What is a switching-mode power supply?

What is a switching-mode power supply?

A power supply is a buffer circuit that provides power with the characteristics required by the load from a primary power source with characteristics incompatible with the load. It makes the load compatible with its power source.

Example: A power source might be the 60 Hz, single phase, 120 V ac power found in a home in the United States or the 50 Hz, single phase, 220 V ac found in the United Kingdom. The load might be a logic circuit in a personal computer that requires regulated 5 V dc power. The power supply is the circuit that makes the 120 V ac or 220 V ac power source and 5 V dc load compatible.A power supply is sometimes called a power converter and the process is called power conversion. It is also sometimes called a power conditioner and the process is called power conditioning. The Power Sources Manufacturers Association's (PSMA) Handbook of Standardized Terminology for the Power Sources Industry gives this definition of a power supply.

Power Supply -- A device for the conversion of available power of one set of characteristics to another set of characteristics to meet specified requirements. Typical application of power supplies include to convert raw input power to a controlled or stabilized voltage and/or current for the operation of electronic equipment.

Power supplies belong to the field of power electronics, the use of electronics for the control and conversion of electrical power. The IEEE Power Electronics Society provides a more formal definition of power electronics in their constitution.

Power Electronics -- This technology encompasses the effective use of electronic components, the application of circuit theory and design techniques, and the development of analytical tools toward efficient electronic conversion, control, and conditioning of electric power.

A switching-mode power supply is a power supply that provides the power supply function through low loss components such as capacitors, inductors, and transformers -- and the use of switches that are in one of two states, on or off. The advantage is that the switch dissipates very little power in either of these two states and power conversion can be accomplished with minimal power loss, which equates to high efficiency. The term switchmode was widely used for this type of power supply until Motorola, Inc., who used the trademark SWITCHMODE TM for products aimed at the switching-mode power supply market, started to enforce their trademark. Then more generic terms had to be found. I started using the term switching-mode power supply to avoid infringing on the trademark. Others used the term switching power supply, which seems to be the more popular term. PSMA does not define either switching-mode power supply or switching power supply, but does define switching regulator.

Switching Regulator -- A switching circuit that operates in a closed loop system to regulate the power supply output.

Application of Neural Networks in Control System

Application of Neural Networks in Control System

1. A method to use neural networks to control highly nonlinear system- "Neural

Networks for Self-Learning Control Systems." Feed-through, multilayered neural networks are used, and learning, via the back-propagation algorithm, is implemented to determine the neural network weights to first model the plant and then design the controller. First, a neural network emulator learns to identify the dynamic characteristics of the system. The controller, another multilayered network, then learns to control the emulator. The self-trained controller is then used to control the actual dynamic system. The learning continues as the emulator and controller improve as they track the physical process. The power of this approach is demonstrated by using the method to steer a trailer truck while backing up to a loading dock.

2. The control of mobile robots is the topic addressed - "Mobile Robot Control by a structured Hierarchical Neural Network." Neural networks are used to process data from many sensors for the real-time control of mobile robots and to provide the necessary learning and adaptation capabilities for responding to the environmental changes in real time. For this, a structured hierarchical neural network and its learning algorithm are used, and the network is divided into two parts connected with each other via short memory units. This approach is applied to several robots, which learn to interact and participate in a form of the cops-and-robbers game.

3. "Integrating Neural Networks and Knowledge-Based Systems for Intelligent Robotic Control," address the issues involved when integrating these quite distinct systems, which offer very different capabilities. To demonstrate the integration technique and the interaction of the two systems, a two-link robot manipulator is taught how to make tennis like swing. The rule based system first determines how to make a successful swing using rules alone. It then teaches a neural network to perform the task. The rule-based system continues to evaluate the neural network performance, and, if changes in the operating conditions make it necessary, it retrains the neural network.

4. Neural networks and back-propagation are proposed for sensor failure detection in "Use of Neural Networks for Sensor Failure Detection During the Operation of a Control System." The ability to reliably detect failures is essential if a certain degree of autonomy is to be attained. Process control systems are of main interest here. Backpropagation is used for sensor failure detection, and the algorithm is compared via simulations with other fault-detection algorithms.

5. In this article a new neural-network based cross-coupled control algorithm that integrates the cross-coupled control and neural network techniques together is presented. In this neural network based cross-coupled control system, fixed gain PID controller for each individual axis is replaced by a heuristic neural network learning controller the conventional cross-coupled controller is substituted by an efficient neural network cross-coupled controller. Experimental results show that the proposed new neural network based cross-coupled control scheme can be successfully applied to the precise circular tracking problem of a nonlinear uncertain linear motor X-Y table. It is also demonstrated that performance of the neural network based cross-coupled control scheme is superior to the conventional cross-coupled control scheme.

6. An intelligent welding robot system with visual sensors is developed in order to realize full automatic welding of thin mild steel plates including automatic seam tracking and automatic control of welding conditions. A system to detect the shape and dimension of molten pool using CCD camera and a penetration control system using Neural Network in TIG arc welding are investigated. In order to characterize the shape of molten pool, width, length and area of the molten pool were measured, and are used to form the contour of the molten pool as shape parameters. These parameters are input to the neural network, which outputs optimum welding condition to control the penetration of the molten pool. Consequently, if unexpected change occurs in welding conditions, such as root gap, welding speed and so on, the welding system can optimally control the welding condition. The constructed system is tested and found to be effective for penetration control in automatic butt welding of thin mild steel plates.

