EI Laminated Power Transformer, 10 W to 30 W, 110/220 V Primary to 12/24/48 V Secondary, Class B/F Insulation, EMI Metal Case, Lead Harness
This is an EI laminated power transformer for equipment that needs an isolated low voltage rail from a 110 V or 220 V AC supply. The core is an EI lamination stack, the winding sits on a flame-retardant bobbin and is vacuum impregnated, and the finished unit is enclosed in a sheet metal case with a bracket and a plug-terminated lead harness. The supplier rates the series from 10 W to 30 W with a 12 V, 24 V or 48 V secondary.
- EI laminated core, described by the supplier as a low loss lamination.
- 10 W to 30 W rating, set by the winding for each order.
- 110 V or 220 V AC primary; 12 V, 24 V or 48 V AC secondary.
- Class B / Class F insulation system on a flame-retardant bobbin rated V-0.
- Dielectric strength stated as 2.5 kV AC or more; insulation resistance 100 MΩ or more at 500 V DC.
- Vacuum impregnated winding, sheet metal case used for EMI shielding, bracket mounting.
- Lead harness to a white multi-way plug; one lead carries a printed 20 AWG marking.
1. Product Name
EI laminated power transformer for 110 V / 220 V AC mains. The designation covers a build-to-order family rated from 10 W to 30 W, with the secondary wound for 12 V, 24 V or 48 V AC. Construction is an EI lamination stack with a layer-insulated winding on a flame-retardant bobbin, vacuum impregnated and enclosed in a sheet metal case on a two-flange mounting bracket.
Because the rating is set per order, one outline carries the whole range and the winding, the lead length and the connector are fixed with the order. The material presents the series as a family; it assigns no model numbers to individual ratings, so the ordering description has to carry the power rating and the voltage pair instead of a part number.
2. Construction & Materials
The magnetic circuit is an EI lamination stack, described in the material as a low loss lamination. The winding is carried on a moulded bobbin with comb barriers at the lead exits, wrapped in yellow insulating tape, and the assembly is impregnated with varnish under vacuum so that the winding layers are bonded and the structure is stiffened against movement.
Insulation is specified as a Class B / Class F system and the bobbin is moulded from a flame-retardant material rated V-0. The winding is enclosed in a sheet metal case that the supplier presents as both mechanical protection and EMI shielding, with the mounting bracket formed from the same sheet. The close-up in the gallery shows the tape wrap and the comb barriers that separate the lead exits.
Leads are soldered to plated posts moulded into the bobbin and gathered into a white multi-way plug. Six insulated leads are visible in the photographs, in white, yellow, black, red, blue and a second red, and one lead carries a printed 20 AWG marking. The source publishes no connection table, so the assignment of each lead to a winding has to come from the drawing issued with the order rather than from this page.
The material includes four elevations of the same build and states only that all dimensions are approximate, in millimetres. No dimension values are printed on that sheet, so no length, width or height is published here and the three dimension fields on the listing are left empty.
3. Feature
EI laminated core. A laminated EI stack rather than a wound core, which is the conventional construction for a mains transformer in this power range.
Build-to-order rating. The 10 W to 30 W spread is set by the winding, so one outline covers several ratings and one mounting position can serve a product family.
Voltage flexibility. A 110 V or 220 V primary with a 12 V, 24 V or 48 V secondary, selected with the order.
Class B / Class F insulation. Two insulation systems are offered, on a bobbin moulded from a flame-retardant material rated V-0.
Vacuum impregnated winding. Varnish under vacuum bonds the winding layers and reduces movement under load, which the supplier links to low noise operation.
Terminated harness. Leads are soldered to posts and brought out to a white multi-way plug, so the unit arrives as a sub-assembly that can be wired on the line.
Bracket mounting. Two flanges with slotted holes let the unit be bolted to a chassis floor or a panel without a separate clamp.
4. Advantage
One outline, several ratings. The same case and bracket suit the whole 10 W to 30 W range, so a family of products can share a mounting position and a service procedure.
Metal case. The enclosure shields the winding and, in the supplier's wording, reduces electromagnetic interference for stable operation.
Thermal headroom at this size. The supplier targets a temperature rise of 45 °C or less, which leaves room inside a closed chassis for the surrounding electronics.
Efficiency target of 92 % or more. This matters where the transformer runs continuously and its loss shows up as heat inside the enclosure rather than on a meter.
Assembly cost. A plug-terminated harness removes a wiring and soldering step on the line compared with flying leads taken to a terminal block.
Serviceability. A plug connection lets the transformer be swapped without desoldering the harness from the board.
5. Application
The uses below are general application context for an EI power transformer of this size, not claims taken from the source.
Mains to low voltage rail Equipment that runs a control board, relay or display from 110 V or 220 V AC and needs 12 V, 24 V or 48 V inside the same enclosure.
