Devices helpers

To debug transistor-based hardware is much easier if you have the regular store stable voltages. Two adjacent shoulders of the bridge rectifier V1, V2 connect the unit Zener diodes V3 — V8 and V9—V14, V15 — V20, V21 —V26 or V27 — V32 (Fig. 1) exercising, in addition to rectifying the current, stabilization of the output voltage 7, 8, 9, 10, 12, 14, 16, 18, 20 or 24 V at a current of 30 mA. When the input voltage is within 110 — 240V output changes by 0.2 V and the current is 1 mA.

Radio, powerful or low-powered — the Fox, which is so earnestly looking for “hunters” at the event. Low-power transmitters on one of the high-frequency transistor of the type ГТ308, П416. They are used for training, demonstrations, and to tune receivers. Diagram of such a transmitter operating in the range of 3.5— 3.65 MHz, — figure 1.

In the early 30-ies of the radio Amateurs of the Soviet Union, mastering of ultrashort waves, for the first time faced the necessity of direction finding of radio transmitters. The experiment was sometimes transformed into an exciting searching game, which gradually take the form of sporting events. In the late 30-ies of the radio orienteering sport is called “foxhunting”. The essence of this new sport was to locate on the ground three to five hidden transmitters with receivers-direction finders. The first transmitter / receiver equipment for “Hunting for foxes” operated in the range of 38 MHz.

Probably few people know that Alexander Graham bell the inventor of the well — known phone made another discovery, which was considered even more significant. We are talking about the electron-optical communication system, it is possible to wirelessly transmit voice at a distance using reflected solar beam. Compared to radiotelephony communication that consumes relatively much electric energy, the invention of hottelephone (so called the bell system) and was, in fact, a real technological miracle.

From Nickel-cadmium batteries with a life expectancy of 100-200 cycles of charge-discharge. Discharge below 1V per cell leads to a sharp reduction in the duration of battery life. How to control a threshold voltage of discharge of the battery during operation? To have with you the measuring device is inconvenient. It functions best to hold the indicator — sound generator with a silicon Zener diode. Its voltage stabilization determines a controlled level of discharge.

Electronics today referred to as the catalyst of scientific-technical progress. It is really hard to find the field of science or engineering, not electronic engineering. Natural popularity that are mugs e-direction in students. As a rule, syut they have a narrow specialization, for example, radio club, club automation, etc. is quite justified. The enduring nature of the lessons (1-3 years) allows students to acquire a deep enough knowledge of the theory and the necessary practical skills by working in any one field of electronics.

Has long been noted that the viewing of slides, movies, TV shows, as well as any other visual activity (reading, drawing, and examined under a microscope), in unfavourable lighting conditions causes a large overvoltage of view.

Good response – what is it? More correct to say “speed of reaction” is the time that elapses between receipt of the alarm to the adoption of concrete measures. For example, the driver reaction time of 0.4 to 1 s depending on the complexity of the track conditions and the type of the vehicle managed by it.

Efficient and reliable operation of electronic devices depends largely on the temperature regime of each individual circuit element, especially if they work for 24 hours a day. Temperature, in turn, depends on the power load and output (key) cascades of stability of supply voltage.

Who does not know the story of the brave poor man’s Ali Baba from the Arabian tales “Thousand and one night”, who overheard the mysterious words, in pronouncing of which opened a magical door to the treasure cave?