XREP – A Combination of Taser and Shotgun

We have already discussed about StunRay Technology and its capability to substitute tasers and guns used in law enforcement. But, there are some limitations to the amount of damage you can do to the suspect if he is not in front of you. That is why tasers are considered more effective as it will leave the suspect electrocuted and numb for a quite a long time, which is more than enough to seize and cuff him up.

But, the tasers used now have a problem of “capability gap”. That is, if the suspect is standing at a distance of 40 feet away from you with a knife, you do have the advantage of using the taser effectively. But if he moves further away with a deadly object in his hand and is ready to use it against you, which will be a problem. The reason is that, most of the tasers work accurately at a range no more than 50 feet. Thus you will be forced to use a gun against the suspect, making the situation more deadly. So, the officers claim that they need a less lethal weapon than a gun and a better weapon than the conventional taser. This is where XREP, comes into action.

XREP stands for Extended Range Electronic Projectile. It is a twelve gauge wireless projectile that has a firing range of 100 feet and can be capacitated from any kind of pump-action shotgun. As soon as the slug is fired from the gun, it speeds through the air and penetrates the suspect’s skin and causes sudden muscle paralysis. Thus, it is better than a Taser and has the common mechanism of a shotgun.

The manufacturers faced a huge challenge when it came to the design of such a device. One problem they faced was in reducing the overall size of the device. As there is a difference in the amount of voltage that is applied by the device on a human body, the circuit size could easily be reduced accordingly. A conventional taser produces almost 50,000 volts of electricity while a XREP uses no more than 500 volts. While a normal taser arcs the current to the body, this device uses barbed electrodes to pierce the skin. According to the engineer behind the device, Mark Hanchett, the voltage may be very less for a person to be stunned, but it is the waveform produced through it that actually matters. The current produced by the device will cause temporary damage to the nervous system. The developers are trying to upgrade the device by releasing a grenade version that is able to launch up to 200 feet.

Features

Bullet

• Wireless
• Size – 12 Gauge
• Weight – 25 gms
• Speed – 270 feet/sec
• Range – 100 feet
• Current Produced – 1.3 mA
• Voltage Produced – 500 V

The diagram of a shock bullet taser XREP is shown below.

Shock Bullet TASER XREP

The electrifying bullet can be released from any pump action shot-gun.

Shot-gun Slug

A picture showing the inside of a XREP bullet shell is given below.

XREP Shell

• Nose – They are basically 4 electrified barbs that are used to pierce the skin. The shock delivered from the nose will first be sensed around a 6 inch area. This will soon be followed by a bigger shock. The speed and force of impact of nose on the skin will cause the remaining chassis of the device to separate from the nose and dangle downward from a live copper wire.

• Barbs – If the assailant is not able to get a hold of the wire to complete the circuit, six longer barbs on the projectile can also pierce the skin. The plastic coating of the barbs will be removed as soon as they come in contact with the body and the half-inch electrodes—called “chollas,” pop out like spikes and swing into the body.

• Hand Trap – The first thought that goes through the assailant’s mind is to grab the dangling wire and rip out the barbs. But, since the wire is pulsing with current, the moment he touches it, electricity will begin to flow from the first set of electrodes in the nose of the projectile to the assailant’s hand. Thus he will be forced to contract from the shock and squeeze the wire tightly. Thus, he will be electrocuted with 15 seconds and will be paralysed.

• Fins – Just like the fins of a fish, the slug also has three fins attached to its rear end. They are used to help the projectile stay on its track as it sails up to 100 feet toward its target. They will be pressed non, when kept inside the slug. As soon as the slug is fired, they will be opened.

• Transformer – It is used to produce a small power so as to convert the energy from the battery to discharge 1.3 mA of current for 15 seconds. Morover, it plays an important role in the propogation and interaction of the current to produce the correct waveform.

• Microprocessor – Once the circuit is complete, an onboard computer commands the voltage capacitor to fire, modulating the intensity, duration and shape of the current.

• Battery – Two Li batteries are used to provide power for the microprocessor and other circuits.

• Shell – The circuitry is potted inside shock-absorbing plastic to ensure that it survives the force of the shotgun blast and collision with the target

PIR Sensor Based Security System

The circuit of an inexpensive and highly secure electronic security system is explained below. This electronic security system can be used in banks and other high security areas.

