CN201491323U - A music colorful light control drive circuit - Google Patents

Abstract

The utility model relates to a low-cost musical colorful lamp control circuit, which comprises a baseband processor (BB), a control drive circuit (CDC) and a three-color LED colored lamp. Under the control of the CDC, the three-color LED lights can flash in color and brightness following the beat of the music. The baseband processor is connected to the control drive circuit, and the communication content of the two includes GPIO control signals and music audio signals; the control drive circuit is connected to the three-color LED colored lights to control the flickering of the colored lights; The circuit arrangement provides power. The circuit has the characteristics of low cost and simple circuit, and at the same time, the flickering of the colored lights is obviously dynamic, and the effect of synchronizing with the beat of the music is good.

Description

A music colorful light control drive circuit

technical field

The utility model relates to a low-cost music colorful light control circuit, in particular to a circuit for controlling three-color LED colored lights to flicker with the rhythm of music. It can be applied to consumer digital devices such as mobile phones, PM3, PDA, etc., as well as toys and other devices related to music beats.

Background technique

The three-color LED lantern can synthesize various colors according to the different brightnesses of the three colors of red light (R), green light (G) and blue light (B) inside it. Using a special control drive circuit, controlling the three-color lights to flash with the beat of the music will produce gorgeous colorful effects, attracting the attention of consumers, especially young and fashionable consumers. Therefore, music rhythm colorful lights are more and more adopted in such as mobile phones, MP3, MP4 and PDA and high-end toys, and have broad development space.

In terms of control methods, there are three main methods of music beat colorful lights: amplitude control, frequency control and amplitude-frequency control. Based on the amplitude control, the color and brightness of the three-color LED lights are controlled by the amplitude of the audio signal; based on the frequency control, the color and brightness of the three-color LED lights are controlled by the frequency of the audio signal; Frequency control means that the color and brightness of the three-color LED lantern are controlled by the amplitude and frequency of the audio signal. At present, amplitude control and amplitude frequency control are mostly used.

At present, most of the technical realization methods of music rhythm colorful lights are realized by using analog circuits or digital circuits. The analog circuit implementation method simply adopts analog circuit technology. The implementation of digital circuits mostly uses ASIC technology. First, the audio signal is digitized through AD, then various digital signal processing is performed, and finally the MOSFET is controlled to drive the LED lantern. This method has good control effect and is flexible and changeable; the disadvantage is that the circuit is complex and expensive.

The traditional audio signal amplitude control method usually mirrors the audio signal according to its DC bias voltage, and mirrors the signal amplitude lower than the bias voltage to the bias voltage, as shown in Figure 1. The mirrored signal is passed through Amplify to drive LED. This control method makes the average current of the LED larger, so the LED is brighter, but at the same time it will reduce the dynamic feeling of the LED flickering.

Utility model content

Based on the above problems, the purpose of this utility model is to provide a control drive circuit for music colorful lights, which can effectively deal with the problems of flickering and brightness of three-color LED lights, so that the three-color LED lights not only have considerable brightness, but also The flickering movement is obvious.

Therefore, the technical problem to be solved by the utility model is to adopt the amplitude-frequency control method and use the hybrid circuit technology to realize the colorful lights of the music rhythm. It is characterized by low cost, simple circuit, obvious flickering dynamics of colored lights, and good synchronization with music beats.

The principle of this device is that the audio signal output by the baseband controller BB is isolated and amplified and then separated into three-way signals of high-frequency, mid-frequency and low-frequency through high-pass, band-pass and low-pass filters; the three-way audio signals are converted into Each LED of one color is controlled based on its amplitude, such as a high audio signal controls a red LED, a mid audio signal controls a blue LED, and a low audio signal controls a green LED.

The utility model is achieved in that:

A control drive circuit for music colorful lights, including a baseband processor (BB), a control drive circuit (CDC), a three-color LED color lamp and a battery, the three-color LED color lights can be controlled by the control drive circuit The color and brightness flicker with the beat of the music, the baseband processor is connected with the control drive circuit and communicates, and the communication content of the two includes control signals and music audio signals; the control drive circuit communicates with the three-color LED lantern Connected to control the flashing of colored lights; the battery provides power for the entire baseband processor, control drive circuit and three-color LED lights.

The control drive circuit (CDC) is mainly composed of an isolation amplifier OP, a power control circuit PRC, a low-pass filter LPF, a high-pass filter HPF, a band-pass filter BPF, a reference voltage generator RVG, a comparison circuit CC1, a comparison circuit CC2, The comparison circuit CC3 and the drive circuit DRC are composed; the isolation amplifier OP is respectively connected to the low-pass filter LPF, the band-pass filter BPF, and the high-pass filter HPF, and the low-pass filter LPF, the band-pass filter BPF, and the high-pass filter HPF are respectively connected to The comparison circuit CC1, the comparison circuit CC2 and the comparison circuit CC3, the baseband processor is directly connected to the power control circuit, the drive circuit and the reference voltage generator, and provides control signals to the power control circuit and the drive circuit, and the output of the reference voltage generator is connected to the comparison circuit CC1 , the comparison circuit CC2, and the comparison circuit CC3 provide a reference voltage. The functions of each part are as follows:

The isolation amplifier OP isolates and amplifies the audio signal from the baseband to prevent the CDC from interfering with the audio signal and reducing the quality of the audio signal. In some occasions that do not require high sound quality, if the baseband output audio signal has a strong load capacity, the isolation amplifier circuit OP can also be omitted.