7. Neural Networks are increasingly finding engineering applications. Most early applications were in the areas of pattern recognition and modeling. This paper shows how neural network models can be used in process control. Two separate techniques are

Illustrated, each with a specific example application. One involves using the network

Itself as the inverse model, by fixing the neural network weights and training on the inputs to give the desired output pattern. The other suggests using the pattern recognition ability of a neural network to identify an appropriate lower order linear model to use for controller design.

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PC-Telephone

PC-Telephone is a powerful communications software application that enables you to exploit the full communications potential of the Internet and public telephone networks (ISDN/PSTN).

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License:	Freeware
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Primary Connectors

Primary Connectors found on the motherboard are:

Power - A 20 pin connector accepts a plug from the power supply. This plug carry DC power to all the circuits on the motherboard.

Keyboard - A Mini-din 6-pin (round) connector found at the back of the motherboard is where the keyboard plugs in.

Mouse - A Mini-din 6-pin connector found next to the keyboard connector is where the where the mouse plugs in.

Display - This connector is not integrated into the motherboard but is included in this list since its function is absolutely necessary. It is a 15-pin, D-shell type connector found on a video card that plugs into the AGP connector of the motherboard (see below).

IDE - stands for Integrated Drive Electronics. These are 40 pin connectors that provide a place to connect the ribbon cables from the drives (hard and CD/DVD). All data between the motherboard and the drives is carried in these cables. They are not accessible unless the PC cover is removed.

FDD connector - it is similar in function to the IDE connector. It is a 34 pin ribbon connector that carries data between the motherboard and any floppy drive installed in the PC. Not accessible with PC cover on.

DRAM - Dynamic Random Access Memory connectors for SIMM and DIMM type memory modules. Not accessible with chassis cover on.

Serial Connectors

• Standard Serial Connector - This connector has been around in PCs since they first appeared. It was originally located on ISA expansion type cards (see below). Today it is an integral part of newer motherboards. It is a 9- pin, D-shell connector that allows you to connect external devices with serial ports to your PC. The maximum data rate is 115 KB/s.
  
  
• USB - Universal Serial Bus This is a relatively new serial bus. Originally specified as low speed, 1.2 Mb/s, it was enhanced to full speed, 12Mb/s. The latest version 2.0 is specified as high speed, 400 MB/s.
  
  Someday USB will completely replace the standard serial connector that has been the workhorse serial port in earlier PCs. USB is now a standard connector on all new motherboards.
  
  Unlike serial and parallel ports, the USB port is designed to power devices connected to it. The devices must be low power devices and must be able to reduce their current draw to less than 0.5uAmps when commanded to do so by the PC.
  
  

Parallel Connectors

• Centronix or Standard Parallel - This connector has been around in PCs since they first appeared. It has 37-pins and is now integrated on new motherboards. It is usually used to connect your printer to the PC and moves data at about 1MB/s.
  
  
• SCSI - Small Computer System Interface moves data at a maximum of up to 80Mb/s. It not integrated into most PC motherboards. It can be added to a PC as an Expansion card (see below). Some printers and hard disk drives use SCSI interfaces.
  

Expansion Card Connectors - The CPU connects to expansion card connectors through one of the chip set ICs mentioned above. They are located on the motherboard near the rear of the PC. These connectors allow special function cards to plug into and work with the PC.

Before motherboards integrated the serial and centronix connectors they were found on expansion boards that plugged into ISA slots.

Most PCs have the following expansion connector types:

• ISA - Industry Standard Architecture connectors have been around since 1980 and first appeared in the IBM XT PC. This type of slot still appears on some newer motherboards so that older expansion boards can still be used. However, many motherboards no longer have ISA connectors on them.
  
  
• PCI - Peripheral Component Interconnect is a newer and faster interface that accepts all expansion cards that have a PCI interface.
  
  
• AGP - Accelerated Graphics Port is a connector that is designed to work with video cards. Your video display plugs into and is controlled by one of these video cards. Many modern video cards offer enhanced 3D-graphics and fast, full motion video.

For learning parallel port programming visit http://www.codeproject.com

The 8051 is an 8-bit microprocessor originally designed in the 1980's by Intel that has gained great popularity since its introduction. Its standard form includes several standard on-chip peripherals, including timers, counters, and UART's, plus 4kbytes of on-chip program memory and 128 bytes (note: bytes, not Kbytes) of data memory, making single-chip implementations possible. Its hundreds of derivatives, manufactured by several different companies (like Philips) include even more on-chip peripherals, such as analog-digital converters, pulse-width modulators, I2C bus interfaces, etc. Costing only a few dollars per IC, the 8051 is estimated to be used in a large percentage (maybe 1/2?) all embedded system products.
The 8051 memory architecture includes 128 bytes of data memory that are accessible directly by its instructions. A 32-byte segment of this 128 byte memory block is bit addressable by a subset of the 8051 instructions, namely the bit-instructions. External memory of up to 64 Kbytes is accessable by a special "movx" instruction. Up to 4 Kbytes of program instructions can be stored in the internal memory of the 8051, or the 8051 can be configured to use up to 64 Kbytes of external program memory The majority of the 8051's instructions are executed within 12 clock cycles.
We developed a VHDL synthesizable model of the 8051 and a C++ based 8051 instruction-set simulator, both found below, on which we've based some research directions. One of those directions is a tuning environment, also found below, to assist a designer who wants to modify the 8051 architecture to be more power efficient for a particular program You see, a particular 8051 will probably execute the same program over and over for its lifetime, so it would be nice to orient the 8051 towards that program. We've also developed some new architectural features that can be used to lower the power of an 8051, which will appear on this page in the future.