LPTC and NTC
temperature sensors
Thermistors are divided into two types: thermistors with a positive temperature coefficient (PTC) and thermistors with a negative temperature coefficient (NTC). When the temperature of thermistors with a positive temperature coefficient is increasing, their resistance is increasing, when the temperature of thermistors with a negative temperature coefficient is increasing, their resistance is decreasing. The thermistors with the positive temperature coefficient are usually manufactured from a ceramic material behaving as a semiconductor. The PTC sensors have a nonlinear curve of resistance and temperature, and resistance increases by steps at a critical temperature (sometimes called as cut-off temperature). This considerable increase of resistance can be used to trigger protective relays cutting off the current to the motor (or any other application), thereby preventing a damage to the winding and insulation.
areas of use
linear PTC thermistors
Another type of thermistor with a positive temperature coefficient is an LPTC silicone linear thermistor (at present it is an alternative to KTY). This thermistor type is manufactured by a different method resulting in an almost linear increase of the thermistor resistance with increasing temperature. As compared with the PTC sensors, they have a lower range of working temperatures.
NTC thermistors
NTC thermistors with a negative temperature coefficient are generally the most frequently used type of temperature sensors because in practice, they can be used in any type of temperature-dependent equipment. When the temperature of NTC thermistors is increasing, their resistance is decreasing.
custom manufacturing
We manufacture linear silicone PTC sensors of LPTC 600 / LPTC 1000 types that are alternatives to the sensor types KTY 84-130 / KTY83-110, which were but are not manufactured by NXP any more. Our LPTC sensors have comparable parameters to those of KTY sensors in the temperature range from -40°C to +180°C, long-term temperature stability, high accuracy and reliability, and they are independent of polarity. Thus, it is a budget-priced solution (as compared with KTY) for temperature measurement that is used in areas such as electric drives, instrumentation and control, industrial automation, automotive industry, etc. We ensure execution of cable accessories for the temperature sensors (sensor connections, conductors, insulation) according to your requirements. Our laboratory is equipped with a testing workplace for the tracking of the basic characteristic of this product, which is the dependence of ohmic resistance on temperature.
we manufacture ready-made products with the following sensors
- linear PTC thermistors LPTC 600 (replacement for KTY84-130)
- linear PTC thermistors LPTC 1000 (replacement for KTY83-110)
- NTC
Bc. Jan Kovář
