Homemade Batteries

Homemade batteries are a popular subject with my readers. Making electricity from things you find around the house is a fun project.

There are lots of easy ways to make homemade batteries. Basically, any two different kinds of metal can be placed in a conducting solution and you get a battery. Familiar homemade batteries include sticking copper and zinc strips into a lemon or a potato to make a battery.

One quick battery is made from a soda can, the soda from the can, and some copper.

The photo above shows a battery made by placing a strip of copper and a strip of aluminum into a glass of Coca-Cola (I used the sugar-free cherry flavored variety because that's what I found in the refrigerator).

You can make the aluminum strip by cutting open the can. You will need some sandpaper to sand off the paint and plastic coating from the aluminum before using it. Or you can get strips of aluminum already free of coatings from a hardware store.

You can get copper flashing from a hardware store and cut out a strip of it, or you can use a bunch of copper wire (the more surface area exposed to the liquid, the more electrical current is produced).

The aluminum-copper-coke battery will produce about three quarters of a volt.

Using a zinc strip instead of the aluminum produces a little over a volt in the copper-zinc-coke battery. That zinc should work better than aluminum in a battery is a little surprising, since aluminum is normally more reactive than zinc, but in this cell I suspect the aluminum has an oxide coating that is interfering with the reaction. I have not seen a thorough scientific study of a Coca-Cola copper aluminum battery, and it may be a while before I do.

Another easy battery to make at home is the zinc-air battery. In this battery, the strip of zinc is oxidized by dissolved oxygen in salt water. We used a level tablespoon of salt in a cup of water.

The "batteries" we have shown here are more correctly called "cells". An actual battery is made up of two or more cells.

The zinc-air cell produces about three quarters of a volt. To get higher voltages, which are needed to run things like light emiting diodes (LEDs) or calculators or watches, we connect two or more cells in series to make a battery.

Two zinc-air cells in series produce about a volt and a half. In the photo above, you can see that this is enough to make a red LED light up. To make it brighter, you can add more cells.

If the LED in your project doesn't light up, try reversing the leads. The diode is a device that only works in one direction. The leads on the diode usually have one lead longer than the other, to make it easy to see which way it is connected. With my diode, the long lead was the one to connect to the copper electrode.

If you don't have a strip of zinc, you can make an aluminum-air battery, as shown in the photo above. It produces a little more than half a volt, so you will need three cells in series to light the LED.

A different chemistry is involved in the copper-zinc-vinegar battery, shown in the photo above. In this battery, the zinc is oxidized by copper ions from the copper strip. In this battery, the copper gradually migrates into the vinegar, and then replaces the zinc at the zinc electrode.

After lighting the LED all night long, you can see a black coating of copper and copper oxide sludge has formed on the zinc.Even though the battery has been lighting the LED all night, it still has a lot of zinc left to keep it lit for several days.

Three of the copper-zinc-coke batteries produce about 3 volts, and can replace the 3 volt lithium battery in this small clock/calendar/calculator. It has been running for days now, and can probably last months. The calculator works, and the alarm chimes play just fine.

some scientific facts..

 How many of you knew?????

The truth about naigira falls...

Momentum

The sports announcer says, "Going into the all-star break, the Chicago White Sox have the momentum." The headlines declare "Chicago Bulls Gaining Momentum." The coach pumps up his team at half-time, saying "You have the momentum; the critical need is that you use thatmomentum and bury them in this third quarter."

Momentum is a commonly used term in sports. A team that has the momentum is on the move and is going to take some effort to stop. A team that has a lot of momentum is really on the move and is going to be hard to stop. Momentum is a physics term; it refers to the quantity of motion that an object has. A sports team that is on the movehas the momentum. If an object is in motion (on the move) then it has momentum.

Momentum can be defined as "mass in motion." All objects have mass; so if an object is moving, then it has momentum - it has its mass in motion. The amount of momentum that an object has is dependent upon two variables: how much stuff is moving and how fast the stuff is moving. Momentum depends upon the variables mass and velocity. In terms of an equation, the momentum of an object is equal to the mass of the object times the velocity of the object.

Momentum = mass • velocity

In physics, the symbol for the quantity momentum is the lower case "p". Thus, the above equation can be rewritten as

p = m • v

where m is the mass and v is the velocity. The equation illustrates that momentum is directly proportional to an object's mass and directly proportional to the object's velocity.

