics of environmental protection, energy conservation, long service life, small size and the like, and because the LED is a semiconductor device with sensitive characteristics and has negative temperature characteristics, the LED control circuit plays a very important role in promoting the LED to be in a stable and reliable working state in the application process of the LED.

In a traditional LED control circuit, a GPIO port of a software configuration control chip is used for outputting a corresponding control signal to realize the flicker of an LED lamp, however, the method has the software problems of driving errors and the like, and is easily interfered by internal or external environments, so that the LED lamp cannot be normally controlled, and the reliability is poor.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present invention is to provide an LED control circuit, which can stably control an LED and has strong anti-interference capability and good reliability.

In order to solve the above technical problem, an embodiment of the present invention provides an LED control circuit, where the control circuit includes at least one driving circuit; each path of the driving circuit correspondingly controls one path of the LED; the input end of the driving circuit is used for receiving a control signal, and the output end of the driving circuit is used for connecting the first end of the LED; the driving circuit comprises a NOR gate, an OR gate, a first NOT gate, a second NOT gate, a first capacitor, a second capacitor, a first resistor and a second resistor; wherein the content of the first and second substances,

the input end of the NOR gate is the input end of the drive circuit, the output end of the NOR gate is connected with the first input end of the OR gate, the output end of the OR gate is connected with the input end of the first NOT gate, the output end of the first NOT gate is connected with the first end of the first capacitor, the second end of the first capacitor is connected with the first end of the first resistor, the second end of the first resistor is grounded, the input end of the second NOT gate is connected with the first end of the first resistor, the output end of the second NOT gate is connected with the first end of the second capacitor, the second end of the second capacitor is connected with the second input end of the OR gate, the second end of the second capacitor is also connected with the first end of the second resistor, the second end of the second resistor is grounded, and the output end of the second not gate is the output end of the driving circuit.

Further, the driving circuit further comprises a third capacitor; and the first end of the third capacitor is connected with the output end of the NOR gate, and the second end of the third capacitor is grounded.

Further, the control circuit further comprises a third resistor; the first end of the third resistor is used for being connected with the second end of the LED, and the second end of the third resistor is grounded.

Further, the number of the input terminals of the nor gate is determined according to the number of the control signals.

Further, the capacitance value of the first capacitor is the same as that of the second capacitor; the resistance value of the first resistor is the same as that of the second resistor.

Compared with the prior art, the embodiment of the invention provides the LED control circuit, the control circuit comprises at least one drive circuit, each drive circuit correspondingly controls one LED, the input end of each drive circuit is used for receiving a control signal, the output end of each drive circuit is used for being connected with the first end of each LED, each drive circuit is formed by connecting a NOR gate, an OR gate, a first NOT gate, a second NOT gate, a first capacitor, a second capacitor, a first resistor and a second resistor, and the control circuit can stably control the LEDs, and is strong in anti-interference capability and good in reliability.

Drawings

FIG. 1 is a schematic diagram of a preferred embodiment of an LED control circuit according to the present invention;

fig. 2 is a schematic structural diagram of another preferred embodiment of an LED control circuit provided by 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 any inventive step, are within the scope of the present invention.

An embodiment of the present invention provides an LED control circuit, which is shown in fig. 1 and is a schematic structural diagram of a preferred embodiment of the LED control circuit provided in the present invention, where the control circuit includes at least one driving circuit; each path of the driving circuit correspondingly controls one path of the LED; the input end of the driving circuit is used for receiving a control signal, and the output end of the driving circuit is used for connecting the first end of the LED; the driving circuit comprises a NOR gate G1, an OR gate G2, a first NOT gate G3, a second NOT gate G4, a first capacitor C1, a second capacitor C2, a first resistor R1 and a second resistor R2; wherein the content of the first and second substances,

the input end of the NOR gate G1 is the input end of the driving circuit, the output end of the NOR gate G1 is connected with the first input end of the OR gate G2, an output terminal of the OR gate G2 is connected to an input terminal of the first NOT gate G3, an output terminal of the first NOT gate G3 is connected to a first terminal of the first capacitor C1, the second end of the first capacitor C1 is connected with the first end of the first resistor R1, the second end of the first resistor R1 is grounded, the input end of the second NOT gate G4 is connected with the first end of the first resistor R1, the output end of the second NOT gate G4 is connected with the first end of the second capacitor C2, a second terminal of the second capacitor C2 is connected to a second input terminal of the OR gate G2, a second terminal of the second capacitor C2 is further connected to a first terminal of the second resistor R2, the second end of the second resistor R2 is grounded, and the output end of the second not gate G4 is the output end of the driving circuit.

