Laser Torch Based Voice Transmitter and Receiver - Download as Word Doc . doc), PDF File Download as DOC, PDF, TXT or read online from Scribd The transmitter circuit comprises condenser microphone transistor amplifier BC followed by an .. REPORT - Advanced Science & Technology in Japan - d Laser Torch-based Voice Transmitter and Receiver Download as DOCX, PDF, TXT or read online from Scribd. Flag for The Rosie Project: A Novel. with laser beam and in receiver an NPN photo transistor, common emitter amplifier and speaker is used . another project of laser torch based voice.
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Laser Torch based Voice Transmitter and Receiver. K. Govinda. 1 AbstractIn this paper we designed the circuit, using that circuit we in the circuit. The laser torch can transmit light up to ..  glametesaspo.ml proceedings vol3 3 glametesaspo.ml Using this circuit you can communi- cate with your neighbours wirelessly. Instead of RF signals, light from a laser torch is used as the carrier in the circuit. Ece project report on laser based communication link free pdf download. PDF DOWNLOAD» Engineering Lecture Notes, ABSTRACT Laser as a .. data rates averaging Gbps. The transmitter and receiver will be set up on . SECTION 2 LASER TORCH 2 RECEIVING SECTION 3
These typically involve a high power laser projecting light upon a distant target and require certain protective measures to avoid damage to the human eye. Moreover, the laser beam expands in diameter with distance. When used for gun sighing, the laser beam provides a path to the sighting device. In other sighting applications various forms of lighted reticules are used such as in optical instruments where the illuminated reticule is superposed on 3 the image of a scene, such as a target in which the illuminated reticule is viewed.
In such systems, one eye is closed and the scene with the superposed reticule superposed thereon is viewed through the one open eye. In other systems such as in photo-grammatic stereo-plotters, periscopes, etc. Free of auto kinesis effects depends on the phenomena of the human brain, which fuses images viewed by one eye with images viewed by the other eye. It uses a collimated, monochromatic, coherent light spot superposed upon the image of a scene viewed through the other eye.
When a scene is observed using the one eye with or without magnification and the other eye of an individual is viewing the collimated light point source of visible monochromatic laser radiation due to the optical fusion property of the human brain, the point light source appears centrally in the fused scene and is substantially free of auto kinesis effects .
This optical instrument can be mounted on a helicopter to assist guiding the helicopter pilot to a landing spot. It can also be used to assist in aiming guns, rockets and like armaments on the aircraft or on the ground, weapons rifles, pistols, rocket launchers, cannons, etc. Rangefinders use lasers to measure distances to targets and can be employed from aircraft and remotely piloted vehicles, as well as on the battlefield.
In many types of weapons systems, laser range finders are becoming standard equipment. They are often mounted on the most modern tanks, armored vehicles  built in both the west and the Warsaw pact nations.
It uses a NdYAG laser rather than a traditional ruby laser to reduce power consumption and features built- in test equipment . Laser rangefinder work on simple principle, that the laser beam is switched on and off in a few billionths of a second producing a very short pulse.
The pulse travels to the target, where some light is reflected back. A timer inside the rangefinder measures how long the pulse took for the round trip. Time is then converted into a distance to the target.
In such a situation laser beam rider guidance is used during initial flight, with terminal homing when missile is sufficiently near the target.
Dual mode guidance entails lower risk technically but is complex and also expensive . It provides guidance from the time of missile launch until the terminal homing device of the missile acquires a target signature that is adequate for it to lock onto the target and guide the missile for the remainder of the flight towards the target. This guidance is based on the phenomenon: i Aerosol particles are naturally present in the atmosphere at all times, even in apparently clean air.
In operation, a laser beam projected from the missile launch station is aimed toward the target. Light from the beam is reflected in random directions scattered from aerosol particles that are ever present in the atmosphere. This scattered light strikes light detectors that are located on the sides of the missile. When the missile flies off the direction of the target, the amplitudes of impacting light on these detectors are different on different sides of the missile.
Guidance controls activated by 4 these amplitude differences cause the missile to veer toward the center of the beam and thus fly in a direction that is more toward the target. Instead of RF signals, light from a laser torch is used as the carrier in the circuit . The laser torch can transmit light up to a distance of about meters.
