Power Supply Units

DC power supply provides the required level of DC power to the load using an AC supply at the input. Input transformer is used to transform the incoming line voltage down to the required level for the power supply. Typically the input transformer provides a step down function. The advantage of the DC supply is greater efficiency because the switching transistor dissipates little power when acting as a switch. Other advantages include smaller size and lighter weight from the elimination of heavy line-frequency transformers, and lower heat generation due to higher efficiency.