Of course, thyristor power switches in household appliances is very compact and convenient, but… КУ201, КУ202 and familiar to all cheap copies, unfortunately, tend unjustly to fail. Failsafe only thyristors for industrial use (TL), but they are quite expensive and overall. Besides working, for example, an electric heater thyristor (triac-like) inclusion creates in radios and tape recorders unpleasant 100-Hertz background. So sometimes you have to go back to the old, but tried and tested method on a powerful load through the contacts of electromagnetic relays.
CUTTER — ANY
Construction and mounting the nail dowel for fixing metal structures to concrete made from hardened steel. If you release hardened on the fire and sharpen the head a certain way, and then tempering it — get a perfect tool to the drill for figured wood and soft metals. L. MOROZOV, G. Samara
In our city a large traffic, not only on the main streets. And traffic lights are sometimes not on every street corner to cross the street in a place unsafe. Especially if the person is elderly or poor vision. Careless movement can result in an accident.
TWO OPTIONS OF HEATERS FOR AQUARIUMS OFFER OUR READERS. Uniform temperature in the aquarium keeps the water-filled Cycling or any other appropriate size camera. It is placed as shown in the figure.
In the manufacture of models or devices containing frequently unscrews detail, there is often a need to do the knurling (knurled) outer surfaces of the nuts or screw heads. With this purpose usually use a special device consisting of one or two fine teeth hardened rollers in the mandrel. During rotation of the part fixed in the Chuck of the lathe, the teeth of the rollers are pressed into the surface and form therein a corrugation. With the appropriate equipment the operation is not complicated. However, if you want to make knurled at home?