PTC Heaters

"This material is named for its 'positive thermal coefficient' of resistance means resistance increases upon heating. "

Most ceramics have a negative coefficient, whereas most metals have positive values. While metals do become slightly more resistant at higher temperatures, this class of ceramics has a highly nonlinear thermal response, so that it becomes extremely resistant above a composition-dependent threshold temperature. This behaviour causes the material to act as its own thermostat, since current passes when it is cool, and does not when it is hot.

The dynamic resistance and output of PTC heaters makes them an excellent choice for providing controlled electrical heat. In many applications it is possible to do away entirely with thermostatic controls.

Applications:-

Thin films of this material are used in automotive rear-window defrost heaters, and honeycomb-shaped elements are used in more expensive hair dryers and space heaters, air heaters, drying appliances, compartment heaters, warming plates, glue guns, tool heating, heating systems for vehicles, dehumidifiers, tumble Driers. Since it advantages in temperature-sensitive, current limiting, time delay and noise-free, it could be applied to initiating refrigerator, protecting transformer as well as mosquito dispellers, iron, roller etc. The glow type material has characters such as stable performance, rapid heating-up and reliability. Therefore, it becomes the most ideal replacement for metal fuse. Now PTC has been used on heater, dryer, air curtain, air conditioner etc.