A normal electronic security system will have a transmitter and a receiver. The transmitter sends out an IR laser and this will be received by the receiver. When an intruder walks past the device, the IR beam is cut and thus the alarm is activated. But, this system has some major disadvantages like limited range and poor line of sight. These disadvantages are eliminated through the PIR sensor circuit explained below.

Working

Instead of infrared or laser transmitters and receivers, PIR (Passive Infrared Radial) sensors are used in this circuit. The sensor is basically a pyroelectric device. When the device is exposed to infrared radiation, it generates an electric charge. The device is made of crystalline material. According to the change in the amount of infrared striking the element, there will be a change in the voltages generated, which is measured by an on-board amplifier.

The infrared light explained here refers to the light radiating from all objects in its field of view. The reason for not having a transmitter and receiver is that the device does not emit one, but only accepts the energy emitted from objects above absolute zero in the form of radiations. Thus the temperature will be different for a human working past a sensor, and that of a wall right in front of it. Thus the word “passive” is used in PIR to explain that it does not emit a radiation and receive it, but instead accepts the incoming infrared radiation passively.

The block diagram of the PIR based security system is given below.

PIR Block Diagram

The device contains a special filter called a Fresnel lens, which focuses the infrared signals onto the element. As the ambient infrared signals change rapidly, the on-board amplifier trips the output to indicate motion. We can say that the PIR sensor is a human body sensor because it is only activated when a human or animal walks past the sensor. The PIR sensor is the heart of the project. We can design the project in such a manner that as soon as the burglar or intruder walks past the sensor, the alarms would turn on and the whole lighting system could turn on.

Circuit Diagram

PIR Sensor Based Security System

• PIR Sensor

D204B PIR sensor is used in this project. The PIR sensor is the heart of the project.

• Two Stage Amplifiers

Two stage OP-amp: LM 324 is used as two stage amplifier. The signal from the PIR sensor is very low so this signal is amplified by using LM324.LM324 is a quad OP-amp. First two op-amps act as amplifiers.

• Comparator

The comparator compares the signal from the amplifier and a reference voltage.3^rd and 4^th OP-amp of LM 324 act as comparator.

• Transistor Switch

Whenever the output of comparator make HIGH Q1 transistor gets ON and relay will be energized causing the alarm and lamp to turn ON.

• Power Supply

Power supply converts 230 Volt AC into 12 Volt DC and 5 Volt DC. IC 7812 is used as the 12 Volt voltage regulator and a 5v zener diode act as the 5 Volt voltage regulator

‘Cling-Film’ Solar Cells – A New Revolution for Renewable Energy

Polymer Solar Cell

Scientists from the Universities of Sheffield and Cambridge have started a new research that promises to produce cost-effective and highly efficient cling film solar cells. The idea was first published in the journal “Advanced Energy Materials”. According to them, these solar cells can also be produced with much ease. This has clearly become a great advancement in the field of renewable solar energy.
To carry out the tests, the ISI Neutron Source and Diamond Light Source at STFC Rutherford Appleton Laboratory in Oxfordshire were used.
Until now, two types of solar cell materials are being used – plastic and silicon. When it comes to manufacturing of the material, plastic is known to be much much cheaper. Due to the simple manufacturing process, they can also be produced in huge quantities. When molecules having complex mixtures are spread on to a surface, the molecules move away from one another and start to accumulate at the top and bottom of the layer. Thus, a highly efficient solar cell is produced. This same principle was used by researchers to prove that by using much better and cost less manufacturing methods, where flexible layers of material are deposited over large areas like cling-film, highly efficient solar cell structures can be produced.
These solar cells are known to be useful for both home use as well as industrial use and since it is very cheap, it can be manufactured on a high-scale. Instead of using high-end fabrication methods to manufacture a certain semi-conductor nanostructure, high number of printing could be used to produce nano-scale films of solar cells that are much thinner than the width of a human hair. Such films can be used to produce cost-effective, light-weight solar cell panels.
According to Dr. Robert Dalgliesh, one of the researchers of the project, the work makes us understand the potential of the joint use of neutron and X-ray scattering sources such as ISIS and Diamond in solving modern challenges for society. Using such sources help in making a stronger internal structure for the solar cell. By studying the layers in the solar cell that is responsible in converting sunlight into electricity, the different processing steps that change the overall efficiency and affect the overall polymer solar cell performance is also known.
Since most of the energy consumed today is through non-renewable sources, the demand for something that generates energy through a renewable source like the Sun is needed for the coming years. Since no highly efficient system that is capable of converting sunlight into electricity has been found until now, the cling-film solar cell will clearly pave way for the new age of renewable energy.

