EI48 Potted PCB Mount Transformer, 220V AC to 12V AC, 10VA, Epoxy Sealed, Through-Hole Pins, 50.7 x 38.3 x 43 mm

1. Product Name

EI48 potted transformer, wound as 220V AC primary and 12V AC secondary, rated power 10VA, through-hole package. The model on the label consolidates all information into a single string: EI48-10W/VA 220V/12V, so the ordering description can be directly composed by combining series, rated power, and voltage without requiring a separate catalog number.

Another panel indicates this series covers a power range from 1W to 12W, so the physical dimensions are common, and windings vary with power. Other rated powers within this range maintain the same footprint and mounting method; windings, pin assignments, and labels change with the order. Confirm the rated parameters in writing because the accompanying materials include specifications for a 5VA unit on the same drawing.

2. Construction and Encapsulation

The core is an EI48 laminated structure, wound on a bobbin, with leads connected to pins molded through the base. The wound assembly is placed into a blue housing, which is filled with epoxy resin, solidifying the coil, core, and pin roots into a single block. The top cap is a separate molded part that fits into the housing, with the seam above the potting line, not at the bottom where pins exit.

The housing is a blue molded part, rated as flame retardant material, featuring a stepped top cover and four corner pads molded into the base. Each corner pad includes a screw hole for mechanical fixing, enabling the device to withstand handling and vibration in equipment that moves after shipping or assembly. The rating label is affixed to the front, keeping the model, voltage, and pin numbering readable after board assembly.

The potting process carries the electrical safety advantages described on this page. Void-free filling eliminates air paths around the windings, thereby extending the creepage distance along the surface between primary and secondary, while locking the laminations to prevent vibration noise. Additionally, it seals the housing against moisture and dust. Information not provided includes: potting material composition, its temperature index, and the test voltage the filler withstands.

3. Termination and Mounting

Termination uses straight pins in a through-hole layout, with the label assigning the primary to pins 1-6 and the secondary to pins 7-12. Four corner mounting ears with screw holes around the pins provide a secondary mechanical fixing method for securing to a PCB or bracket, which is uncommon for devices of this small size and explains why the corner pads are molded into the base.

4. Dimensions

External dimensions are marked on a dedicated drawing: pin-side width 50.7mm, front-to-back depth 38.3mm, height from the mounting surface to the top of the stepped cover 43mm, pin row spacing 28.8mm, and each row span marked as 6 x 4.2mm.

5. Features

Sealed against environmental attack. Epoxy casting keeps moisture, dust, and condensation away from the coil, so this device needs no additional sealed enclosure.

Through-hole terminals. Pins are inserted and soldered along with other board components, eliminating wiring steps and connectors in assembly.

Four-corner screw mounting ears. Four molded mounting ears share the mechanical stress on solder joints when the board endures vibration.

10 VA in a small volume. The 50.7 mm × 38.3 mm × 43 mm size allows a 10 VA linear power supply to be mounted directly on the control board without side placement.

Class II construction. The material bears the double square symbol, and this construction provides basic insulation without relying on a ground connection.

Stepped top cover. The cover fits into the housing, with the seam above the potting line, away from pin exits.

Front-mounted label. The model, input, output, and pin numbers are printed on the label, so the part can be identified after assembly.

6. Advantages

No separate housing needed. The housing and potting are part of the component itself, eliminating additional boxes, brackets, or conformal coating in the design.

Fewer assembly steps. Pins and four corner screws replace flying leads, terminal blocks, and wire harness management.

Stable under vibration. The solid epoxy block has no loose laminations or layers that can shift or wear insulation.

Predictable handling. A single smooth molded part goes straight to the line, with no exposed copper, tape edges, or sharp core corners to cause damage.

Multiple power ratings share one footprint. The same package covers 1 W to 12 W, allowing the product family to keep the same cutouts and screw positions.

Serviceability. This part can be desoldered and removed directly without cutting wires, suitable for long-term field use.

7. Specifications

Values are transcribed from the supplier drawing. Where the drawing is not marked, it is noted as "not specified"; where the drawing is contradictory, the contradiction is pointed out rather than resolved.

7.1 Overview

7.2 Electrical Parameters

7.3 Mechanical Parameters

7.4 Pin Definitions

7.5 Quality and Compliance

8. Applications

The following uses are general scenarios for a potted 10 VA power transformer, not claims originating from the source document.

Home appliances. Household devices needing 12 V from mains, with a sealed housing suitable for steam and cleaning environments.

Industrial controls. Control boards and panels where a direct soldered power source is preferred over wiring to a separate terminal block.

Security equipment. Cameras and access control systems, where sealed parts avoid corrosion issues in damp cabinets.

Smart home systems. Panels, hubs, and gateways needing an isolated power rail on a compact, low-profile board.

LED power supplies. Strips and modules operating on a 12V AC rail, with drives accepting AC input rather than rectified DC.

Audio and communication. Equipment requiring low hum power, which is exactly what the solid potting process provides.

9. Ordering

Request quotes based on rated power and pin configuration. A valid inquiry should include: your required power rating (within 1 W to 12 W), primary and secondary voltages, pin configuration or the footprint you are laying out, whether corner screws are used, and order quantities per order and per batch. Upon receipt, we will confirm windings, pin assignments, and pricing.

About compliance: The material shows CE, Class II double square, and cRUus marks, along with a RoHS declaration, but it does not include certificate numbers, issuing bodies, or test reports, so no compliance claim is made here. If your market requires such claims, request certificates for specific standards. The mark panel alone is not a basis for certification.

Brand/Manufacturer: ZXY, Shenzhen Zhi Xiang Yuan Electronics Co., Ltd. http://www.zxycoil.com