CN210381385U

CN210381385U - LED drive circuit

Info

Publication number: CN210381385U
Application number: CN201920942870.9U
Authority: CN
Inventors: 沈文学
Original assignee: Huizhou Laite Lighting Technology Co ltd
Current assignee: Huizhou Laite Lighting Technology Co ltd
Priority date: 2019-06-21
Filing date: 2019-06-21
Publication date: 2020-04-21
Anticipated expiration: 2029-06-21

Abstract

The LED driving circuit of the utility model is provided with a control unit, a transformer unit and a driving unit. The setting of the rectifier bridge can rectify the voltage input by the external power supply. Combined with the capacitor C1, the resistor R1, the resistor R2 and the Zener diode ZD1, the capacitor C1, the resistor R1 and the resistor R2 all play the role of reducing the current and reducing the voltage. The voltage diode ZD1 plays a role in regulating the input voltage, transforming the input voltage into the input voltage required by the control unit; in addition, the setting of the built-in power supply BT can prevent the external power supply from having no input voltage. The control unit supplies power; in addition, the resistor R5 acts as a current limiter, and the resistor R5 can prevent the LED from directly breaking down the LED due to excessive current at the moment of power-on, thereby damaging the LED. The circuit structure of the present application is relatively simple, and the manufacturing cost of the circuit is low, which can reduce the operating cost of the enterprise to a certain extent.

Description

LED drive circuit

Technical Field

The utility model relates to a LED technical field especially relates to a LED drive circuit.

Background

Currently, a light emitting diode is referred to as an LED for short. Is prepared from the compound containing Ga, As, P, etc. When electrons and holes are recombined, visible light is radiated, so that the light-emitting diode can be manufactured. In circuits and instruments as indicator lights or to form text or numerical displays. Gallium arsenide diodes emit red light, gallium phosphide diodes emit green light, silicon carbide diodes emit yellow light, and gallium nitride diodes emit blue light. Organic light emitting diodes OLED and inorganic light emitting diodes LED are classified by their chemical properties. The technical revolution from the indicator light level to the level exceeding the general light source has LED to new applications such as automotive signal lights, traffic signal lights, outdoor full-color large displays and special lighting sources, not only is the luminous efficiency exceeding that of incandescent lamps, the luminous intensity reaching the candle level, but also the color covering the entire visible spectral range from red to blue.

For the existing illuminating lamps, the existing illuminating lamps mostly adopt LEDs (light emitting diodes) in consideration of the reasons of environmental protection, energy conservation and service life. In order to realize the illumination of the LED, an LED driving circuit must be disposed inside the illumination lamp, and the voltage output by the LED driving circuit is used to drive the LED to emit light, thereby realizing the illumination. For the existing LED driving circuit, because the voltage required by the LED is to be provided, the LED driving circuit usually transforms the input voltage, and most of the existing LED driving circuits transform the voltage by using a transformer chip, but the manufacturing cost of the LED driving circuit is increased by using the transformer chip, which undoubtedly increases the operation cost of the enterprise; in addition, the existing LED driving circuit is not provided with a built-in standby power supply, and if the LED driving circuit loses the voltage input by the external power supply, the LED driving circuit cannot supply power to the LED, that is, the lighting effect of the LED is lost; moreover, the conventional LED driving circuit is not provided with corresponding electronic components to protect the LED, so that the LED is damaged due to excessive current at the moment of power-on.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the weak point among the prior art, provide a circuit structure is comparatively simple, can carry out vary voltage processing to input voltage, circuit manufacturing cost is lower, built-in stand-by power supply prevents not having can also be for the LED power supply when the external power supply input, can protect LED, prevents that LED from being in the LED drive circuit who is punctured in the twinkling of an eye at circular telegram.

The purpose of the utility model is realized through the following technical scheme:

an LED driver circuit comprising:

the ground terminal of the control unit is grounded;

a transforming unit including a rectifier bridge, a capacitor C1, a resistor R1, a resistor R2, a zener diode ZD1, an internal power supply BT, and a switch SW1, a first input terminal of the rectifier bridge being connected to an anode of an external power supply, a second input terminal of the rectifier bridge being connected to one terminal of the capacitor C1, the other terminal of the capacitor C1 being connected to one terminal of the resistor R1, the other terminal of the resistor R1 being connected to a cathode of the external power supply, a first output terminal of the rectifier bridge being connected to one terminal of the resistor R2, the other terminal of the resistor R2 being connected to a cathode of the zener diode ZD1, an anode of the zener diode BT 1 being connected to a cathode of the internal power supply BT, a second output terminal of the rectifier bridge, and a ground terminal of the control unit, an anode of the internal power supply being connected to a cathode of the zener diode ZD1, and one terminal of the switch SW1 being connected to a cathode of the zener diode ZD1, the other end of the switch SW1 is used as the output end of the voltage transformation unit and is connected with the power supply input end of the control unit; and

