Varför använder flest temp. regulatorer PTC givare...?

[olaa]

Söker information om varför det ser ut som om de flesta
elektroniska temperatur -styrningar, -termostater, -regulatorer
använder PTC och inte NTC som givare.
I mitt fall så tycker jag NTC är attraktiva ur pris och mångfald. PTC finns färre, är dyrare…

/Ola A.

[Icecap]

Om du menar att de använder PT100 eller PT1000 är det för att de är mycket mer linjära och exakta med reproducerbara resultat, stabilare sensorer och har en "standard".

[TomasL]

Och PT100/500/1000 är inte vad man i dagligt tal menar med en PTC-givare utan en RTD

[prototypen]

Jag har inte en aning men PTC kanske är linjärare och bättre tolerans.

Protte

[TomasL]

Det jag sett, så är NTC-termistorer absolut vanligast, RTDer (dvs PT100/500/1000) förekommer där man vill ha en hög noggrannhet.

[hcb]

Nja, om något är de flesta PTC-motstånd avsevärt mindre linjära (de har mer en av/på-karakteristik) än NTC-dito. I alla fall om jag minns rätt ...

[TomasL]

Förvisso, jag gissar att TS har blandat ihop det här med RTD och termistorer.
PTC används oftast när man vill skydda mot skadliga temperaturer/kortslutningar i elektronik, dvs begränsa ström eller liknande.

[SeniorLemuren]

Om man vill, så kan man ju alltid googla.

PTC thermistors can be used as current-limiting devices for circuit protection, as replacements for fuses. Current through the device causes a small amount of resistive heating. If the current is large enough to generate more heat than the device can lose to its surroundings, the device heats up, causing its resistance to increase, and therefore causing even more heating. This creates a self-reinforcing effect that drives the resistance upwards, reducing the current and voltage available to the device.
PTC thermistors were used as timers in the degaussing coil circuit of most CRT displays. When the display unit is initially switched on, current flows through the thermistor and degaussing coil. The coil and thermistor are intentionally sized so that the current flow will heat the thermistor to the point that the degaussing coil shuts off in under a second. For effective degaussing, it is necessary that the magnitude of the alternating magnetic field produced by the degaussing coil decreases smoothly and continuously, rather than sharply switching off or decreasing in steps; the PTC thermistor accomplishes this naturally as it heats up. A degaussing circuit using a PTC thermistor is simple, reliable (for its simplicity), and inexpensive.
PTC thermistors were used as heater in automotive industry to provide additional heat inside cabin with diesel engine or to heat diesel in cold climatic conditions before engine injection.
NTC thermistors are used as resistance thermometers in low-temperature measurements of the order of 10 K.
NTC thermistors can be used as inrush-current limiting devices in power supply circuits. They present a higher resistance initially which prevents large currents from flowing at turn-on, and then heat up and become much lower resistance to allow higher current flow during normal operation. These thermistors are usually much larger than measuring type thermistors, and are purposely designed for this application.
NTC thermistors are regularly used in automotive applications. For example, they monitor things like coolant temperature and/or oil temperature inside the engine and provide data to the ECU and, indirectly, to the dashboard.
NTC thermistors can be also used to monitor the temperature of an incubator.
Thermistors are also commonly used in modern digital thermostats and to monitor the temperature of battery packs while charging.
Thermistors are often used in the hot ends of 3D printers; they monitor the heat produced and allow the printer's control circuitry to keep a constant temperature for melting the plastic filament.
NTC thermistors are used in the Food Handling and Processing industry, especially for food storage systems and food preparation. Maintaining the correct temperature is critical to prevent food borne illness.
NTC thermistors are used throughout the Consumer Appliance industry for measuring temperature. Toasters, coffee makers, refrigerators, freezers, hair dryers, etc. all rely on thermistors for proper temperature control.
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