for Heater

This type thermistor heats up quickly and
evenly until reaching the desired temperature.

One of the main types of thermistors, those used for heaters, has a proven track record in in-vehicle supplemental heaters.


Rated Voltage : 
12 to 220V
Resistance : 
0.5 to 2kΩ

Resistance value changes at rated voltage

How it works

Thermistors for heaters require safety and power saving performance. The Posi-R quickly heats up when current flows through it. The Posi-R reaches the heating temperature evenly throughout its entire structure. The heating temperature can be controlled by adjusting the construction of Posi-R’s material make-up. In addition, because Posi-R maintains a constant temperature thanks to a balance between heat generation and heat dissipation, it will not exceed the heating temperature.

【Voltage application time and product temperature】

Temperature quickly rises, and temperature and power usage are constant

【Thermistor for in-vehicle heater】

Posi-R is used as the heat generating element in heater units.

Record on the market

Posi-R has a proven track record for in-vehicle applications, a field where reliability is of the utmost importance. It is widely used as the heat-generating element in supplemental heaters used in hybrid vehicles and other eco-cars.


  • Quickly heats up to desired temperature.
  • Its temperature is uniform and never gets red hot, making it very safe.
  • Posi-R’s self-temperature-control effect prevents excessive heating.
  • The Posi-R’s self-temperature-control function ensures power savings.
  • Users can select their desired temperatures.


  • In-vehicle supplemental heaters
  • Facial massage heaters
  • Condensation-prevention heaters for office equipment
  • Clothes drying heaters
  • Defrost heaters for refrigerators


A disc type Posi-R is ideal for a small-power heater, making use of its self-heating and self-equilibrium characteristics. As a Posi-R self-heats when voltage is applied, the size of a heater element and the switching temperature can be optionally selected in accordance with the shape of appliances. Since this is of a non-contact control type, it is highly reliable for such applications. It is used for a Automobile-related appliances, house hold appliances and business machines.

Rated Voltage Resistance Switching temperature
12V class 0.5 to 3.0Ω 260℃ or less
100V class 100 to 2000Ω
200V class 200 to 2000Ω

Resistance varies with size and Curie point.

  • When considering evaluation, please contact your local authorized distributor along with required specifications and annual usage quantities.

Application Guidelines

Application Guidelines of Positive Thermistors “Posi-R ”

General Observations
  • Do not use”Posi-R” in the presence of oil or water. The parts could fail.
  • Do not apply voltage in excess of the maximum operating voltage. This could cause a short circuit or burn-out.
  • Do not use “Posi-R” with reactive gas, reducing gas, or oxygen-free environment-electrical characteristics may deteriorate or burn-out may occur.
Notes on Usage
  • Please use the parts within the rated operating temperatures according to the catalog.
  • Please use at maximum operating voltage as specified in the catalog.
  • Excessive press or shock (ex. drop) should not be applied to the "Posi-R".
Notes on Storage
  • Packaged parts should be stored under the following conditions :
    temperature : –10 to +40˚C
    humidity : 85% or less
  • Storage of “Posi-R” devices may result in increased resistive characteristics.
    They will return to the initial value by applying rated voltage prior to using the parts.
  • Shall be used shortly after opening the package.

Entry Form

Characteristics of
Positive Thermistors “Posi-R”


Products Catalog