Independent manufacture of a night vision device
|Independent manufacture of a night vision device|
DEVICE OF THE NIGHT VISION ON THE BASIS OF THE LENS OF AN OLD CAMERA OR LENS.
Any body has the ability to emit or reflect infrared (infrared) rays. On this principle, and built "NVD" (night vision device) developed in 1984 by the German company "Elektrisch Manufactur". This device is based on an internal photo effect. When projecting the IR image, the electrical conductivity of the irradiated areas of the photosemiconductor (2) (see figure 1) changes and a potential distribution corresponding to the brightness distribution of the image on the photoconductor (2) is created on the adjacent electroluminescent layer (4). To accomplish this process, it is necessary to apply an alternating voltage of 250-500 volts with a frequency of 400-3000 Hz and a current of no more than 10 mA to the extreme transparent electrodes.
1. glass plates. 2. photoconductor. 3. silver layer. 4. electroluminescent lens 5. lens or lens from the camera.
So, we proceed to the manufacture of NVD. Chemical elements necessary for the manufacture of the device can be obtained in any chemical cabinet of a school or chemical laboratory of any enterprise. First, take two glass plates, tin chloride SnClz, silver, zinc sulfide ZnS (crystalline) and copper. Hold the glasses for 4 hours in a mixture of H2SO4 and K2Cg2O7 (potassium dichromate). Dry it. Then take a porcelain cup, put SnCl2 in it and put it in a muffle (or electric) oven. Above it at a distance of 7-10cm fix the glass. Cover the cup with a metal plate and turn on the stove. As soon as it warms up to 400-480 degrees, remove the metal plate. As soon as the thinnest conductive coating forms, turn off the oven and leave the glass in it until it cools completely. Coverage check with a tester. Then apply a photosemiconductor on one of these plates. To do this, prepare equal amounts of a 3% aqueous solution of thio-carbamide Na4 C (S) NH2 and 6% aqueous solution of lead acetate. Pour both solutions into a glass jar. Using a pair of tweezers, add a glass plate to the solution and hold it vertically. But before that, apply a varnish that is free of conductive coating on the side. Wearing rubber gloves, pour into a vessel with plates, to the top a concentrated solution of alkali / carefully !! / and very gently stir with a glass rod, not touching the plates. After 10 minutes, remove the plate (gently) and wash it under running tap water. Dry it. Turn on the stove and place silver in a clean china cup. Repeat the process described above at 900 degrees. The coating is applied on a plate with a photosemiconductor. Get a mirror film. To prepare the phosphor, prepare pure ZnS crystals. If there are any impurities, the brightness of the glow drops or disappears. Cook the stove. Put pure copper in a porcelain cup. Copper and ZnS crystals should be as small as possible. Observe the proportion of ZnS - 100%, Cu (copper) - 10%. In the furnace, create circulation of copper vapors and passing them through the gaps between the crystals. The resulting crystals are in no way not to grind. Should get a colorless powder. Mix the crystals with the crystals. Take the minimum amount of lacquer. Pour the mixture on a plate with a layer of silver and wait for the full spread and the formation of a flat surface. On top, apply a second plate of conductive coating on the varnish and press lightly. After drying, seal the obtained NVD. Before all these operations, after applying a conductive coating should be soldered wiring as conclusions on the edges of the plates.
Now you need to assemble a high voltage generator circuit and assemble it all into a single package. It can be of any shape. But it is recommended all the same offered by the developer (sm.ris.2). The lens can be from any camera, preferably short-focus, for example from "FED", "Change-M". An eyepiece can be any biconvex lens. After final assembly, check all connections for proper connections and strength. Turning on the NVD should quietly whisper a transformer. If the image does not appear do not despair. Change the generator frequency or voltage level. Set maximum sensitivity.
SCHEME OF NIGHT VISION DEVICE
TR - П213, П 217 RI - from 75 to 150 Ohm; CI - from 0.33 to 1 μF. SI - any pushbutton switch. The generator frequency is measured: with a capacitor CI - roughly; and the resistor smoothly.
TI - is wound on any transformer of suitable sizes. Winding I contains 2000 - 2500 turns, wires - 0.05 - 0.1 mm; Winding II contains 60 turns, Winding III - 26 turns, wires - 0.3 mm.