Instrument and laboratory equipment Bench instruments and test fixtures that want an isolated low voltage supply in a metal case with a short lead harness rather than a bare open-frame transformer.
Industrial control cabinets Panel builds where the transformer is bolted to the plate and the secondary is wired through a plug instead of a terminal block.
Audio and small appliance builds Products where a low noise supply and a contained stray field matter, which is why the unit is offered with a metal case and vacuum impregnation.
Custom builds Any application where the voltage pair, the rating, the lead length or the connector are set per order instead of taken from a catalogue part.
6. Specifications
The tables below separate what the material states from what it leaves open. Values that are not published in the source are marked Not stated rather than filled with a typical figure, because the same outline is wound to very different ratings across the 10 W to 30 W range.
6.1 Summary
| Item | Specification | Note |
|---|---|---|
| Product | EI laminated power transformer | Build-to-order family, mains to low voltage |
| Power rating | 10 W to 30 W | Set by the winding for each order |
| Primary | 110 V / 220 V AC | Winding arrangement not stated |
| Secondary | 12 V / 24 V / 48 V AC | Tap or separate winding not stated |
| Insulation system | Class B / Class F | Class fitted per order not stated |
| Core | EI lamination, low loss | Lamination grade not stated |
| Case | Sheet metal enclosure | EMI shielding, supplier wording |
| Mounting | Two-flange bracket, slotted holes | Hole size and slot length not stated |
| Termination | Lead harness, white multi-way plug | Pin-out not published |
| Model number | Not assigned | Identify the part by rating and voltage pair |
| Dimensions | Not stated | Elevation sheet carries no values |
| Weight | Not stated | Confirm on the order |
6.2 Electrical
| Parameter | Value | Note |
|---|---|---|
| Efficiency | 92 % or more | Supplier figure; load and method not given |
| Temperature rise | 45 °C or less | Load, ambient and method not given |
| Dielectric strength | 2.5 kV AC or more | Duration and test points not given |
| Insulation resistance | 100 MΩ or more at 500 V DC | Printed in the material as dielectric isolation |
| Operating frequency | Not stated | Confirm on the order |
| Rated current | Not stated | Follows from the rating and the secondary voltage |
| Voltage regulation | Not stated | Ask for it at the stated load |
| No load current | Not stated | Ask for it with the winding data |
| Winding resistance | Not stated | Per winding, at a stated temperature |
| Leakage inductance | Not stated | Relevant where the secondary feeds a switching stage |
6.3 Winding and insulation
| Item | Specification | Note |
|---|---|---|
| Insulation system | Class B / Class F | Temperature limit per class not stated |
| Bobbin | Flame-retardant moulding, rated V-0 | A material rating, not a transformer test |
| Winding insulation | Layer insulation under yellow tape | Tape class not stated |
| Impregnation | Vacuum impregnated varnish | Varnish class not stated |
| Barrier | Comb barriers at the lead exits | Creepage and clearance not stated |
| Case | Sheet metal enclosure | No earth terminal is shown in the photographs |
| Isolation path | Winding to core and winding to winding | Construction detail not stated |
6.4 Termination and mounting
| Item | Specification | Note |
|---|---|---|
| Leads | Six insulated leads to a white plug | Colours visible: white, yellow, black, red, blue, red |
| Lead marking | 20 AWG printed on one lead | Gauge of the other leads not stated |
| Lead length | Not stated | Set with the order |
| Joint at the coil | Leads soldered to plated posts | Solder alloy and post material not stated |
| Connector | White multi-way plug | Series and mating part not stated |
| Mounting bracket | Two flanges, one slotted hole each | Hole size and slot length not stated |
| Marking | Not stated | No label or rating plate is visible |
| Finish | Not stated | Case finish not described |
6.5 Quality and compliance
| Item | Statement | Note |
|---|---|---|
| Certification logos | CCC, CE, RoHS and UL marks appear in the material | No certificate number, issuing body or test report supplied |
| Position taken here | No compliance claim is made | Ask us for the certificate your market needs |
| Routine test | Not stated | Confirm the test list on the order |
| Dielectric test | Stated as 2.5 kV AC or more | Duration and test points to be confirmed |
| Temperature rise test | Stated as 45 °C or less | Load and ambient to be confirmed |
| Traceability | Not stated | Confirm marking and batch records on the order |
7. Ordering
Quote against the electrical requirement. A useful enquiry gives the power rating or the secondary current, the primary voltage, the secondary voltage or tap arrangement, the lead length and connector you want, the space available, and the quantity per order and per delivery. With those we confirm the core size, the winding, the harness and the price.
On compliance: the material carries CCC, CE, RoHS and UL logos, but no certificate number, no issuing body and no test report come with it, so no compliance claim has been made here. If your market needs a declaration, ask for the certificate for the specific standard. A logo panel on its own is not evidence of certification.
Brand / manufacturer: ZXY, Shenzhen Zhixiangyuan Electronics Co., Ltd. http://www.zxycoil.com