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Archive for the ‘Dc Power Supply’ Category

The DC Power Supply is a rather fundamental electronic device, however there are hundreds of DC Power Supply products on the market from dozen of manufacturers. Narrowing down the best product for your application and budget can be a daunting task. This article addresses DC Power Supply differentiators, functions and the applications they are best suited for. The article’s focus is DC Power Supplies used by engineers, manufacturers, quality professionals and electronic hobbyists for the purposes of R&D, manufacturing and testing.

Power Supplies can range in price from to ,000 and the cost is often directly proportional to the amount of power the device outputs. The primary function of a power supply is to regulate output voltage and current. It takes an input power and regulates the output power as to enforce a constant voltage and current. In the case of DC Power Supplies, the input power is converted from alternating current (AC) to direct current (DC). There are two basic types of regulated DC Power Supplies: Linear and Switching.

Linear power supplies can never output a higher voltage than the input source. In theory, a linear power supply that is driven by typical 110V wall outlet could only output 110V, assuming the device were 100% efficient. Realistically, no power supply is 100% efficient because power conversion always results in energy loss, usually in the form of heat dissipation. Therefore, linear power supplies usually output voltage that is significantly less than the input.

Power Supplies can be divided into two types for electronic devices, linear and switching power supplies. A switching mode power supply has the same rating as a Linear Power Supply but will be a lot more complex and usually Switching Mode Power Supplies are smaller. A Linear Power Supply is used for high current devices. They tend to be a lot bigger and bulkier than the Switching Mode Power Supply and a lot simpler in design.

The drive for smaller power supplies goes hand in hand with a need for greater efficiency. There’s a direct relationship here because the smaller the power unit, the smaller the area available for dissipating heat through conduction and convection. Through both measurement and calculation, XP Power has developed a guide to the maximum power loss that can be tolerated for a given size of power supply, based on using convection cooling.

This is the loss that keeps all components in the unit operating within their temperature ratings. Of course, forced-air cooling can have a big impact, however, in many applications, forced-air cooling is to be avoided, not least because adding a fan to a power supply inevitably decreases its reliability, adds cost, creates noise, and introduces a maintenance headache.

The most important thing to remember when investing in a power supply is that efficiency is affected by the way in which the product is operated and the environment in which it finds itself.

As a result, power supply efficiency is usually specified based on the operating conditions that are most favourable to the figure concerned, for example, at maximum rated load. Whilst economic necessity will mean that you are unlikely to specify a power supply rated at much more power than you need, it could be that the maximum rating is only needed for a relatively small proportion of the unit’s operating time in your application. For the rest of the time, it will be operating below full load, and efficiency is likely to be much lower than the headline figure.

Ups Power Solutions: an Innovative Solution of Power Supply

UPS: The Basics

UPS is an acronym for the term Uninterrupted Power Supply. UPS Power Solutions are basically used to provide battery on electrical power failure or unacceptable voltage level loss. Small UPS systems meant for offering power for a few minutes or hours while larger UPS systems have the capacity to hold the battery backup for several hours. In comprehensive terms UPS is a power supply unit that provides power to a computer in the event of power failure or power loss. Different UPS systems provide power for different duration of time depending upon the equipment used.

UPS: The Mechanism

Generally UPS system used in UPS Power Solutions ,transmit the entire electric current acknowledged from the outlet to the electric equipments and only toggle to provide power from the battery when a power hitch is detected in the utility power. This entire process takes several milliseconds, during which time the power inverter starts supplying electric current from the battery to the device, electricity is needed for.

UPS: The Types

1. Standby UPS: This UPS is called standby UPS as it only starts when the power fails. The major benefits it offers to the customers are high efficiency, small size, and low cost and elegant design. With right filter and gush circuitry, these systems can also supply ample noise filtration and surge control.

2. Line Interactive UPS: Line Interactive UPS design usually accommodates a tap-changing transformer that adds voltage regulation by adjusting transformer taps as the input voltage varies. Voltage regulation is an imperative attribute when short voltage situation subsists.

DC Regulated Power Supply – How To Use It To Find Out Shorted Components In Main Board

Quite often whenever electronic equipment don’t function or work, we would immediately suspect a faulty switch mode power supply. But do you know that defective or shorted components in the motherboard or main board could cause the power supply to stop working too?

Switch mode power supply (SMPS) are designed so efficiently that whenever there is any short circuit occur in the main board the power supply would shut itself off and totally stop working. If you have no experience about troubleshooting switch mode power supply, you may think that the power supply have problem where in fact the main board is the real cause of no power problem.

Switch mode power supply have a current sense circuit (if you look at UC3842 PWM IC pin 3, it stated I-sense which mean current sense) and if there is short circuit in the secondary side (either in secondary diodes or main board), the current drawn would be increase and this will lead the PWM IC to stop generating output to the power fet and thus the power supply would shut down. All this happen in a split of seconds and you do not have the chance to know if there are output voltages at the secondary side.

Some older design of SMPS power supply do not use the PWM IC, but it do have the circuit to detect over current drawn and shut itself down whenever it detects a shorted component in the secondary side. One good example was the power supply used in printer. Printers usually have two boards; one was the power supply while the other was main board. If there is any short circuit in the main board, the power supply would not work. In order to isolate at where the problem is, one must remove the connector from the power supply board. Once the supply connector to the main board was removed, you can now switch on the printer and check if there is any voltages present at the power supply connector.