SMPSs can be used to step-down a supply voltage, just as linear supplies do. Unlike a linear regulator, however, an SMPS can also provide a step-up function and an inverted output function. Typical applications are given below.
Typical application for a ste-down switching regulator:
Generation of 5V for TTL-based circuits from a 12V battery (particularly suitable if the 12V battery has limited capacity, as switching regulators are far more efficient than linear regulators).
Typical application for a step-up switching regulator:
Generation of 25V from a 5V supply in an EPROM programmer.
Typical application for an inverting switching regulator:
Generation of a double-ended supply from a single-ended for OP-AMP.
Generation of a negative bias for MOS devices eg Dynamic RAMS.
The term switch mode regulator is used to describe a circuit which takes a DC input and provides a DC output of the same or opposite polarity, and of a lower or higher voltage. Switch Mode regulators use an inductor and there is no input to output regulation.
The term switch mode converter is used to describe a circuit which takes a DC input and provides a single or multiple DC outputs, again of same or opposite polarity and lower or higher voltage. Converters use a transformer and may provide input to output isolation.
The term Switch Mode Power Supply or SMPS is used to describe switch mode regulators and converters.
For more info pls visit http://www.hills2.u-net.com/electron/smps.htm
Function of motherboard:
Function: The motherboard is a printed circuit board (PCB) that contains and controls the components that are responsible for processing data.
Description: The motherboard contains the CPU, memory, and basic controllers for the system. Motherboards are often sold with a CPU. The motherboard has a Real-time clock (RTC), ROM BIOS, CMOS RAM, RAM sockets, bus slots for attaching devices to a bus, CPU socket(s) or slot(s), cache RAM slot or sockets, jumpers, keyboard controller, interrupts, internal connectors, and external connectors.
The bus architecture and type of components on it determine a computers performance. The motherboard with its ribbon cables, power supply, CPU, and RAM is designated as a "bare bones" system.
Clock: The motherboard contains a systems clock to synchronize the operation of the bus and other components. Jumpers on the motherboard allow a user to set different clock rates to work with the CPU. Other jumpers control other components on the motherboard.
386 motherboards have an extra slot to add a math coprocessor (ALU - arithmetic and logic unit). 486's and Pentiums have a math coprocessor (ALU) already built into the chip.
The motherboard determines: (info taken from Motherboard HomeWorld)
1.CPU type and speed
2.chipset (the specialized chips that control the memory, 3.cache, external buses, and some peripherals)
4.secondary cache type
5.types of slots: ISA, EISA, MCA, VESA local bus, or PCI slots
6.number of slots
7.type of memory (EDO, SDRAM, parity, ECC, etc.)
8.number of memory sockets and maximum memory
9.type of case and P/S
10.ROM (this will most certainly already be installed)
11.Plug and Play compatibility
12.type of keyboard connector
Plz refer to http://www.millbury.k12.ma.us/hs/techrepair/motherboard.html
Func of RAM:
In a nutshell, RAM is defined as Random Access Memory, which means that any byte or section of the memory can be accessed at any given time, verus say a tape drive which is sequential access memory since it must scroll to arrive at a section of the tape.
RAM functions using transistors. Currently the most common RAM is SDRAM or DDR RAM, DDR Ram is based off of SDRAM, SDRAM stands for Synchronous dynamic random access memory. This RAM uses transistors and capacitors. The capacitors are set to a voltage if they are to be a one, or they are cleared to no voltage if there is to be a 0. Since capacitors leak slowly, SDRAM must read and write every bit very often, which is called refreshing the RAM, this either fills the capacitor back to full, or keeps it at zero.
Processor: The name suggests all....