Step-by-step assembly of a simple design of LED color music, with a passing study of amateur radio programs

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We assemble LED light music (color music).
Part 1.

At today's lesson in Beginning radio amateur school we will start collecting LED light music. During this lesson, we will not only assemble light music, but also study another amateur radio program "Cadsoft Eagle"– a simple, but at the same time powerful, comprehensive tool for the development of printed circuit boards and we will learn how to make printed circuit boards using film photoresist. Today we will choose a circuit, look at how it works, and select the details.

Light and music (color and music) devices were very popular during the Soviet Union. They were mainly three-colored (red, green or yellow and blue) and were most often assembled using the simplest circuits on more or less affordable KU202N thyristors (which, if my memory serves me correctly, cost more than 2 rubles in stores, i.e. were quite expensive) and the simplest audio frequency input filters on coils wound on sections of ferrite rods from radio receivers. They were made mainly in two versions - in the form of three-color spotlights on 220-volt light bulbs, or a special case was made in the form of a box, where a certain number of light bulbs of each color were located inside, and the front of the box was closed with frosted glass, which made it possible to obtain a fancy look on such a screen. light accompaniment of music. Also, ordinary glass was used for the screen, and small fragments of car glass were glued on top of it for better light scattering. It was such a difficult childhood. But today, in the age of the development of incomprehensible capitalism in our country, it is possible to assemble a light and sound device for every taste, which is what we will do.

We will take as a basis LED light circuit diagram published on the website:

To this diagram we will add two more elements:

1. . Since we will have a stereo signal at the input, and in order not to lose sound from any channel, or not to connect two channels directly to each other, we will use the following input node (taken from another light-music circuit):

2. Device power supply . We will supplement the light and music circuit with a power supply assembled on a KR142EN8 microcircuit stabilizer:

This is approximately the set of parts we need to assemble:

LEDs for this device can be used of any type, but they must be super-bright and of different colors. I will use ultra-bright, highly directional LEDs, the light from which will be directed towards the ceiling. You, of course, can use a different option for the light display of the sound signal and use a different type of LEDs:

How does this scheme work? . The stereo signal from the sound source is supplied to the input node, which sums the signals from the left and right channels and feeds it to variable resistances R6, R7, R8, which regulate the signal level for each channel. Next, the signal goes to three active filters, assembled according to an identical circuit using transistors VT1-VT3, which differ only in capacitor values. The meaning of these filters is that they pass through only a strictly defined band of the audio signal, cutting off the unnecessary frequency range of the audio signal from above and below. The upper (according to the diagram) filter passes the band 100-800 Hz, the middle one – 500-2000 Hz and the lower one – 1500-5000 Hz. Using trimming resistors R5, R12 and R16, you can shift the transmitted band in any direction. If you want to obtain other signal bandwidths of the filters, you can experiment with the values ​​of the capacitors included in the filters. Next, the signals from the filters are sent to microcircuits A1-A3 - LM3915. What kind of microcircuits are these?

LM3914, LM3915 and LM3916 chips from National Semiconductors allow you to build LED indicators with various characteristics - linear, stretched linear, logarithmic, special for monitoring an audio signal. In this case, LM3914 is for a linear scale, LM3915 is for a logarithmic scale, and LM3916 is for a special scale. We use LM3915 chips - with a logarithmic scale for monitoring the audio signal.

The initial page of the microcircuit datasheet:

(327.0 KiB, 4,279 hits)

In general, I advise you that when faced with a new, unknown radio component, look for its datasheet on the Internet and study it, especially since there are also datasheets translated into Russian.

For example, what can we glean from the first sheet of the LM3915 datasheet (even with minimal knowledge of English, and in extreme cases, using a dictionary):
- this microcircuit is an analog signal level indicator with a logarithmic display scale and a step of 3 dB;
– you can connect both LEDs and LCD indicators;
– indication can be carried out in two modes: “dot” and “column”;
– maximum output current for each LED – 30 mA;
- and so on…

By the way, what is the difference between a “dot” and a “column”. In the “dot” mode, when the next LED is turned on, the previous one goes out, and in the “column” mode, the previous LEDs do not go out. To switch to the “point” mode, just disconnect pin 9 of the microcircuit from the “+” power source, or connect it to “ground”. By the way, these microcircuits can be used to assemble very useful and interesting circuits.