The phototransistor of the receiver must be accurately oriented towards the laser beam from the torch. Normally the transmitter uses 9V power supply. To avoid 50Hz hum noise in the speaker, the phototransistor should be kept away from AC light sources such as bulbs.
The reflected sunlight, however, does not cause any problem. But the sensor should not directly face the sun. The block diagram of the unit shown in Figure 3 depicts the overall arrangement for providing security to sensitive place.
A laser torch powered by 3V power-supply is used for generating a laser beam. A combination of plain mirrors M1 through M6 is used to direct the laser beam around the sensitive place to form a net. The laser beam is directed to finally fall on an LDR that forms part of receiver unit as shown in Figure 3.
Here human eye is the target. Although killing damage cannot be incur by the ordinary laser, but the permanent damage to the eye can be possible with the laser operating within the retinal hazard spectrum, which is in the range of 0. Laser operating in this spectrum gets focused on to a small spot on the retina, thus burning or destroying the retina.
Thus soldier can be disabled in the battlefield . The threshold energy level for a laser wavelength of 0. This wavelength, which creates a very high degree of retinal hazard, may be produced by a frequency doubled Nd:YAG laser.
Somewhat non-lethal anti personnel use of laser can be possible by using laser as a dazzler . This can form as the part of the electro optic countermeasure system.
Lasers with comparatively low power can dazzle or flash blind the soldier for 15 to 30 second, preventing them from using sensors or weapon. A frequency doubled, Q switched Nd- Glass laser producing around to mJ pulse energy having a width of 12 to 20 ns has the potential of being a portable system that could be used by a soldier in a close combat in an anti personnel dazzling role.
Out of band radiation can be used as dazzler. In experiments using an out of band laser This beam is specially encoded. With this encoding lased guided weapons can lock onto a target, and distinguish it from other targets that might be simultaneously designated by other systems. Munitions with laser seekers which operate in the near infrared region and which 5 track the energy reflected by laser guidance Target designators have been based on neodymium- YAG lasers but could also be based on CO2 lasers, which could extend their operation from the1.
Target designators are semi-active illuminators used to "tag" a target.
Typical laser guided bomb receivers use an array of photodiodes to derive target position signals. These signals are translated into control surface movements to direct the weapon to the target. An airborne detector can provide steering information to the pilot, via his gun sight, for example, and lead him on a direct heading to the target, finally giving him an aim point for a conventional weapon. Satellites of this type are positioned above the equator and move in synch with Earth's rotation.
In J. Pierce advocated an approach of reaching geostationary orbit in successive stages of technology development, starting with nonsynchronous, low-orbit satellites. Hughes Aircraft Company advocated a geostationary concept based on the company's patented station-keeping techniques.
In the Soviet Union launched Sputnik, the first satellite to be placed in orbit. Amateur radio operators were able to pick up its low-power transmissions all over the world. The first satellite-based voice message was sent by President Dwight Eisenhower using passive transmission techniques.
Because it was placed in an elliptical orbit that varied from low to medium altitudes, the satellite was visible contemporaneously to Earth stations on both sides of the Atlantic for only about 30 minutes at a time. Clearly geostationary orbits were desirable if satellites were to be used for continuous telephone and television communications across long distances. The satellite was placed in an orbit of approximately 36, km, a distance that allowed it to remain stationary over a given point on Earth's surface.
SYNCOM led the way for the next several decades of satellite systems by demonstrating that synchronous orbit was achievable, and that station keeping and attitude control were feasible. Today most satellites, both military and commercial, are of the GEO variety. The Evolution of Untethered Communications.
Air Force in Three launches placed 26 lightweight pound satellites in near-geosynchronous orbit. These systems supported digital voice and data communications using spread-spectrum technology an important signal-processing approach discussed extensively in Chapter 2.
The satellites were replaced in the s by the DSCS-II group, which increased channel capacity by using spot-beam antennas with high gain to boost the received power. Satellites offer several advantages over land-based communications systems. Rapid, two-way communications can be established over wide areas with only a single relay in space, and global coverage with only a few relay hops. Earth stations can now be set up and moved quickly.