The units for momentum would be mass units times velocity units. The standard metric unit of momentum is the kg•m/s. While the kg•m/s is the standard metric unit of momentum, there are a variety of other units that are acceptable (though not conventional) units of momentum. Examples include kg•mi/hr, kg•km/hr, and g•cm/s. In each of these examples, a mass unit is multiplied by a velocity unit to provide a momentum unit. This is consistent with the equation for momentum.

CNC

Numerical control (NC) is the automation of machine tools that are operated by abstractly programmed commands encoded on a storage medium, as opposed to controlled manually via handwheels or levers, or mechanically automated via cams alone. Most NC today is computer numerical control(CNC), in which computers play an integral part of the control.

In modern CNC systems, end-to-end component design is highly automated using computer-aided design (CAD) and computer-aided manufacturing(CAM) programs. The programs produce a computer file that is interpreted to extract the commands needed to operate a particular machine via a postprocessor, and then loaded into the CNC machines for production. Since any particular component might require the use of a number of different tools – drills, saws, etc., modern machines often combine multiple tools into a single "cell". In other installations, a number of different machines are used with an external controller and human or robotic operators that move the component from machine to machine. In either case, the series of steps needed to produce any part is highly automated and produces a part that closely matches the original CAD design.

The first NC machines were built in the 1940s and 1950s, based on existing tools that were modified with motors that moved the controls to follow points fed into the system on punched tape. These early servomechanisms were rapidly augmented with analog and digital computers, creating the modern CNC machine tools that have revolutionized the machining processes.

Description

Modern CNC mills differ little in concept from the original model built at MIT in 1952. Mills typically consist of a table that moves in the X and Y axes, and a tool spindle that moves in the Z (depth). The position of the tool is driven by motors through a series of step-down gears in order to provide highly accurate movements, or in modern designs, direct-drive stepper motor or servo motors. Open-loop control works as long as the forces are kept small enough and speeds are not too great. On commercial metalworking machines closed loop controls are standard and required in order to provide the accuracy, speed, and repeatability demanded.

As the controller hardware evolved, the mills themselves also evolved. One change has been to enclose the entire mechanism in a large box as a safety measure, often with additional safety interlocks to ensure the operator is far enough from the working piece for safe operation. Most new CNC systems built today are completely electronically controlled.

CNC-like systems are now used for any process that can be described as a series of movements and operations. These include laser cutting, welding, friction stir welding, ultrasonic welding, flame and plasma cutting, bending, spinning, hole-punching, pinning, gluing, fabric cutting, sewing, tape and fiber placement, routing, picking and placing (PnP), and sawing.

CHEVROLET VOLT.

A MASTERPIECE BY ENGINEERS..

The Chevrolet Volt is a plug-in hybrid electric vehicle manufactured by General Motors, also sold as the Holden Volt in Australia and New Zealand. With a different styling it is sold as the Vauxhall Ampera in Great Britain and as the Opel Ampera in the rest of Europe. Sales of the 2011 Chevrolet Volt commenced in the U.S. in mid-December 2010 followed by various European countries and other international markets in 2011. As of 30 June 2013, the Volt and Ampera models have combined global sales of over 50,000 units, and the leading market is the U.S. with 41,313 Chevrolet Volts delivered since its introduction in 2010, making the Volt the top selling plug-in electric vehicle in the United States, and the Volt/Ampera family the best selling plug-in hybrid in the world.

As of July 2013, the Volt is the most fuel-efficient car with a gasoline engine sold in the United States, as rated by the United States Environmental Protection Agency (EPA), with a combined electric mode/gasoline-only rating of 62 mpg_-US (3.8 L/100 km; 74 mpg_-imp)equivalent (MPG-equivalent) for the 2013 model year.^[4][5] The Volt operates as a pure battery electric vehicle until its plug-in battery capacity drops to a predetermined threshold from full charge. From there its internal combustion engine powers an electric generator to extend the vehicle's range if needed. When the engine is running it may be periodically mechanically linked (by a clutch) to the traction motor, to improve energy efficiency. The Volt's regenerative braking also contributes to the on-board electricity generation.