Let's continue. Since alternating voltage is supplied to the inputs of the microcircuits, the glowing column of LEDs will have uneven brightness, i.e. As the input signal level increases, not only will successive LEDs light up, but their brightness will also change. Below is a table of the threshold activation of each LED for different microcircuits in volts and decibels:

Characteristics and pinout of transistor KT315:

This concludes the first part of the lesson on assembling LED light music and begins to assemble the parts. In the next part of the lesson, we will study the PCB design program “Cadsoft Eagle” and make a printed circuit board for our device using film photoresist.

Do-it-yourself color music - what could be more pleasant and interesting for a radio amateur, because it is not difficult to assemble if you have a good circuit.

In modern radio engineering there is a huge variety of radio elements and LEDs, the advantages of which are difficult to doubt. A wide range of colors, bright and rich light, high speed of response of various elements, low energy consumption. This list of advantages can be continued endlessly.

The principle of operation of color music: LEDs assembled according to the circuit blink from an existing sound source (this can be a player or a radio and speakers) at a certain frequency.

Advantages of using LEDs over those previously used in CMU:

• luminous saturation of light and a wide color range;
• good speed;
• low energy consumption.

The simplest schemes

A simple color music that can be assembled has one LED and is powered by a 6–12 V DC source.

You can assemble the above circuit using an LED strip and selecting the necessary transistor. The disadvantage is that there is a dependence of the LED blinking frequency on the sound level. In other words, the full effect can be observed only at one sound level. If you lower the volume, there will be a rare blinking, and if you increase the volume, a constant glow will remain.

This drawback can be eliminated using a three-channel sound converter. Below is a simple circuit; it is not difficult to assemble it with your own hands using transistors.

Color music circuit with three-channel sound converter

This circuit requires a 9-volt power supply, which will allow the LEDs in the channels to light. To assemble three amplification stages, you will need KT315 transistors (analogous to KT3102). Multi-colored LEDs are used as a load. A step-down transformer is used for amplification. Resistors perform the function of adjusting LED flashes. The circuit contains filters for passing frequencies.

The scheme can be improved. To do this, you need to add brightness with 12 V incandescent light bulbs. You will need control thyristors. The entire device must be powered from a transformer. You can already work according to this simplest scheme. Color music using thyristors can be assembled even by a novice radio technician.

How to make color music using LEDs with your own hands? The first thing you need to do is select an electrical circuit.

Below is a diagram of a light and music system with an RGB strip. For such an installation, a 12 volt power supply is required. It can work in two modes: as a lamp and as a color music. The mode is selected by a switch installed on the board.

Manufacturing stages

It is necessary to make a printed circuit board. To do this, you need to take foil fiberglass with dimensions of 50 x 90 mm and a thickness of 0.5 mm. The board manufacturing process consists of several stages:

• preparation of foil PCB;
• drilling holes for parts;
• drawing paths;
• etching.

The board is ready, components have been purchased. Now begins the most crucial moment - the wiring of radio elements. The final result will depend on how carefully they are installed and sealed.

We assemble our printed circuit board with the components soldered on it into such an accessible lampshade.

Brief description of radioelements

Radioelements for an electrical circuit are quite affordable; purchasing them at your nearest electrical goods store will not be difficult.

For color and musical accompaniment, wirewound resistors with a power of 0.25–0.125 W are suitable. The amount of resistance can always be determined by the colored stripes on the body, knowing the order in which they are applied. Trimmer resistors can be both domestic and imported.

Capacitors produced by industry are divided into oxide and electrolytic. It won’t be difficult to select the ones you need by doing basic calculations. Some oxide capacitors may have a polarity that must be observed during installation.

