Hello everyone, in this article we will consider a detailed assembly of the ULF (Low Frequency Amplifier) on the TDA8560. The circuit is quite simple, and this article will also differ from others in that here we will assemble the structure not by surface mounting, as is often done with specialized microcircuits, but on a printed circuit board. Although for those who are just starting to master the self-assembly of the UMZCH, it is recommended to connect it "on the wires" for the experiment. In general, let's get started. First, let's study the datasheet for the microcircuit and the circuit diagram of the amplifier itself:
We will need:
Amplifier frequency response
Let's start assembling the device and first etch the board, PCB file .
We solder the microcircuit itself
Soldering ceramic capacitors at 0.47 mF
Solder a 22 kΩ resistor and a 2200 uF electrolytic capacitor
Achtung! Do not turn on the device without a heatsink! We connect the speakers and start ... It started for me the first time, because I soldered it without errors and the microcircuit got workable.
This amplifier chip is almost no different from its sotovarok, such as TDA8563, TDA1555, TDA1552 And TDA1557. The difference is only in the output power - the connection is exactly the same. You can watch a video of the operation of this chip below:
The power supply of the amplifier can be taken ready, from the computer. Since it will have enough power in excess - you can even turn off the cooler, it still will not overheat. I assembled the scheme boiler.
Discuss the article SOUND AMPLIFIER OWN HANDS
It will have different dimensions and complexity of building a circuit. The article will immediately touch upon three types of amplifiers - on transistors, microcircuits and lamps. And it is worth starting with the latter.
These can often be found in old equipment - televisions, radios. Despite being obsolete, this technique is still popular with music lovers. There is an opinion that the tube sound is much cleaner and more beautiful than "digitized". It is quite possible, in any case, that such an effect as from lamps cannot be achieved using transistor circuits. It is worth noting that the sound amplifier circuit (the simplest, using tubes) can be implemented on only one triode.
In this case, it is necessary to apply a signal to the radio tube grid. A bias voltage is applied to the cathode - it is corrected by selecting the resistance in the circuit. A supply voltage (over 150 volts) is supplied to the anode through the capacitor and the primary winding of the transformer. Accordingly, the secondary winding is connected to the speaker. But this is a simple circuit, and in practice two- or three-stage designs are often used, in which there is a preliminary and final amplifier (on powerful lamps).
What is the disadvantage of lamp technology? It was mentioned above that the anode voltage should be over 150 volts. In addition to this, a 6.3 V alternating voltage is required to power the filaments of the lamps. Sometimes 12.6 V is required, since there are lamps with such a filament voltage. Hence the conclusion - a huge need to use massive transformers.
But there are advantages that distinguish lamp technology from transistor technology: ease of installation, durability, it is almost impossible to disable the entire circuit. Unless you need to break the bulb of the lamp to break it. What can not be said about transistors - an overheated soldering iron tip or static can easily destroy the junction structure. The same problem with microchips.
Above is a diagram of a transistor audio amplifier. As you can see, it is quite complex - a large number of components are used that allow the entire system to work. But if you break them down into small components, it turns out that not everything is so complicated. And the whole circuit works in almost the same way as the one described above on a vacuum triode. Basically, a semiconductor transistor is nothing but a triode.
The simplest design is a circuit on a single semiconductor, to the base of which three voltages are applied at once: from the plus of the supply through the positive resistance and from the common wire negative, as well as from the signal source. The amplified signal is removed from the collector. The above is an example of a sound amplifier circuit (the simplest on transistors). It is not used in its pure form.
The amplifier on microcircuits will be much more modern and better. Luckily, there are a lot of them today. The simplest sound amplifier circuit on a chip contains an extremely small number of elements. And any person who can more or less tolerably handle a soldering iron can make a good ULF on their own. As a rule, microcircuits contain a couple of capacitors and resistances.
All other elements necessary for operation are present in the crystal itself. But the most important thing is food. For some designs, you need to use bipolar power supplies. Often the problem arises in them. Microcircuits that need such power, for example, are quite difficult to use for the manufacture of a car amplifier.
Since the conversation about amplifiers on microcircuits has already begun, it would be useful to mention that they can be used with tone blocks. Microcircuits are produced specifically for such devices. They contain all the necessary components, it remains only to properly install the entire device.
And you will have the opportunity to adjust the tone of the sound of music. Together with the LED equalizer, it will be not only convenient, but also a beautiful sound visualization tool. And the most interesting thing for car audio lovers is, of course, the ability to connect a subwoofer. But this is worth devoting a separate section to, because the topic is interesting and informative.
Having considered all possible types of amplifiers, we can conclude that the most high-quality and simple ones are made only on a modern element base. A lot of microcircuits are produced specifically for low-frequency amplifiers. As an example, we can cite ULF type TDA with various digital designations.
