CN201054839Y - A LED lamp cascading drive and control circuit - Google Patents

Abstract

The utility model announces a cascade drive and control circuit for LED lamp groups, including a DC power supply, a control circuit connected to the DC power supply to control the lighting of the lamp groups, and a driving circuit group connected to each LED lamp group. It is characterized in that a cascaded latch circuit group is set between the control circuit and the driving circuit group. The beneficial effect of the utility model compared with the prior art is: under the condition that the power supply is sufficient to guarantee, the LED lamp groups with an unlimited number of cascades can be controlled in a simple and cheap way: the same clock control, the same lock storage control and the same on and off control. Since the circuit has only one control terminal, all drive cascaded circuits are the same, and it also has the characteristics of simple assembly and convenient maintenance.

Description

A Cascade Driving and Control Circuit for LED Lamp Groups

technical field

The utility model relates to a circuit for a general electric light source, in particular to a cascade driving and control circuit for LED lamp groups.

Background technique

Light Emitting Diode (LED for short) is an optoelectronic semiconductor element that emits light by exciting electrons with an external voltage. It has the advantages of low power consumption, high brightness, long life, and small size. At present, a typical high luminous flux LED device can produce a luminous flux of several lumens to tens of lumens. The updated design can be a cascade combination of multiple LEDs in series, that is, multiple devices can be installed in a single assembly, or more LEDs can be integrated in one device, so that the output lumens are equivalent to small incandescent lamps . For example, a high-power 12-chip monochrome LED device can output 200 lumens of light energy and consume between 10 and 15 watts. LEDs have been widely used in a variety of lighting equipment, such as battery-powered flashlights, miniature voice-activated lights, security lights, indoor and outdoor road and stair lighting, and building and marking continuous lighting. However, when driving a cascade combination of multiple LEDs in series and parallel, the driving conditions are different, which brings inconvenience to the operation, control and maintenance of the LED lamp group.

Contents of the invention

The technical problem to be solved by the utility model is to make up for the defects of the above-mentioned prior art, and propose a cascaded drive and control circuit for LED lamp groups under the condition of low DC power supply such as 5V DC power supply.

The technical problem of the utility model is realized by the following technical solutions:

The cascaded drive and control circuit for LED lamp groups includes a DC power supply, a control circuit connected to the DC power supply to control the lighting of the lamp groups, and a driving circuit group connected to each LED lamp group.

The characteristics of this LED light group cascade drive and control circuit are:

A cascaded latch circuit group is provided between the control circuit and the driving circuit group.

The technical problem of the utility model is realized by the following further technical solutions:

The input terminal of the first-stage latch circuit of the cascaded latch circuit group is connected to the output terminal of the control circuit;

The output terminal of the first-stage latch circuit of the cascaded latch circuit group is connected to the input terminal of the first group of driving circuits driving the first group of LED lamp groups in the driving circuit group, and the first group of driving circuits The control output end of the circuit and the control output end of the first-stage latch circuit are respectively connected to the input end of the second-stage latch circuit;

The output terminal of the second-stage latch circuit of the cascaded latch circuit group is connected to the input terminal of the second group of driving circuits driving the second group of LED lamp groups in the driving circuit group, and the second group of driving circuits The control output end of the circuit and the control output end of the second-stage latch circuit are respectively connected to the input end of the third-stage latch circuit, and so on;

The output terminal of the penultimate stage latch circuit of the cascaded latch circuit group is connected to the input terminal of the penultimate group of driving circuits driving the penultimate group of LED lamp groups in the driving circuit group, and the penultimate The control output terminals of the second group of driving circuits and the control output terminals of the penultimate second-stage latch circuit are respectively connected to the input terminals of the penultimate first-stage, that is, the last-stage latch circuit;

The output terminal of the last stage latch circuit of the cascaded latch circuit group is connected to the input terminal of the last group of driving circuits driving the last group of LED lamp groups in the driving circuit group.

