Tag Archives: SMPS

What Is Switch Mode Power Supply

Switch Mode Power Supply

Switch Mode Power Supply

Every electrical or electronic device needs power for work and the computer is not exception to it. Computers, too, have a particularly designed power supply component known as Switch Mode Power Supply (SMPS). SMPS converts raw input power to controlled voltage and current for the operation of various components of the computer. SMPS uses switches for high efficiency. The primary function of SMPS is to convert the alternating current (AC) power available in homes into direct current (DC) required for a computer system. In desktop computers, a metal box found in the corner of the CPU case supplies
power to various components in the CPU box. The power supply converts 115-230 volt AC into DC that is required for computer components to work.

The terms such as voltage, AC, DC, etc., are closely associated with the power supply or SMPS. Voltage is an electric potential difference between two points and is measured in volts. AC stands for alternating current. It is an electric
current whose magnitude and direction vary cyclically. DC stands for direct current. It is considered as the constant flow of electrons in a single direction from low to high potential. Computers use DC power. Because of the advantage of alternating current over direct current in transforming and transmission, electric power distribution today is nearly everywhere alternating current.

The SMPS or power supply of a computer comes in different form factor styles. The form factor refers to the physical dimensions of a component. The form factor of the power supply must match with the form factor of the computer case into which the SMPS is inserted. There are various industry standard form factors available. Some of the commonly used form factors with their characteristics are given below:
1. LPX
2. ATX
3. SFX

The LPX form factor style power supply has exactly the same motherboard and disk drive connectors as the previous standard power supply form factors. LPX form factor power supply differs in its reduced size that allows building much smaller and consumer oriented PCs. Due to their small size, they can be put into almost every type of computer cases.

The ATX form factor is developed by Intel in 1995. ATX is similar to LPX in physical dimensions. The difference between the two is that the power pass through-outlet for the monitor has been removed from ATX. Another difference is that in ATX, the cooling fan is mounted along the inner side of the power supply. With this kind of arrangement, the fan draws air in from the
back of the chassis and blows it inside across the motherboard.

The SFX form factor style power supply is 100 mm wide, 125 mm deep, and 63.5 mm in height. It includes a 60 mm power supply fan for cooling. The main SFX motherboard connector is in the same shape and size as the ATX connector. The one difference here is that the SFX power supply specification does not support the -5V compatibility voltage and, therefore, should not be used with motherboards that have ISA slots.

See also:

Computer Smps Service Manual Detailed Information On Finding Gold Quality Smps Repair Manual

If you need a computer SMPS service manual, then allow me to share with you a few tips to ensure you get only the best quality manual.

I know its not easy to find a high-quality manual for servicing and repairing switch mode power supplies or SMPS. Actually, Ive downloaded a couple of PDF repair guides but they werent much help.

Here are some negative things about those guides

(1) The instructions were difficult to understand.

(2) The instructions were not organized in a proper manner. For example, basic chapters like understanding SMPS components and how to read schematic diagrams were placed at the END of the manual!

And worst of all

(3) Those computer SMPS service manuals did not have any step-by-step photo instructions!

Now Im going to tell you how I discovered the best guide on troubleshooting and fixing all types of SMPS not just computer SMPS.

The first thing I did was visit an online forum that is related to the subject of electronics. Believe me, youll find many seasoned technicians hanging around electronics forums.

Some are very friendly and would be willing to offer valuable tips, advice and resources. In fact, I found a very high quality computer SMPS service manual thru recommendation from a respected forum member.

So you should definitely seek help from online forums. If you post your questions properly, youd great answers from forum members including links to the best resources on repairing SMPS.

A couple more tips

Make sure you get a SMPS repair guide that teaches you everything in a step-by-step fashion AND provides in-depth information on safety guidelines, tools and test equipment to conduct proper SMPS repair and troubleshooting.

Some SMPS reparation manuals do not provide such information which I think is a shame because topics on safety and testing tools are absolutely crucial.

LastlyAnd this is very, very important!

Try obtaining a manual that includes PERSONAL email consultation support from technicians who are experts in repairing SMPS.

If you have personal email access to an expert, then I guarantee youll have very little trouble repairing faulty switch mode power supplies.

Think about it, any problems you may have can easily be addressed by sending an email to the expert. Now thats POWERFUL!