At Thermistors Unlimited, we deliver high-quality PTC thermistors (Positive Temperature Coefficient) engineered for reliability across a wide range of applications — from heater elements and motor temperature monitoring to overcurrent protection in advanced electronics.
Our thermistors power innovation across industries including Aerospace, Automotive, Energy, Defense, and beyond. Whether you're designing for precision, protection, or performance, our team has the expertise to deliver exactly what you need.
We specialize in custom PTC elements in a variety of shapes and sizes, with disc and rectangular formats being among the most popular. Our flexible designs allow us to create custom heater assemblies — including single-sided heaters — that solve even the most complex thermal challenges.
With fast sample and prototype turnaround, Thermistors Unlimited helps you move from idea to implementation — quickly, confidently, and with a partner you can trust.
We are also proudly ISO 9001:2015 Certified and many of our products are UL Listed.
Thermistors Unlimited traces it's roots back to the PTC Thermistor product line of Advanced Thermal Products (1991 to 2006), the PTC Thermistor product line of Spectrum Sensors & Controls (2006 to 2012), and to the PTC Thermistor product line from RTI Electronics (Anaheim, CA). [All PTC thermistor products built by RTI Electronics over the years will be supported by Thermistors Unlimited]. TU incorporated in January 2015, and they look to focus on both standard and custom PTC Thermistor Products.
The vision that we have here at Thermistors Unlimited is to continue to support all PTC thermistor products developed in the past, (including the PTC Products from Advanced Thermal Products, Spectrum Sensors & Controls, and RTI Electronics), but also to help develop new products via our present relationships and the many new relationships that we look to develop in the years to come.
Thermistor Products' Prior Business Entities That We Can and Do Support:
1991 - 2006: Advanced Thermal Products
2006 - 2014: RTI Electronics and Spectrum Sensors & Controls
Greg Stauffer
President