TDK’s new high-voltage-resistant temperature sensors for connectors are designed to protect batteries operating at high voltages. The company designed these sensors to respond quickly, remain stable at high temperatures, and integrate directly into connectors.
The company says its challenge in the design was finding a material with both high electrical insulation properties and strong thermal conductivity, and then developing a design that could physically integrate a negative temperature coefficient (NTC) element. A ceramic sleeve enveloping the sensor die proved to be the key.
Testing has shown that the TDK temperature sensor meets the design requirements. The high-voltage test produced a 5 kV dielectric strength of the sensor head, above the 1 kV DC system voltage. The response time also met design targets, important for starting derating in good time given a case of sudden overheating. A τ-value (63%) of well under 10 seconds was recorded in a typical installation situation. The permitted temperature range is -40 to +150° C, with brief 180° C applications allowed. Sensor precision also met testing targets. At 25° C, the new sensor has a maximum ±0.2 K deviation with the R25 resistance at 10 kΩ under a one-percent tolerance. The upper plastic section of the sensor is designed so that customer fitting requirements, such as screw-on, clip-in or clip-on, can be implemented.