a driving unit, the driving unit includes a touch key, an oscillation resistor R3, a switch K1, a switch K2, a resistor R4, a resistor R5, a triode Q1 and a sampling capacitor C2, the touch key is connected with an input end of the control unit, one end of the oscillation resistor R3 is connected with an oscillation input end of the control unit, the other end of the oscillation resistor R3 is connected with the other end of the switch SW1, a control input end of the switch K1 is connected with a first control output end of the control unit, a first output end of the switch K1 is respectively connected with a first output end of the switch K2 and an emitter of the triode Q1, a second output end of the switch K1 is respectively connected with a second output end of the switch K2 and the other end of the oscillation resistor R3, a control input end of the switch K2 is connected with a second control output end of the control unit, the one end of resistance R4 with the output of the control unit is connected, the other end of resistance R4 with triode Q1's base is connected, the one end of resistance R5 is connected with the anodal of LED, the other end of resistance R5 with switch SW 1's the other end is connected, triode Q1's collecting electrode is connected with the negative pole of LED, triode Q1's projecting pole ground connection, sampling capacitor C2's one end with the sampling end of the control unit is connected, sampling capacitor C2's other end ground connection.

In one embodiment, the transformation unit further includes a polarity capacitor C3, an anode of the polarity capacitor C3 is connected to the power input terminal of the control unit, and a cathode of the polarity capacitor C3 is connected to the ground terminal of the control unit.

In one embodiment, the transforming unit further includes a capacitor C4, one end of the capacitor C4 is connected to the power input terminal of the control unit, and the other end of the capacitor C4 is connected to the ground terminal of the control unit.

In one embodiment, the polarity capacitor C3 has a capacitance size of 10 uF.

In one embodiment, the rectifier bridge includes a diode D1, a diode D2, a diode D3, and a diode D4, a cathode of the diode D1 is connected as a first input terminal of the rectifier bridge, an anode of the diode D2 is connected to a cathode of the diode D1, a cathode of the diode D2 is connected as a first output terminal of the rectifier bridge, a cathode of the diode D3 is connected to a cathode of the diode D2, an anode of the diode D3 is connected to a second input terminal of the rectifier bridge, a cathode of the diode D4 is connected to an anode of the diode D3, and an anode of the diode D4 is connected to an anode of the diode D1 as a second input terminal of the rectifier bridge.

In one embodiment, the voltage of the built-in power supply BT is 5.1V.

In one embodiment, the transistor Q1 is an NPN transistor.

In one embodiment, the resistance R1 has a value of 100 Ω.

In one embodiment, the resistance value of the resistor R5 is 5.1 Ω.

In one embodiment, the oscillating resistor R3 has a resistance of 47K Ω.

The utility model discloses compare in prior art's advantage and beneficial effect as follows:

the utility model discloses a LED drive circuit, through setting up the control unit, vary voltage unit and drive unit. In the practical application process, the arrangement of the rectifier bridge can rectify the voltage input by an external power supply, and in combination with the capacitor C1, the resistor R1, the resistor R2 and the zener diode ZD1, the capacitor C1, the resistor R1 and the resistor R2 all play a role in reducing current and voltage, and the zener diode ZD1 plays a role in stabilizing voltage of the input voltage and transforms the input voltage into the input voltage required by the control unit; in addition, the built-in power supply BT is arranged, so that the power supply for the control unit can be prevented when the external power supply has no input voltage; moreover, the resistor R5 plays a role in limiting current, and the resistor R5 can prevent the LED from being directly broken down due to overlarge current at the moment of electrifying the LED, so that the LED is damaged. The circuit structure of the application is simple, the manufacturing cost of the circuit is low, and the operation cost of an enterprise can be reduced to a certain extent.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention, and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic circuit diagram of an LED driving circuit according to an embodiment of the present invention.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. The preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

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. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

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 invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. 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 LED driving circuit 10 includes a control unit 100, a voltage transformation unit 200, and a driving unit 300.

Thus, it should be noted that the control unit 100 plays a role of control; the voltage transformation unit 200 plays a role of transforming voltage, and transforms the voltage input by the external power supply into the voltage required by the control unit 100; the driving unit 300 is used for driving the LEDs to emit light.