Specifically, the LED control circuit includes at least one driving circuit, each driving circuit correspondingly controls one LED, and the circuit topology of each driving circuit is the same; aiming at any path of driving circuit, the driving circuit is composed of a nor gate G1, a nor gate G2, a first not gate G3, a second not gate G4, a first capacitor C1, a second capacitor C2, a first resistor R1 and a second resistor R2, wherein an input end of the nor gate G1 is an input end of the driving circuit and is used for receiving a Control signal (Control), an output end of the second not gate G4 is an output end of the driving circuit and is used for connecting a first end of an LED (i.e. an anode of the LED), a second end of the LED (i.e. a cathode of the LED) is grounded, the first capacitor C1 and the first resistor R1 form a first RC charging and discharging circuit, the second capacitor C2 and the second resistor R2 form a second RC charging and discharging circuit, and the first RC charging and discharging circuit and the second RC charging and discharging circuit are used for controlling the flickering frequency of the LED and the duration of each time of on and off of the LED; after the LED control circuit receives the control signal, the output end of the drive circuit can output a corresponding square wave signal through the logic operation of each logic gate device in the drive circuit and the charging and discharging processes of the RC circuit, so that the flicker of the LED is controlled.

It should be noted that the Control signal (Control) may flexibly adopt an available signal sent by a chip in the device, for example, a PA enable signal, a switch enable signal, and the like sent by a transceiver chip are all available signals, and as long as the available signals can be used as signals for controlling when the LED flickers or when the LED does not flicker, the Control signal (Control) in the embodiment of the present invention can be used.

Assuming that the LED Control circuit receives two Control signals, namely Control1 and Control2, when Control1 and Control2 are at low level, the output terminal of nor gate G1 is at high level, or the output terminal of gate G2 is at high level, so that the output terminal of first not gate G3 is limited at low level, the output terminal of second not gate G4 is limited at high level, and the LED is normally on; when Control1 or Control2 changes from low level to high level, the output end of the nor gate G1 is low level, the first input end of the or gate G2 changes from high level to low level, and with the continuous repetition of the charging and discharging process of the RC circuit, the output ends of the first and second not gates G3 and G4 can both output a square wave signal, thereby controlling the flickering of the LED, and the flickering frequency of the LED and the duration of each on and off of the LED can be adjusted correspondingly through the capacitance values of the first and second capacitors C1 and C2, and the resistance values of the first and second resistors R1 and R2, i.e., adjusting the charging and discharging time of the RC circuit.

Referring to fig. 2, which is a schematic structural diagram of another preferred embodiment of the LED control circuit provided in the present invention, in another preferred embodiment, the driving circuit further includes a third capacitor C3; the first terminal of the third capacitor C3 is connected to the output terminal of the nor gate G1, and the second terminal of the third capacitor C3 is grounded.

Specifically, in combination with the above embodiments, the third capacitor C3 is connected to the output terminal of the nor gate G1, and is used for filtering the output signal of the nor gate G1, so that the nor gate G1 outputs a stable high level or a stable low level.

It should be noted that the value of the third capacitor C3 may be set according to a signal that actually needs to be filtered, for example, C3 ═ 22 μ F, and if the signal output by the nor gate G1 is stable enough, the third capacitor C3 may not be added, so as to simplify the circuit topology and reduce the cost.

In yet another preferred embodiment, shown in conjunction with fig. 2, the control circuit further comprises a third resistor R3; the first end of the third resistor R3 is used for connecting the second end of the LED, and the second end of the third resistor R3 is grounded.