The technical problem of the utility model is also realized by the following further technical solutions:

The latch circuits at all levels include 8-bus latches of the 74LS/HC series, a sequential logic circuit that can store multi-bit binary codes at a time, and its output is enabled by the output control. The output data is output through the tri-state gate, and the output state does not change with the state change of the input terminal, and is in a holding state.

The DC power supply is a low DC power supply with power greater than that of the LED lamp group.

The beneficial effect of the utility model compared with the prior art is:

Under the condition that the power supply is sufficient, the three identical controls can be realized in a simple and cheap way for the cascaded unlimited number of LED lamp groups: the same clock control, the same latch control and the same on-off control. Since the circuit has only one control terminal, all driving cascaded circuits are the same, and it also has the characteristics of simple assembly and convenient maintenance.

Description of drawings

Fig. 1 is a circuit composition block diagram of the utility model embodiment one;

Fig. 2 is a kind of circuit diagram of Fig. 1;

Fig. 3 is a circuit composition block diagram of the second embodiment of the utility model;

FIG. 4 is a circuit diagram of FIG. 3 .

Detailed ways

Specific implementation mode one

Driving and control circuit suitable for cascade connection of white or monochromatic LED lamp groups

The drive and control circuit shown in Figures 1 and 2, the control circuit 01 includes three signal output terminals:

P2.7 is the CLK signal, that is, the synchronous clock signal, which controls the clock of the entire LED light group, and uses the characteristics of fast response speed of the LED itself to make the entire LED light group turn on and off synchronously;

P2.6 is the LAT latch signal, and the LED light group is controlled by the driver IC with data serial input and output. The latch signal is used to indicate the completion of a set of data transmission, and also enables the entire light group to be used synchronously;

P2.5 is the /EN enable signal, its function is to control the work of the drive IC, that is, to control the LED light group to turn on and off.

The first stage cascade circuit 10 in FIG. 2 mainly includes a first stage latch circuit 11 , a first group of driving circuits 12 and a first group of LED lamp groups 13 .

The first stage latch circuit 11 adopts the IC whose model is 74LS/HC245, and this circuit also has the function of preventing signal attenuation in the cascaded circuit;

The first group of drive circuits 12 adopts drive ICs of serial input and parallel output type 595 or 62726, which can drive 8 and 16 parallel LED lamp groups with constant current at most, and at the same time, add adjustable resistors at the negative feedback end to adjust each branch. The output current of the circuit can be used to adjust the brightness of the white LED lamp.

The second stage cascade circuit 20 in FIG. 2 mainly includes a second stage latch circuit 21 , a second group of driving circuits 22 and a second group of LED lamp groups 23 . Its composition is the same as that of the cascode circuit 10 of the first stage.

The driving and control of the above-mentioned LED lamp group is realized in this way: when the low-voltage DC power supply is normally supplied, the control signal is sent by the control circuit 01, which is latched and entered into the first group of driving circuits 12, and then the latched signal enters the second group The drive circuit 22, and so on, can achieve the purpose of simultaneously controlling multiple LED lamp groups with the same control signal.

The number of LED lamp groups that can be driven by the circuit of this embodiment is limited by the maximum power of the low-voltage DC power supply.

Specific implementation mode two

Driving and control circuit suitable for cascading of RGB three-color mixed light LED lamp groups

The drive and control circuit shown in Figures 3 and 4, the control circuit 101 includes five output terminals:

P2.7 is the CLK signal, that is, the synchronous clock signal, which controls the clock of the entire LED light group. The same clock signal of the RGB three colors uses the fast response characteristics of the LED itself to make the entire LED light group turn on and off synchronously;

P2.6 is the LAT latch signal, and the LED light group is controlled by the driver IC with data serial input and output. The latch signal is used to indicate the completion of a set of data transmission, and also enables the entire light group to be used synchronously;

P2.5 is the blue light/EN enable signal, its function is to control the drive IC to work, that is, to control the blue light LED light group to turn on and off;

P2.4 is the green light/EN enable signal, its function is to control the drive IC to work, that is, to control the green LED light group to turn on and off;

P2.3 is the red light/EN enable signal, its function is to control the work of the drive IC, that is, to control the red light LED light group to turn on and off.

