Custom Transformers and Custom Magnetic Products
Since 1949, Transformer Manufacturers, Inc.’s (TMI) expertise in manufacturing quality custom designed transformers and magnetic products has enabled us to solve problems for our customers while meeting or exceeding their specifications and requirements.
We manufacture custom-designed transformers for a wide range of industries including:
- Audio Transformers
- Power Transformers (isolation transformers and autotransformers)
- Choke Transformers, Reactors, Inductors
- Small Toroidal Transformers
Coil types include bobbin, layer, or stick wound, precision wound and toroidal.
Transformer manufacturing is our core business, and all products are proudly made in America. Transformer Manufacturers serves the global market from our facilities centrally located in the Chicago transportation hub.
Rely upon Transformer Manufacturers as your magnetics manufacturing partner for:
- Value engineering
- Prototyping
- Quality centered manufacturing
- Value-added manufacturing services
- Just-in-time and other delivery options
- High-quality products
- Custom solutions

Transformer Manufacturers, Inc. designs and manufactures high quality, precision, layer-wound transformers for the Class A audio industry.
Transformer Manufacturers, Inc. designs and manufactures isolation transformers, whose primary purpose is to isolate the AC source from your device or equipment. TMI can design to your custom requirements when you need to isolate and physically separate two circuits.
Autotransformers are non-isolating and are used to step-up or step-down the voltage of the AC input. Autotransformers from Transformer Manufacturers, Inc. have a single winding, which is tapped at various points along the winding, allowing you different voltages.
Choke transformers have high reactance to block or filter a specific frequency in an electronic circuit. Transformer Manufacturers, Inc. custom manufactures choke transformers to meet the particular requirements and space considerations for your application.
Transformer Manufacturers, Inc. designs and manufactures Toroidal Transformers and Inductors that transfer electrical energy from one circuit to another.