The EI19 is a single-phase low-frequency audio transformer in a toroidal autotransformer configuration. Copper wire winding, pin leads for direct mounting and soldering, compact closed magnetic circuit with low leakage inductance. The electrical specification is customized to the customer's requirement and agreed per order.
The EI19 is a single-phase low-frequency audio transformer built in a toroidal, autotransformer configuration. It is wound with copper wire and terminated with pins, and is supplied for use in electronic equipment. Because the electrical specification of this model is customized, the winding data is agreed for each order rather than taken from a fixed catalogue value.
1T Series high-frequency pulse and drive transformer with dual-colour insulation and PCB mount
Close-up of the coil wrapping and the 1T top marking
Key highlights and customisation capabilities: custom turns ratio, inductance and power ratings, OEM / ODM
Dual-colour insulation structure: high-dielectric red coil wrapping plus yellow margin tape
A toroidal winding keeps the magnetic flux inside a continuous ring instead of a stack of laminations. The magnetic circuit is short and closed, so magnetic efficiency is high, leakage inductance is low and very little stray field escapes towards neighbouring components. That matters in electronic equipment, where the transformer usually sits close to other parts on the same assembly.
Because the EI19 is an autotransformer, input and output share a single winding rather than using separate primary and secondary windings. A tapped winding of this kind needs fewer windings and a simpler coil build, which makes the part compact and economical where a shared winding is sufficient for the circuit. It is intended for low-frequency audio signals in electronic equipment.
The winding is made from copper wire, which keeps resistance low and conductivity stable, and the leads are brought out as pins so the transformer can be mounted and soldered directly onto an assembly. Since the electrical specification is customized, the winding can be built to the customer's own requirement instead of a fixed standard value, and finished units are packed in cartons.
High-permeability ferrite core and low core loss at high frequencies
The transformer is specified as an audio transformer for electronic equipment and operates at low frequency.
Industrial and power electronics applications: MOSFET / IGBT gate drive, SMPS and DC-DC converters, inverters and EV chargers
Transformers mounted on a PCB assembly
| Item | Value |
|---|---|
| Model Number | EI19 |
| Usage | Electronic equipment |
| Phase | Single |
| Coil Structure | Toroidal |
| Coil Number | Autotransformer |
| Product Categories | Audio transformer |
| Wire Material | Copper wire |
| Lead Way | Pins |
| Packaging | Carton |
| Electrical Specification | Customized |
| Frequency | Low frequency transformer |
Note: the rows above are transcribed from the specification table supplied for this model.
| Item | Summary |
|---|---|
| Product | Low-frequency audio transformer |
| Model | EI19 |
| Configuration | Toroidal autotransformer, single phase |
| Winding | Copper wire |
| Termination | Pin leads |
| Electrical specification | Customized to customer requirement |
| Packaging | Carton |
Top, bottom, side and isometric views of the pin-mounted transformer
Close-up of the pin leads and moulded bobbin
Quality assurance and testing standards: 100% Hi-Pot and turns ratio / inductance tested
Units under electrical test on the bench
Model: EI19 | Type: Low-Frequency Audio Transformer | Configuration: Toroidal Autotransformer, Single Phase. Electrical specification is customized per order: please send your winding data, quantity and destination port for a quotation.