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.
NOV OLD RELAY
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?
As a hobbyist designer with years of experience and a former captain of the regional team sports radiointerview (the hunt for “foxes”) offer a development designed to significantly improve the organization and conduct of training, competition, as well as to facilitate to beginners the way to the fascinating world of radio sport. In essence, this is a homemade compact and reliable transmitter “Fox” (PL). However, it is assembled by an improved wiring diagram, with keying in the power circuit of the crystal oscillator (Fig. 1).
For works in chemical laboratory hydrogen is produced usually by the reaction of zinc with hydrochloric acid (HCL). Sometimes you need a small amount of gas, and 1 g of zinc makes about 400 ml of hydrogen, so that, using part of it, the rest have to release into the atmosphere.
The prototype of the computer mouse — a two-dimensional analog of the manipulator, connected to a personal computer (PC or PC) via the serial port corresponding to the RS-232 standard, and is equipped with a couple of buttons on a convenient and compact housing, is a device created almost 40 years ago at the Stanford research Institute and has incorporated a number of principles, authored by the famous inventor Douglas Engelbart (Douglas Engelbart). In appearance it is a wooden box with a “tail” — a communication cable. Obeying the movements of the operator’s hand, sneaking on the table on wheels, counting their speed and turns, this device is like sniffing the information that was immediately entered into the computer and controls the cursor movement on the screen. Indeed, what is not nosy mouse!..
Music lovers understand the interest shown by people of different ages and professions to all new in the field of stereophony. The development of electronics and improvement on the basis of sound engineering techniques have enabled the lovers of house concerts to listen to gramophone records and tape recordings with a sound quality close to natural. Stereo replay system allows to obtain aesthetically the most complete and accurate representation of the executable composition, all the colors, the nuances that are sought to convey in a recording musicians.
A very simple device in order to train the hand for, say, playing table tennis, can be done in just one evening. Here are the materials you will need for this. Two boards: one size 200X300 mm (6 mm) and the other 300X150 mm thick (18 — 20 mm); Reiki 20X250 mm; the bar from which we will make the holders; a piece of wire for the installation of electrical circuits, copper wire thickness of 0.5 mm for the coil and the hook. Oh, and do not forget to prepare the light bulb from the flashlight with cartridge mounting and battery KBS-L.
