500W Powerex VA Power Supply 500W Powerex VA Power Supply A power supply is an electrical device that supplies electric power to an electrical load. The main purpose of it to convert electric current from a source to the correct voltage, current, and frequency to power the load. 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 (uninterruptible power supply). All have a power input connection. Which receives energy in the form of electric current from a source. And one or more power output or rail connections that deliver current to the load. The source power may come from the electric power grid. Such as an electrical outlet, energy storage devices such as batteries or fuel cells, generators or alternators. Solar power converters, or another power supply. Some power supplies have other types of inputs and outputs as well, for functions such as external monitoring and control. Moreover,. So,.