They are used almost everywhere, as there are both low-power and high-power microcircuits. For example, for portable computer speakers, it is best to use microcircuits whose power is not higher than 2-3 watts. But for automotive equipment or home theater acoustics, it is desirable to use chips with a power of over 30 watts. But pay attention to the fact that they need sound protection. The circuits must contain a fuse that will protect against short circuits in the circuit.
Another plus is that a massive power supply is not required, so you can easily use a ready-made one, for example, from a laptop, PC, old MFPs (new ones, as a rule, have a power supply inside). Ease of installation is what is important for beginner radio amateurs. The only thing that is required for such devices is high-quality cooling. If we are talking about powerful equipment, then you will have to install a forced one - one or more coolers on the radiator.
The winding wire is sold where you can find it, I don’t even know where you live, so I can’t advise anything, although you can write to [email protected] and ask for availability and price. They don’t have wires in the price lists, but they can get it and send it cash on delivery. For what I don't know...For the normal operation of an amplifier with a unipolar supply, it is necessary that the amplifier output has half the supply voltage, and the load is connected through a high-capacity isolation capacitor - 470 ... 2200 μF. The amplitude of the output signal cannot be greater than the supply voltage, therefore, the amplitude of the output AC voltage will ideally be half the supply voltage, i.e. when powered by 12 V, the amplitude will not exceed 6 volts. However, it should be noted that the transistors of the output stage in the open state have some kind of finite resistance, therefore there will be a voltage drop across them.
Let's say that they are very heaped up and only 0.5 V falls on them, therefore the signal amplitude will already be equal to 5.5 V, but this is the amplitude, and the effective value is only 70% of the amplitude, therefore 3.888 V remains.
From the above, it follows that the power of a typical amplifier when powered from 12 V to a load of 4 Ohms will in no way be higher than UxU / R (Ohm's law), i.e. 3.888x3.888 / 4 \u003d 3.8 W.
In modern automotive technology, bridge amplifiers are used, i.e. each speaker is connected to two amplifiers, the signal on which goes in antiphase. Thus, they achieve an increase in the voltage supplied to the load and, accordingly, the output power. In this embodiment, the amplitude increases by 2 times, which means it is 7.77 V, and the output power will not exceed 15.1 W.
You can hit the demagoguery that in a car the on-board voltage rises to 14.2 V, but even in this embodiment, the output power will not exceed 21.8 watts.
Well, the added 50W are obtained only if the signal has a rectangular shape, i.e. this is the maximum possible power, but it’s impossible to call it sound power, it’s noise power and you shouldn’t buy into its value, since the difference between 4x45 and 4x50 is barely noticeable ...
Now a few words about "twisting" the volume and the cavity of car acoustics:
If you carefully re-read what was written above, it will immediately become clear that the main problem of car audio equipment is the limitation of the supply voltage. Those. you won’t get above 22 W, and now, without straining, we estimate:
With a flat frequency response, i.e. without tone control, the device provides 22 W, the signal is recorded with the same level and all playback paths are designed for this, therefore at the output we get a normal signal without distortion.
However, the handles itch, because the ears are dissatisfied and the person starts to chatter the bass up, and the adjustment is at least 10dB, and this is an increase in the signal level by 3 times !!! A total of 22W x 3 times, this is 66W, and the power supply is clearly not enough to deliver such power, and as a result, the output of the power amplifier is a kind of rectangular box with weak modulation by a musical fragment ...
But if this does not happen, then the acoustics are so oaky that they are simply not able to reproduce the entire sound picture in full and its place is in a public toilet to sound the “BUSY!!!” signal.
As for the cavity, the number of lanes is not at all an indicator of quality, and a two-way speaker can outdo a 4-way speaker with chic. Not in advertising, but as an example:
We went 3 weeks ago with a friend to choose speakers for him on the back, he wanted 6x9, he took me as a consultant. We arrived, went into the store, I ask a friend what his heart desires, he says: “I want music!”, And he looks askance at the Pioneers. The seller caught his eye and began to sell some kind of noodles about their excellent sound, but while he was talking, he put three bands into the test stand (the head of JVC + strengthened, which was not visible, the stand was 20 liters per section). Well, he talked, it seems they are singing, a friend starts talking about cavity, well, the seller immediately inserts four-bands. We listen ... Razintsy is not audible ...
Well, here your obedient servant began to talk, because he got acquainted with the showcase ...
I say: "Plug in the GBC and prepare the MACROMES and GV-SI." A familiar mouth opened slightly - on everything where I pointed with my finger there were 2 stripes !!! And the size of the magnets was not very big!!! The seller said such a mysterious phrase: “So you need acoustics ...” and smiled mysteriously ...
