An AC powered unregulated power supply usually uses a transformer to convert the voltage from the wall outlet (mains) to a different, nowadays usually lower, voltage. If it is used to produce DC, a rectifier is used to convert alternating voltage to a pulsating direct voltage, followed by a filter, comprising one or more capacitors, resistors, and sometimes inductors, to filter out (smooth) most of the pulsation. A small remaining unwanted alternating voltage component at mains or twice mains power frequency (depending upon whether half- or full-wave rectification is used)-ripple-is unavoidably superimposed on the direct output voltage.

B&K Precision

B&K Precision offers a full range of quality power supplies for a variety of applications and environments such as education, design, service, maintenance, and manufacturing. From small benchtop power supplies for the hobbyist, student, or for low-powered applications, to high-powered, ATE-ready, rack-mountable power supplies, B&K Precision's power supplies provide a wide range solutions for both AC or DC measurement and testing. B&K Precision's power supply families cover basic to high performance, 30 W to 5100 W, single or multiple outputs, programmable and non-programmable, linear, switching, mixed mode, multi range (auto), dual range, as well as support for all industry standard computer interfaces such as USB, GPIB, and LAN.

Kepco Inc.

Kepco, an ISO 9001:2008 company, has been making electronic power supplies, both modular and instrument type, since 1946. Kepco's power supplies comply with all international safety EMI and EMC directives and most Kepco power supplies are CE marked.

Keysight Technologies Inc.

Power Supply Overview: Single- & multiple-output DC power supplies, system power supplies, solar array simulators. Keysight has the DC power supply to meet your needs.

TDK-Lambda Americas Inc.

Genesys Series Programmable DC Power Supplies 750W ~ 2400W Model name Features Highest power density 2400W available in 1U size. Output voltage up to 600V, Output current up to 400A. Built in RS323/RS485 Interface (optional GPIB) Miniaturization with heat dissipation design.