What is an open frame or internal AC-DC Power supply?

Open frame AC-DC power supplies are also known as AC-DC converters and are a type of internal power supply. The open frame AC to DC power supply is built into the inside of a system and used to convert the AC current into DC voltage.

What is a IEC 62368-1:2018 power supply?

IEC 62368-1:2018 is applicable to the safety of electrical and electronic equipment within the field of audio, video, information and communication technology, and business and office machines with a rated voltage not exceeding 600 V. This is a product safety standard that classifies energy sources, prescribes safeguards against those energy sources, and provides guidance on the application of, and requirements for, those safeguards. The prescribed safeguards are intended to reduce the likelihood of pain, injury and, in the case of fire, property damage. An IEC 62368-1 rated AC to DC converter or power supply is a power supply that has been tested to and certified to comply with the said standard.

Did IEC 62368-1 power supplies replace IEC60950-1 power supplies?

On December 20, 2020 the safety standards that historically have applied to information technology equipment and audio video equipment, IEC 60065 and IEC 60950-1,transition to IEC 62368-1. In North America ETL and UL 60950-1 certifications will continue to stay valid and may continue to be used until further notice. 

What is the difference between an IEC 62368-1 and a IEC 60950-1 power supply?

While the structure and contents of the standards are very different in general most products that previously complied with IEC 60950-1 comply with the latest standard IEC 62368-1 with little or no modification.

Will my IEC60950-1 power supply remain available?

GlobTek will continue to manufacture and supply IEC 60950-1 power supplies indefinitely until further notice.

What is an LPS (Limited power source)?

A Limited Power Source (LPS) as defined in IEC 62368-1 and IEC 60950, is a secondary circuit with an open circuit output voltage, UOC, not exceeding the SELV circuit limits of 42.4 VPEAK or 60 VDC. The maximum apparent power, S, available on the output under any load condition, and the maximum fault current, ISC, available on the output under any load condition, (including a short-circuit), are limited to magnitudes not likely to cause ignition under fault condition in components mounted on, or circuits constructed from, suitably rated materials.

Why is a LPS (limited power source) necessary?

Providing LPS (limited power source) limitations to part or all of the circuits in a product design gives the mechanical design more flexibility in polymeric material choices and openings in the enclosure, as a fire enclosure need not be provided for LPS-powered circuits.

Can a Class 2 power unit or UL1310 power supply be replaced by an LPS (limited power source)?

Many and product standards will stipulate the use of either an LPS rated 62368-1 power supply or AC to DC converter or a Class 2 power unit certified to UL 1310. If the end product standard allows for the substitution of a class 2 power unit with an LPS rated supply one may be used.

What is the difference between a Class 2 power unit certified to UL 1310 and a LPS (limited power source)?
UL1310 is a product safety standards which aims to keep humans safe by lowering the possibility of a hazardous situation. UL1310 requires that all AC/DC power supplies and AC/DC adapters carrying UL1310 certification have limited output power capability. The limits are defined in Section 28 of the standard. UL 1310 AC adapters and power supplies are also known as Class 2 Transformers. IEC62368-1 gives the name “Limited Power Source” (LPS) to a class of AC to DC and DC to DC power supplies which meet a set of criteria defined in Annex Q of the standard. It is important to note that a power supply certified to IEC62368-1 does not imply that it also LPS compliant; LPS compliance is optional. The two essentially require the same technical requirements but differ in marking requirements on the nameplate.

How Does an AC-DC Wall Adapter Work?

The AC to DC adapter or external power supply consists of a power supply which is enclosed in a housing similar to an AC plug, hence the term plug type, wall plug in, plug-in or plugtop power adapter. The power supply is plugged into the mains socket and the AC Voltage is then converted by the AC to DC adapter power supply into a DC voltage that is fed into the appliance via the output cable connection.