The World’s Largest Fusion Reactor

Since, 1932, researchers have been successful in combining hot fusion with nuclei. Till then the concept of cold fusion was used and did not produce any satisfactory results. The research in hot fusion is still continuing and they have been successful in providing danger-free, very good potential energy source without producing much wastes.
Some of the main advantages of a fusion power plant is that they will not produce any high radioactive waste which will live for a long period. They cannot be used as a deadly weapon and cannot be subjected to meltdown. Thus, it is clear that hot fusion reactor is a very good energy producer when compared to other low efficient conventional methods.
In order to produce such a reactor, an international research and experimenting project was made by the name International Thermonuclear Experimental Reactor (ITER). Researchers at ITER have decided to build the world’s biggest and most efficient “tokamak” nuclear reactor. Tokamak refers to the device that uses a magnetic field to restrict the plasma inside a vessel. Thus the fusion reaction process is experimented inside this vessel. The plasma that is restricted inside the vessel with the help of magnetic field is composed of deuterium and tritium, and two isotopes of hydrogen. The radio waves and micro waves, along with the particle beams rise the temperature inside the vessel to as high as 270 million degrees Fahrenheit. This is the minimum temperature that is required to support the fusion process.
The inside schematic of an ITER Tokahama nuclear reactor is shown below.

Fusion Reactor

The basic working of a reactor is given below.
Firstly, the fuel in the form of two hydrogen isotopes, deuterium and tritium is injected into the tokamak. The vessel will be filled with plasma, a huge mix of changed particles, as soon as an electric current heats the deuterium and tritium gases and ionizes them.The plasma produces high temperature heat as soon as radio waves, microwaves and high-energy deuterium particle react with it. This high temperature causes further reaction between deuterium and tritium and forms products like helium atom and a neutron.
Great care has to be taken in avoiding the plasma from touching the wall of the fusion reactor. Since it will have high temperatures, they may cause holes on the walls and hence leakage. To avoid this from happening, the charged particle is restricted in a magnetic field made from 39 superconducting poloidal, toroidal and central solenoid magnets positioned inside and outside the doughnut shaped vessel. Since the walls may also be affected from high energy neutrons, a 2 feet thick steel blanket lining is also coated around the wall.
When a tritium and deuterium nuclei react together they give away helium and a neutron. If the same process is carried out inside a tokamak fusion reactor, it would produce enormous heat (energy) that is more than enough to generate electricity by rotating a turbine.
The whole experiment is to be carried out in a place called Cadarache, the south of France. The researchers claim that this reactor will be the largest tokamak in the world, since it is capable of producing 500 megawatts of power.
But, they have clearly stated that the whole process will just be an experiment and thus, the reactor will not be used to produce electricity. After an outline of the whole experiment is made and the budget estimated, the work will start by 2019. If it turns out to be successful, a 2,000 to 4,000 megawatt producing power plant will be built by 2040!!
According to Richard Pitts, a scientist who is working on the project, the whole process is claimed to be very safe. He says that there will be no hazards or radiation leaks like what happened in Chernobyl and Fukoshima.
In order to carry out experiments, the researchers will have to face a lot of technical problems. Some of them are
The breeding of tritium is extremely difficult since the material is scarcely found anywhere on Earth. At any time, only 50 pounds of tritium is produced and it has a high decay rate. This scarcity is because the material is not naturally produced. But, there will not be any problem in producing deuterium as it not radio-active and it can be distilled from water. They can use the tritium used in other power plants, but if high-end experiments are to be carried out, they will have to produce their own supply. Neutrons from the fusion reaction could be used to convert a little of lithium into tritium.The inside schematic of an ITER Tokahama nuclear reactor is shown below.
According to Richard Pitts, a scientist who is working on the project, the whole process is claimed to be very safe. He says that there will be no hazards or radiation leaks like what happened in Chernobyl and Fukoshima.
In order to carry out experiments, the researchers will have to face a lot of technical problems. Some of them are:
The breeding of tritium is extremely difficult since the material is scarcely found anywhere on Earth. At any particular time only 50 pounds of tritium is produced and it has a high decay rate. This scarcity is because the material is not naturally produced. But, there will not be any problem in producing deuterium as it not radio-active and it can be distilled from water. They can use the tritium used in other power plants, but if high-end experiments are to be carried out, they will have to produce their own supply. Neutrons from the fusion reaction could be used to convert a little of lithium into tritium.
The researchers must also know which material can be used to build tokamak walls, as it could be easily worn down from the reaction with the by-products from the fusion reaction.
There could also occur maintenance problems as the workers inside the vessel could be affected by residual radioactivity. Thus, they will have to design robots that are capable of carrying small tasks like replacing faulty parts and so on

