Electrical Power Supply
The Requirement For Power Supplies
Batteries could be used to supply the power for almost all electronic equipment if it were not for the high cost of the energy they provide compared to commercial power lines. Power supplies were once called battery eliminators, an apt name because they made it possible to use less expensive energy from a commercial power line where it is available. Batteries are still an appropriate and economical choice for portable equipment having modest energy requirements.
Additional topics
Science EncyclopediaScience & Philosophy: Dysprosium to Electrophoresis - Electrophoretic TheoryElectrical Power Supply - The Requirement For Power Supplies, Plug-in Power Supplies, Power Supply Voltage Regulation, Voltage-regulation Circuits - Batteries as power supplies, Power supplies and load interaction, Simple transformer power supplies