The basis of a capacitive relay — a low-power generator of high frequency such as local oscillator of a radio receiver. To the circuit L1C4 (see diagram) of the connected metal plate sensor. Approached to him the palm of the hand represents the second plate of the capacitor CD. The capacity of such a condenser is the greater, the more area it covers and the smaller the distance between them.CONTACTLESS CAPACITIVE RELAY
The basis of a capacitive relay — a low-power generator of high frequency such as local oscillator of a radio receiver. To the circuit L1C4 (see diagram) of the connected metal plate sensor. Approached to him the palm of the hand represents the second plate of the capacitor CD. The capacity of such a condenser is the greater, the more area it covers and the smaller the distance between them.
Perhaps the most difficult stage in the process of creating radiokonstruktor — setting. But if you have even the simplest instrumentation, to establish any electronic device will be much easier. At least, for this job you need avometr, or simply tester. For example, very popular among ham radio uses a simple inexpensive device C-20. But the problem is, he is not entirely comfortable, and this tester is limited. So for those of you who already have such avometr, we propose to improve it by extending the limits of measurement and adding the generator probe with the test transistors.
To the line “Start” suitable for a student with basketball ball in hands, and comes on the panel associated with the starting button of the examiner, the Machine still does not work: it can be switched on only after the button is released.
Before describing the operation of the device as a whole will focus on one of its constituent elements — the Converter of the spectrum of the electrical signal, or “FUZZ”device. To To obtain this effect, it is necessary to enrich the original signal a large number of odd harmonics. There are several ways, and thus the schemes to achieve them. We will stop at the spectrum Converter, which is a ULF with parapremium.
In annually conducted by our magazine national competition “Cosmos” among the many models fantasies occupy a significant place different kinds of self-propelled tools “planetary Rovers”. According to young technicians, they are indispensable transport in the study of nearby planets the astronauts.
First steps in radio, many often begin with independent fabrication of a transistor radio. Along the way, introduces the electronic components, acquired the skills in installation and work with measuring devices. And achieve rapid practical results is to the same positive stimulus for further study of fundamentals of electronics, gives confidence in their abilities and capabilities.
Electronic devices based on microprocessors and integrated circuits are less sensitive to the parameters of the supply voltage. To ensure the safe operation of these devices use voltage regulators with protection. In many power supplies is reduced to cut power to the circuit if a short circuit in it or a sudden increase in load current. Such, for example, the popular voltage stabilizers КР142ЕН5. 
As you know, speaker of the personal computer (PC) it is necessary to include separately. If they are installed at some distance from the operator, this situation is hardly comfortable, especially if the user wishes to view on a DVD movie recorder or any other video, accompanied by sound effects.
There are many games in which, for example, the number of points scored by the player. is determined by throwing dice. It is easy to make and the electronic “dice” random number generator. Schemes of such generators and descriptions found in Amateur radio literature.
Perhaps in the near future when the new spacecraft will go to the moon, Venus or Mars in the Arsenal of the astronauts will be robots who will come first to the planet’s surface to conduct scientific researches, to perform simple welding and Assembly work. So I decided the guys from the mug space simulation Sumy city station of young technicians and build a similar robot with their hands.