Referring to fig. 1 again, the ground terminal of the control unit 100 is grounded, and the ground terminal of the control unit 100 is the GND terminal identified in fig. 1; the power input terminal of the control unit 100 is the VDD terminal identified in fig. 1; the oscillation input of the control unit 100 is the OSC terminal identified in fig. 1; the sampling end of the control unit 100 is the VC end identified in fig. 1; the input terminal of the control unit 100 is the TI terminal identified in fig. 1; the output terminal of the control unit 100 is the SO terminal identified in fig. 1; a first control output of the control unit 100, i.e. the OPT1 terminal identified in fig. 1; the second control output of the control unit 100 is the OPT2 terminal identified in fig. 1. Referring to fig. 1 again, the transforming unit 200 includes a rectifier bridge, a capacitor C1, a resistor R1, a resistor R2, the power supply comprises a voltage stabilizing diode ZD1, a built-in power supply BT and a switch SW1, wherein a first input end of a rectifier bridge is connected with an anode of an external power supply, a second input end of the rectifier bridge is connected with one end of a capacitor C1, the other end of the capacitor C1 is connected with one end of a resistor R1, the other end of the resistor R1 is connected with a cathode of the external power supply, a first output end of the rectifier bridge is connected with one end of a resistor R2, the other end of the resistor R2 is connected with a cathode of the voltage stabilizing diode ZD1, an anode of the voltage stabilizing diode ZD1 is respectively connected with a cathode of the built-in power supply BT, a second output end of the rectifier bridge and a grounding end of the control unit 100, an anode of the built-in power supply BT is connected with a cathode of the voltage stabilizing diode 1, one end of the switch SW1 is connected with a cathode of the voltage stabilizing diode.

Thus, it should be noted that when the transforming unit 200 is started, the input voltage of the external power source is input into the rectifier bridge, and the rectifier bridge performs the rectifying operation on the input voltage; the capacitor C1, the resistor R1 and the resistor R2 all play a role of current and voltage reduction, and finally, the input voltage subjected to current reduction and current reduction is regulated by the voltage regulator diode ZD1 and transformed into the working voltage required by the control unit 100.

Referring to fig. 1 again, the driving unit 300 includes a touch button, an oscillation resistor R3, a switch K1, a switch K2, a resistor R4, a resistor R5, a transistor Q1 and a sampling capacitor C2, the touch button is connected to an input terminal of the control unit, one end of the oscillation resistor R3 is connected to an oscillation input terminal of the control unit 100, the other end of the oscillation resistor R3 is connected to the other end of the switch SW1, a control input terminal of the switch K1 is connected to a first control output terminal of the control unit, a first output terminal of the switch K1 is connected to a first output terminal of the switch K2 and an emitter terminal of the transistor Q1, a second output terminal of the switch K1 is connected to a second output terminal of the switch K2 and the other end of the oscillation resistor R3, a control input terminal of the switch K2 is connected to a second control output terminal of the control unit 100, one end of the resistor R4 is connected to an output terminal of the control unit 100, the other end of the resistor, one end of the resistor R5 is connected with the positive electrode of the LED, the other end of the resistor R5 is connected with the other end of the switch SW1, the collector of the triode Q1 is connected with the negative electrode of the LED, the emitter of the triode Q1 is grounded, one end of the sampling capacitor C2 is connected with the sampling end of the control unit 100, and the other end of the sampling capacitor C2 is grounded.

Thus, it should be noted that the control unit 100 can select a chip with model number SGL8022W, and a chip with model number SGL8022W is a chip commonly sold in the market, and the working principle and the working mode thereof are well known to those skilled in the art. When the driving unit 300 starts to operate, the first control output terminal and the second control output terminal of the control unit 100 both output low level signals, so as to enable the control input terminal (i.e., terminal a shown in fig. 1) of the switch K1 to be connected with the first output terminal (i.e., terminal b shown in fig. 1) of the switch K1, and the control input terminal (i.e., terminal d shown in fig. 1) of the switch K2 to be connected with the first output terminal (i.e., terminal e shown in fig. 1) of the switch K2, at this time, a user can enable the control unit 100 to output a voltage by pressing a TOUCH key (i.e., TOUCH shown in fig. 1), and the output voltage is input to the LED through the triode Q1, so that the LED emits light.

It should be noted that, due to the arrangement of the resistor R5, the resistor R5 plays a role of limiting current, so as to prevent the LED from being broken down by a large current at the moment of being turned on, and further, the lighting operation cannot be completed.

