When a power supply is listed as isolated, it is normally referring to input to output isolation. An isolated power supply is typically achieved by the use of a transformer. A non-isolated power supply is generally using a type of chip conversion.
When a multi-output power supply has power isolation between the outputs, it means there is an electronic barrier between outputs and not tied to a common ground.
The following explores input-to-output isolation and non-isolation.
Isolated power supplies provide a clear barrier across which dangerous voltages won’t pass, which provides safety. The disadvantage is low efficiency, and the package size is bigger than a non-isolated power supply due to the transformer needed for isolation.
A non-isolated power supply is usually >95 % efficient and more compact than an isolated one. The downside is, there is no isolation between the input and output. Non-isolated power supplies are commonly board-mounted near the load they drive and are referred to as point-of-load (POL) power supplies. They are usually downstream from an isolated power supply, which helps with safety concerns.
Typical applications that look for isolated power supplies are those that have to meet safety as well as system requirements. Often, medical devices require isolation between the input voltage and the output where the load can be a human. In contrast, some applications need non-isolated because of where it is being used, like lighting, appliances, and sensors.
Advanced Conversion Technology (ACT) has designed and manufactured both types of power supplies over the years for a variety of land, naval, and air applications. An example of our isolated power supply is the SW2512001-54. An example of a non-isolated ACT power supply is the SW2511001-28. Whatever you might need, contact ACT to see how we can best meet your power supply needs.