At Thermistors Unlimited, we design and manufacture a wide range of Positive Temperature Coefficient (PTC) thermistors, serving applications from heater elements and motor temperature validation to overcurrent protection in electronic systems. Our products support a diverse set of industries, including Aerospace, Automotive, Energy, and Defense — and many more. We specialize in custom-engineered PTC components, offering elements in various shapes and sizes, with disc and rectangular formats being the most in demand. Leveraging this versatility, we also create unique, application-specific heater assemblies. Our single-sided heaters are especially well-suited for complex thermal challenges, providing innovative solutions where standard designs fall short. At every stage, from concept to prototype, we are committed to fast turnaround times and responsive support — helping our customers bring high-performance solutions to market with speed and confidence.

Although we highlight our custom-made abilities, we do carry standard products that can be purchased and shipped quickly. Datasheets for these standard products are located here. Contact us with questions about our products or to request more information.

To learn more about the science behind PTC thermistors and their various applications visit here.

Our five most popular applications - Standard Heaters, Single-Sided Heaters, Over-Current Protectors, Motor Temperature Sensors, and Over-Temperature Sensors - and part-specific codes can be found under our Applications tabs. Contact us for questions about applications.