The R1011B DC Power Supply provides a highly filtered, voltage regulated and current limited power source for servicing all types of solid state communications equipment, from low power portable receivers to high power mobile transceivers. The output voltage of 0-40 V is available in two ranges: 0-20 V or 0-40 V: and is continuously adjustable in either range. The output current is available in three ranges: 0-5A, 0-20A, or 0- 40A; and provides up to 30A continuously or up to 40A intermittently, The low ripple content of the output eliminates the need for external filtering. A solid state, pulse-width modulated switching type voltage regulator maintains output voltage stability under sharply varying load con- ditions, such as where a high power transmitter is keyed- up. This excellent stability allows the Power Supply to be connected directly to the load equipment eliminating the need for Power Supply operation as a battery charger, with an automotive type battery. (This mode of operation is often required when using other high current power supplies.