OBD-II codes consist of a number of parts. Here is a sample OBD2

OBD-II codes consist of a number of parts. Here is a sample OBD2 code:

P0171

Here is a breakdown of what each digit of the code means:

First Character - System

The first character identifies identifies the system related to the trouble code.

• P = Powertrain
• B = Body
• C = Chassis
• U = Undefined

Second Digit - Code Type

The second digit identifies whether the code is a generic code (same on all OBD-II equpped vehicles), or a manufacturer specific code.

• 0 = Generic (this is the digit zero -- not the letter "O")
• 1 = Enhanced (manufacturer specific)

Third Digit - Sub-System

The third digit denotes the type of sub-system that pertains to the code

• 1 = Emission Management (Fuel or Air)
• 2 = Injector Circuit (Fuel or Air)
• 3 = Ignition or Misfire
• 4 = Emission Control
• 5 = Vehicle Speed & Idle Control
• 6 = Computer & Output Circuit
• 7 = Transmission
• 8 = Transmission
• 9 = SAE Reserved
• 0 = SAE Reserved

Fourth and Fifth Digits

These digits, along with the others, are variable, and relate to a particular problem. For example,a P0171 code means P0171 - System Too Lean (Bank 1). To lookup your particular code, visit our OBD Trouble Codes section.

A five-gear space rocket engine

A five-gear space rocket engine

Georgia Tech researchers have had a brilliant idea. Rocket engines used today to launch satellites run at maximum exhaust velocity until they reach orbit. For a car, this would be analog to stay all the time in first gear. So they have designed a new space rocket which works as it has a five-gear transmission system. This space engine uses 40 percent less fuel than current ones by running on solar power while in space and by fine-tuning exhaust velocity. But as it was designed with funds from the U.S. Air Force, military applications will be ready before civilian ones.

This technology has been developed by a team led by Mitchell Walker, an assistant professor in the Aerospace Engineering Department and leader of the High-Power Electric Propulsion Laboratory.

Before going further, below is a diagram showing how this new rocket engine "uses a novel electric and magnetic field design that helps better control the exhaust particles. Ground control units can then exercise this control remotely to conserve fuel" (Credit: Mitchell Walker's team, Georgia Tech). Here is a link to a larger version.

Here is how this new engine could pave the way "for deep space missions, lower launch costs and more payload in orbit."

The efficient satellite engine uses up to 40 percent less fuel by running on solar power while in space and by fine-tuning exhaust velocity. Satellites using the Georgia Tech engine to blast off can carry more payload thanks to the mass freed up by the smaller amount of fuel needed for the trip into orbit. Or, if engineers wanted to use the reduced fuel load another way, the satellite could be launched more cheaply by using a smaller launch vehicle.

And here is how the engine will shift from first to fifth gear.

The new Georgia Tech engine allows ground control units to adjust the engine�s operating gear based on the immediate propulsive need of the satellite. The engine operates in first gear to maximize acceleration during orbit transfers and then shifts to fifth gear once in the desired orbit. This allows the engine to burn at full capacity only during key moments and conserve fuel.

Finally, as Walker's lab doesn't contain many details about this military-funded project, here are some tidbits of information on how the engine works.

The Georgia Tech engine operates with an efficient ion propulsion system. Xenon (a noble gas) atoms are injected into the discharge chamber. The atoms are ionized, (electrons are stripped from their outer shell), which forms xenon ions. The light electrons are constrained by the magnetic field while the heavy ions are accelerated out into space by an electric field, propelling the satellite to high speeds.

Sources: Georgia Institute of Technology news release, via The Engineer Online, UK, February 22, 2007; and various other websites

You'll find related stories by following the links below.

• Aerospace
  
• Engineering
  
• Military Applications
  
• Innovation
  
• Space
  

What is a Stirling Engine

A Depiction of a Dish Stirling On Sun→ On September 27, 1816, Robert Stirling applied for a patent for his Economiser at the Chancery in Edinburgh, Scotland. By trade, Robert Stirling was actually a minister in the Church of Scotland and he continued to give services until he was eighty-six years old. But, in his spare time, he built heat engines in his home workshop. Lord Kelvin used one of the working models during some of his university classes. In 1850 the simple and elegant dynamics of the engine were first explained by Professor McQuorne Rankine. Approximately one hundred years later, the term "Stirling engine" was coined by Rolf Meijer in order to describe all types of closed cycle regenerative gas engines.

Original engine developed in 1816		Today, Stirling engines are used in some very specialized applications, like in submarines or auxiliary power generators, where quiet operation is important. Stirling engines are unique heat engines because their theoretical efficiency is nearly equal to their theoretical maximum efficiency, known as the Carnot Cycle efficiency. Stirling engines are powered by the expansion of a gas when heated, followed by the compression of the gas when cooled. The Stirling engine contains a fixed amount of gas which is transferred back and forth between a "cold" and and a "hot" end. The "displacer piston" moves the gas between the two ends and the "power piston " changes the internal volume as the gas expands and contracts.
Automotive Stirling Engine		The gasses used inside a Stirling engine never leave the engine. There are no exhaust valves that vent high-pressure gasses, as in a gasoline or diesel engine, and there are no explosions taking place. Because of this, Stirling engines are very quiet. The Stirling cycle uses an external heat source, which could be anything from gasoline to solar energy to the heat produced by decaying plants. No combustion takes place inside the cylinders of the engine.
Solar Stirling Engine		The SES Solar Dish Stirling technology is well beyond the research and development stage, with more than 20 years of recorded operating history.  The equipment is well characterized with over 25,000 hours of on-sun time.  Since 1984, the Company's solar dish Stirling equipment has held the world's efficiency record for converting solar energy into grid-quality electricity.   SES has teamed with the U.S. Department of Energy and Sun-Labs (NREL and Sandia National Laboratories) to endurance test and commercialize the SES solar Stirling system.
Click here to view a time-lapse video of the dish on-sun. (Windows Media File)

