NTC Thermistors: Core Applications in Daily Life & UF NTC Series

Thermistors are classified into positive temperature coefficient thermistors (PTC thermistors, whose resistance increases sharply with temperature rise) and negative temperature coefficient thermistors (NTC thermistors, whose resistance decreases sharply with temperature rise) based on their different temperature coefficients.

 

With advancements in technology, thermistors have found widespread applications in various aspects of daily life, including household appliances, industrial, medical, and environmental fields for temperature control and temperature detection, as well as in office automation.

 

The main application areas of thermistors include:

 

Temperature control and detection in household appliances such as induction cookers, electric pressure cookers, rice cookers, electric ovens, disinfection cabinets, water dispensers, microwave ovens, electric heaters, and industrial, environmental, and meteorological equipment, as well as food processing devices.

 

Temperature detection and compensation in office automation equipment (such as photocopiers and printers), coil assemblies, integrated circuits, quartz crystal oscillators, and thermocouples.

 

1. Liquid Level Control 

 

Two NTC thermistors can be placed at the high and low liquid level safety positions in a container and subjected to a constant heating current. The thermistor immersed in the liquid at the bottom will have a surface temperature equal to the surrounding temperature, while the thermistor exposed to air at the higher position will have a higher surface temperature than the surrounding temperature. If the liquid level rises to submerge the higher thermistor, its surface temperature will drop, causing an increase in resistance. The control circuit can detect this change in resistance and promptly activate an alarm device or cut off the liquid supply line to prevent overflow. Conversely, if the liquid level drops to the lower position, the bottom thermistor will gradually be exposed to air, causing its surface temperature to rise and its resistance to decrease. The control circuit can then detect this change and activate the liquid supply line to replenish the liquid, thus maintaining the liquid level within a safe range.

 

2. Temperature Measurement 

 

Thermistors used for temperature measurement generally have a simple structure and low cost. Since they have a relatively high resistance value, the contact resistance at the connection points can be ignored, and they can be used in remote sensing applications over distances of several kilometers.

 

3. Temperature Compensation 

 

The negative temperature coefficient characteristic of NTC thermistors can be utilized for compensation in certain electronic devices. When an electronic device is overloaded, causing an increase in current and temperature, the resistance of the thermistor increases, which in turn reduces the current, providing compensation and protection. In this case, the thermistor should be connected in series in the electronic circuit, ensuring it directly monitors the current temperature of the device.

 

4. Temperature Control 

 

In electromechanical protection and control systems, critical point thermistors are often connected in series with relay control circuits. When a device encounters a sudden fault causing an overload and a subsequent increase in temperature, if the temperature reaches the critical point, the resistance of the thermistor suddenly drops. This causes the relay current to exceed its rated operating current, triggering the relay to cut off the circuit and provide protection.

5.Temperature Protection 

 

Thermistors play a crucial role in the functional management of certain devices, such as wireless phones and notebook computers. If the charging resistance is too high, the battery in these devices will charge quickly. However, this also poses the risk of overheating. If the temperature exceeds the Curie temperature of the battery due to overheating, the damage to the battery may be irreversible. On the other hand, if the charging voltage is too low, the charging time will become unacceptably long. By using a thermistor in the battery, it is possible to detect overheating of the battery and adjust the charging speed accordingly. As a result, the battery can be charged quickly with a higher voltage at the beginning of the charging process. When the critical voltage or temperature is about to be reached, the charging speed can be controlled to slow down, allowing for a more stable completion of the charging process.

 

6. Overheat Protection 

 

The increasingly smaller size of notebook computers means that the motherboard is highly sensitive to temperature, especially since it is close to the heat-generating power resistors. The continuous increase in CPU clock speed not only enhances the performance of the CPU but also raises its operating temperature. In such cases, surface-mounted thermistors can provide rapid response and overheat protection, and they are relatively easy to use.

 

UF's NTC Thermistors 

 

Among the NTC thermistors widely used in the above scenarios, products from UF Capacitors stand out for their high performance and cost-effectiveness.

 

UF Capacitors offers a wide range of high-quality NTC thermistors designed to meet the diverse needs of various industries. UF's NTC thermistors are known for their reliability, can replace first-tier brands such as TDK, EPCOS, and Thinking-TVR —with equivalent electrical parameters and better compatibility for most application scenarios—more competitive pricing and shorter lead times, making them an excellent choice for temperature control and detection applications.

 

Welcome to visit our website: https://www.ufcapacitors.com and send RFQ to Email: karin@ufcapacitors.com   for a free quotation.

 

Cross to:

 

Photo	Description	UF Capacitors Series Code	TDK/EPCOS	Thinking-TVR
	MF72 Power NTC Thermistor	NTC Series	B57 Series B57153S Series	SCK*** Series