The magazine “Amaterske Radio” (Czechoslovakia) proposed scheme is a simple audio probe to detect logic levels; low (logic 0) and high (logical 1). The device consists of a bitonal multivibrator, is made of two elements of D1.1, D1.2 chip D1, and two keys, collected three transistors V2—V4 (see circuit diagram).ACOUSTIC PROBE
The magazine “Amaterske Radio” (Czechoslovakia) proposed scheme is a simple audio probe to detect logic levels; low (logic 0) and high (logical 1). The device consists of a bitonal multivibrator, is made of two elements of D1.1, D1.2 chip D1, and two keys, collected three transistors V2—V4 (see circuit diagram).
For school discos and Amateur recording magazine “Funkamateur” (GDR) offers a scheme of five “anal stereomixer (Fig. 1). It is designed to connect two stereophonically (X1, x2), two stereos, (XS, X4) and one microphone (X5) for a soloist or a master program.
It’s tempting to assemble a simple Telegraph device and to communicate using Morse code. Reliable two-way communication is needed in the conduct of military sports games and competitions, in a tourist campaign and in summer camp, it is interesting to set it up at home or at the cottage.
The electric signal amplitude decreases rapidly — within 2-4 s after pinch the strings, it accounts for only 20-30% of the maximum level. At the same time changing the tone color of the sound. This circumstance restricts the possibility of using the electric guitar as a solo instrument. That’s why natural “voice” strings replaced its electronic similarity with a constant volume level. For the first time such a device has used the group “the Beatles”. Now the same email attachment to AMY is known as disturber (deformer), or “FUZZ”.
“I know, I know— says a reader, after reading the title.— Yes, but neither “alive” nor “dead” water does not happen. Tales!..” Is he right? A few years ago, the magazine “Inventor and rationalizer” announced that we have developed a device that allows you to do “live” and “dead” water. And if you speak the language of chemists, water with a very strong acidic and alkaline reaction. It turned out, ordinary water can be decomposed as two components with opposite properties. According to statements of many who have experienced their actions, “living” water beneficial to the complexion, softens wrinkles, improves hair growth, reduces hair loss, is a good remedy for burns. But “dead” water bad acts on the mouth, reduces gum bleeding.
Many motorists available means, to improve the performance of various components of your machine. Considerable help in providing them electronics. To take at least a variety of electronic ignition system, which “M-K” repeatedly told. Today we offer the owners of “Lada” and “Cossacks” to build a simple electronic voltage regulator (ZRN), constructed in Kharkiv by B. Krutikova.
What motorist don’t care how secure your vehicle against theft or intrusion by unauthorized persons? Here, as a rule, comes to the aid of electronics. However, most electronic devices designed for protection of vehicles, often complex and expensive; moreover, they often need isolated from the body of limit switches. This limits the wide application of such “watchmen” motorists.
The device, whose scheme is published in the journal “Popular electronics” (USA), produces a positive pulse when a sound (for example, firing of the gun) reaches the microphone B1 (see diagram). The variable resistor RZ adjust the sensitivity of the instrument, and the led V4 indicates it is turned on. Break contact S1, the finish associated with a ribbon, breaks the supply circuit of SCR V5 as soon as the athlete crosses the finish line.
The gliders don’t need to explain how important the safety speed indicator. Such a device is especially valuable for beginners: its tip in a timely manner saves the pilot the novice from fatal errors in the management of the aircraft. In hang gliding, apply sound speed indicators. Our magazine has already told about similar designs (see “M-K”,