Class 2 linear transformer manufacturer

A US company you buy from
One accountable contact
Own factories · China + Vietnam
Origin documented per unit

Build to your spec

HTS 8504.31.40

SecondaryAny winding to your drawing — 16.5 VAC / 40 VA and 24 VAC common

Primary120 VAC 60 Hz · US flat-pin plug, flying leads, or hardwired can

StandardUL 1310 Class 2 — energy-limited secondary, 100 VA ceiling at 30 V and below

ProtectionThermal fuse in the winding (130 °C) · current fuse on the secondary

Efficiency87.6% at full load on a 40 VA linear build · DoE Level VI versions where your application needs one

Core loss< 2.5 W at 120 VAC with no secondary load

Temperature rise87 °C max on the primary coil, 25 °C ambient at full load

Production testHi-pot 2.8 kV AC, 1 s, 100% of units · insulation > 100 MΩ at 500 V DC

TerminationM4 screw terminals, flying leads, or to your drawing

CertificationUL 1310 · cUL · FCC · CE / UKCA and other regional marks on request

OriginVietnam or China — your election, documented per unit

The figures above are typical of builds we have shipped, not a limit. Secondary voltage and VA, core size, termination, enclosure, fusing and agency marks are all set per order — send a target spec and we will quote against it.

Discuss your spec

Where linear transformers are used

Video doorbells and chimes (16.5 VAC)
HVAC controls and thermostats (24 VAC)
Access control, door strikes, and maglocks
Irrigation and sprinkler controllers
Alarm, security, and life-safety panels
Landscape and low-voltage lighting

How we build them

We wind Class 2 transformers on our own lines to UL 1310 — EI laminated cores, a thermal fuse in the primary winding and a current fuse on the secondary, in a plug-in body or a hardwired can. A 16.5 VAC 40 VA build runs 87.6% at full load with core loss under 2.5 W unloaded, and every unit is hi-pot tested at 2.8 kV AC before it leaves the line. Where your application needs a DoE Level VI supply instead, we build that too and will tell you straight which one your product should carry.

How to read a power adapter spec sheet →

How we test them — IQC to OQC →

Linear transformer vs switching adapter — what changes

	Class 2 linear transformer	Switching adapter
Output	AC — 16.5 / 24 VAC typical	DC — 5 / 12 / 24 V typical
Standard	UL 1310 (Class 2)	UL 62368-1
Efficiency	87.6% at full load on a 40 VA build	DoE Level VI, computed per wattage
Behaviour on overload	Energy-limited secondary, fuse protected	Electronic OCP, auto-recovery
Electrical noise	Very low — no switching harmonics	Switching ripple, typically 200 mV
MFN base duty	6.6% · HTS 8504.31.40	Free · HTS 8504.40.85

The marks every build carries.

Product certifications on the label, the packaging, and the documentation your procurement team audits against — verifiable by file number on request.

cULus LISTED

cRUus REC.

cETLus

FCC PART 15

RoHS

REACH

Manufacturing operates under ISO 9001:2015 · ISO 14001:2015 ·ISO/IEC 27001:2022 · TL 9000-H · QC 080000 HSPM · ESD S20.20 ·Amfori BSCI

See how we source

Related products

Wall-mount power adaptersInterchangeable AC blades, 5–65 W Custom & OEM power suppliesBuilt to your drawing — switching supplies to 250 W and AC-AC linear transformers; medical & industrial on request.

Request a quote

Send the spec or drawing, target volume, certification, and destination — five lines get you a real quote for linear transformers.