Gears Rotary Engine

Code of Author

The present invention, whose publication date is detailed above, it is liberated by the author's desire being able to use for any study or application, included the development and commercialization of the same, and alone subjected to the conservation of the invention name and to the author name, and in the case of being marketed, to the compensation to its author to testimonial title of 1% of the marketed value in concept of use and economic exploit of inventions.

Description and elements.

The present system in a motor of rotation of very simple structure consists, in which, systems of revolving gears inside a shell are used as base that serves at the same time as explosion shell.
As I have said, its structure is so simple that it is enough a simple look to the descriptive drawing to understand its basic operation.
The main elements of the motor are:
--Shell that contains the support gears (P) and the rotor gear (rotor). Likewise this shell forms one or two holes or lateral chambers where the explosion or combustion of gases that impel the rotor is carried out.
--A valve (V) of entrance of the compressed air for each explosion chamber, which will close when the explosion takes place and during the time that there is high pressure in the chamber.
--Injector/s of combustible.
--Heating and/or spark plugs to facilitate the combustion or explosion of the combustible gases.
--Besides we have the entrance of the compressed air and the exits or escapes (S) of the combustion gases.

Operation.

This rotation motor can work as explosion or combustion motor depending on the different parameters that we apply, as pressure of the compressed air of entrance, of the applied combustible, etc.
The operation, for example for the combustion, it is the following one:
The compressed air impels and opens the entrance valve (V) and it begins of filling the combustion chamber. When the chamber is full with air (or during its filled) the combustible is injected mixing with the air, and so, the combustion takes place (helping by heaters or spark plugs if it is necessary).
The combustion of gases produces a great pressure inside the chamber, which closes the valves of combustible and injector and this pressure makes rotate the rotor.
When the turning rotor expels the gases and the pressure get lower in the chamber, the valve (V) opens up again and the cycle goes repeating it.
As you can see, with alone an appropriate mechanical adjustment, you can get that the motor rotates automatically (turbine type) being managed in its turn with the contribution of the appropriate quantity of fuel only. The situation of the injector of fuel and the heaters or spark plugs and their possible coordination with the turn motor depend on the ignition type and pressure that we use.
The appropriate synchronization of the injector aperture, which can be regulated with the rotor turning, is another consideration to take in mind.
Likewise it can be convenient to put in the air compressor a valve of return between the high pressure of exit and the entrance at the same one with object of impeding some too high pressures to the motor entrance or any blockade due to this pressure.

As we see, to get the rotor turn we use the principle of the pulley, in which the force is applied alone on a lateral of the same one (rotor) to get the lever effect on the rotor axis.

Pieces
Lateral view of a motor module

---

Compressor of air.

As we see this motor needs have compressed air for its work.
So as the diversity of compressors it is very extensive, it can use the one that the maker wants.
Nevertheless, as a compressor is required, I give my model that has similar principles to those of the motor.
As we can see in the drawing, this model in a central gear and several satellite gears that make of compressors of air when rotating consists. In this model you can adjust the different dimensions and parameters as they are the number of gears, longitude of battle of the compressor, speed of turn of the gears, etc. to obtain the flow and compression of air that is required.

Dimensions and characteristics

Motor modules ---------------Compressor

According to my calculation, this motor type would be very compact and of low dimensions. An equivalent motor to a cylinder capacity (flow of air by two rotor turns) of 8000 c/c. with two motor modules and four combustion chambers, it could have dimensions next to 20 cm. of diameter for 25 cm. long, including compressor and motor only.
On the other hand, this model can have till four times more combustions per time unit (in two modules with four chambers) than the courrent ones, and so, it is possible to get much power in smaller motors.

Uses

As we can see this motor type can transforms the expansion force of gases in rotational movement, so this way, this model can be used so much in explosion and combustion engines as in any other type of chemical reaction that produces emission of gases, which can be used for the rotor turn.
--In the same sense, it is possible the use of this gears system in method of transmission by means of liquid or gasses, which go from an impulse pump until the rotors in the wheels of the automobiles. In this case the change power-speed is gotten by the load in the pump of impulse, as it is exposed in my patent on this question: Hydraulic transmission

Other uses

This system of gears that is used for this rotary engine can also be used for other forms of getting rotational movements by means of pressure.
For example, it could be useful in the electric power production for pressure in water, because although its yield for time would be smaller than in turbines, however, its yield for volume of water is very bigger for what can be used when the water is scarce.