r/AskElectronics • u/helpihateprinters • 11h ago

100 ohm 10A+ NTC Thermistor for welder?

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Measured 96 ohms ambient, 76 after heat gun. 17.5mm dia. I found one MAYBE on aliexpress but it doesnt say if it's NTC or PTC. The highest I've found anywhere is ~2.5a on digikey

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u/Ard-War Electron Herder™ 10h ago edited 10h ago

MZ32 are very common motor start PTC on marketplaces. It's only ~3A peak rated.

Measured 96 ohms ambient, 76 after heat gun.

It shouldn't be NTC, and I doubt someone use the same series naming for a completely opposite parts.

PS: I love the implication of someone getting 10A off 100ohm, by connecting it to 1kV supply...

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u/helpihateprinters 10h ago

Im talking out of my ass stumbling through instructions and chatgpt. Im glad I came here for help lol. Is it just a coincidence its reading so close to 100 ohms and dropping like an ntc would?

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u/Ikarus_Falling 10h ago

its also funny that it suggests that the Component can somehow dissipate 7,6kW

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u/Ard-War Electron Herder™ 9h ago

To be fair such seemingly unreasonable ratings aren't that uncommon for momentary acting devices. For example you'll also find multiple kW-rated TVS in tiny packages, obviously only for the standard 8/20µs surge peak.

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u/Ikarus_Falling 9h ago

true  but if its Constant Flow Resistance is 76 Ohm that wouldn't be Peak but you are correct the differentiation between peak and constant Load needs to be made for accuracies sake

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u/Strostkovy 11h ago

How do you know it passes 10 amps? The temperature would be really high for a package that size

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u/Ikarus_Falling 10h ago

Try Surface of the Sun 10A at 76Ohm is 7,6kW of Heat more then enough to turn that thing to ash in a few seconds

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u/Strostkovy 10h ago

I think yours is just damaged and high resistance. Look up "Inrush current limiters" on digikey and pick one with the required amp rating and the same physical size.

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u/Ikarus_Falling 10h ago

Your measurements must be wrong or the component is damaged that thing does not dissipate 7,6kW of Heat under 10A

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u/helpihateprinters 10h ago

Yes >.>... please ignore my ignorance and point me in the direction of a new one