The low-pass filter LPF, band-pass filter BPF, and high-pass filter HPF filter the isolated and amplified audio signal, and separate the audio signal into three signals of low frequency, intermediate frequency and high frequency. The filtering circuit can adopt active filtering and passive filtering circuits based on RC or LC.

The comparison circuit CC1 , the comparison circuit CC2 and the comparison circuit CC3 respectively shape the filtered low-frequency, intermediate-frequency and high-frequency signals. The reference voltage generator RVG is used to generate the reference voltage required for signal shaping, and the reference voltage can change in real time with the amplitude of the input audio signal.

The shaped pulse waveform controls the driving circuit DRC to drive the three-color LED lights. At the same time, the DRC can be controlled by the baseband controller BB through GPIO to enable the music colorful function. When the colorful function is not enabled, it can emit light according to the control method of ordinary keyboard backlight. The utility model pulses the audio signal and controls it through a hybrid circuit. The circuit has the advantages of low cost, simple circuit, obvious flickering dynamics of colored lights, and good synchronous effect with music rhythm.

Moreover, the reference comparison voltage of the utility model can be adaptively changed with the amplitude of the input audio signal; the three-color LED lights are controlled by combining frequency and amplitude; the music dazzling function can be turned off without affecting the LED lighting Function.

The power control circuit PRC is controlled by the baseband controller BB through the GPIO, and is used to enable and disable the power of the device to save power consumption of the mobile terminal.

Description of drawings

The utility model will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is the image waveform diagram of the audio signal of the prior art;

Fig. 2 is a block diagram of the utility model;

Fig. 3 is a structural block diagram of the concrete realization of the utility model;

Fig. 4 is the waveform diagram of audio signal shaping of the utility model;

Fig. 5 is a waveform schematic diagram of the correlation between the audio signal amplitude and its zero-crossing interval;

Fig. 6 is a circuit diagram of a voltage-controlled voltage source second-order low-pass filter.

7 is a schematic diagram of the signal processing process of the reference voltage generator RVG;

8 is a schematic diagram of the principle of the driving circuit DRC;

FIG. 9 is a schematic diagram of the principle of the power control circuit PRC.

Detailed ways

The specific embodiment is described according to the block diagrams shown in FIG. 2 and FIG. 3 .

Fig. 1 is the structural block diagram that the utility model implements, and in the figure, the utility model comprises baseband processor (BB), control drive circuit (CDC) and three-color LED color lamp and battery, and described three-color LED color lamp can be in Under the control of the control drive circuit, the color and brightness flicker with the beat of the music, the baseband processor is connected to the control drive circuit and communicates, and the communication content of the two includes control signals and music audio signals; the control drive circuit It is connected with the three-color LED colored lights to control the flickering of the colored lights; the battery provides power for the whole circuit device.

Fig. 3 is the block diagram of the colorful circuit of the music rhythm of the utility model. The baseband controller BB provides audio signals, and controls the control drive circuit CDC through GPIO (general input and output ports); in the figure, the baseband controller BB provides audio signals, and controls the control drive circuit CDC through GPIO (general input and output ports). control. The control drive circuit CDC is mainly composed of isolation amplifier OP, power control circuit PRC, low-pass filter LPF, high-pass filter HPF, band-pass filter BPF, reference voltage generator RVG, comparison circuit CC1, comparison circuit CC2, comparison circuit CC3 and The drive circuit DRC and other parts are composed.

In order to take into account the dynamics and brightness of LED flickering, the utility model shapes the audio signal and pulses the audio signal, as shown in Figure 4 . The device first generates a reference voltage, and drives the LED to light up when the audio signal is higher than the voltage; turns off the LED when the audio signal is lower than the reference voltage. Since the frequency of the audio signal is not very high, there is a strong correlation between its amplitude (a in Figure 5) and the length of time the audio signal crosses the reference voltage (d in Figure 5), as shown in Figure 5. Based on this correlation, the blinking brightness of the LED in the above-mentioned control method can be changed with the amplitude of the audio signal. The advantage of this processing method is that the audio signal is not mirrored, and there is a sufficient time interval between the LED on and off, so the flashing dynamics of the LED will be enhanced. On the other hand, the average current of the LED is large enough to make the LED flash bright enough.

The audio isolation amplifier OP is not necessary. If the driving ability of the audio signal is strong enough, the audio amplifier may not be used. Usually, an operational amplifier can be used to realize the isolation amplifier OP, the simplest such as a voltage follower, etc.