Simple programming by the matching MCU can realize the RGB seven-color color mixing change of the three-color LED light group.

The first stage cascade circuit 110 in FIG. A set of green LED light sets 123 , a first set of blue light driving circuits 132 and a first set of blue LED light sets 133 .

The first stage latch circuit 111 adopts the IC of model 74LS/HC245, and this circuit also has the function of preventing signal attenuation in the cascaded circuit;

The first group of drive circuits 112, 122, and 132 respectively use serial-in parallel-out drive ICs of 595 or 62726, which can drive up to 8 and 16 parallel LED lamp groups with constant current, and at the same time add adjustable Resistors, adjust the output current of each branch to adjust the best light mixing effect.

The second level cascade circuit 210 in FIG. 4 mainly includes a second level latch circuit 211 , a second group of driving circuits 212 , 222 , 232 and a corresponding second group of LED lamp groups 213 , 223 , 233 . Its composition is the same as that of the first-stage cascode circuit 110 .

The drive and control of the above-mentioned LED lamp group are the same as those in the first embodiment.

The number of LED lamp groups that can be driven by the circuit of this embodiment is also limited by the maximum power of the low-voltage DC power supply.

The above content is a further detailed description of the present invention/utility model in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the utility model is limited to these descriptions. For a person of ordinary skill in the technical field to which the utility model belongs, without departing from the concept of the utility model, some simple deduction or substitutions can also be made, which should be regarded as belonging to the protection scope of the utility model.

Claims (4)

1. A cascade drive and control circuit for LED lamp groups, comprising a DC power supply, a control circuit for controlling the lighting of the lamp groups connected to the DC power supply, and a drive circuit group connected with each LED lamp group, characterized in that : A cascaded latch circuit group is provided between the control circuit and the driving circuit group. 2. The cascaded drive and control circuit for LED lamp groups as claimed in claim 1, characterized in that: The input terminal of the first-stage latch circuit of the cascaded latch circuit group is connected to the output terminal of the control circuit; The output terminal of the first-stage latch circuit of the cascaded latch circuit group is connected to the input terminal of the first group of driving circuits driving the first group of LED lamp groups in the driving circuit group, and the first group of driving circuits The control output end of the circuit and the control output end of the first-stage latch circuit are respectively connected to the input end of the second-stage latch circuit; The output terminal of the second-stage latch circuit of the cascaded latch circuit group is connected to the input terminal of the second group of driving circuits driving the second group of LED lamp groups in the driving circuit group, and the second group of driving circuits The control output end of the circuit and the control output end of the second-stage latch circuit are respectively connected to the input end of the third-stage latch circuit, and so on; The output terminal of the penultimate stage latch circuit of the cascaded latch circuit group is connected to the input terminal of the penultimate group of driving circuits driving the penultimate group of LED lamp groups in the driving circuit group, and the penultimate The control output terminals of the second group of driving circuits and the control output terminals of the penultimate second-stage latch circuit are respectively connected to the input terminals of the penultimate first-stage, that is, the last-stage latch circuit; The output terminal of the last stage latch circuit of the cascaded latch circuit group is connected to the input terminal of the last group of driving circuits driving the last group of LED lamp groups in the driving circuit group. 3. The cascaded drive and control circuit for LED lamp groups according to claim 1 or 2, characterized in that: The latch circuits at all levels include 8-bus latches of the 74LS/HC series, a sequential logic circuit that can store multi-bit binary codes at a time, and its output is enabled by the output control. 4. The cascaded drive and control circuit for LED lamp groups as claimed in claim 3, characterized in that: The DC power supply is a low DC power supply with power greater than that of the LED lamp group.

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