Terminology

The Society of Automotive Engineers' (SAE) definition of a hybrid vehicle states that the vehicle shall have "two or more energy storage systems both of which must provide propulsion power, either together or independently." General Motors has avoided the use of the term "hybrid" when describing its Voltec designs, even after the carmaker revealed that in some cases the combustion engine provided some assist at high speeds or to improve performance. Instead General Motors describes the Volt as an electric vehicle equipped with a "range extending" gasoline powered internal combustion engine (ICE) as a genset and therefore dubbed the Volt an "Extended Range Electric Vehicle" or E-REV. In a January 2011 interview, the Chevy Volt's Global Chief Engineer, Pamela Fletcher, referred to the Volt as "an electric car with extended range."

According to the Society of Automotive Engineers (SAE) definitions, the Volt is a plug-in hybridvehicle, due to the combination of an internal combustion engine and two electric motors, along with a battery that can accept off-board energy.^[17] The Volt operates as a purely electric vehicle for the first 25 to 50 miles (40 to 80 km) in charge-depleting mode. When the battery capacity drops below a pre-established threshold from full charge, the vehicles enters charge-sustaining mode, and the Volt's control system will select the most optimally efficient drive mode to improve performance and boost high-speed efficiency.

Operating and driving modes

Technically the Voltec drivetrain has three power converting elements:

• Primary traction electric motor/generator, provides good acceleration for driving at lower speeds and regeneration for braking, its maximum output of 111 kW setting the maximum output of the whole system.
• Secondary electric motor/generator, assists the primary electric motor or works as generator capable of producing 54 kW.
• Internal combustion engine of 63 kW power, engaged when the batteries reach the predetermined threshold.

These units are connected via a planetary gear and electric clutches to provide power output for propulsion in four programmed operating modes:

1. Single motor electric - The primary motor runs solely on battery power, maximum propulsion power is 111 kW.
2. Dual motor electric - At higher vehicle speeds the secondary motor engages over the planetary gear such that it reduces the speed of the primary motor. This facilitates higher efficiency and better mileage for the combined system, without increasing the maximum power.
3. Single motor extended - The battery reaches its minimum charge which triggers the combustion engine. The engine drives the secondary motor which now works as a generator, via the charging electronics, to keep the minimum battery charge level. The primary motor can still provide its 111 kW for short acceleration, albeit not sustained.
4. Dual motor extended - The electric motors are used again in dual configuration with increased efficiency at higher speeds. Additionally the gasoline engine contributes propulsion power via the planetary gear. While power is drained from the battery the amount is less than in mode 2 for the same propulsion power, thus extending the range.

The drivetrain platform permits the Volt to operate as a pure battery electric vehicle until its battery capacity has been depleted to a defined level, at which time it commences to operate as a series hybrid design where the gasoline engine drives the generator, which keeps the battery at minimum level charge and provides power to the electric motors. The full charge of the battery is replenished only by loading it on the electrical grid.
While in this series mode at higher speeds and loads, (typically above 30 miles per hour (48 km/h) at light to moderate loads) the gasoline engine can engage mechanically to the output from the transmission and assist both electric motors to drive the wheels, in which case the Volt operates as apower-split or series-parallel hybrid. After its all-electric range has been depleted, at speeds between 30 to 70 miles per hour (48 to 110 km/h), the Volt is programmed to select the most efficient drive mode, which improves performance and boosts high-speed efficiency by 10 to 15 percent.

While operating modes are switched automatically the Volt allows the driver to choose from three drive modes: normal, sport and mountain. The mountain mode, which is expected to be required only under unusual power demand conditions, increases minimum battery state of charge (SOC) to around 45%, thus maintaining performance on steep and long grades. The driver will hear more engine noise here due to the higher rate of power generation required to maintain this mode The sport mode causes the engine to rev higher, and the response to the throttle pedal is quicker. The Ampera has an additional option, the "City Mode" or "battery hold", which allows battery management to the needs of the driver, allowing to save the energy currently stored in the battery for use when traveling urban areas or restricted zones. The 2013 model year Volt includes the "Hold Drive" button to provide the same choice.

Performance

The Volt has a top speed of 100 mph (160 km/h). According to Edmunds.com road tests, the Volt's 0 to 60 mph (0–97 km/h) acceleration time is 9.2 seconds running on electric-only mode, and 9.0 seconds with the gasoline engine assisting propulsion. Motor Trend reports the Volt's quarter mile (402 m) time is 16.9 sec @ 84.3 mph (135.7 km/h),while Edmunds reports a quarter mile (402 m) time of 16.8 sec @ 81.5 mph (131.2 km/h) in electric-only operation, and 16.6 sec @ 85.5 mph (137.6 km/h) with the gasoline engine assisting. Motor Trend reports a 60 to 0 mph (97 to 0 km/h) braking distance of 112 ft (34 m) and Edmunds.com of 124 ft (38 m).