As filters (high-pass filter HPF, band-pass filter BPF, low-pass filter LPF), passive filters or active filters may be used. In order to ensure sufficient amplitude, an active filter is used in this device; in order to separate the audio signal into high, medium and low frequency bands as much as possible, so that the color changes of red, green and blue lights are obvious, this device uses A second-order filter circuit is used. The high, medium and low filters adopt the classic voltage-controlled voltage source second-order low-pass filter, voltage-controlled voltage source second-order band-pass filter and voltage-controlled voltage source second-order high-pass filter respectively. The low-pass filter is shown in Figure 6, and its parameters can be adjusted according to the actual flickering effect of the three-color lamp. In order to ensure that the signal amplitude difference of the three frequency bands obtained after audio filtering is not very large, it is necessary to specially adjust the gain of the filter to ensure that the brightness difference of the red, green and blue LEDs is not too large. In order to obtain a good flicker effect, the frequency range selection of the high, medium and low frequency bands needs to be carefully adjusted.

The comparison circuit is mainly used to digitize the filtered audio signal, that is, to realize the waveform shaping function shown in Fig. 4 . There are many specific circuits to realize the above-mentioned shaping function, and the simplest one is a comparator. Of particular concern is the voltage reference (comparison voltage) of the compare circuit. Since the amplitude of the audio signal output from the baseband to the device may be different (for example, the user adjusts the volume), in order to make the brightness difference of the colored lights as small as possible under the condition of high volume and low volume, that is, the colorful flickering effect is not affected by the amplitude of the audio signal. Influence, the reference voltage generator RVG needs to output different reference voltages according to different audio signal amplitudes.

The signal processing process of the reference voltage generator RVG is shown in Figure 7. Its input is the output of the isolation amplifier OP, which passes through the rectifier circuit, passes through the low-pass filter and passes through the signal conditioning circuit to generate the reference voltage reference.

The driving circuit DRC is used to drive three-color LEDs. If the LED load is relatively light, it can be directly driven by a comparison circuit (CC) composed of a comparator. If the number of three colors to be driven is large, a special driving circuit DRC is required to drive it. In this device, an NPN transistor is used to form a driving circuit DRC, as shown in FIG. 8 . The driving circuit can be controlled by GPIO1 output from the baseband BB. When using the colorful function, GPIO1 is set to input mode (high impedance state); when not using the colorful function, set GPIO1 to high, so as to turn off without affecting the lighting of the keyboard backlight Function.

The power control circuit PRC is used to turn off the power supply of the whole device, reduce the standby current of the portable mobile terminal, and prolong the standby time. The power control circuit PRC in this device uses a P-channel MOSFET, as shown in FIG. 9 , and its on and off is controlled by the baseband BB through GPIO2.

According to different application occasions and different LED loads, the several functional modules described in Figure 3 can be implemented together using simpler specific circuits. For example, when the driving ability of the audio source is strong and the LED load is small, the isolation amplifier OP, filter, comparison circuit and driving circuit can be integrated and implemented using three operational amplifiers.

The above description is only a description of one of the possible implementation modes of the utility model, and does not constitute a limitation to the protection scope of the utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention are within the protection scope of the claims of the present invention.

Claims (3)

1. A control drive circuit for music colorful lights, characterized in that the control drive circuit includes a baseband processor, a control drive circuit, a three-color LED colored light and a battery, and the three-color LED colored light can be controlled and driven Under the control of the circuit, the color and brightness flicker with the beat of the music. The baseband processor is connected to the control drive circuit and communicates. The communication content of the two includes control signals and music audio signals; the control drive circuit communicates with the three The colored LED lights are connected to control the flickering of the colored lights; the battery provides power for the entire baseband processor, the control drive circuit and the three-color LED lights. 2. The music dazzling light control drive circuit as claimed in claim 1, characterized in that the control drive circuit is mainly composed of an isolation amplifier OP, a power supply control circuit PRC, a low-pass filter LPF, a high-pass filter HPF, and a band-pass filter. BPF, reference voltage generator RVG, comparison circuit CC1, comparison circuit CC2, comparison circuit CC3 and drive circuit DRC; the isolation amplifier OP is respectively connected to the low-pass filter LPF, band-pass filter BPF, high-pass filter HPF, low-pass Filter LPF, band-pass filter BPF, and high-pass filter HPF are respectively connected to comparison circuit CC1, comparison circuit CC2, and comparison circuit CC3. The drive circuit provides a control signal, and the output of the reference voltage generator is connected to the comparison circuit CC1, the comparison circuit CC2, and the comparison circuit CC3 to provide a reference voltage. 3. The music dazzling light control driving circuit as claimed in claim 2, characterized in that the filter circuits of the above-mentioned low-pass filter LPF, band-pass filter BPF, and high-pass filter HPF adopt active filtering or LC based on RC or LC. Passive filter circuit.

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