You can take a ready-made diode bridge, but if you don’t have it, then a rectifier bridge can be easily assembled using diodes of the KD or 1N4007 series. LEDs are taken as usual, with a multi-colored glow. The use of LED RGB strips is a promising direction in radio electronics.

LED RGB strip

Possibility of assembling a color and music console for a car

If you manage to please with color music from an LED strip made by yourself, then a similar installation with a built-in radio can be made for a car. It is easy to assemble and quick to set up. It is proposed to place the set-top box in a plastic case, which can be purchased in the electrical and radio engineering department. The installation is reliably protected from moisture and dust. It is easy to install behind the dashboard of your car.

You can also make a similar case yourself using plexiglass.

The plates of the required dimensions are selected, two holes are made in the first part (for power supply), and all parts are sanded. We assemble everything using a heat gun.

An excellent lighting effect is achieved if you use multi-colored (RGB) tape.

Conclusion

The well-known saying “it is not the gods who burn the pots” remains relevant today. A diverse range of electronic components gives craftsmen wide scope for imagination. DIY color music on LEDs is one of the manifestations of limitless creativity.

The other day I decided to assemble a color music installation. The local club really wanted to add lighting effects. After a good search on the Internet, I found a 3-channel CMU (color music unit). The circuit does not look complicated, and it turned out to be easy to solder. Here it is:

This 3-channel DMU is very easy to manufacture, but has some disadvantages. This is, firstly, the high required input signal level, secondly, low input impedance, and thirdly, the sharp blinking of the lamps, caused by the lack of compression and the simplicity of the filters used. But for beginner radio amateurs, the scheme will be just right.

The flashes are controlled by thyristors. They can be placed in the KU202 series with the letters k, l, m, n. Of course, it’s better to take ones like those in the diagram. Power supply from 220V network. Each channel is adjusted using variable resistors. The circuit does not require any configuration; it works immediately after proper assembly. When working with color music, keep in mind that you need a fairly large music signal.

Transformer TP1 is made on a Ш16x24 core made of transformer steel. Winding I contains 60 turns of PEL 0.51 wire. Winding II - 100 turns PEL 0.51. Any other small-sized transformer (for example, from transistor receivers) with a ratio of turns in the windings close to 1:2 can be used. Thyristors must be installed on heat sinks if the total lamp power per channel exceeds 200 W.

Assembled and checked. Works very well. Here is the device itself in the case:

This is the arrangement of elements inside the box that I chose. It is better to turn it on via a diode bridge. It's cheap. But I think it’s not this that’s important to a radio amateur, but the repetition of the device itself. Even a beginner can solder the circuit. The finished color music device operates without interference, and does not strain the thyristors for a long time. They don't even heat up. Author of the material: Max.

In this article we will talk about color music. Probably every beginning radio amateur, and not only others, at one time or another had the desire to assemble color music. What this is, I think, is known to everyone - to put it simply, it is the creation of visual effects that change to the beat of the music.

That part of color music that emits light can be performed using powerful lamps, for example, in a concert setup; if color music is needed for home discos, it can be done using ordinary 220 volt incandescent lamps, and if color music is planned, for example, as computer modding, for everyday use, it can be done with LEDs.

Recently, with the advent of LED strips on sale, color and music consoles using such LED strips are increasingly used. In any case, to assemble Color Musical Installations (CMUs for short) a signal source is required, which can be a microphone with several amplifier stages assembled.

Also, the signal can be taken from the linear output of a device, a computer sound card, from the output of an mp3 player, etc., in this case an amplifier will also be required, for example, two stages on transistors; for this purpose I used KT3102 transistors. The preamplifier circuit is shown in the following figure:

Preamplifier - circuit

The following is a diagram of a single-channel color music with a filter, working in conjunction with a preamplifier (above). In this circuit, the LED flashes along with the bass (low frequencies). To match the signal level, a variable resistor R6 is provided in the color music circuit.

