About Us

Welcome to Prem Magnetics. We are trusted transformer manufacturers and coil winders based in Johnsburg, Illinois.

The History of Prem Magnetics


Prem Magnetics was founded in 1972 by W.T. Peterson and Frank Prem, as a division of Prem Enterprises, a machine shop. 

Mr. Peterson and Mr. Prem recognized that other products in the industry lacked quality, and decided to make coils and transformers to the highest standards. 

As the business grew rapidly, Mr. Peterson needed additional help with the operations. In 1978, Roger Liston was hired as General Manager. Mr. Liston came to Prem after holding executive roles at several large coil manufacturers, but his entrepreneurial spirit made him want to strike out on his own. 

In 1979, Prem Magnetics became a separate Illinois corporation owned by Mr. Liston and Mr. Peterson. After several more years of success, Mr. Peterson retired in 1984, and Mr. Liston became President of the company.  

After a fulfilling career, Mr. Liston retired in 1994, and his two sons took over the business. They continued to expand the company’s transformer manufacturing capabilities until their retirement in 2010. Today, the company is in its third generation of family stewardship.  


A Family-Owned Company



As a multi-generation family-owned transformer manufacturer, company culture and family values are very important to us. At our Johnsburg, Illinois headquarters, over 25 employees focus on office operations, complex part and small quantity production, as well as warehousing and shipping of finished products. Our Mexican facility is the workplace of over 30 employees, and produces high-volume orders.  
With an average employee length of service of roughly ten years, our team members become part of the Prem Magnetics family. We are also proud to have four Prem Magnetics employees with over 20 years of service, and three employees that have spent over 40 years with the company! 


Company Values

Prem Magnetics is one of the few manufacturing businesses in Johnsburg, standing strong thanks to key company values. 

There are three things that Prem is renowned for in the industry: our coil manufacturing experience, our capabilities and our reputation for producing high quality transformers, inductors and coils. Most of our standard products are UL and CSA certified, and the company itself carries ITAR certification.

Our products are built with care by a close-knit team that has vast experience working together to ensure quality. As expert transformer manufacturers and coil winders, our key goal is to manufacture dependable products that last. We work hard to supply 100% tested transformers and coils that we are proud to offer to our customers.

We are here to meet your needs to your exact specifications, and will be by your side providing exceptional customer service throughout the transformer, coil and inductor manufacturing process.


Our Products: Transformers, Coils and Inductors

 Prem Magnetics specializes in crafting power transformers, coils and inductors for applications ranging from HVAC to emergency lighting. Prem Magnetics manufactures magnetic transformers including single phase linear power transformers, instrument-current transformers, switchmode transformers and more.

 With dedication to providing the very best customer service, we also provide custom solutions and regularly craft original transformers to meet our customers’ unique needs. Our sister company, Remington Industries, distributes the high quality wire we use to wind our reliable transformers, inductors and coils.

 Thank you for visiting our website and learning a little more about the Prem Magnetics team. We look forward to doing business with you. We welcome you to browse our range of existing transformers or order a custom solution today.


Our main office is open from 8:00 AM to 4:30 PM (Central Time), Monday to Friday.