Motorists made electronic blocks of ignition, as a rule, according to the classical scheme consisting of a high voltage source, a storage capacitor and a thyristor key. However, such devices have several drawbacks. The first of them is low efficiency. Since the charge storage capacity can be likened to the charging of the capacitor through a resistor, the efficiency of the charging circuit does not exceed 50%. So, about half consumed by the power Converter will be allocated in the form of heat” on the transistors. So they need more heat sinks.SPARK WITHOUT THE “WHIMS”
Motorists made electronic blocks of ignition, as a rule, according to the classical scheme consisting of a high voltage source, a storage capacitor and a thyristor key. However, such devices have several drawbacks. The first of them is low efficiency. Since the charge storage capacity can be likened to the charging of the capacitor through a resistor, the efficiency of the charging circuit does not exceed 50%. So, about half consumed by the power Converter will be allocated in the form of heat” on the transistors. So they need more heat sinks.
Beginner ham radio production of “solid” light and music installation on the thyristors — it is difficult to implement. The scheme is simple SMU, not containing thyristors, offers the magazine “Funkamater” (GDR). The device can be connected as a mono and stereo; for that purpose, two identical input stage transistors V5, V6 (see diagram). They are connected with a three-band crossover.
Recently Russia adopted a law allowing drivers to get behind the wheel of a car with a small residual content of alcohol in the blood. Knowing how topical this subject in Russia, I think it is important to highlight some technical aspects of control (and self control) persons who consumed alcohol. Of course, the objective of this study is not in dispute is that the law or the causes of the problem. Below we consider the technical issues on breath alcoholic couples. But first, let’s look at the history and production technology of industrial sensors of various vapor and impurities in the air. In many European countries (Germany, Finland, Poland and others) a few years ago appeared in the free sale breathalyzer, or so-called “alcohol vapor detectors” (Roadtest).
Conventional Bicycle bell has a number of disadvantages: inconvenient to work with, rattles while driving even on a flat road makes a sharp, unpleasant sound.
Every radio Amateur knows that without a source of constant and alternating stresses of different magnitudes in practical work is not enough. He needed to establish radiocontrole, repair equipment, charge batteries, test the motors and relays, to conduct physical experiments. All this is possible to do with a universal power supply, which we offer to the readers.
In this case doctors usually recommend to warm up the area of nose and the bridge of the nose with bags of hot sand or a medical reflector. But here’s the problem: the bag has to hold hands and to periodically change the sand cooled and the heat from the reflector heats not only the nose but the whole face, and even the light from the lamp is blinding. Heating pads, too uncomfortable — too big. But perhaps the most significant drawback of all mentioned devices is the inability to smoothly adjust the heating temperature.
It often happens when someone from the household forgets to turn the lights off in the toilet — he may be there without the use of a lot of hours. A simple automatic device which, when necessary, turns on the light in the bathroom, and when not — turn off. The electrical circuit of such device is presented in figure 1. It contains: a low-power transformer T1, rectifier VD1 — VD4, filter capacitor C1, two limit switches SB1 and SB2 relay K1. How the device works and how it performs its functions?
It is used in teaching music in rhythmic gymnastics, in experiments in physics etc. a Metronome, a scheme which offers Bulgarian journal “Radio Television Electronics” (see Fig.), gives not only audio but also visual signals. With the help of variable resistors R1, R2 their frequency change in the range of 40 to 200 cycles / min. which corresponds to the musical pace from “grave” to “Prestissimo”.
Every time, going to work in the morning, we try not to forget to turn off the apartment lights and appliances. Meanwhile, the function can be run machine consisting of three main blocks (Fig. 1): sensors, digital control unit and key. Here’s how it works.
A simple power control of the load can be made from industrial phase speed controller electric BUE-ЗВР1. This device has small dimensions 50×55 mm, excluding handles and a reversible switch. Its purpose is to regulate the speed commutator AC motors.