LASER SHOOTING

Popular infantile pastime became now the so-called laser (light) pointer. Produced as a miniature working tool for teachers, lecturers and guides, it attracts the daring fans of science fiction an opportunity to play “the hyperboloid of engineer Garin”, highlighting the highly directional light beam of a particular item of interest at a considerable distance. Fortunately, the cost of these games without any negative consequences, because the data pointers are allowed to use only semiconductor lasers or LEDs (option, which often go manufacturers) with integrated optics, the radiation power of which should not exceed 1 mW. The increase in the concentration of light energy in an extremely small solid angle can create, according to experts, a danger to vision when hit by the beam in the eye directly or after reflection from the mirror surface.

 

The owners of laser pointers can be adapted for their interesting and quite safe fun — home fotocasa. The light pulse will serve as the analogue of the bullet, and the receiver will be the photo sensor of the target. In the case of hitting the target will be an electric signal which will cause the light (completely harmless) a confirmation of well-aimed “shot”.

Weapon of photothera — laser (light) pointer, complemented by a simple electrical device on and encased in ready-made or self-made model of the gun, the rifle, etc. When such a weapon is removed from the fuse (closed contacts SA1) and the trigger guard is not pressed (the button SB1 in the open position), the electricity from entering the battery GB1 through the current limiting resistor R1, the maximum charge bolsheselsky the capacitor C1. When fotovitrina (pressing SB1) switches and fast discharge of C1 on the laser pointer A1. The latter will give a short pulse of directional light, which is in contact with the photo sensor will cause a reaction of the target (the flash of the led indicator of hitting the target).

The glow of a laser pointer in a makeshift fototime — decreasing intensity, in the range of breakdown voltages on C1 from 4.5 to 3 V. After releasing the button SB1 will “smothered” bolsaescola condenser, and after about three seconds of light weapons ready to defeat the target, where as perceiving light element applied to the phototransistor VT1. From the usual bipolar semiconductor triode of the latter are distinguished by fundamentally different control the collector current, when the result is achieved not by changing the electrical bias on the base, and the light from an external source, which in the housing that protects the crystal provides a translucent window (on the phototransistor, see, for example, “modelist-Konstruktor” No. 7 of 1993).

 

In the initial state, when the switch БА1 photomixing on the already submitted supply voltage, and the phototransistor is not yet lighted and locked, with manifold /T1 receives the high logic level (log. 1) to the input 1 of the integrated circuit cell 001.1 type 2I-NЄ forming together with 001.2, capacitor C1 and resistor R!3 the signal Converter. Inputs 5 and 6, 001.2 “grounded” through the YAZOO, and the log.1 is transmitted from the output 4 of the cell 2 to the input 001.1, why the output is 3 001.1 “duty” level signal (log.O) and the inputs 8, 9 and 12, 13 threshold level 001.3, 001.4. Obeying the logic of this device, coupled to the outputs 10, 11 of the chip 001 is a high level signal which is applied to the base of the transistor 1Т2 (power amplifier, operating in key mode) and locks it.

 

Minimalia revision in which a laser pointer is converted into “light weapons” for photothera

 

When a well-aimed “shot” the light pulse falls in the window sensitive /T1. Is unlocked phototransistor. As a result, the voltage at its collector (i.e., the input 1 of the chip 001) will fall to the log.About. Cell 001.1 will switch to another stable state, and its output appears a high level. This signal will be immediately transmitted through the uncharged capacitor C1 to the inputs 5, 6 of the cell 001.2 that immediately switch and output 4 will submit the log.On the entrance 2 D01.1. Output 3 will remain the log.1, despite the termination of the exposure light pulse and restoring a low level at the input 1. The state of the cells DD1.1 and DD1.2 is maintained until the charge capacitor. All this time the cells DD1.3, DD1.4 also remain in the switched condition, and the log.On their outputs allows to keep the VT2 transistor is open, creating conditions for the return signal of target — illumination solid-state indicator HL1.

 

A circuit diagram of photomeson

 

When the capacitor C1 is charged, the current flowing through it and resistor R3 will stop. The voltage at the inputs 5, 6 DD1.2 falls, and the entire device will return to its original state. That is, the length of the response signal of the target (illumination of a semiconductor indicator HL1) is determined by the values of C1, R3, and subject to the values specified in the circuit diagram of photomechanic is approximately 2 s.

The main purpose of the led HL2 — signal on connection targets to a power source. With the placement of this indicator (and, of course, the phototransistor) to the center of the “bullseye” will have the opportunity to train and hold competitions on marksmanship in fototime but strict and complex rules. For example, in a dimly lit room or even in complete darkness, using as targeting a green “spark” led HL1. Red “light” more powerful HL1 (hit indicator) can be placed at the edge of the target.

 

“Electronics” of the target, with the exception of the phototransistor, LEDs and power switch mounted to pseu-prepress split the Board with one-sided foil plastic.

 

Pseudospectra Welt circuit boards and photomeson of plastic foil

 

In the construction of improvised photothera using a laser pointer as the basics of “weapons” acceptably familiar and well-established fixed resistors MLT-0,25 and “shells” SP-0.4 or their analogues, microcopy KM 1-1, condensers K50-6, K50-38, microtubles MT1-1. The power of photomechanic from compact 9-volt “Crown” (if training intensity is relatively small; otherwise, cannot do without a more powerful source that can, for example, be composed of two series-connected batteries type 3R12). Needs energy security “laser weapon” to guarantee three of the cells AAA (LR03) batteries, connected in series.

 

Debugging handmade photothera takes a minimum of time and limited to setting the desired level of sensitivity photoreceptive cascade variable resistor R1 Yes to align the sighting device with the beam for the distance of photomechanic. Power to the pointer during such harmonization is supplied directly from the battery GB1 with switch SA1.

Yu PROKOPTSOV