During the experiments, building various electronic projects there is often a need for a DC source of relatively high capacity. For example, the battery voltage of 4.5 V is composed of three elements of “373.” To do this, you can put them in the original container tape out cut Velocimetry (see “M-K”, 1986, № 4), bonding like candy wrappers, wrapped in heavy paper (“M-K”, 1988, № 6), or dock in a unit with paper capsules-“shirts” from the same items (“M-K”, 1989, № 11). But still to provide a sufficiently reliable contact in such cases is not always possible. That is why many are still doing the old-fashioned way — connect the elements with each other lengths of wire with rations.
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Repair of electronic devices in radio is associated primarily with the need to restore the holes and the possibility of damage to conductor paths of printed circuit boards. We offer universal soldering iron with suction device, solder and interchangeable tips will allow to replace the radio quickly and efficiently.
Not long ago, musical instruments even pop bands — be it saxophone, violin, accordion, piano, double bass and even a drum — gave his listeners a natural, “natural” sound. Today music has become different — is now in Vogue “electronic” sound.
Every driver knows how it is sometimes difficult to start the engine of a car on a winter morning after long Parking. However, a relatively simple device powered from an AC mains voltage of 220 V will greatly facilitate this task. The device consists of two parts (Fig. 1), one AC power supply (voltage 12 to 14 V); the second part is mounted in the engine compartment of the vehicle. They are connected to each other using a special connector.
Burned out incandescent lamps, unfortunately, not to recover but to use their metal caps is possible. To separate them from glass bulbs, the bulb wrapped in a thick cloth and crushed. Then the caps carefully and thoroughly cleaned from the composition, which to them were glued to glass flasks. The Central contact with the insulator should remain intact.
Many readers of the magazine are building all kinds of model planes, ships, trains, cars and other equipment. However, for greater affinity with their prototypes it is desirable to “voice”, which will give them even greater appeal. Recall, for example, sounded like a train. First heard a gradually increasing noise of a train, then near the station he blows his whistle to his approximation, and stood, and noisily blowing off steam, making a sound like “poof poof poof”. Before leaving the station bell sounds, and the locomotive gives a farewell whistle before the journey.
When developing propeller systems snowmobiles, trikes, aircraft and model aircraft designer is required to know the exact values of some parameters. And most importantly — the frequency of rotation of the propeller. It is necessary and when the force of the engines, and the selection of the propeller. The frequency of rotation is also one of the main parameters in the process of operation of the motor: the value of this parameter is possible to objectively judge the reliability of the engine.
Design welding transformer I have, so experience in this are. I want to offer the readers of my last — as it seems the most successful — the development of a welding machine is not entirely conventional design.
Talking about various musical instruments, it is impossible not to recall the, perhaps, popular and indispensable in modern orchestras and rock bands. Of course, this is the electric guitar.