In general, now my friend rides with GBI-ELs and wonders how it turns out that the general opinion turned out to be deceptive ...
As for the filters, it's a hassle to divide the signal going to the speakers with the help of filters, although quite real, but VERY troublesome. I propose to postpone this topic for the time being - it is still equal ...
As for the power, the power of the speakers should be one and a half times the power of the amplifier, only in this option is it possible to correctly reproduce the entire dynamic range with a margin for peak operating modes. It should also be noted that the power of the power transformer should be one and a half times the total power of the amplifier.
Yes, usually a “ground” wire and a screen between the windings are soldered to the trance - the interference created by the transformer is greatly reduced.
YUG 21 is absolutely right - you need a trans with 2 secondary windings, or as they say - one with a tap from the middle, because the required power supply is bipolar ...
And you can’t solve the problem with resistance, since the consumption is dynamic - therefore, the drop in resistance will change and the output voltage of the trance will also begin to dance. So this idea with resistance is fundamentally not suitable !!!
By the way, on the TDA7294, not bad amps are obtained for the rear speakers ...
Crap! In scribbled!!! At least ask 1-2 questions, otherwise I got my fingers numb while typing all this ...
How to achieve high-quality sound of your favorite music? Arm yourself with the necessary knowledge, a tool, after which you can assemble a sound amplifier with your own hands.
How many radio amateurs there are, so many opinions. Basically, the choice depends on the person, so it is very difficult to draw any specific conclusions. Today, you can assemble a sound amplifier with your own hands on:
Before you make a sound amplifier, you need to clearly understand in what conditions and for what purpose it will be used. It directly depends on how much power it should have. In order to listen to your favorite songs at home, a small device is quite enough, which will provide high-quality sound with a power of 30 - 50 W. The situation will be completely different if you need to create equipment for large-scale events. In this case, it becomes necessary to assemble a more complex sound amplifier with your own hands. 200W is far from the limit of power that will be needed during operation.
You should also stock up on everything you need:
Every case has its own subtleties. PCB manufacturing at home is no exception. It is she who will subsequently become the basis of all further work and will allow you to assemble a sound amplifier with your own hands. First, let's look at everything we need:
In order to properly assemble a sound amplifier with your own hands, it is not enough to correctly draw a board pattern or solder a wire. You need to be able to qualitatively etch all the tracks on the chip.
For these purposes, ferric chloride has always been used. However, this solution is very expensive and not always commercially available. For this reason, it can be replaced with a homemade solution of copper sulfate and table salt, which are not deficient. The proportions for the mixture are as follows:
When all the components are dissolved, clean and fat-free metal products (for example, a couple of nails), the workpiece itself, a small motor with blades or an aquarium compressor are lowered into the container. To enhance the reaction, it is necessary to place a container with a solution in warm water. Approximate track etching time is 25-30 minutes.
The first step that needs to be done in order to assemble a sound amplifier with your own hands is to install all the radio components on the printed circuit board. Here you should pay special attention to the polarity. It is also worth noting that all work should be carried out with special care and attention. Otherwise, a short circuit may occur, which will lead to the inevitable failure of the components of the future amplifier.
After the above procedure, the body assembly follows. Its dimensions will directly depend on the dimensions of the amplifier board, power supply and the method of implementing volume control and balance between channels. At this stage, you can use a ready-made factory case with some design changes. However, the best way is still the manual manufacture of the shell of the electrical appliance. Thus, you can realize the possibility of creating a unique design. The option of installing the board in the case of one of the speakers also has the right to life.
Before putting everything together, it is necessary to conduct a test run of the future electrical appliance and, if necessary, fix all problems.
The last step is the assembly of the amplifier, which consists in installing the board, power supply and all other components.
When assembling sound power amplifiers with your own hands, it is not always possible to achieve the desired effect. The secret lies in the fact that the so-called acoustics is not able to cope with the tasks assigned to it. For this reason, sometimes you have to additionally assemble even speakers yourself. This approach to the issue will not only guarantee the maximum satisfaction of all wishes, but will also help get rid of a stand-alone device by hiding the amplifier in the speaker case.
Evgenia Smirnova
To send light into the depths of the human heart - this is the purpose of the artist
Content
Connecting speakers to a laptop, TV, or other music source sometimes requires amplifying the signal with a separate device. The idea of building an amplifier is a good one if you are prone to PCB work at home and have some technical skills.
Getting started on assembling an amplifying device for speakers of one type or another consists of finding tools and components. The amplifier circuit on a printed circuit board is assembled using a soldering iron on a heat-resistant support. It is recommended to use special soldering stations. If DIY assembly is for circuit testing purposes or for short term use, the on-wire option will do, but you will need more space to accommodate the components. The printed circuit board guarantees compactness of the device and convenience in further use.