There are also simpler color music circuits that any beginner can assemble, using 1 transistor, and also not requiring a preamplifier; one of these circuits is shown in the picture below:

Color music on a transistor

The pinout diagram for the Jack 3.5 plug is shown in the following figure:

If for some reason it is not possible to assemble a pre-amplifier using transistors, you can replace it with a transformer turned on as a step-up. Such a transformer must produce voltage on the windings of 220/5 Volts. The transformer winding with a smaller number of turns is connected to a sound source, for example, a radio tape recorder, parallel to the speaker, and the amplifier must produce a power of at least 3-5 watts. A winding with a large number of turns is connected to the color music input.

Of course, color music is not only single-channel, it can be 3, 5 or more multi-channel, when each LED or incandescent lamp blinks while reproducing the frequencies of its range. In this case, the frequency range is set by using filters. In the following circuit, a three-channel color music system (which I recently assembled myself), there are capacitors as filters:

If we wanted to use not individual LEDs in the last circuit, but an LED strip, then the current-limiting resistors R1, R2, R3 should be removed from the circuit. If the strip or LED is used RGB, it must be made with a common anode. If you plan to connect long LED strips, then to control the strip you should use powerful transistors installed on radiators.

Since LED strips are designed for 12 Volt power supply, we should accordingly raise the power supply in the circuit to 12 Volts, and the power supply should be stabilized.

Thyristors in color music

Until now, the article has only talked about color and music devices using LEDs. If there is a need to assemble a digital control unit using incandescent lamps, then thyristors will need to be used to control the brightness of the lamps. What is a thyristor anyway? This is a three-electrode semiconductor device, which accordingly has Anode, Cathode And Control electrode.

KU202 Thyristor

The figure above shows the Soviet thyristor KU202. Thyristors, if you plan to use them with a powerful load, also need to be mounted on a heat sink (radiator). As we see in the figure, the thyristor has a thread with a nut and is attached similarly to powerful diodes. Modern imported ones are simply equipped with a flange with a hole.

One of these thyristor circuits is shown above. This is a three-channel color music circuit with a step-up transformer at the input. When selecting analogue thyristors, you should look at the maximum permissible voltage of the thyristors, in our case for the KU202N it is 400 volts.

The figure shows a similar color music circuit to the one shown above, the main difference in the lower circuit is that there is no diode bridge. Also, LED color music can be built into the system unit. I assembled such a three-channel color music with a preamplifier in a casing from a cider. In this case, the signal was taken from the computer’s sound card using a signal divider, the outputs of which connected active acoustics and color music. It is possible to adjust the signal level, both overall and separately by channel. The preamplifier and color music were powered from a 12 Volt Molex connector (yellow and black wires). The preamplifier and three-channel color music circuits for which they were assembled are shown above. There are other LED color music schemes, for example this one, also three-channel:

Color music on 3 LEDs - diagram

In this circuit, unlike the one I assembled, inductance is used in the mid-frequency channel. For those who want to first assemble something simpler, here is the following diagram for 2 channels:

If you collect color music using lamps, you will have to use light filters, which in turn can be either homemade or purchased. The figure below shows the filters that are commercially available:

Some fans of color and musical effects assemble devices based on microcontrollers. Below is a diagram of four-channel color music on the AVR tiny 15 MK:

The Tiny 15 microcontroller in this circuit can be replaced with tiny 13V, tiny 25V. And at the end of the review, I would like to say on my own that color music using lamps is inferior in terms of entertainment to color music using LEDs, since lamps are more inertial than LEDs. And for self-repetition, I can recommend this one:

The inexhaustible potential of LEDs has once again been revealed in the design of new and modernization of existing color and music consoles. 30 years ago, color music, assembled from multi-colored 220-volt light bulbs connected to a cassette recorder, was considered the height of fashion. Now the situation has changed and the function of a tape recorder is now performed by any multimedia device, and instead of incandescent lamps, super-bright LEDs or LED strips are installed.

