HEAR COMES THE TRAIN!

HEAR COMES THE TRAIN!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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SCREW ON THE CONTROL

SCREW CONTROLWhen 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.

THE LIGHT WILL ACTIVATE THE SIREN

LIGHT WILL ACTIVATE THE SIREN

The proposed German magazine “Funkamateur” light relay is activated when light falls on the photoresistor R1 (see diagram) — when this occurs, a loud siren sound. Transistors VT1, VT2 equivalent odnoimennogo of the transistor included under the circuit of the sawtooth generator. The oscillator frequency is determined by the capacitance of the capacitor C1, the internal resistance of the photoresistor R1 and the resistor R2. Transistors VT3, VT4 included in the Darlington circuit, perform the function of the AF amplifier. It is possible to replace. Photoresistor — any domestic; transistors: VT1 – КТ3107, KT361, КТ203; VT2, VT3 blocking – KT315, КТ312; VТ4 – КТ503, КТ603, КТ815 with any alphabetic indexes.

INSTEAD OF NEONKI – TIRATRON

INSTEAD OF NEONKI - TIRATRON

Specialists in service and repair of industrial electrical installations will appreciate, I think, a convenient small-sized probe – “kontrolka” on 220/380 V. Indicator is not “neonka”, and the thyratron MTX-90. And as for the case, fit any size transparent (plastic or glass) bottle from under the drugs. Moreover, if the material of the “case” glass, to protect its integrity (for example, in case of an accidental drop) I recommend to wrap the probe in two or three places with electrical tape (in the form of shock-absorbing rings). Well, at the styli wear a PVC tube.

WANTED TO MAKE IRON…

during the period covering the country’s public deficit even the most that neither is ordinary iron burst in a number of regions in the category of “trudnoreshaemyh”. And is — alas! — quite expensive. But for the resourceful craftsman to make the original iron, as they say, no problem. You only need to thoroughly want… unlike the hero of the once popular song where the words are in the title of this material, the success of saadeldin guaranteed.

HAIRDRYER PAINTER

HAIR PAINTER

To strip layers of old paint in the repair of the “woodwork” is a handful for the home worker. Apart from the fact that the work is time-consuming and unproductive, it is also a source of debris and dust, which during the repair and without that is enough. There is, however, an easier way to remove the painted surface of the old coating, which involves the use of a gas burner or blowtorch. But use it indoors I would not recommend it at any time paint can erupt, and then the trouble will be inevitable.