Archive for April, 2009

Importance of Car Electronics and Stability of In-Car Voltage

April 29, 2009
Electrical systems in our cars are interconnected to each other. To get perfect performance you need a good and harmony electrical circuit environment. For example, if you have a old and less efficient ignition circuit in your car, you will have very poor fuel consumption, low throttle response, misfiring problem, jerking gear shift, all problems may occurred due to a single defect in another electrical problem. So to maintain optimum electrical performance in your car, we need to have a very stable voltage environment. Here comes a new electronic device – MAXI POWER SYSTEM, a multi-purpose Voltage Stabilizer with built in Battery Doctor System and Interference Reducer System. Once you use MAXI POWER SYSTEM, your car is in best control by this product, it will solve small problems that due to unstable voltage during driving. What is more wonderful, it is so easy to installed, with just a plug into cigar-lighter socket, will activate this device. Unlike other fuel saving product, by adding chemical and tablets into the fuel tank, increase the risk of car damages.

Feature
MAXI POWER SYSTEM Voltage Stabilizer has the following three systems:
• Voltage Stabilizer System
• Interference Reducer System
• Battery Doctor System

Benefits
• Fuel saving
• Better RPM response
• Increase engine torque
• Engine power up
• Optimized all electronic devices in car

Advantages
• Faster throttle response, engine power up.
• Reduce car CPU noise signal, improve CPU reaction time, improve electronic efficiency.
• Smoother gear shift on automatic car.
• Improve engine power, better acceleration response, hence improve fuel saving.
• Maximize ignition efficiency, easier engine start.
• Prolong engine and electrical device life-span.
• Easy installation, totally DIY, the first choice for ladies drivers.
• Universal for all cars and motorcycles
• Reduce noise with built in noise filter, improve sound system performance.
• Equipped with double fuse protection, for better product life and safety.
• Faster RPM response, it gives you powerful acceleration even when your car’s air condition turn on to maximum load.
• Cleaner exhaust emission on HC and CO gas. So more environment friendly.
• Twelve (12) months Limited Product Warranty.

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Sensor-less Vector Control

April 22, 2009
This sensor-less vector control performs the vector control of the induction motor without use of the speed sensor. Conventionally, there has been the V/f control without the speed sensor. However, this sensor-less vector control provides the simple control feature of the V/f control and the high performance of the vector control. The following describes the features of the sensor-less vector control.

(1) Sensor installation and wiring construction are not required.
(2) This control is applicable to motors, in which the sensor cannot be installed, such as two-axis motors or super high-speed motors, and other motors, which require special sensors, such as explosion-proof motors.
(3) This vector control technology is used for parallel drive of multiple motors, which is difficult to control by the conventional vector control.
(4) This sensor-less vector control provides excellent stability and large start-up torque when compared to the V/f control.
(5) The torque can be limited, ensuring stable rapid acceleration and deceleration.

Normal and Reverse Winding Operations

April 22, 2009

Torque Control

April 22, 2009
In winding machines, the winding materials are controlled at a specified tension. Therefore, the host PLC calculates the torque (reference) to be output from the motor. Additionally, the drive unit controls to output a torque corresponding to this torque reference. Furthermore, operation is made with speed control when the winding is completed or winding of next materials is started.

On the other hand, if operation based on the torque reference sent from the host PLC continues in case of a fault, such as material breakage, overspeed may result. In such case, the control is automatically changed to the speed control. (Torque control with speed limit function) The following describes how to use the torque control for operation with normal rotation and positive torque.

Auto Field Weakening Control

April 22, 2009
Operation shown in Fig. (a) to make the magnetic flux constant is used for general operation method of the induction motor. Operation is performed with the magnetic flux and ID_REF made constant. At this time, the induced voltage is calculated by multiplying the speed by the magnetic flux. The voltage is then increased in proportion to the speed.

In the auto field weakening control, when operating at a higher speed, the induced voltage is controlled at a constant level based on the magnetic flux reference in inverse proportion to the speed feed back after the voltage has reached the rated voltage.
If the speed exceeds the start speed of the field weakening control, the induced voltage becomes constant and the motor output shows the constant output characteristics. (Fig. (b)).

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How does a lightning arrester work?

April 17, 2009
ANSWER I:
Lightning, is a form of visible discharge of electricity between rain clouds or between a rain cloud and the earth. The electric discharge is seen in the form of a brilliant arc, sometimes several kilometres long, stretching between the discharge points. How thunderclouds become charged is not fully understood, but most thunderclouds are negatively charged at the base and positively charged at the top. However formed, the negative charge at the base of the cloud induces a positive charge on the earth beneath it, which acts as the second plate of a huge capacitor.