Specifically, in combination with the above embodiment, the third resistor R3 is connected to the second end of the LED (i.e., the cathode of the LED), the third resistor R3 is a current-limiting resistor for controlling the current flowing through the LED and preventing the current flowing through the LED from being too large or too small, the value of the third resistor R3 may be set according to the LED, and the brightness of the LED may also be adjusted by the value of the third resistor R3.

In a further preferred embodiment, the number of inputs of the nor gate G1 is determined according to the number of the control signals.

Specifically, in combination with the above embodiments, since the Control signal (Control) may be one path or multiple paths, accordingly, the number of the input terminals of the nor gate G1 needs to be determined according to the number of the specific Control signals, for example, when the Control signal has only one path, one input terminal of the nor gate G1 in fig. 1 and 2 is used to receive one path of Control signal, and the other input terminal may be directly grounded (at a low level), or the nor gate G1 in fig. 1 and 2 may be directly replaced by a nor gate; when the control signal is n (n >1), the nor gate G1 corresponds to a nor gate having at least n inputs.

In yet another preferred embodiment, the capacitance of the first capacitor C1 and the capacitance of the second capacitor C2 are the same; the resistance value of the first resistor R1 is the same as that of the second resistor R2.

Specifically, with reference to the above embodiment, the frequency of LED flashing and the duration time of each on/off of the LED can be adjusted accordingly through the capacitance values of the first capacitor C1 and the second capacitor C2 and the resistance values of the first resistor R1 and the second resistor R2, where C1 and R1 are used to control the duration time of each off (i.e., the duty ratio of the low level of the square wave signal) corresponding to the LED flashing, C2 and R2 are used to control the duration time of each on (i.e., the duty ratio of the high level of the square wave signal) corresponding to the LED flashing, and when C1 is equal to C2 and R1 is equal to R2, the duration time of each on/off of the LED is the same (i.e., the duty ratios of the high level and the low level of the square wave signal are the same); for example, assuming that C1 ═ C2 ═ 1 μ F and R1 ═ R2 ═ 118k Ω, the frequency of LED blinking is approximately 6 Hz.

It can be understood that values of C1, C2, R1, and R2 may be set according to actual needs, as long as the frequency of LED blinking can be controlled within a visible range of human eyes, and values of C1 and C2 may be the same or different, and similarly, values of R1 and R2 may be the same or different, and may be flexibly adjusted to adjust the time when the LED turns on or off, when C1 ≠ C2 and R1 ≠ R2, duty ratios of high level and low level of the square wave signal output by the driving circuit are the same, and when C1 ≠ C2 or/and R1 ≠ R2, duty ratios of high level and low level of the square wave signal output by the driving circuit are different.

In summary, the LED control circuit provided in the embodiments of the present invention has the following advantages:

(1) the LED can be stably controlled, and the LED has strong anti-interference capability and good reliability;

(2) the LED control circuit is simple in design and operation, and the flicker frequency of the LED is adjustable

(3) The components and parts adopted in the LED control circuit are all stock materials, so that the use is convenient, and the cost is lower.

The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.

Claims

1. The LED control circuit is characterized by comprising at least one path of drive circuit; each path of the driving circuit correspondingly controls one path of the LED; the input end of the driving circuit is used for receiving a control signal, and the output end of the driving circuit is used for connecting the first end of the LED; the driving circuit comprises a NOR gate, an OR gate, a first NOT gate, a second NOT gate, a first capacitor, a second capacitor, a first resistor and a second resistor; wherein the content of the first and second substances,

2. The LED control circuit of claim 1, wherein the driver circuit further comprises a third capacitor; and the first end of the third capacitor is connected with the output end of the NOR gate, and the second end of the third capacitor is grounded.

3. The LED control circuit of claim 1, wherein the control circuit further comprises a third resistor; the first end of the third resistor is used for being connected with the second end of the LED, and the second end of the third resistor is grounded.

4. The LED control circuit of claim 1, wherein the number of inputs of the nor gate is determined according to the number of the control signals.

5. The LED control circuit of claim 1, wherein the capacitance of the first capacitor is the same as the capacitance of the second capacitor; the resistance value of the first resistor is the same as that of the second resistor.