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.
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Light setup is very popular among young people. Scheme of another variant of this device suggested that the magazine “Radio, TV, electronics” (NRB). It consists of three color channels (red, yellow, blue) with frequencies section: 700 Hz to 3.5 kHz of 13.5 kHz. The design is greatly simplified thanks to the use of four similar blocks. “Filling” each block consists of two transistors and three resistors (see the diagram of block # 1).
The scheme is simple electronic guard device published the magazine “Funkamateur” (GDR). Across the doors of the protected object stretched thin wire. Until he is whole, the tension on the bases of the transistors VT1—VT3 are few and they are closed. In case of wire break on VT1 through a resistor R2 receives the bias voltage, and this semiconductor device is opened. Now, through a chain of R2—R4, the transistor VT3 will get more offset. Relay K1 will work, and its contact system will include a siren, a buzzer or a lamp. Moreover, the elimination of wire break will not change the situation is to disable the watchdog is possible only with the switch ЅА1.
The Romanian magazine “Technium” offers a diagram of the electronic timer operates on the principle of the 5-minute hourglass clock every minute. The indication to carry out the LEDs. Such a device will find use in a home darkroom, sports training and rhythmic gymnastics. If the time interval exceeds 5 minutes, the device as a normal hourglass, you can restart and continue counting. Here’s how it works.
It never hurts to have your own car, in addition to the cigarette lighter socket, and even first connector, adapted to USB or even mini USB. Such adapters are useful in many cases, for example, to power peripheral equipment of PC, charging mobile phones, video recorders of events and everything is designed under USB power. This is quite possible.
Electric hand drill machine (or drill) there are many home craftsmen. But its opportunities will be wider if it is to provide a speed controller. In this case, the tool, in addition to its direct purpose, can be used as a screwdriver, and as a machine for winding coils. In particular, the design of the boring machine of IE-1019А allows you to embed an electronic controller in her butt — in the place where is located the entrance of the condenser, and the start button and variable resistor to set the handle of the tool.
Hard for the uninitiated to understand anglers who sit all day, as if hypnotized, with a fishing rod, not taking his eyes off the float. Of course, patience in the end lost even the most avid, especially if the fish are not often pleasing bites. Therefore, many experimenting, testing in practice, various devices, signaling a bite. Considerable help in providing electronics. An example of this is a simple electronic device which allows you to monitor from up to four fishing rods — the bite on any of them will notify you of the light and sound signals. Indicator can be use by fishing from the shore, from boats and off the ice, determining the time of the bite to any of the four fishing rods in the evening and at night, and stay at some distance from the place of fishing.
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.
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.