When the electrical potential between two clouds or between a cloud and the earth reaches a sufficiently high value (about 10,000 V per cm or about 25,000 V per in), the air becomes ionized along a narrow path and a lightning flash results.
Many meteorologists believe that this is how a negative charge is carried to the ground and the total negative charge of the surface of the Earth is maintained.
The possibility of discharge is high on tall trees and buildings rather than to ground. Buildings are protected from lightning by metallic lightning rods extending to the ground from a point above the highest part of the roof. The conductor has a pointed edge on one side and the other side is connected to a long thick copper strip which runs down the building. The lower end of the strip is properly earthed. When lightning strikes it hits the rod and current flows down through the copper strip. These rods form a low-resistance path for the lightning discharge and prevent it from travelling through the structure itself.

ANSWER II:

The lightning arrestor protects the structure from damage by intercepting flashes of lightning and transmitting their current to the ground. Since lightning strikes tends to strike the highest object in the vicinity, the rod is placed at the apex of a tall structure. It is connected to the ground by low-resistance cables. In the case of a building, the soil is used as the ground, and on a ship, water is used. A lightning rod provides a cone of protection, which has a ground radius approximately, equal to its height above the ground.

Using Work Management Best Practices to Achieve Asset Optimization (6)

April 3, 2009
Stage Five: Asset Optimization

Asset optimization—the tying together of service, quality, performance, and cost—is the ultimate goal of any asset-intensive company. But to get there, companies must have progressed through the other four stages, putting in place the processes that will allow them to achieve this goal.
Once this groundwork is laid, they have all the resources and tools required to drive continuous improvement.

“As success is gained from the initial improvement efforts, organizations must institute a process of continuous improvement to guide the [EAM] process. Continuous improvement is driven by prioritized failure analysis that includes proactive identification, prioritization by risk, and action to eliminate the defect. The strategy and implementation is adjusted and refined, as necessary, to ensure progress.”
(Pennsylvania State University Applied Research Laboratory2 )

At this point, the foundation is firmly in place. Companies are now able to understand what areas
they need to focus on for greater improvement.

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Using Work Management Best Practices to Achieve Asset Optimization (5)

April 3, 2009
Stage Four: Best in Class

Once a company has established a culture of reliability and has put in place maintenance best practices to optimize asset utilization, it can begin to work toward becoming a best-in-class organization. What does it mean to be best in class? It means being able to maximize profit margins and asset availability. Just as importantly, it means being recognized as an industry leader.

Each industry has its own benchmarks to define what a best-in-class company looks like. PeopleSoft and PCA have identified just a few of the benchmarks that asset-intensive companies should measure themselves against (see below table).

To become best in class, companies must be able to measure themselves against benchmarks such as those shown in above table. They must have access not only to the raw data but also to the KPIs and management reports that allow them to translate data into actionable information. And, in the current environment of increasing regulatory control, Sarbanes-Oxley, and mounting financial and shareholder pressure, having the actionable information to continually improve performance levels is essential.

Using Work Management Best Practices to Achieve Asset Optimization (4)

April 3, 2009
Stage Three: Culture of Reliability

Once a company has the best practices in place to create proactive maintenance plans and schedules that are designed to maximize capacity and minimize cost, it is time to move to the next stage—creating a culture of reliability. This stage is critical for achieving asset optimization, but it cannot be attained by software alone.


It is at this point that companies can begin emphasizing a total productive maintenance (TPM) approach. TPM empowers employees who operate assets to take responsibility for these assets’ maintenance and performance. Because TPM depends on autonomous maintenance, equipment performance data, focused teamwork, leadership, training to improve skills, and knowledge and design for operability and maintainability, a successful implementation requires the foundation established in Stages One and Two.

Using Work Management Best Practices to Achieve Asset Optimization (3)

April 3, 2009
Stage Two: Proactive Maintenance

Proactive maintenance is of vital importance to asset-intensive companies. By performing preventive maintenance, companies are able to prevent problems with assets and minimize the risk of sudden failure. Firms are then in a better position to optimize asset availability, increase productivity, and reduce maintenance costs and capital outlays.


To perform preventive and predictive maintenance effectively, companies need to implement an
integrated solution that allows them to generate, store, and act on the data they need to support their maintenance programs. Best practices that facilitate proactive maintenance can be associated with:
• Equipment history tracking for capturing data about equipment that helps with making decisions about maintenance and eventual retirement.
• Preventive maintenance for developing maintenance plans that reflect calendar- or usagebased
schedules.
• Condition-based maintenance for continually monitoring physical attributes that collectively indicate the condition of an asset and using this information to perform maintenance only when factors indicate a potential problem.
• Reliability-centered maintenance for developing maintenance plans based on the reliability and criticality of various components of each piece of equipment.