Water level alarm circuit

Description.

Here is a simple water level alarm circuit that will produce an audible alarm when the water level reaches  a preset level.The circuit can be powered of a  3V battery and is very handy to use.

The circuit is based on an astable multivibrator wired around IC1 (NE 555).The operating frequency of the astable multivibrator here will depend on capacitor C1, resistances R1,R2 and the resistance across the probes A&B.When there is no water up to the probes,they will be open and so the multivibrator will not produce oscillations and the buzzer will not beep.When there is water up to the level of probes,some current will pass through the water,the circuit will be closed to some extend,and the IC will start producing oscillations in a frequency  proportional to the value of C1,R1,R2 and the resistance of water across the probes.The buzzer will beep to indicate the presence of water up to the level of the sensing probes.

Circuit diagram with Parts list.

Notes.

• The circuit can be powered of a 3V battery.
• Assemble the circuit on a good quality PCB or common board.
• The probes can be made of two insulated copper Aluminiun wires.
• Place the probes at the position where you have to sense the level

Door bell circuit using NE555

Description.

The main part of this doorbell circuit are two NE555 timer ICs.When some one presses switch S1 momentarily ,the loud speaker sounds a bell tone as long as the time period of the monostable multivibrator built around IC1.

When the switch S1 pressed, IC1 is triggered at its pin 2 and output pin 3 goes high for a time period previously set by the values of POT R4 and POT R5.When the output ofIC1 goes high it resets IC2 and it starts to oscillate to make a bell sound through the speaker.The IC2 is configured as an astable multivibrator whose oscillation frequency can be varied with the help of POT R5.By adjusting the values of R4 & R5, modifications on the tone are possible.

Circuit diagram with Parts list.

Notes.

• The circuit has to assembled on a good quality PCB or common board.
• The IC1 & IC2 has to be mounted on IC holders.
• Power the circuit from a 9V battery or 9V DC power supply.
• Switch S1 is push button switch

IC based TV transmitter circuit

TV transmitter circuit.

A very simple and high quality TV transmitter circuit based on IC MC374 is shown in this article.MC1374 is an integrated TV modulator circuit that can be used in various TV transmitter applications. The MC1374 includes all necessary circuitries required for a TV modulator such as sound carrier oscillator, FM audio modulator, dual input RF modulator etc. The IC packed with a lot of great features like wide dynamic range, single supply operation, low distortion, variable gain radio frequency modulator section, minimum intermodulation distortion, + or – Sync etc. The IC requires few external components and can be operated from a supply voltage range from 5 to 12V DC.The circuit diagram of the TV transmitter using MC1374 is shown below.

MC1374 TV transmitter circuit

Circuit description.

Video section.

The video signal input to the circuit can be either negative or positive. The RF output will be approximately zero when the voltages at pin 1 and 11 are equal and the RF output increases linearly as the difference in voltage increases. Resistors R1,R2 and R3 determines the Q factor of the circuit are here their values are so chosen that the Q factor is around 15 which is the desired value for this IC. Resistor R8 connected between pins 12 and 13 sets the modulator gain. The RF output is available from pin 9 which is actually a source which drives a load connected from positive supply line to pin 9. The frequency of the RF oscillator is controlled by the tank circuit comprising of components L1 and C2 connected in association with pins 7 and 6. With the present values of L1 and C2 the RF oscillator frequency is around 105MHz. Components L3, L4, C11, C12 and C13 forms a double pi low pass filter which filters away second harmonics from the radio frequency output. These second harmonics usually occur at very high frequencies due to small imbalances in the device. Resistors R9 and R11 forms the bias circuit for the video input pin. Switch S1 can be used for selecting channel 3 or channel 4 operations.