Battery

The 2011 Volt's lithium-ion battery (Li-ion) battery pack weighs 435 lb (197 kg) and consists of 288 individual cells arranged into nine modules. Plastic frames hold pairs of lithium-ion cells that sandwich an aluminum cooling fin. The design and construction of that aluminum plate was critical to ensuring an even temperature distribution with no hot or cool spots across the flat, rectangular cell. The battery pack has its own cooling circuit that is similar to, but independent from, the engine cooling system.

Drivetrain

The 2011 Chevrolet Volt has a 16 kW·h / 45 A·h (10.4 kW·h usable) lithium-ion battery pack that can be charged by plugging the car into a 120-240 VAC residential electrical outlet using the provided SAE J1772-compliant charging cord. No external charging station is required. The Volt is propelled by an electric motor with a peak output of 111 kW (149 hp) delivering 273 lb·ft (370 N·m) of torque.

While driving, after the Volt battery has dropped to a predetermined threshold from full charge, a small naturally aspirated 1.4-liter 4-cylinder gasoline fueled internal combustion engine (Opel's Family 0) with approximately 80 hp (60 kW), powers a 55 kW generator to extend the Volt's range. The vehicle also has a regenerative braking system. The electrical power from the generator is sent primarily to the electric motor, with the excess going to the batteries, depending on the state of charge (SOC) of the battery pack and the power demanded at the wheels.

The Volt requires premium gasoline (91 octane or higher) because the higher octane rating fuel permits the 10.5:1 compression ratio engine to utilize more ignition timing advance in order to maximize its fuel efficiency by 5 to 10% as compared to regular gasoline. For users who drive mostly in electric mode and to avoid maintenance problems caused by storing the same gasoline in the tank for months, the 2011 Volt has a sealed and pressurized fuel tank to avoid evaporation, and as a result, the fuel filler has to be depressurized before opening the tank. Also the engine management system monitors the time between engine running and it is programmed to prompt the driver to run past the 40-mile (64 km) all-electric range before recharging in order to consume some gasoline. If the driver does not run on gasoline, the system will automatically run the maintenance mode which starts the engine to consume some of the aging fuel and circulate the fluids within the engine. A configuration with an E85 flex-fuel capable engine is under development and was expected to be available in 2013.

Official introduction

General Motors held a ceremony at its Detroit Hamtramck Assembly Plant on November 30, 2010, to introduce the first Chevrolet Volt off the assembly line. The first Volt built for retail sale was earmarked for display at General Motors' Heritage Center museum in Sterling Heights, Michigan. The second unit was offered at a public auction, with an opening bid of US$50,000 and it was won by Rick Hendrick who paid US$225,000. The proceeds went to fund math and sciences education in Detroit through the Detroit Public Schools Foundation. Deliveries to retail customers began in mid December 2010.

Next generation

In April 2013, CEO Daniel Akerson announced that GM expects the second generation Volt to be priced on the order of US$7,000 to US$10,000 lower than the 2013 model year with the same features. As of July 2013, GM is developing the next generation model which is expected to be launched between 2015 and 2016.

KARL BENZ. Founder- MERCEDES BENZ. And finest mechanical engineer.

 Karl Friedrich Benz  (November 25, 1844 – April 4, 1929) was a German engine designer and car engineer, generally regarded as theinventor of the petrol-powered automobile, and together with Bertha Benz, pioneering founder of the automobile manufacturer Mercedes-Benz. Other German contemporaries, Gottlieb Daimler and Wilhelm Maybach working as partners, also worked on similar types of inventions, without knowledge of the work of the other, but Benz received a patent for his work first, and, subsequently patented all the processes that made the internal combustion engine feasible for use in an automobile. In 1879, his first engine patent was granted to him, and in 1886, Benz was granted a patent for his first automobile.

