Amateur radio is still one of the most common hobbies. If at the beginning of its glorious path amateur radio mainly affected the design of receivers and transmitters, then with the development of electronic technology the range of electronic devices and the range of amateur radio interests expanded.

Of course, such sophisticated devices as, for example, a VCR, a CD player, a TV or a home theater at home will not even be assembled by the most qualified radio amateur. But repair of industrial production equipment involved in a lot of amateur radio enthusiasts, and quite successfully. Another area is the design of electronic circuits or the refinement of “up to luxury” industrial devices. The range in this case is quite large ...

The temperature regulator in everyday life is used in a wide variety of devices, from the refrigerator to the irons and soldering irons. Probably, there is no radio amateur who would bypass such a scheme. Most often, temperature sensors, transistors or diodes are used as a sensor or temperature sensor in various amateur designs. The operation of such temperature controllers is quite simple, the operation algorithm is primitive, and as a result a simple electrical circuit.

The preset temperature is maintained by turning the heating element (TEN) on and off: as soon as the temperature reaches the set value, the comparator (comparator) is activated and the TEN is turned off. This principle of regulation is implemented in all simple regulators. It would seem that everything is simple and clear, but this is only until it comes to practical experiments. The most difficult and time-consuming process ...

There are many transistor circuits (just remember the number of at least household equipment) for amplifying and converting electrical signals, but, with all the diversity, these circuits consist of separate stages, the basis of which are transistors. To achieve the necessary signal amplification, it is necessary to use several stages of amplification, connected in series. To understand how amplifier stages work, you need to become more familiar with transistor switching circuits.

The transistor alone cannot amplify anything. Its amplifying properties are that small changes in the input signal (current or voltage) lead to significant changes in voltage or current at the output of the cascade due to the expenditure of energy from an external source. It is this property that is widely used in analog circuits - amplifiers, television, radio, communication, etc. To simplify the presentation, we will consider here...

Currently, this problem is solved quite easily. On any radio market, for starters, you will have to buy several screwdrivers (a set is better), to turn it off - tighten M2.5 screws - 6, wire cutters - side cutters, and of course a soldering iron. At first, an ordinary soldering iron with a capacity of 25 - 40W with a copper sting. Such a soldering iron can be called educational. If such a soldering iron is supplemented with a simple power regulator, then practically anything can be soldered.

If soldering with this soldering iron will turn out “perfectly and perfectly”, and it will not be simply abandoned, then the next step can be considered the purchase of a real branded soldering iron, for example, “Weller” with a fireproof tip and a temperature setter. Any soldering iron will need solder, POS-61, and flux are best.At first, an ordinary pine rosin is enough, which should be transparent and light ...

Many of those who have turned electronics into an entertaining pastime often ask themselves the question: “Why am I doing this?” I read magazines and books from the section “Electronics is Simple” and other literature from the series “For Dummies”. More sophisticated and clever books simply lack patience.

And then the reasoning goes approximately along this line: here, they say, made a simple amplifier, collected several flashing lights (lighting effects), a charger. But it turns out that all this can be bought, if not new, then at least used, and it will turn out to be of the best quality, in branded cases, even in working condition. The question is, where is the benefit, the economic effect of such occupations?

But perhaps you should not bother with such thoughts. After all, there are many examples that do not bring any benefits. These activities are called hobbies, i.e. a hobby in which one should hardly look for meaning ...

In the case of repair of electronic devices, the “ringing” of the transistor installed in the circuit is not always possible, so you have to solder it from the circuit. Often this interference leads to damage to the printed circuit boards, and sometimes to the transistors themselves. Therefore, it is very good if there is a device at hand that allows you to determine the health of the transistor without evaporating it from the board. Schemes of such devices are given in this article.

The basis of the circuit is a classic blocking generator. The output of such a generator produces short rectangular pulses. Naturally, in order to get a working blocking generator to the probe connector, you need to get the tested transistor. Fluctuations are obtained due to the positive feedback in the transformer through the coupling winding.The optimal feedback value is selected by rotating a variable resistor ...

Checking transistors has to be done quite often. Even if you have a knowingly new transistor in your hands, it is better to check it before installing it in the circuit. There are frequent cases when transistors purchased on the radio market turned out to be worthless, and not even one single copy, but a whole batch of pieces of 50-100. Most often this happens with powerful transistors of domestic production, less often with imported ones.

Sometimes in the design descriptions some requirements for transistors are given, for example, the recommended gear ratio. For these purposes, there are various transistor testers, of a rather complicated design and measuring almost all the parameters that are given in the manuals. But more often it is necessary to check transistors on the principle of "good, bad". It is precisely such verification methods that will be discussed in this article. Often used transistors are at hand in a home lab ...

There are so many different amplifiers that in one article, even very briefly, it is impossible to describe them, but sound amplifiers cannot be ignored. Of course, we will not write about tube monsters here, but we will have to remember a few semiconductor structures suitable for independent manufacture.

One of the most popular designs for beginner hams is UMZCH. With the seeming simplicity, well, there, just to play the music, it is these UMZCHs that are one of the most complex devices in the repair and independent manufacturing and adjustment. It is enough to take the old Radio magazines and get acquainted with the methodology for setting up amplifiers. But, in fairness, it must be said that some schemes work completely without adjustment. True, there are not very many of them.In modern conditions, if you do not want to be killed by the pangs of creativity, painstakingly establish a obstinate scheme ...