Further, referring to fig. 1 again, in an embodiment, the transforming unit 200 further includes a polarity capacitor C3, an anode of the polarity capacitor C3 is connected to the power input terminal of the control unit 100, and a cathode of the polarity capacitor C3 is connected to the ground terminal of the control unit 100.

In this way, it should be noted that the polar capacitor C3 functions as an energy storage, and prevents the polar capacitor C3 from being able to supply power to the control unit 100 in the case where there is no voltage input from the external power source and the built-in power source BT fails.

Further, referring to fig. 1 again, in an embodiment, the transforming unit 200 further includes a capacitor C4, one end of the capacitor C4 is connected to the power input terminal of the control unit 100, and the other end of the capacitor C4 is connected to the ground terminal of the control unit.

In this way, it should be noted that the capacitor C4 plays a role of filtering, so as to improve the waveform of the input voltage and make the circuit stability better. Specifically, the capacitance of the polarity capacitor C3 is 10uF in size. It should be noted that the capacitance of the polarity capacitor C3 can be flexibly set according to actual situations.

Further, referring to fig. 1 again, in an embodiment, the rectifier bridge includes a diode D1, a diode D2, a diode D3, and a diode D4, a cathode of the diode D1 is used as a first input terminal of the rectifier bridge, an anode of the diode D2 is connected to a cathode of the diode D1, a cathode of the diode D2 is used as a first output terminal of the rectifier bridge, a cathode of the diode D3 is connected to a cathode of the diode D2, an anode of the diode D3 is used as a second input terminal of the rectifier bridge, a cathode of the diode D4 is connected to an anode of the diode D3, and an anode of the diode D4 is connected to an anode of the diode D1 as a second input terminal of the rectifier bridge.

In this way, the rectifier bridge performs a rectifying function, and after the input voltage passes through the diode D1, the diode D2, the diode D3, and the diode D4, the diode D1, the diode D2, the diode D3, and the diode D4 all perform a rectifying function on the input voltage, thereby improving the input voltage.

Specifically, in one embodiment, the voltage of the built-in power supply BT is 5.1V; the triode Q1 is an NPN triode; the resistance value of the resistor R1 is 100 omega; the resistance value of the resistor R5 is 5.1 omega; the oscillation resistor R3 has a resistance of 47K Ω.

In this way, it should be noted that the voltage level of the built-in power supply BT, the type of the transistor Q1, the resistance value of the resistor R1, the resistance value of the resistor R5, and the resistance value of the oscillation resistor R3 can be flexibly set according to actual situations.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. An LED driving circuit, comprising:

the ground terminal of the control unit is grounded;

2. The LED driving circuit as claimed in claim 1, wherein the transforming unit further comprises a polarity capacitor C3, the positive pole of the polarity capacitor C3 is connected to the power input terminal of the control unit, and the negative pole of the polarity capacitor C3 is connected to the ground terminal of the control unit.

3. The LED driving circuit as claimed in claim 2, wherein the transforming unit further comprises a capacitor C4, one end of the capacitor C4 is connected to the power input terminal of the control unit, and the other end of the capacitor C4 is connected to the ground terminal of the control unit.

4. The LED driving circuit according to claim 2, wherein the polarity capacitor C3 has a capacitance of 10 uF.

5. The LED driving circuit according to claim 1, wherein the rectifier bridge comprises a diode D1, a diode D2, a diode D3 and a diode D4, a cathode of the diode D1 is used as a first input terminal of the rectifier bridge, an anode of the diode D2 is connected to a cathode of the diode D1, a cathode of the diode D2 is used as a first output terminal of the rectifier bridge, a cathode of the diode D3 is connected to a cathode of the diode D2, an anode of the diode D3 is used as a second input terminal of the rectifier bridge, a cathode of the diode D4 is connected to an anode of the diode D3, and an anode of the diode D4 is used as a second input terminal of the rectifier bridge and connected to an anode of the diode D1.

6. The LED driving circuit according to claim 1, wherein the voltage of the built-in power supply BT is 5.1V.

7. The LED driving circuit according to claim 1, wherein the transistor Q1 is an NPN transistor.

8. The LED driving circuit according to claim 1, wherein the resistance of the resistor R1 is 100 Ω.

9. The LED driving circuit according to claim 1, wherein the resistance of the resistor R5 is 5.1 Ω.

10. The LED driving circuit according to claim 1, wherein the oscillating resistor R3 has a resistance of 47K Ω.