A cheap and common amplifier for headphones or small speakers is created on the basis of a microcircuit - a miniature control unit with a pre-wired set of commands for controlling an electrical signal. It remains to add only a few resistors and capacitors to the circuit with a microcircuit. The total cost of an amateur-class amplifier is, as a result, much lower than the price of finished professional equipment from the nearest store, but the functionality is also limited to changing the output volume of the audio signal.
Remember the features of compact single-channel amplifiers assembled by yourself based on TDA series microcircuits and their analogues. The chip generates a lot of heat during operation, so you should avoid or minimize its contact with other parts of the device. Radiator grill for heat dissipation is recommended for use. Depending on the model of the microcircuit and the power of the amplifier, the size of the required radiator increases. If the amplifier is assembled in a case, you should first plan a place for a heat sink.
Another feature of assembling a sound amplifier with your own hands is the low voltage consumption. This allows you to use a simple amplifier in cars (powered by a car battery), on the road or at home (powered by a special unit or batteries). Some simplified audio amplifiers require only 3 volts of current. The power consumption depends on how much amplification of the audio signal is required. The sound amplifier from the player for standard headphones consumes about 3 watts.
A novice radio amateur is recommended to use a computer program to create and view circuit diagrams. Files for such programs may have the extension *.lay - they are created and edited in the popular virtual tool Sprint Layout. Creating a DIY circuit from scratch makes sense if you have already gained experience and want to experiment with the knowledge gained. Otherwise, look for and download ready-made files, according to which you can quickly assemble a replacement for a low-frequency amplifier for a car radio or a digital combo amplifier for a guitar.
A do-it-yourself sound amplifier is being assembled for a laptop in one of two cases: the built-in speakers are out of order, or their volume and sound quality are not enough for your needs. You will need a simple amplifier, designed for external speakers up to 2 watts, and winding resistance up to 4 ohms. To assemble it with your own hands, in addition to standard radio amateur tools (pliers, a soldering station), you will need a printed circuit board, a TDA 7231 chip, and a 9-volt power supply. Choose your own cabinet to house the components of the amplifier.
Add the following items to the list of purchased components:
Determine the assembly order yourself, depending on which *.lay format wiring diagram you downloaded. Choose a radiator of such a size that its thermal conductivity allows you to keep the operating temperature of the microcircuit below 50 degrees Celsius. If the device is constantly used with a laptop outdoors, it will require a homemade case with slots or holes for air circulation. You can assemble such a case with your own hands from a plastic container or the remnants of old radio equipment, fixing the board with long screws.
The simplest stereo amplifier for portable headphones should have little power, but the most important parameter will be power consumption. In an ideal example, the design is powered by AA batteries, in extreme cases, from a simple 3 Volt adapter. You will need a high-quality TDA 2822 chip or its equivalent (for example, KA 2209), an electronic circuit for assembling an amplifier with your own hands on a TDA 2822. Additionally, take the following components:
A heat sink element is needed if you want to make the amplifier compact and with a closed case. You can assemble the amplifier on a finished or home-made printed circuit board or by surface mounting. The pulse transformer in the power supply can create noise, so do not use it in this variant of the amplifier. The ready amplifier will provide a pleasant and powerful sound from the player (records or radio signal), tablet or phone.
The low-frequency amplifier is assembled by hand on the TDA 7294 chip. It is used both to create powerful acoustics with bass in the apartment, and as an auto amplifier - in this case, however, you need to purchase a bipolar 30-35 Volt power supply. The figures below describe the location of components, as well as the rating of resistors and capacitors. This subwoofer amplifier will provide up to 100 watts of output power with prominent low frequencies.
As a sound amplification device for domestic or foreign home speakers, the design described above for laptops is suitable. Stationary placement of the device will allow you to choose any power adapter available. You can ensure the miniature and acceptable appearance of an inexpensive amplifier by observing a few rules:
Tube audio amplifiers are expensive devices, provided that you purchase all the components with your own funds. Older radio amateurs sometimes keep collections of lamps and other parts. Assembling a tube amplifier at home is relatively easy if you are willing to spend a few days searching the internet for detailed schematics. The sound amplifier circuit in each case is unique and depends on the sound source (old tape recorder, modern digital technology), power source, estimated dimensions and other parameters.
Assembling a sound preamplifier with your own hands without the use of complex microcircuits is possible on transistors. The amplifier on germanium transistors is easily built into modern audio systems, it does not require additional configuration. The disadvantage of transistor circuits is the larger size of the assembled boards. Dependence on the "purity" of the background is also unpleasant - you will need a shielded cable, or an additional noise and ripple suppression circuit from the network.
