A power supply is an electrical device that supplies electric power to an electrical load. The primary function of a power supply is to convert electric current from a source to the correct voltage, current, and frequency to power the load. As a result, power supplies are sometimes referred to as electric power converters. Some power supplies are separate standalone pieces of equipment, while others are built into the load appliances that they power. Examples of the latter include power supplies found in desktop computers and consumer electronics devices.
Other functions that power supplies may perform include limiting the current drawn by the load to safe levels, shutting off the current in the event of an electrical fault, power conditioning to prevent electronic noise or voltage surges on the input from reaching the load, power-factor correction, and storing energy so it can continue to power the load in the event of a temporary interruption in the source power
Given that the converter of interest is an AC/DC converter, the input is naturally from an AC power supply. Fortunately, the AC power for homes and offices is governed by established nominal voltages. While in Japan it is 100VAC, worldwide we must address at least a range encompassing 100VAC to 240VAC. Moreover, since these numbers are nominal values, including tolerances, in many cases a lower limit of -15%, which is 85VAC, and an upper limit of +10%, or 264VAC may have to be accommodated.
Since in some countries electrical power is poorly regulated or delivered, establishing adequate tolerances requires considerable experience and an understanding of the actual conditions that prevail in a given country. In a nutshell, the input voltage range for the power supply device being designed is determined by the conditions in the country to which the systems are shipped incorporating the power supply device.
The output voltage from the AC/DC converter must be set to the DC voltage required by the system and the circuit board for which the converter is intended. In the case of an industrial device, for example, common standard voltages such as 24DC and 12DC are predominant. Nowadays, however, it is not unusual that the converter output voltage is set to 5VCD, 3.3VDC, and other direct-drive voltages. At any rate, a ±5% accuracy requirement must be met by output voltages, subject to the requirements imposed by the particular device to which power is supplied. In the design process, the parts and methods to meet the required voltage accuracy need to be evaluated.
Power supplies are a fundamental component of many electronic devices and therefore used in a diverse range of applications. This list is a small sample of the many applications of power supplies.
Source : Wikipedia, Rohm, Kupandu
Home / Contact Us / Brand / About Us