The advantages of LEDs over light bulbs in color music consoles are undeniable:

• wide color gamut and more saturated light;
• various design options (discrete elements, modules, RGB strips, rulers);
• high response speed;
• low power consumption.

How to make color music using a simple electronic circuit and make LEDs blink from an audio frequency source? What options for converting an audio signal are there? Let's look at these and other questions using specific examples.

The simplest circuit with one LED

First you need to understand a simple color music circuit, assembled on one bipolar transistor, resistor and LED. It can be powered from a DC source with a voltage of 6 to 12 volts. This color music works on one transistor according to the principle of an amplification stage with a common emitter. A disturbing influence in the form of a signal with varying frequency and amplitude arrives at the VT1 base. As soon as the oscillation amplitude exceeds a certain threshold value, the transistor opens and the LED flashes.

The disadvantage of this simplest scheme is that the rate of blinking of the LED depends entirely on the level of the sound signal. In other words, a full-fledged color-musical effect will be observed only at one volume level. Lowering the volume will result in a rare wink, while increasing the volume will result in an almost constant glow.

Scheme with single-color LED strip

The simplest color music above on a transistor can be assembled using an LED strip in the load. To do this, you need to increase the supply voltage to 12V, select a transistor with the highest collector current exceeding the load current and recalculate the resistor value. This simple color music from an LED strip is perfect for beginning radio amateurs to assemble with their own hands, even at home.

Simple three-channel circuit

A three-channel audio converter allows you to get rid of the shortcomings of the previous scheme. The simplest scheme of color music with the division of the sound range into three parts is shown in the figure.
It is powered by a constant voltage of 9V and can illuminate one or two LEDs in each channel. The circuit consists of three independent amplifier stages assembled on KT315 (KT3102) transistors, the load of which includes LEDs of different colors. As a pre-amplification element, you can use a small step-down network transformer.

The input signal is fed to the secondary winding of the transformer, which performs two functions: galvanically isolates the two devices and amplifies the sound from the line output. Next, the signal goes to three parallel-connected filters assembled on the basis of RC circuits. Each of them operates in a specific frequency band, which depends on the values ​​of resistors and capacitors. The low-pass filter passes sound vibrations with a frequency of up to 300 Hz, as indicated by the blinking red LED. Sound in the range of 300-6000 Hz passes through the mid-pass filter, which is manifested in the flickering of the blue LED. The high-pass filter passes a signal whose frequency is greater than 6000 Hz, which corresponds to the green LED. Each filter is equipped with a trimming resistor. With their help, you can set the uniform glow of all LEDs, regardless of the musical genre. At the output of the circuit, all three filtered signals are amplified by transistors.

If the circuit is powered from a low-voltage DC source, then the transformer can be safely replaced with a single-stage transistor amplifier.
Firstly, galvanic isolation loses its practical meaning. Secondly, the transformer is several times inferior to the circuit shown in the figure in terms of weight, size and cost. The circuit of a simple audio amplifier consists of a KT3102 transistor, two capacitors that cut off the DC component, and resistors that provide the transistor with a common emitter. Using a trimmer resistor, you can achieve overall amplification of a weak input signal.

In the case when it is necessary to amplify the signal from the microphone, an electret microphone is connected to the input of the previous circuit, applying potential to it from the power source. The circuit of a two-stage preamplifier is shown in the figure.
In this case, the trimming resistor is located at the output of the first amplifier stage, which gives more opportunities for adjusting sensitivity. Capacitors C1-C3 pass the useful component and cut off the direct current. Any electret microphone is suitable for implementation; for normal operation, a bias of 1.5 V is sufficient.

Color music with RGB LED strip

The following circuit of a color music console operates on 12 volts and can be installed in a car. It combines the main functions of the previously discussed circuit solutions and is capable of operating in color music and lamp modes.

The first mode is achieved through contactless control of the RGB strip using a microphone, and the second mode is achieved through the simultaneous illumination of red, green and blue LEDs at full power. The mode is selected using a switch located on the board. Now let’s take a closer look at how to make color music that is perfect even for installation in a car, and what parts are required for this.

