Petrosani Hobby Magazine - no7 - 2005

Petrosani Hobby Magazine - no. 7 - 2005 - Will amateur radio disappear?

Reading time: 3 minute

Author: Petrosani Children's Club
Quarterly magazine of the circle of electronic constructions and amateur radio
Coordinator: Prof. Kovacs Imre - YO2LTF

Did you know that ...? Sailing was a "bankrupt" business using steam engines that survived only in the yachting segment - whether they were passionate builders or sailors?

And now, in the new direction of using unconventional, non-polluting energies, sailing is back, building even a medium-sized transatlantic ship, fully computer-controlled, where many servomotors pull cables and sails?

From the design of the sails was drawn the design of propellers and aircraft wings (the first planes had canvas wings), and in recent decades, sailing techniques and sail design have been dramatically changed by the application of the "load-bearing effect" used in aeronautics.

The structure of the magazine

1. Electronic construction contest

In period June 30 - July 2, 2005 The county contest of electronic constructions took place in Botosani, a contest in which a number of nine crews from all over the country participated.

Besides the organizers, the Children's Palace - Slobozia, the Children's Palace - Pitesti, the Children's Palace - Suceava, the Children's Palace - Oradea, the Children's Palace - Piatra Neant, the Children's Club - Darabani, the Children's Club - Tg.Frumos, and the Children's Club - Petrosani participated

The practical test consisted in designing a printed wiring, its practical realization, corrosion, drilling, assembly of parts, verification of the operation of the assembly according to a given electronic scheme, depending on the age category of the competitor…

2. First aid in case of accidents

In electrical installations, touching the conductive parts that are under current (voltage) causes in most cases a sudden and involuntary contraction of the muscles. Because of this, when the injured person holds the conductor in his hand, the fingers tighten so much that their release from the conductor becomes impossible. If it remains in contact with the conducting parts of the current, then it is necessary to know that without applying the necessary safety measures, touching the current is dangerous for the life of the intervener…

3. County competition topics

Details are presented on "The inter-county contest of electronic constructions TEAM - Botosani - 2005", XNUMXnd Edition; Theoretical Test - Category C;

4. Curiosities

  • In which hemisphere are most oceans found?
  • What is the deepest oceanic point on the planet?
  • How did the old navigators from the Atlantic Ocean to the Pacific Ocean pass?
  • What is the origin of the name Pacific Ocean?
  • What are the dimensions of the Great Barrier Reef?
  • What is the saltiest sea in the world?
  • What is the highest waterfall in the world?

5. Will amateur radio disappear?

We live in a constantly changing world. And technologies are evolving, they specialize, some are entering a dead end. It is observed that some primitive technologies resist the passage of time, because new technologies evolve more easily from them.

Several technologies have emerged from the radio:

  • The television; It is a specialized branch, in principle, it has not evolved;
  • Mobile telephony, standards: NMT -> GSM -> GPRS -> UMTS;
  • Morse Telegraphy (the first digital transmission mode) -> telex ->… -> Internet…

6. Medical kit on vacation

What is good not to be missing from the medical kit you take with you on vacation, especially if you go with the children ..

7. Converter from RS232 to TTL

It is often necessary to connect to the electronic computer the various electronic assemblies made by electronics enthusiasts.

Apparently it's simple ... only there is a difference in logic levels between the two devices. As we well know, TTL logic levels are 0 and 5v. CMOS levels are higher: 0 and 12V. The level at the serial port of the computer is different from the classic levels (for reasons of immunity to noise). To solve the problem, the integrated circuit was made MAX232...

8. Automatic fan control

There are many situations in which it is necessary to start a fan when the temperature exceeds a certain pre-set level.

The sensor is a thermally compensated zenner type diode LM335. The controller is made with an AO type circuit with FET inputs, type TL 072, on the output with a 3.1V zenner diode, which controls a mounting made with two transistors in Darlington connection. The stabilization of the voltage necessary for the assembly is made with the integrated type stabilizer 7809 (9V)...


If you want to collaborate with this magazine, please access the contact section on the last page of each publication.

A comment

  1. Jack Yves Cousteau once built on his ship a wind propulsion system consisting of a vertical wing with an empty cylinder in the widest area of ​​the section, open with a slit along its length to the soffit. If necessary, in the absence of wind, a weak ascending air current is injected at the base, which draws the air outside the wing. Thus, through the Coanda effect, the air sucked into the cylinder from the wing on the extrados and the soffit of the wing, creating pressure differences, also creates a force perpendicular to the wing that propels the ship, the same force supporting the planes.

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