Audio section.

Frequency modulation is used for transmitting the audio signals. Inductor L2 connected between pin 2 & 3 and the capacitor C3 from pin 3 to ground forms the necessary tank circuit for the FM sections oscillator. Resistor R12 and R13 forms a biasing network for the audio input pin (pin14). C6 is the decoupling capacitor for the audio input while C10 is the decoupling capacitor for the video input. The modulate FM signal available at pin 3 of the IC is coupled pin 1 of the IC through resistor R6 and capacitor C4 and then this signal is modulated onto the AM carrier. Capacitor C9 filters off noise if any from the power supply. R4 and R5 form a biasing network for the pin 1 of the IC. C14 a noise bypass capacitor for the oscillator B+ pin (pin14) of the IC. This pin can be used for shutting down the sound system during the alignment of the AM section.

Notes.

• Assemble the circuit on a good quality PCB.
• Use a holder for mounting the IC.
• Circuit can be powered from anything between 5 to 12V DC.
• Using a battery for powering the circuit will reduce noise and improve the performance.
• If a DC power supply is used, then it must be well regulated.
• For L1 make 4 turns of #22 enamelled copper wire on a 0.25 inch plastic former.
• For L2 make 40 turns of #36 enamelled copper wire on a 0.18 inch plastic former

Magnetic Microprocessors Can Make High-End Computers in Future

Two researchers at the University of California, Berkeley, Jeffrey Bokor and Brian Lambson are developing a new concept called “Magnetic Microprocessors”. According to them, this new concept would be so efficient that the energy consumed by them will be very less as described by the 2nd law of thermodynamics. Though the multi-processors used today are known to be efficient, the fact is that the energy consumed by them is fairly high when compared to its speed and multi-tasking capability.
As the name implies, the magnetic microprocessor will work on the principle of magnetic properties, and without the use of electrons. The microprocessors used now work on the principle of electricity, which means that they produce the energy required, by the movement of electrons. This movement of electrons generate heat and thus reduces the efficiency of the system. Since, magnetic microprocessors work without electrons, the researcher’s claim that the device would be a million times more efficient than the conventional processors used today.
In this device, the digital memory (combination of 0′s and 1′s) is represented with the help of nano-magnet polarities. The size of these magnets will be very small and millions of them will be kept close together so that their poles will interact and create the basic logic operations, similar to the transistors used now

A diagram showing the interaction between the North and South Pole is given below.

Magnetic Microprocessors

Theoretically, during a basic AND or OR logical operation, the minimum energy loss that a device produces `at normal temperature is supposed to be 18 millielectron volts. This loss limit is known as Landauer limit and was proposed by Rolf Landauer 50 years ago. The researchers are trying to bring this theory into practise with the help of magnetic microprocessors. If they succeed in bringing this theory into practise, it would mean that the energy dissipated by the device is lesser than the thermal energy of atoms at normal temperature!!
They also claim that since the Landauer limit is proportional to temperature, the use of such a device at cold conditions would further increase its efficiency.
According to Jeffrey Bokor, the device would turn out to be revolutionary, even if the efficiency would be within a factor of 10 of the Landauer limit. They came to the conclusion that they could reach Landauer limit after conducting a simple memory operation with a magnetic logic circuit. The experiment was to erase a magnetic bit and the energy lost to conduct the test was very close to Landauer limit.
The problem with such a device is that, somehow electricity is needed for the generation of a magnetic field. This will clearly lessen the efficiency to a great extent. But, the researchers believe that in future, materials like multiferroic alloys could make the electrical currents unnecessary. Thus, the electronics world would be clearly dominated by magnetonics.

There may be doubts as to whether if such a device is replaced with the microprocessor used now and then made to work with a conventional computer, will there be any problems? The answer is not at all. Though there will be magnetic effects around the device, it will not be strong enough to wipe out the contents of the hard drive. The magnetic fields produced will be very small and thus have smaller strength. They would only work, and interact with each other, because of the inverse relationship between field intensity and distance. At a billionth of a meter such fields would interact with each other, but however strong they are then would weaken by more than a billion fold when they are very near.
Actually, the problem may occur the other way around. The conventional hard drive could easily overpower any of these that were too close