Structural scheme

To understand how this color music console works, let’s first consider its structural diagram. It will help trace the full path of the signal.
The source of the electrical signal is a microphone, which converts sound vibrations from the phonogram. Because This signal is too small and must be amplified using a transistor or operational amplifier. Next comes the automatic level controller (AGC), which keeps the sound fluctuations within reasonable limits and prepares it for further processing. Filters divide the signal into three components, each of which operates only in one frequency range. In the end, all that remains is to amplify the prepared current signal, for which transistors operating in switching mode are used.

Schematic diagram

Based on the structural blocks, we can proceed to a consideration of the circuit diagram. Its general appearance is shown in the figure.
To limit current consumption and stabilize the supply voltage, resistor R12 and capacitor C9 are installed. R1, R2, C1 are set to set the microphone bias voltage. Capacitor C fc is selected individually for a specific microphone model during the setup process. It is needed in order to slightly muffle the signal of the frequency that prevails in the microphone’s operation. Usually the influence of the high-frequency component is reduced.

Unstable voltage in the vehicle network can affect the operation of color music. Therefore, it is most correct to connect homemade electronic devices through a 12V stabilizer.

Sound vibrations in the microphone are converted into an electrical signal and, through C2, are supplied to the direct input of the operational amplifier DA1.1. From its output, the signal goes to the input of the operational amplifier DA1.2, equipped with a feedback circuit. The resistances of resistors R5, R6 and R10, R11 set the gain DA1.1, DA1.2 equal to 11. The elements of the OS circuit: VD1, VD2, C4, C5, R8, R9 and VT1, together with DA1.2, are part of the AGC. At the moment a signal of too large an amplitude appears at the output of DA1.2, transistor VT1 opens and, through C4, closes the input signal to the common wire. This results in an instantaneous reduction in the output voltage.

Then the stabilized alternating current of audio frequency passes through the cut-off capacitor C8, after which it is divided into three RC filters: R13, C10 (LF), R14, C11, C12 (MF), R15, C13 (HF). In order for the color music on LEDs to shine brightly enough, you need to increase the output current to the appropriate value. For tape with a consumption of up to 0.5A per channel, medium-power transistors such as KT817 or imported BD139 without mounting on a radiator are suitable. If the do-it-yourself light-music assembly involves a load of about 1A, then the transistors will require forced cooling.

In the collectors of each output transistor (parallel to the output) there are diodes D6-D8, the cathodes of which are connected to each other and connected to switch SA1 (White light). The second contact of the switch is connected to the common wire (GND). While SA1 is open, the circuit operates in color music mode. When the switch contacts are closed, all the LEDs in the strip light up at full brightness, forming a total white stream of light.

Printed circuit board and assembly parts

To make a printed circuit board, you will need a single-sided PCB measuring 50 by 90 mm and a ready-made .lay file, which can be downloaded. For clarity, the board is shown from the side of the radio elements. Before printing, you must set its mirror image. Layer M1 shows 3 jumpers placed on the parts side.
To assemble color music from an LED strip with your own hands, you will need accessible and inexpensive components. An electret type microphone, suitable in a protective case from old audio equipment. Light music is assembled on a TL072 chip in a DIP8 package. Capacitors, regardless of type, must have a voltage reserve and be designed for 16V or 25V. If necessary, the board design allows you to install output transistors on small radiators. A terminal block with 6 positions is soldered on the edge for supplying power, connecting an RGB LED strip and a switch. A complete list of elements is given in the table. In conclusion, I would like to note that the number of output channels in a homemade color music set-top box can be increased as many times as desired. To do this, you need to divide the entire frequency range into a larger number of sectors and recalculate the bandwidth of each RC filter. Connect LEDs of intermediate colors to the outputs of additional amplifiers: violet, turquoise, orange. Do-it-yourself color music will only become more beautiful from such an improvement.

The given diagrams belong to the site cxem.net

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