Early life[edit source | editbeta]

Karl Benz was born Karl Friedrich Michael Vaillant, in November 25, 1844 in Mühlburg, now a borough of Karlsruhe, Baden, which is part of modernGermany, to Josephine Vaillant and a locomotive driver, Johann George Benz, whom she married a few months later.^{[1][2][3][4][5]} When he was two years old, his father was killed in a railway accident, and his name was changed to Karl Friedrich Benz in remembrance of his father.^[6]

Despite living in near poverty, his mother strove to give him a good education. Benz attended the local Grammar School in Karlsruhe and was aprodigious student. In 1853, at the age of nine he started at the scientifically oriented Lyceum. Next he studied at the Poly-Technical University under the instruction of Ferdinand Redtenbacher.

Karl Benz, 1869, 25 years old (Zenodot Verlagsges. mbH)

Benz had originally focused his studies on locksmithing, but eventually followed his father's steps toward locomotive engineering. On September 30, 1860, at age fifteen, he passed the entrance exam for mechanical engineering at the University of Karlsruhe, which he subsequently attended. Benz was graduated July 9, 1864 at nineteen.

During these years, while riding his bicycle, he started to envision concepts for a vehicle that would eventually become the horseless carriage.

Following his formal education, Benz had seven years of professional training in several companies, but did not fit well in any of them. The training started in Karlsruhe with two years of varied jobs in a mechanical engineeringcompany.

He then moved to Mannheim to work as a draftsman and designer in a scales factory. In 1868 he went to Pforzheim to work for a bridge building companyGebrüder Benckiser Eisenwerke und Maschinenfabrik. Finally, he went to Vienna for a short period to work at an iron construction company.

In 2011, a dramatized television movie about the life of Karl and Bertha Benz was made named Carl & Bertha which premiered on 11 May and was aired by Das Erste on 23 May. A trailer of the movie and a "making of" special were released on YouTube.

What is Mechanical Engineering?

Mechanical engineering is a diverse subject that derives its breadth from the need to design and manufacture everything from small individual parts and devices (e.g., microscale sensors and inkjet printer nozzles) to large systems (e.g., spacecraft and machine tools). The role of a mechanical engineer is to take a product from an idea to the marketplace. In order to accomplish this, a broad range of skills are needed. The mechanical engineer needs to acquire particular skills and knowledge. He/she needs to understand the forces and the thermal environment that a product, its parts, or its subsystems will encounter; to design them for functionality, aesthetics, and the ability to withstand the forces and the thermal environment they will be subjected to; and to determine the best way to manufacture them and ensure they will operate without failure. Perhaps the one skill that is the mechanical engineer’s exclusive domain is the ability to analyze and design objects and systems with motion.

Since these skills are required for virtually everything that is made, mechanical engineering is perhaps the broadest and most diverse of engineering disciplines. Mechanical engineers play a central role in such industries as automotive (from the car chassis to its every subsystem—engine, transmission, sensors); aerospace (airplanes, aircraft engines, control systems for airplanes and spacecraft); biotechnology (implants, prosthetic devices, fluidic systems for pharmaceutical industries); computers and electronics (disk drives, printers, cooling systems, semiconductor tools); microelectromechanical systems, or MEMS (sensors, actuators, micropower generation); energy conversion (gas turbines, wind turbines, solar energy, fuel cells); environmental control (HVAC, air-conditioning, refrigeration, compressors); automation (robots, data and image acquisition, recognition, control); manufacturing (machining, machine tools, prototyping, microfabrication).

To put it simply, mechanical engineering deals with anything that moves, including the human body, a very complex machine. Mechanical engineers learn about materials, solid and fluid mechanics, thermodynamics, heat transfer, control, instrumentation, design, and manufacturing to understand mechanical systems. Specialized mechanical engineering subjects include biomechanics, cartilage-tissue engineering, energy conversion, laser-assisted materials processing, combustion, MEMS, microfluidic devices, fracture mechanics, nanomechanics, mechanisms, micropower generation, tribology (friction and wear), and vibrations. The American Society of Mechanical Engineers (ASME) currently lists 36 technical divisions, from advanced energy systems and aerospace engineering to solid-waste engineering and textile engineering.

The breadth of the mechanical engineering discipline allows students a variety of career options beyond some of the industries listed above. Regardless of the particular path they envision for themselves after they graduate, their education will have provided them with the creative thinking that allows them to design an exciting product or system, the analytical tools to achieve their design goals, the ability to overcome all constraints, and the teamwork needed to design, market, and produce a system. These valuable skills could also launch a career in medicine, law, consulting, management, banking, finance, and so on.

For those interested in applied scientific and mathematical aspects of the discipline, graduate study in mechanical engineering can lead to a career of research and teaching.