NTC and PTC Application

NTC thermistors are made up of sintered metal oxides. Some of the metals found in an NTC thermistor are iron, nickel, manganese, aluminum, copper, and cobalt. The most popular shapes for NTC thermistors are discs and shapes. The form of the thermistor will depend on the specific applications in the device.

There are five applications found in NTC thermistors. Temperature measurement is one of these applications. Thermistors feature a high sensitivity. The high sensitivity makes them ideal for low-cost temperature measurement applications.

Temperature control and temperature compensation are two more NTC thermistor applications. Using a minimum amount of circuitry, NTC thermistors can be used for temperature control. Additionally, most circuit precision requires some temperature compensation.

Inrush Current Limiter is another application found in NTC thermistors. This application is associated with disc-shaped thermistors subject to a change in power. They will experience a time lag before they reach a lower resistance. The time lag can be used to limit the inrush surge current.

The last applications associated with NTC thermistors are Fluid Level Applications. Thermistors can be used to determine if a liquid is present or absent. NTC thermistors determine this by using the difference in dissipation constants between a liquid and gas.

In most cases, a PTC thermistor is a polycrystalline ceramic material. PTC thermistors are composed of oxyalate or carbonate. PTC thermistors also feature five different applications.

One application for PTC thermistors is overcurrent protection. Overcurrent protection reacts when a fault condition occurs. When this condition happens, the thermistor will heat up. The higher heat will cause it to switch from a low to a high resistance.

Electronic ballast design is another PTC thermistor application. This application is uses a time delay element when the circuit is energized. Two more applications are motor starting, which relates to time delay, and battery management, which refers to a rechargeable battery.

The last application associated with PTC thermistors is a linear PTC thermistor. Linear PTC thermistors are a recently developed application. The application uses a thick film technology similar to the thick film resistor.

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