A DC power supply typically takes the AC power from a wall outlet and converts it into a DC voltage. This direct current (DC) is then used to run everyday electronic devices, circuits, or components such as your cell phone and computer.

DC power supplies come in many types and sizes, offering different voltage levels, current capacities, and power ratings depending on the application.

A variable DC power supply lets you adjust the output voltage and current as needed, typically with set screws or potentiometers that require some sort of tool.

An adjustable DC power supply is similar to a variable one. It allows users to manually change the voltage and current settings, typically using knobs, dials, or digital controls. It’s a great tool for engineers and technicians working with multiple devices that need different power levels.

Difference Between Adjustable, Variable, and Programmable DC Power Supplies

• Adjustable/Variable: Usually manually controlled via knobs, buttons or set screws and trim potentiometers.
  
• Programmable: Controlled through software, interfaces, or automation systems. They allow precise settings, remote control, and repeatable test setups—ideal for advanced or automated applications.

DC power supplies are essential when your device or circuit requires a constant, stable voltage or current to operate correctly. They are widely used in testing labs, product development, electronics servicing, and more.

A converter typically refers to an electronic device that takes AC energy and converts it into DC energy. For example, your cell phone and laptop all utilize a converter that takes the AC energy from the wall outlet and converts it to DC.

The opposite is true for an inverter, which takes AC energy and turns it into DC energy with an example being what is used to take solar panel energy and put it back onto the grid in your house.

It depends on your application:

• Linear power supplies are quieter and better for sensitive analog work.
• Switching power supplies are lighter, more efficient, and better for high-power or portable applications. Modern switching designs have significantly improved in terms of noise performance.

Transient response measures how quickly and accurately a power supply reacts to sudden changes in load. A good transient response ensures your supply can handle varying demands without affecting performance or stability.

Slew rate refers to how fast the DC output can rise or fall when adjusted. It's influenced by internal components like capacitors and the energy demand of the connected device. A higher slew rate means quicker response time and slew can be used for a number of parameters such as voltage, current, power and resistance.

Load regulation indicates how much the output voltage changes when the connected device (load) draws more or less current. A high-quality power supply maintains a steady voltage, even when load conditions vary.

Line regulation describes how stable the output voltage stays when the AC input voltage fluctuates. A well-designed supply compensates for these changes and delivers consistent performance.

Stability refers to how much the output voltage or current drifts over time. It’s often measured in parts per million (ppm). Good long-term stability is important for precision testing or long-duration experiments.

Start by knowing your voltage, current, and power requirements. Then consider:

• Linear vs. switching type
• Precision and stability
• Manual vs. programmable control
• Size, efficiency, and cooling
• Safety features and ease of use

Choosing the right model ensures reliability and saves time during setup and operation.

Sorensen, a brand by AMETEK Programmable Power, offers a wide range of reliable DC power supplies—ideal for everything from lab testing to industrial use. Power levels range from 30 watts to 650 kilowatts, with options to scale up to 1.3 megawatts using parallel configurations.